Technical field

The present disclosure relates to a method of obtaining a capability and pre-coding a data packet for a multi-antenna transmitter and receiver arrangement, a computer program product, a non-transitory computer-readable storage medium, a wireless device, and a transceiver node.

More specifically, the disclosure relates to a method of obtaining a capability and precoding a data packet for a multi-antenna transmitter and receiver arrangement, a computer program product, a non-transitory computer-readable storage medium, a wireless device, and a transceiver node as defined in the introductory parts of the independent claims.

Background art

Presently, e.g., in the millimetre wave (mmW) frequency range, there are three basic multiple-input multiple-output (MIMO) and beamforming (BF) transceiver architectures:

Analog BF, in which the radio signals from/to antennas are combined in the analog domain. This architecture may have problems, such as slow beam tracking, and that there is no channel knowledge per antenna, as only the combined channel is known. An example of analog BF can be found in US 2021/050893 Al.

Hybrid BF, in which radio signals of a subset of antennas is combined in the analog domain to combined streams and the combined streams are analog-to-digital (AD) converted and further combined in the digital domain for reception and in which signals are processed in the digital domain before digital-to-analog (DA) converted and thereafter further processed in the analog domain for transmission. An example of hybrid BF can be found in US 9319124 B2.

Digital BF, in which all streams are AD converted and combined in the digital domain for reception and in which signals are processed in the digital domain before DA conversion (and no beamforming processing is performed in the analog domain) for transmission. In digital BF there is full channel knowledge for each/all antenna(s). However, processing may be very complex and/or power consuming, e.g., if the number of antennas is large. An example of digital BF can be found in US 9054845 B2.

As digital BF in theory is capable of handling an infinite number of directions, while analog BF can only handle a single direction and hybrid BF typically can handle the same number of directions as the number of transceivers, digital BF is able to handle more complex radio channels, such as non-Line-of-Sight, than analog BF and hybrid BF.

Hence, depending on the radio channel characteristics the performance may differ between analog, hybrid, and digital BF, and in order to achieve higher or optimal capacity there may be a need for a method and an apparatus in transceiver nodes informing each other about the performance or capability of the respective transceiver nodes, e.g., as different transceiver nodes may have different capabilities, and thereafter perform pre-coding accordingly.

US 9478857 B2 discloses that a terminal transmits information regarding a beamforming capability to a base station. Furthermore, US 2013/0045690 Al discloses an apparatus and a method for supporting diversity in a beamformed wireless communication system. However, there may be a need for improved or alternative methods of informing other transceiver nodes about the performance or capability of pre-coding data packets.

An object of the present disclosure is to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above-mentioned problem.

According to a first aspect there is provided a method for a multi-antenna transmitter and receiver arrangement, the multi-antenna transmitter and receiver arrangement being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, wherein the obtained capability is indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatiotemporal dispersion; and pre-coding one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability. According to some embodiments, the method further comprises receiving/obtaining reception statistics associated with the first and/or second pre-coding mode(s).

According to some embodiments, obtaining a capability of the remote multi-antenna transmitter and receiver arrangement comprises deriving he capability of the remote multiantenna transmitter and receiver arrangement from the received reception statistics.

According to some embodiments, the reception statistics is associated with one or more of a first pre-coding mode and a second pre-coding mode.

According to some embodiments, the reception statistics is received from the remote TNode, and comprise one or more signal quality reports.

According to some embodiments, the one or more signal quality reports comprises one or more of channel state information, CSI, signal to noise ratio, SNR, reference signal received power, RSRP, reference signal received quality, RSRQ, Power delay Profile, PDP, and NAK/ACK statistics.

According to some embodiments, the reception statistics is obtained, at the WD, from a signal received from the remote TNode, and wherein the reception statistics comprises one or more of channel state information, CSI, signal to noise ratio, SNR, reference signal received power, RSRP, reference signal received quality, RSRQ, Power delay Profile, PDP, and NAK/ACK statistics.

According to some embodiments, the method further comprises obtaining channel characteristics for a plurality of radio channels between the remote TNode and the multiantenna transmitter and receiver arrangement.

According to some embodiments, the pre-coding is further based on the obtained channel characteristics.

According to some embodiments, the method further comprises: determining if the obtained capability is a first capability or a second capability, different from the first capability, the second capability indicative of the remote TNode being able to manage the second spatiotemporal dispersion and the first capability indicative of the remote TNode being able to manage only the first spatio-temporal dispersion; performing pre-coding in a first pre-coding mode if the obtained capability is determined to be the first capability; and performing pre- coding in a second pre-coding mode, different from the first pre-coding mode, if the obtained capability is determined to be the second capability.

According to some embodiments, the method further comprises deriving a channel tap filter length from the obtained channel characteristics.

According to some embodiments, performing pre-coding in the first pre-coding mode comprises allocating a first transmit power associated with a first number of channel taps.

According to some embodiments, performing pre-coding in the second pre-coding mode comprises allocating a second transmit power associated with a second number, larger than the first number, of channel taps.

According to some embodiments, the first and second numbers of channel taps are less than or equal to the channel tap filter length.

According to some embodiments, the method further comprises deriving a time delay from the obtained channel characteristics.

According to some embodiments, performing pre-coding in the first pre-coding mode comprises utilizing a first set of phase shifts and time delays for the one or more data packet(s) to be transmitted, performing pre-coding in the second pre-coding mode comprises utilizing a second set, different from the first set, of phase shifts and time delays for the one or more data packet(s) to be transmitted, and the first and second sets of phase shifts and time delays are determined based on the channel tap filter length and/or the time delay derived from the obtained channel characteristics.

According to some embodiments, the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the second spatio-temporal/spatial dispersion if the remote TNode is able to manage digital beamforming or is able to manage hybrid beamforming with a first number of transceivers, and the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the first spatio- temporal/spatial dispersion if the remote TNode is able to manage analog beamforming or is able to manage hybrid beamforming with a second number of transceivers, the second number being smaller than the first number, but not able (i.e., unable) to manage digital beamforming or hybrid beamforming with the first number of transceivers. According to some embodiments, obtaining a capability of the remote multi-antenna transmitter and receiver arrangement comprises directly receiving from the remote TNode the capability of the remote multi-antenna transmitter and receiver arrangement.

According to some embodiments, the method further comprises transmitting the one or more pre-coded data packet(s) to the remote TNode.

According to a second aspect there is provided a computer program product comprising instructions, which, when executed on at least one processor of a processing device, cause the processing device to carry out the method according to the first aspect or any of the embodiments mentioned herein.

According to a third aspect there is provided a non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a processing device, the one or more programs comprising instructions which, when executed by the processing device, causes the processing device to carry out the method according to the first aspect or any of the embodiments mentioned herein.

According to a fourth aspect there is provided a wireless device (WD) comprising a multi-antenna transmitter and receiver arrangement and controlling circuitry configured to cause: obtainment of a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, the obtained capability indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatio-temporal dispersion; and pre-coding of one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability.

According to a fifth aspect there is provided a transceiver node (TNode) comprising a multi-antenna transmitter and receiver arrangement and controlling circuitry configured to cause: obtainment of a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, the obtained capability indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatio-temporal dispersion; and pre-coding of one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability. Effects and features of the second, third, fourth, and fifth aspects are fully or to a substantial extent analogous to those described above in connection with the first aspect and vice versa. Embodiments mentioned in relation to the first aspect are fully or largely compatible with the second, third, fourth, and fifth aspects and vice versa.

An advantage of some embodiments is that the capacity of a wireless communication system is improved/increased (e.g., optimized).

Another advantage of some embodiments is a reduced power consumption for reception and/or transmission of data between transceiver nodes.

Yet another advantage of some embodiments is that robustness (of the communication) is improved/increased.

A further advantage of some embodiments is that performance is improved or optimized.

Yet a further advantage of some embodiments is that complexity (of the implementation) is reduced (or minimized).

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes, and modifications may be made within the scope of the disclosure.

Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such apparatus and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only and is not intended to be limiting. It should be noted that, as used in the specification and the appended claims, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps. Furthermore, the term "configured" or "adapted" is intended to mean that a unit or similar is shaped, sized, connected, connectable, programmed or otherwise adjusted for a purpose.

Brief of the

The above objects, as well as additional objects, features, and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figure 1A is a schematic drawing illustrating method steps according to some embodiments;

Figure IB is a schematic drawing illustrating a multi-antenna transmitter and receiver arrangement according to some embodiments;

Figure 2 is a schematic drawing illustrating a computer readable medium according to some embodiments;

Figure 3 is a flowchart illustrating method steps implemented in a multi-antenna transmitter and receiver arrangement, or in a control unit/control circuitry thereof, according to some embodiments;

Figure 4 is a schematic drawing illustrating a conversion unit according to some embodiments;

Figure 5 is a schematic drawing illustrating a switch for switching transceivers between the transmitter arrangement and the receiver arrangement according to some embodiments; and

Figure 6 is a schematic drawing illustrating a receiver arrangement connected to transceivers and antennas according to some embodiments.

Detailed description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

Terminology

Below is referred to a wireless device (WD). A wireless device is any device capable of transmitting or receiving signals wirelessly. Some examples of wireless devices are user equipment (UE), mobile phones, cell phones, smart phones, Internet of Things (loT) devices, vehicle-to-everything (V2X) devices, vehicle-to-infrastructure (V2I) devices, vehicle-to-network (V2N) devices, vehicle-to-vehicle (V2V) devices, vehicle-to-pedestrian (V2P) devices, vehicle- to-device (V2D) devices, vehicle-to-grid (V2G) devices, fixed wireless access (FWA) points, tablets, laptops, wireless stations, relays, repeater devices, reconfigurable intelligent surfaces, and large intelligent surfaces.

Below is referred to a "transceiver node" (TNode). A TNode may be a remote radio unit (RRU), a repeater, a remote wireless node, or a base station (BS), such as a radio base station (RBS), a Node B, an Evolved Node B (eNB) or a gNodeB (gNB). Furthermore, a TNode may be a BS for a neighboring cell, a BS for a handover (HO) candidate cell, a remote radio unit (RRU), a distributed unit (DU), another WD (a remote WD) or a base station (BS) for a (active/deactivated) secondary cell (SCell) or for a serving/primary cell (PCell, e.g., associated with an active TCI state), a laptop, a wireless station, a relay, a repeater device, a reconfigurable intelligent surface, or a large intelligent surface.

Herein is referred to millimeter Wave (mmW) utilization, mmW communication, mmW communication capability and mmW frequency range. The mmW frequency range is from 24.25 Gigahertz (GHz) to 71 GHz or more generally from 24 to 300 GHz. MmW may also be referred to as Frequency Range 2 (FR2).

Below is referred to a first and second beamforming processing units (and other processing units). The processing unit may be a digital processor. Alternatively, the processor may be a microprocessor, a microcontroller, a central processing unit, a co-processor, a graphics processing unit, a digital signal processor, an image signal processor, a quantum processing unit, or an analog signal processor. The processing unit may comprise one or more processors and optionally other units, such as a control unit. Below is referred to a digital interface. A digital interface is a unit converting analog signals from e.g., transceivers to digital signals, which digital signals are conveyed to e.g., a baseband processor, and/or converting digital signals from e.g., a baseband processor to analog signals, which analog signals are conveyed to e.g., one or more transceivers. A digital interface possible also comprises filters and other pre-processing functions/units.

Below is referred to an antenna unit. An antenna unit may be one single antenna. However, an antenna unit may also be a dual antenna, such as a dual patch antenna with a first (e.g., horizontal) and a second (e.g., vertical) polarization, thus functioning as two separate antennas or an antenna unit having two ports.

Below is referred to a chip. A chip is an integrated circuit (chip) or a monolithic integrated circuit (chip) and may also be referred to as an IC, or a microchip.

Below is referred to a "filter". A filter is a device or process that removes some features, components, or frequencies from a signal.

Below is referred to "spatio-temporal dispersion". Spatio-temporal dispersion comprises spatial dispersion and/or temporal dispersion. Spatial dispersion (dispersion in space) may be defined as the number of spatial directions in which the transceiver can simultaneously transmit and/or receive. Thus, spatial dispersion represents scattering or spreading effects (originating from reflections of the transmitted radio wave from a surface of objects). Temporal dispersion, i.e., dispersion in time, represents memory effects in systems.

Herein is referred to "analog beamforming", "hybrid beamforming" and "digital beamforming". Digital beamforming means that the beamforming processing, e.g., multiplication of a coefficient, is performed before digital to analog conversion (DAC) for transmission (and after analog to digital conversion, ADC, for reception), i.e., in the digital domain. Analog beamforming means that the beamforming processing, e.g., phase shifting, is performed after DAC for transmission (and before ADC for reception), i.e., in the analog domain. Hybrid beamforming means that some beamforming processing, e.g., phase shifting, is performed after DAC and some beamforming processing, e.g., multiplication of a coefficient, is performed before DAC for transmission (and before and after ADC for reception), i.e., processing in both digital and analog domains. Herein is referred to a power delay profile (PDP). The PDP gives the intensity of a signal received through a multipath channel as a function of time delay. The time delay is the difference in travel time between multipath arrivals.

Basic concept

A basic concept of the invention is to perform capability signalling for a multi-antenna transmitter and receiver arrangement, such as a multi-antenna transceiver arrangement, comprised in a WD or a TNode. The multi-antenna transmitter and receiver arrangement capability comprises capability to handle spatial-temporal dispersion of the radio channel utilized for communication with a remote TNode. As an example, the selection of pre-coding (or beamforming) method/procedure is based on an obtained capability of a multi-antenna transmitter and receiver arrangement for a remote Tnode, wherein the capability can be obtained by reception of a capability report or by determination by probing of performance of the transmission of data packets.

Embodiments

In the following, embodiments will be described where figure 1A illustrates method steps according to some embodiments and figure IB illustrates a multi-antenna transmitter and receiver arrangement according to some embodiments. The method 100 is for a multiantenna transmitter and receiver arrangement 400. Furthermore, the multi-antenna transmitter and receiver arrangement 400 is comprisable or comprised in a wireless device (WD) or in a transceiver node (TNode), i.e., in some embodiments a WD or a TNode comprises the multi-antenna transmitter and receiver arrangement 400. The method 100 comprises obtaining 110 a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode. The obtained capability is indicative of a first (spatio-temporal dispersion) or a second spatio-temporal dispersion (of radio channels) (that) the remote multiantenna transmitter and receiver arrangement (or the WD/TNode comprising it) is able to manage. Furthermore, the first spatio-temporal dispersion is smaller than the second spatiotemporal dispersion. In some embodiments, obtaining 110 a capability of the remote multiantenna transmitter and receiver arrangement comprises directly receiving 106, from the remote TNode, the capability of the remote multi-antenna transmitter and receiver arrangement. In some embodiments, the method 100 comprises receiving or obtaining 108 reception statistics. Furthermore, in some embodiments, the reception statistics is received from the remote TNode. Alternatively, or additionally, the reception statistics is obtained, at the WD, from a signal received from the remote TNode. The obtained/received reception statistics is or may be associated with the first and/or second pre-coding mode(s). In these embodiments (receiving or obtaining 108 reception statistics), obtaining 110 a capability of the remote multi-antenna transmitter and receiver arrangement comprises deriving (or obtaining/calculating) 111 the capability of the remote multi-antenna transmitter and receiver arrangement from the received/obtained reception statistics. Some examples of reception statistics are signal quality reports. In some embodiments, the reception statistics and/or the signal quality reports comprise channel state information (CSI), signal to noise ratio (SNR), reference signal received power (RSRP), reference signal received quality (RSRQ), Power delay Profile and/or NAK/ACK statistics (ACK/NAK statistics).

Moreover, the method 100 comprises pre-coding 120 one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability. In some embodiments, the method 100 comprises transmitting 130 the one or more pre-coded data packet(s) to the remote TNode. Furthermore, in some embodiments, the method 100 comprises obtaining 112 channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement 400 (when comprised in the WD/TNode). In these embodiments, pre-coding 120 is (further) based on the obtained channel characteristics. Furthermore, in some embodiments, the method 100 comprises determining 116 if the obtained capability is a first capability or a second capability, the second capability being different from the first capability. The second capability is indicative of the remote TNode being able to manage the second spatio-temporal dispersion and the first capability is indicative of the remote TNode being able to manage only the first spatio-temporal dispersion, i.e., indicative of the remote TNode being able to manage the first spatio-temporal dispersion but not able (i.e., unable) to manage the second spatio-temporal dispersion. In these embodiments, the method 100 comprises performing 122 pre-coding (120) in a first precoding mode if the obtained capability is determined to be the first capability, and performing 124 pre-coding (120) in a second pre-coding mode if the obtained capability is determined to be the second capability. The second pre-coding mode is different from the first pre-coding mode. Moreover, in some embodiments, the method 100 comprises deriving (or obtaining or calculating) 114 a channel tap filter length from the obtained channel characteristics. In these embodiments, performing 122 pre-coding in the first pre-coding mode comprises allocating 123 a first transmit power associated with a first number of channel taps and/or performing

124 pre-coding in the second pre-coding mode comprises allocating 125 a second transmit power associated with a second number of channel taps. In some embodiments, the second number of channel taps is larger than the first number of channel taps. Thus, in some embodiments the second transmit power is larger than the first transmit power. However, in other embodiments, the first and second (total) transmit power is the same (even though the second number is larger than the first number of channel taps). In some embodiments, the transmit power per channel tap is larger in the first pre-coding mode than in the second precoding mode (e.g., if the first and second transmit power is the same and the second number of channel taps is larger than the first number of channel taps). Furthermore, in some embodiments, each of the first and second numbers of channel taps are less than or equal to the channel tap filter length, i.e., the first number of channel taps is less than or equal to the channel tap filter length and the second number of channel taps is less than or equal to the channel tap filter length. E.g., the first number is 1, the second number is 2 and the channel tap filter length is 2. Channel taps etc. may be derived regardless of whether the characteristics are determined in frequency or time domain by utilizing well-known relationships between frequency (f) and time (t). In some embodiments, the method 100 comprises deriving (or obtaining or calculating) 115 a time delay, e.g., of one or more radio channels, from the obtained channel characteristics, e.g., in addition to deriving 114 the channel tap filter length from the obtained channel characteristics. In these embodiments, performing 122 pre-coding (120) in the first pre-coding mode comprises utilizing 126 a first set of phase shifts, time delays and optionally scaling factors for the one or more data packet(s) to be transmitted, and/or performing 124 pre-coding (120) in the second pre-coding mode comprises utilizing 128 a second set of phase shifts, time delays and optionally scaling factors for the one or more data packet(s) to be transmitted. Each of the first and second sets of phase shifts, time delays and optionally scaling factors comprises one or more phase shifts, one or more scaling factors and/or one or more time delays. In some embodiments, the second set of phase shifts, time delays and optionally scaling factors is different from the first set of phase shifts, time delays and optionally scaling factors. In some embodiments, the first and second sets of phase shifts, time delays and optionally scaling factors are determined based on the channel tap filter length and/or the derived time delay and optionally a coefficient derived from the obtained channel characteristics. E.g., the phase shifts of the first and second sets are determined based on the channel tap filter length, the scaling factors of the first and second sets are determined based on the derived coefficient, and the time delays of the first and second sets are determined based on the derived time delay. In some embodiments, the phase shifts, time delays and optionally scaling factors of the second set are different from the ones in the first set only for line-of-sight channels. However, in some embodiments, the phase shifts, time delays and optionally scaling factors of the second set are different from the ones in the first set also for non-line-of-sight channels. Furthermore, in some embodiments, the relative phase between two different antennas is dependent on the distance between the two different antennas.

In some embodiments, the first pre-coding mode gives/has/provides, or is associated with, a first beamwidth, and the second pre-coding mode gives/has/provides, or is associated with, a second beamwidth. E.g., in the first pre-coding mode, the data packet to be transmitted is pre-coded to be transmitted with a first beamwidth and in the second precoding mode, the data packet to be transmitted is pre-coded to be transmitted with a second beamwidth. The first beamwidth is different from the second beamwidth. In some embodiments, the first beamwidth is broader than the second beamwidth. E.g., the first beamwidth may include many, several (such as more than 3 spatial directions) or all spatial directions (i.e., be omnidirectional; i.e., the beam is formed widely to comprise many or all spatial directions) and the second beamwidth may be a single spatial direction (i.e., the beam is formed narrowly to comprise only one or a few directions, such as 2 or 3 spatial directions). This may be beneficial, e.g., if/when the radio channel(s) comprises multi-path Non-Line-of- Sight (NLOS) signals from different directions. In some embodiments, the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the second spatio- temporal/spatial dispersion if the remote TNode/multi-antenna transmitter and receiver arrangement is able to manage digital beamforming. In some embodiments, the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the second spatio-temporal/spatial dispersion if the remote TNode/multi-antenna transmitter and receiver arrangement is able to manage hybrid beamforming with a first number of transceivers. In some embodiments, the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the first spatio-temporal/spatial dispersion if the remote TNode/multi-antenna transmitter and receiver arrangement is able to manage analog beamforming (but unable/not able to manage digital beamforming or hybrid beamforming with the first number of transceivers). In some embodiments, the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the first spatio- temporal/spatial dispersion if the remote TNode/multi-antenna transmitter and receiver arrangement is able to manage hybrid beamforming with a second number of transceivers (but unable/not able to manage digital beamforming or hybrid beamforming with the first number of transceivers). The second number of transceivers is smaller than the first number of transceivers. As an example, the first number is 3 and the second number is 2. As another example, the first number is 2 and the second number is 1. As yet another example, the second number is 1 and the first number is 3.

Furthermore, in some embodiments, the pre-coding 120 is performed in one or more of a complex frequency domain, a wavelet domain, a frequency domain, a spatial domain, and a time domain. As an example, the pre-coding 120 is performed in the frequency domain only. As another example, the pre-coding 120 is performed partly in the frequency domain and partly in the time domain (e.g., if the transceivers utilize orthogonal frequency-division multiplexing, OFDM). As yet another example, the pre-coding 120 is performed in the time domain only. As a further example, the pre-coding 120 is performed (only) in a spatial domain and a time domain, i.e., in a spatio-temporal domain. Thus, as it is possible to select in which domain the pre-coding 120 is performed, an increased flexibility for pre-coding is achieved.

In some embodiments, as shown in figure IB, the multi-antenna transmitter and receiver arrangement 400 comprises a transmitter arrangement 404. The transmitter arrangement 404 comprises a pre-coder 2018. The pre-coder 2018 pre-codes or is configured to pre-code data packets in a complex frequency domain, a wavelet domain, or a frequency domain. Furthermore, the transmitter arrangement 404 comprises a first beamforming processing unit 1940. The first beamforming processing unit 1940 converts or is configured to convert the pre-coded data packets from a complex frequency domain, a wavelet domain, or a frequency domain to a time domain. Moreover, the transmitter arrangement 404 comprises a second beamforming processing unit 1810. The second beamforming processing unit 1810 is configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals. In some embodiments, the second beamforming processing unit 1810 comprises a plurality (m) of filters, such as spatio-temporal filters 1800, ..., 1807. The filters, e.g., the spatio-temporal filters 1800, ..., 1807, processes or are configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals. In some embodiments, the pre-coder 2018 comprises the first beamforming processing unit 1940. Furthermore, in some embodiments, the pre-coder 2018 comprises the second beamforming processing unit 1810. Moreover, in some embodiments, the pre-coder 2018 comprises the first and second beamforming processing units 1940, 1810. Thus, in some embodiments, the first and/or second beamforming processing is part of the pre-coding/pre-coder 2018. The transmitter arrangement 404 comprises a filter control unit 1920. The filter control unit 1920 determines or is configured to determine coefficients, such as filter coefficients of the plurality (m) of spatio-temporal filters 1800, ..., 1807 or beamforming weights, for the first and/or the second beamforming processing units 1940, 1810. Furthermore, the transmitter arrangement 404 comprises a plurality (N) of combiners 1840, ..., 1847. The combiners 1840, ..., 1847 combines or are configured to combine the plurality (N) of digital signals to obtain a plurality (N) of combined digital signals. Moreover, the transmitter arrangement 404 comprises a plurality (I) of conversion units 620, ..., 635. The conversion units 620, ..., 635 convert or are configured to convert each of the plurality (N) of combined digital signals to respective analog signals. In some embodiments, there is one conversion unit 620, ..., 635 for each transceiver/analog signal. However, in other embodiments, there are two conversion units for each analog signal, e.g., one for an in-phase (I) branch and one for a quadrature phase (Q) branch. Alternatively, there are four conversion units for each analog signal, e.g., if dual polarized antenna units are utilized and each (transceiver) chip comprises 2 transceivers.

In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a receiver arrangement 402 (shown in figure 6 and described below in connection with figure 6).

Furthermore, the multi-antenna transmitter and receiver arrangement 400 comprises a plurality of transceivers 500, 501, ..., 515. The transceivers 500, 501, ..., 515 transmits or are configured to transmit each of the analog signals via a plurality of (respective) antenna units 700, 701, ..., 715 (e.g., during a transmission mode). In some embodiments, the transceivers 500, 501, ..., 515 receives or are configured to receive a plurality of analog radio signals via the plurality of (respective) antenna units 700, 701, ..., 715 (e.g., during a reception mode).

In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a chip 412 (shown in figure IB). The chip 412 comprises the pre-coder 2018, the first beamforming processing unit 1940, the second beamforming processing unit 1810, the filter control unit 1920 and the combiners 1840, ..., 1847. Furthermore, the chip is clocked with a clock (or an oscillator) having a chip frequency/rate.

However, in some embodiments, the multi-antenna transmitter and receiver arrangement (400) comprises a first chip. The first chip comprises the pre-coder 2018, the first beamforming processing unit 1940 and the filter control unit 1920. Furthermore, the multiantenna transmitter and receiver arrangement 400 comprises a second chip. The second chip comprises the second beamforming processing unit 1810, and the combiners 1840, ..., 1847. Moreover, the multi-antenna transmitter and receiver arrangement 400 comprises a digital interface, DI. The DI interfaces or is configured to interface the first and second chips. In some embodiments, the remote multi-antenna transmitter and receiver arrangement is identical to the multi-antenna transmitter and receiver arrangement 400 (and may thus comprise the parts described above).

According to some embodiments, a computer program product comprising a non- transitory computer readable medium 200, such as a punch card, a compact disc (CD) ROM, a read only memory (ROM), a digital versatile disc (DVD), an embedded drive, a plug-in card, a random access memory (RAM) or a universal serial bus (USB) memory, is provided. Figure 2 illustrates an example computer readable medium in the form of a compact disc (CD) ROM 200. The computer readable medium has stored thereon, a computer program comprising program instructions. The computer program is loadable into a data processor (PROC) 220, which may, for example, be comprised in a computer 210 or a computing device or a control unit. When loaded into the data processor, the computer program may be stored in a memory (MEM) 230 associated with or comprised in the data processor. According to some embodiments, the computer program may, when loaded into and run by the data processor, cause execution of method steps according to, for example, the method illustrated in figure 1A, which is described herein. Furthermore, in some embodiments, there is provided a computer program product comprising instructions, which, when executed on at least one processor of a processing device, cause the processing device to carry out the method illustrated in figure 1A. Moreover, in some embodiments, there is provided a non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a processing device, the one or more programs comprising instructions which, when executed by the processing device, causes the processing device to carry out the method illustrated in figure 1A.

Figure 3 illustrates method steps implemented in a WD, TNode, or multi-antenna transmitter and receiver arrangement 400 (or in a control unit or controlling circuitry comprised therein or associated therewith, e.g., a processing unit, and configured to control the multi-antenna transmitter and receiver arrangement 400) according to some embodiments. The multi-antenna transmitter and receiver arrangement 400 comprises controlling circuitry. Alternatively, a WD or a TNode comprising the multi-antenna transmitter and receiver arrangement 400 comprises the controlling circuitry. The controlling circuitry causes or is configured to cause obtainment 310 of a capability of a (remote) multi-antenna transmitter and receiver arrangement comprised in a remote TNode, wherein the obtained capability is indicative of a first spatio-temporal dispersion or a second spatio-temporal dispersion (that) the remote multi-antenna transmitter and receiver arrangement (or remote TNode) is able to manage. The first spatio-temporal dispersion is smaller than the second spatio-temporal dispersion. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a first obtainment unit (e.g., first obtaining circuitry, first obtainer or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). Furthermore, the controlling circuitry causes or is configured to cause pre-coding 320 of one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a pre-coding unit (e.g., pre-coding circuitry or the pre-coder 2018).

Moreover, in some embodiments, the controlling circuitry causes or is configured to cause reception or obtainment 308 of reception statistics associated with the first and/or second pre-coding mode(s) from the remote TNode. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a first reception unit (e.g., first receiving circuitry or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). Alternatively, or additionally, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a sixth obtainment unit (e.g., sixth obtaining circuitry, transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715 and/or a processing unit). In some embodiments, the controlling circuitry causes or is configured to cause derivation/obtainment 311 of the capability of the remote multi-antenna transmitter and receiver arrangement from the (received/obtained) reception statistics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second obtainment/derivation unit (e.g., second obtaining circuitry, a second obtainer or a processing unit). Furthermore, in some embodiments, the controlling circuitry causes or is configured to cause direct reception 306, from the remote TNode, of the capability of the remote multi-antenna transmitter and receiver arrangement. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second reception unit (e.g., second receiving circuitry, a second receiver or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). Moreover, in some embodiments, the controlling circuitry causes or is configured to cause obtainment 312 of channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement 400. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a third obtainment unit (e.g., third obtaining circuitry, a third obtainer and/or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). In some embodiments, the controlling circuitry causes or is configured to cause derivation/obtainment 314 of a channel tap filter length from the obtained channel characteristics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a fourth obtainment unit (e.g., fourth obtaining circuitry, a fourth obtainer and/or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). Furthermore, in some embodiments, the controlling circuitry causes or is configured to cause derivation 315 of a time delay from the obtained channel characteristics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a fifth obtainment/derivation unit (e.g., fifth obtaining/derivating circuitry, a fifth obtainer/derivator and/or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715). Moreover, in some embodiments, the controlling circuitry causes or is configured to cause determination 316 of whether/if the obtained capability is a first capability or a second capability. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a determination unit (e.g., determining circuitry, a determiner, or a processing unit). In some embodiments, the controlling circuitry causes or is configured to cause performance 322 of pre-coding (320) in a first pre-coding mode if the obtained capability is determined to be the first capability, and to cause performance 324 of pre-coding (320) in a second pre-coding mode if the obtained capability is determined to be the second capability. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a mode actuation unit (e.g., actuating circuitry, an actuator, switch, or a processing unit). Furthermore, in some embodiments, the controlling circuitry causes or is configured to cause utilization 326 of a first set of phase shifts, time delays and optionally scaling factors for the one or more data packet(s) to be transmitted. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a first utilization unit (e.g., first utilizing circuitry, a first utilizer or a processing unit). Moreover, in some embodiments, the controlling circuitry causes or is configured to cause utilization 328 of a second set of phase shifts, time delays and optionally scaling factors for the one or more data packet(s) to be transmitted. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second utilization unit (e.g., second utilizing circuitry, a second utilizer or a processing unit). Furthermore, in some embodiments, the controlling circuitry causes or is configured to cause (when performing 122 pre-coding in the first pre-coding mode) allocation 323 of a first transmit power associated with a first number of channel taps and the controlling circuitry causes or is configured to cause (when performing 124 pre-coding in the second pre-coding mode) allocation 325 of a second transmit power associated with a second number of channel taps. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) an allocation unit (e.g., allocating circuitry, an alligator, or a processing unit). In some embodiments, the controlling circuitry causes or is configured to cause transmission 330 of the one or more pre-coded data packet(s) to the remote TNode. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a transmission unit (e.g., transmitting circuitry, a transmitter, or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715).

Figure 4 illustrates a conversion unit 620 according to some embodiments. The conversion unit 620 comprises a digital to analog (DA) converter 642 and an up-converter 640. The DA converter 642 converts a digital signal into an analog signal and the up-converter 640 converts an analog signal, such as a baseband signal, to an analog signal with a higher frequency, such as a carrier frequency radio signal. Although only the converter 620 is shown in figure 4, all converters 620, ..., 635 function the same way (i.e., comprises a DA converter 642 and an up-converter 640). Moreover, in some embodiments, as illustrated in figure 5, the multi-antenna transmitter and receiver arrangement 400 comprises a switch 406 configured to switch the plurality of transceivers 500, 501, ..., 515 (which are connected or connectable to antenna units 700, 701, ..., 715) between the transmitter arrangement 404 and the receiver arrangement 402. As an example, the switch connects the transmitter arrangement 404 to the transceivers 500, 501, ..., 515 when the multi-antenna transmitter and receiver arrangement 400 enters a transmission mode (and/or while the multi-antenna transmitter and receiver arrangement 400 is in the transmission mode) and the switch connects the receiver arrangement 402 to the transceivers 500, 501, ..., 515 when the multi-antenna transmitter and receiver arrangement 400 enters a reception mode (and/or while the multi-antenna transmitter and receiver arrangement 400 is in the reception mode).

Figure 6 illustrates a receiver arrangement 402 connected or connectable to transceivers 500, 501, ..., 515 and to antenna units 700, 701, ..., 715. In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises the receiver arrangement 402. The receiver arrangement 402 comprises a plurality of analog to digital (AD) converters 600, 601, ..., 615. The AD converters 600, 601, ..., 615 convert or are configured to convert the plurality of analog radio signals into a plurality of digital (baseband) signals. In some embodiments, there is one AD converter for each receiver/transceiver/analog signal. However, in other embodiments, there are two AD converters for each analog signal, e.g., one for an in-phase (I) branch and one for a quadrature phase (Q) branch. In some embodiments, the receiver arrangement 402 comprises down-converters (not shown), which converts an analog signal, such as a carrier frequency radio signal, to another analog signal, such as a baseband signal, with a lower frequency (before AD conversion). Furthermore, the receiver arrangement 402 comprises an extraction unit 900. The extraction unit 900 extracts or is configured to extract reference signals from each of the plurality of digital signals. In some embodiments, the extraction unit 900 comprises a plurality (N) of sub-extraction units 901, 902, ..., 916, i.e., one sub-extraction unit for each digital signal. Moreover, the receiver arrangement 402 comprises a channel analyzer 920. The channel analyzer 920 determines or is configured to determine characteristics for each of the plurality of digital signals based on the extracted reference signals. In some embodiments, the characteristics is a (time domain) radio channel characteristics. In some embodiments, the characteristics comprises channel estimates, such as radio channel estimates, e.g., for each of the digital signals. Furthermore, in some embodiments, the characteristics comprises (radio) channel filter taps indicative of the radio channel characteristics. Moreover, in some embodiments, the filter control unit 1920 (of the transmitter arrangement 404) obtains/receives determined characteristics from the channel analyzer 920 and determines the coefficients (e.g., filter coefficients or beamforming weights) for the first and/or second beamforming processing unit(s) 1940, 1810 based on the determined characteristics. In some embodiments, the coefficients, e.g., the beamforming weights, are determined to be the (set of) coefficients which optimizes a certain signal quality measure, such as SNR, RSRP, or RSRQ, from the received (radio channel) characteristics. Furthermore, in some embodiments, the signal quality measure is different for the first and second pre-coding modes. In some embodiments, the coefficients are selected based on maximum SNR (given by the obtained radio channel characteristics) in the second pre-coding mode (i.e., for transmission to a remote TNode having the second capability) whereas the coefficients are selected based on maximum SNR under the constraint/condition that only the spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage can be utilized in the first pre-coding mode (i.e., for transmission to a remote TNode having the first capability), thus assuming some uncertainty of the obtained (radio) channel characteristics. Furthermore, in some embodiments, the coefficients are selected based on maximum SNR under the constraint/condition that the second capability cannot be exceeded in the second pre-coding mode (i.e., for transmission to a remote TNode having the second capability) whereas the coefficients are selected based on maximum SNR under the constraint/condition that the first capability cannot be exceeded in the first pre-coding mode (i.e., for transmission to a remote TNode having the first capability).

Furthermore, the receiver arrangement 402 comprises a plurality of spatio-temporal filters 800, ..., 807. The spatio-temporal filters 800, ..., 807 are configured to process or processes the plurality of digital signals to obtain a plurality of combined signals. In some embodiments, the receiver arrangement 402 comprises a transform unit 940. The transform unit 940 is configured to transform or transforms each of the plurality of combined signals into a frequency domain. In some embodiments, the transform unit 940 has or comprises a plurality of transform sub-units. Each transform sub-unit is configured (connected and otherwise adapted) to process a respective signal of the plurality of combined signals. In some embodiments, the transform unit transforms each of the combined signals in a serial manner. Furthermore, in some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a post-processing unit 960. The post-processing unit 960 is configured to postprocess or post-processes the transformed signals in the frequency domain to obtain a plurality of frequency domain processed signals. Moreover, in some embodiments, the plurality of analog radio signals is coded. Thus, in some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a decoder 980. The decoder 980 is configured to decode or decodes the plurality of frequency domain processed signals (in order to obtain information signals or one or more data packets).

The description has been disclosed in terms of a single MIMO layer and pre-coding with respect to channel characteristics for a single layer. However, in some embodiments, multiple MIMO layers are utilized, e.g., pre-coding with respect to channel characteristics may be applied either in a combined pre-coding with the ordinary MIMO multi-layer pre-coding or as a separate pre-coding per MIMO layer.

List of examples:

Example 1

A method (100) for a multi-antenna transmitter and receiver arrangement (400), the multiantenna transmitter and receiver arrangement (400) being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining (110) a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, wherein the obtained capability is indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatiotemporal dispersion; and pre-coding (120) one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability.

Example 2

The method of example 1, further comprising: obtaining (112) channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement (400); and wherein pre-coding (120) is further based on the obtained channel characteristics.

Example 3

The method of any of examples 1-2, further comprising: determining (116) if the obtained capability is a first capability or a second capability, different from the first capability, the second capability indicative of the remote TNode being able to manage the second spatio-temporal dispersion and the first capability indicative of the remote TNode being able to manage only the first spatio-temporal dispersion; performing (122) pre-coding in a first pre-coding mode if the obtained capability is determined to be the first capability; and performing (124) pre-coding in a second pre-coding mode, different from the first pre-coding mode, if the obtained capability is determined to be the second capability.

Example 4

The method of example 3, further comprising: deriving (114) a channel tap filter length from the obtained channel characteristics; and wherein performing (122) pre-coding in the first pre-coding mode comprises allocating (123) a first transmit power associated with a first number of channel taps; wherein performing (124) pre-coding in the second pre-coding mode comprises allocating (125) a second transmit power associated with a second number, larger than the first number, of channel taps; and wherein the first and second numbers of channel taps are less than or equal to the channel tap filter length.

Example 5

The method of example 4, further comprising: deriving (115) a time delay from the obtained channel characteristics; wherein performing (122) pre-coding in the first pre-coding mode comprises utilizing (126) a first set of phase shifts and time delays for the one or more data packet(s) to be transmitted, wherein performing (124) pre-coding in the second pre-coding mode comprises utilizing (128) a second set, different from the first set, of phase shifts and time delays for the one or more data packet(s) to be transmitted, and wherein the first and second sets of phase shifts and time delays are determined based on the channel tap filter length and/or the time delay derived from the obtained channel characteristics.

Example 6

The method of any of examples 1-5, wherein the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the second spatial dispersion if the remote TNode is able to manage digital beamforming or is able to manage hybrid beamforming with a first number of transceivers, and wherein the capability of the remote multi-antenna transmitter and receiver arrangement is indicative of the first spatial dispersion if the remote TNode is able to manage analog beamforming or is able to manage hybrid beamforming with a second number of transceivers, the second number being smaller than the first number, but not able to manage digital beamforming or hybrid beamforming with the first number of transceivers.

Example 7

The method of any of examples 1-6, wherein obtaining (110) a capability of the remote multiantenna transmitter and receiver arrangement comprises directly receiving (106) from the remote TNode the capability of the remote multi-antenna transmitter and receiver arrangement.

Example 8

The method of any of examples 1-6, further comprising: receiving (108) reception statistics associated with the first and/or second pre-coding mode(s) from the remote TNode; and wherein obtaining (110) a capability of the remote multi-antenna transmitter and receiver arrangement comprises deriving (111) the capability of the remote multi-antenna transmitter and receiver arrangement from the received reception statistics. Example 9

The method of any of examples 1-8, further comprising: transmitting (130) the one or more pre-coded data packet(s) to the remote TNode.

Example 10

A computer program product comprising a non-transitory computer readable medium (200), having stored thereon a computer program comprising program instructions, the computer program being loadable into a data processing unit (220) and configured to cause execution of the method of any of examples 1-9 when the computer program is run by the data processing unit.

Example 11

A wireless device, WD, comprising a multi-antenna transmitter and receiver arrangement (400) and controlling circuitry configured to cause: obtainment (310) of a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, wherein the obtained capability is indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatio-temporal dispersion; and pre-coding (320) of one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability.

Example 12

A transceiver node, TNode, comprising a multi-antenna transmitter and receiver arrangement (400) and controlling circuitry configured to cause: obtainment (310) of a capability of a remote multi-antenna transmitter and receiver arrangement comprised in a remote TNode, wherein the obtained capability is indicative of a first or second spatio-temporal dispersion the remote multi-antenna transmitter and receiver arrangement is able to manage, the first spatio-temporal dispersion being smaller than the second spatio-temporal dispersion; and pre-coding (320) of one or more data packet(s) to be transmitted to the remote TNode based on the obtained capability.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. Reference has been made herein to various embodiments. However, a person skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the claims. For example, the method embodiments described herein discloses example methods through steps being performed in a certain order. However, it is recognized that these sequences of events may take place in another order without departing from the scope of the claims. Furthermore, some method steps may be performed in parallel even though they have been described as being performed in sequence. Thus, the steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. In the same manner, it should be noted that in the description of embodiments, the partition of functional blocks into particular units is by no means intended as limiting. Contrarily, these partitions are merely examples. Functional blocks described herein as one unit may be split into two or more units. Furthermore, functional blocks described herein as being implemented as two or more units may be merged into fewer e.g., a single) unit. Any feature of any of the embodiments/aspects disclosed herein may be applied to any other embodiment/aspect, wherever suitable. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Hence, it should be understood that the details of the described embodiments are merely examples brought forward for illustrative purposes, and that all variations that fall within the scope of the claims are intended to be embraced therein.