A control unit for determining impairment compensation parameters for a transmitter, a digital interface chip, a method, a computer program product, and a non-transitory computer-readable storage medium

Abstract

A control unit, CU, (100) for determining impairment compensation parameters, ICPs, (70) for a transmitter (20), wherein the CU (100) is connectable to the transmitter (20) and to a first receiver (30, 40) and configured to: receive a first signal (10); configure the transmitter (20) with a first transmitter configuration and to transmit the first signal (10) with a first bandwidth, BW, (BW1) at a first carrier frequency, CF, (CF1); configure a first receiver (30, 40) to receive a second signal with a second BW (BW2, BW3) at a second CF (CF1, CF2); receive the second signal (50, 60) from the first receiver (30,40); and determine the ICPs (70) based on the first and second signals (10, 50, 60) and based on the first transmitter configuration, wherein the first BW (BW1) is different from the second BW (BW2). Corresponding digital interface chip, method, computer program product, and non-transitory computer-readable storage medium are also disclosed.

Description

[0001] A control unit for determining impairment compensation parameters for a transmitter, a digital interface chip, a method, a computer program product, and a non-transitory computer-readable storage medium

[0002] Technical field

[0003] The present disclosure relates to a control unit for determining impairment compensation parameters for a transmitter, and to corresponding digital interface chip, method, computer program product, and non-transitory computer-readable storage medium. More specifically, the disclosure relates to a control unit for determining impairment compensation parameters for a transmitter, a digital interface chip, a method, a computer program product, and a non- transitory computer-readable storage medium as defined in the introductory parts of the independent claims.

[0004] Background art

[0005] Transmitters are widely used within the field of wireless devices and mobile / cellular phones. A transmitter may transmit a signal using an array or a set of antennas. Furthermore, a transmitter normally comprises various components, such as a power amplifier (PA). As an example, the transmitter may include a separate PA for each antenna in the array / set, in which each PA amplifies the signal with sufficient power for wireless transmission to a remote device via the respective antenna. Each PA is typically a non-linear device with a limited linear dynamic range (DR). For power efficiency, it is desirable to drive each PA as close as possible to saturation. However, driving each PA close to saturation causes each PA to operate outside its linear range, which can lead to significant non-linear distortion if not corrected. Moreover, the PA and / or other components of the transmitter may have other impairments, such as direct current (DC) offset, and / or imbalances in / between quadrature signals (in-phase and quadrature components, IQ components).

[0006] Thus, there is a need for compensation of impairment of the transmitter or components thereof.

[0007] US 2019 / 0089389 Al discloses a method for wireless communication comprising predistorting a first signal based on a set of coefficients to generate a first pre-distorted signal, outputting the first pre-distorted signal for a first transmission to a receiving device, and receiving a first feedback signal from the receiving device, wherein the first feedback signal provides feedback of a first receive signal at the receiving device corresponding to the first transmission.

[0008] Furthermore, EP 2568616 Bl discloses compensation of a transmitter within a mobile wireless communications device.

[0009] However, there is still a need for improvements, such as provision of more flexibility and / or lower complexity.

[0010] 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 / or solve at least the above-mentioned problem or other problems.

[0011] According to a first aspect there is provided a control unit (CU) for determining impairment compensation parameters (ICPs) for a transmitter, wherein the CU is connected / connectable to the transmitter and to a first receiver, and configured / adapted to: receive a first signal; configure the transmitter with a first transmitter configuration and to transmit the first signal with a first bandwidth (BW) at a first carrier frequency (CF); configure a first receiver to receive a second signal with a second BW at a second CF; receive the second signal from the first receiver; and determine the ICPs based on the first and second signals and based on the first transmitter configuration, the first BW is different from the second BW and / or the first CF is different from the second CF.

[0012] According to some embodiments, the control unit is further configured / adapted to: receive a third signal to be transmitted by the transmitter; configure the transmitter with a second transmitter configuration and to transmit the third signal with the first BW at the first CF; configure the first receiver to receive a fourth signal with the second BW at the second CF; receive the fourth signal from the first receiver; and determine the ICPs is further based on the third and fourth signals and / or the second transmitter configuration.

[0013] According to some embodiments, the control unit is further configured / adapted to configure a transmitter impairment compensation unit (TICU) with the determined ICPs. According to some embodiments, the transmitter comprises a power amplifier (PA) and the TICU compensates for one or more of: a non-linear characteristic of the PA; a DC offset of the transmitter; and an IQ-imbalance of the transmitter.

[0014] According to some embodiments, the TICU comprises one or more of: a non-linear filter unit; a DC offset compensation unit; and an IQ imbalance compensation unit.

[0015] According to some embodiments, a first transceiver chip comprises the transmitter and the first receiver.

[0016] According to some embodiments, a first transceiver chip comprises the transmitter and a second transceiver chip comprises the first receiver.

[0017] According to a second aspect there is provided a digital interface chip (DIC) comprising one or more spatial TRX filters, and the control unit of the first aspect or of any of the embodiments herein, and the DIC is connected to the first and second transceiver chips and to a baseband (BB) processor.

[0018] According to a third aspect there is provided a method for determining (transmitter) impairment compensation parameters (ICPs) for a transmitter, the method comprises: receiving a first signal from a baseband (BB) processor; configuring the transmitter with a first transmitter configuration, and to transmit the first signal with a first bandwidth (BW) at a first carrier frequency (CF); configuring a first receiver to receive a second signal with a second (BW) at a second (CF); receiving the second signal from the first receiver; and determining the ICPs based on the first and second signals and based on the first transmitter configuration, the first BW is different from the second BW and / or the first CF is different from the second CF.

[0019] According to a fourth aspect there is provided: a computer program product comprising a non-transitory computer readable medium, having stored thereon a computer program comprising program instructions, the computer program being loadable into a data processing unit and configured to cause execution of the method of the third aspect or any of the embodiments mentioned herein when the computer program is run by the data processing unit; 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 third aspect or any of the embodiments mentioned herein; or 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 third aspect or any of the embodiments mentioned herein.

[0020] According to a fifth aspect there is provided a multi-antenna transmitter and receiver arrangement (MATARA), the MATARA comprising two or more antennas, the DIC of the second aspect, a baseband (BB) processor, a first transceiver chip, a second transceiver chip, and the MATARA is comprisable in a wireless device (WD).

[0021] According to some embodiments, the first transceiver chip comprises the transmitter and the first receiver.

[0022] According to some embodiments, the first transceiver chip comprises the transmitter and the second transceiver chip comprises the first receiver.

[0023] According to a sixth aspect there is provided a wireless device (WD) comprising the MATARA of the fifth aspect.

[0024] According to a seventh aspect there is provided a chip.

[0025] Effects and features of the second, third, fourth, fifth, sixth and seventh aspects are fully or to a substantial extent analogous to those described above in connection with the first aspect and vice versa.

[0026] Embodiments mentioned in relation to the first aspect are fully or largely compatible with the second, third, fourth, fifth, sixth and seventh aspects and vice versa.

[0027] An advantage of some embodiments is that performance (of the antennas, of the radio transmission, of one or more transmitters, of one or more PAs, of the MATARA, or of the WD) is improved or optimized.

[0028] Another advantage of some embodiments is that the radio transmission is more reliable.

[0029] A further advantage of some embodiments is that power consumption is reduced or optimized (for the WD, for the base station, for one or more transmitters, and / or for one or more PAs). Yet a further advantage of some embodiments is that DC offset, and / or imbalances in / between quadrature signals is avoided, reduced, or compensated for.

[0030] Yet another advantage of some embodiments is that a simplified and / or more flexible digital pre-distortion is achieved.

[0031] Yet another further advantage of some embodiments is that excellent performance is achieved.

[0032] Yet an advantage of some embodiments, is an optimized / improved trade-off between performance and power consumption.

[0033] Other advantages are that the signal quality is increased and / or that non-linear distortion is reduced or avoided.

[0034] 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 / or modifications may be made within the scope of the disclosure.

[0035] 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 the 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 do not exclude other elements or steps. Moreover, the term "configured" or "adapted" is intended to mean that a unit or similar is shaped, sized, connected, connectable or otherwise adjusted for a purpose.

[0036] Brief descriptions of the drawings

[0037] 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.

[0038] Figure 1 is a schematic drawing illustrating a multi-antenna transmitter and receiver arrangement (MATARA) according to some embodiments;

[0039] Figure 2 is a line chart illustrating the total output power of a PA versus frequency according to some embodiments;

[0040] Figure 3A is a chart illustrating a BB signal to be transmitted versus frequency according to some embodiments, e.g., DC offset;

[0041] Figure 3B is a chart illustrating a transmitted signal versus frequency according to some embodiments, e.g., DC offset;

[0042] Figure 3C is a chart illustrating a received BB signal versus frequency according to some embodiments, e.g., DC offset;

[0043] Figure 4A is a chart illustrating a BB signal to be transmitted versus frequency according to some embodiments, e.g., Quadrature signal imbalance;

[0044] Figure 4B is a chart illustrating a transmitted signal versus frequency according to some embodiments, e.g., Quadrature signal imbalance;

[0045] Figure 4C is a chart illustrating a received BB signal versus frequency according to some embodiments, e.g., Quadrature signal imbalance;

[0046] Figure 5 is a flowchart illustrating some method steps according to some embodiments;

[0047] Figure 6 is a schematic drawing illustrating a computer readable (storage) medium according to some embodiments;

[0048] Figure 7 is a flowchart illustrating actions / method steps implemented in a wireless device and / or in a processor / control unit thereof according to some embodiments; and

[0049] Figure 8 is a schematic drawing illustrating a system comprising one or more wireless devices and one or more transceiver nodes according to some embodiments. Detailed description

[0050] 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.

[0051] Terminology

[0052] Herein is referred to a processor / processing unit. The processor 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 (GPU), a digital signal processor (DSP), 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. Thus, the processor may be implemented as a single-processor, a dualprocessor system, or a multiprocessor system. Furthermore, the invention can also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network, e.g., 5G, to one or more local processors. In a distributed computing environment, program modules can be located in both local and remote memory storage devices. Moreover, some processing (e.g., for the data plane) may be moved to a centralized node, such as a centralized transceiver node (TNode). For example, baseband processing and / or higher layer processing, such as processing at layers above the physical layer, may be moved to a cloud, such as an mmW RAN cloud (wherein processing is performed by cloud processors). Such a (mmW) cloud deployment may bring significant cost savings to the operator due to centralized processing, collaborative radio processing, and availability of cheap commodity hardware.

[0053] Herein is referred to a baseband (BB) processor / processing unit. A BB processor is a processor specifically adapted for processing baseband signals / data.

[0054] Herein is referred to millimetre 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. The mmW frequency range may also be referred to as Frequency Range 2 (FR2). Herein is referred to centimetre Wave (emW) utilization, emW communication, emW communication capability and emW frequency range. The emW frequency range is from 7 or

[0055] 10 Gigahertz (GHz) to 30 GHz.

[0056] Herein is referred to Frequency range / band 1 (FR1) utilization, FR1 GHz communication, FR1 communication capability and FR1 frequency range / band. FR1 may also be referred to as sub 6 GHz. The sub 6 GHz frequency range / band may comprise the interval from 0.5 to 6 or 7 GHz.

[0057] Herein 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.

[0058] Herein 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, and tablets.

[0059] Herein is referred to a "transceiver node" (TNode). A TNode may be a radio unit (RRU), a repeater, a 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). Thus, a TNode may be a network (NW) node. Furthermore, a TNode may be a BS for a neighbouring cell, a BS for a handover (HO) candidate cell, a radio unit (RRU), a distributed unit (DU), another WD (e.g., 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.

[0060] Herein 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. Moreover, an antenna unit may be an antenna array, e.g., if analog beamforming is performed. Herein is referred to an antenna port. An antenna port comprises one or more antenna units.

[0061] Herein is referred to a non-terrestrial network (NTN). Non-terrestrial networks (NTNs) are wireless communication systems that operate above the Earth's surface. One or more NTNs comprises one or more NTN units, such as one or more satellites at low Earth orbit (LEO), one or more satellites at medium Earth orbit (MEO), one or more satellites at geostationary orbit (GEO), one or more high-altitude platforms (HAPs) and / or one or more unmanned aerial vehicles (UAVs). In some embodiments, an NTN comprises one or more (wireless) networks providing connectivity through one or more NTN units, such as one or more spaceborne vehicles (e.g., one or more GEO, MEO, and / or LEO satellites), one or more airborne platforms (e.g., one or more airships and / or one or more air balloons), and / or one or more unmanned aircraft system (UAS) platforms. A UAS platform may comprise one or more unmanned aerial vehicles (UAVs), such as one or more drones.

[0062] Herein the expression "based on" is equivalent to any of the expressions "in accordance with" and "in dependence of" (and vice versa).

[0063] Herein the term "comprise" is equivalent to the term "include".

[0064] Basic concept

[0065] The basic concept of the invention is to determine (transmitter) impairment compensation parameters (ICPs) for a transmitter. The ICPs are determined by a control unit (CU). The CU receives a first (digital) signal from a baseband (BB) processor. Furthermore, the CU configures the transmitter with a first transmitter configuration (e.g., with a first power configuration comprising a first power level for the PA). Moreover, the CU configures the transmitter to transmit the first signal with a first (information) bandwidth (BW) at / utilizing a first carrier frequency (CF). The CU further configures a first receiver to receive a second signal with a second BW at / utilizing a second CF (the second signal comprising the transmitted and received first signal). Furthermore, the CU receives the (digital or digitized / digitalized) second signal from the first receiver. Moreover, the CU determines the ICPs based on the first and second signals (e.g., by comparing the first and second signals) and based on the first transmitter configuration. The first BW is different from the second BW. Alternatively, or additionally, the first CF is different from the second CF. In some embodiments, the CU sends the determined parameters to a transmitter impairment compensation unit (TICU) and / or configures the TICU with the determined parameters. The TICU then compensates for the impairment (e.g., non-linearities of the PA, a DC offset of the transmitter and / or a quadrature signal imbalance of the transmitter). In some embodiments, the first receiver is a receiver utilized for receiving regular radio signals (i.e., not a dedicated measurement receiver). Thus, complexity is reduced. Furthermore, in some embodiments, a receiver encapsulated together with and / or in the same chip as the transmitter is utilized for in-band measurements, and a second receiver in a chip different from the chip the transmitter is in is utilized for out-of-band measurements (e.g., by utilizing a CF for the receiver, which CF is different from the CF utilized for the transmitter). Thus, more flexibility (e.g., in the measurements and / or in the compensation) is achieved.

[0066] Embodiments

[0067] In the following, embodiments will be described where figure 1 illustrates a multiantenna transmitter and receiver arrangement (MATARA) 300 according to some embodiments. The MATARA 300 comprises two or more antenna units 301, 302, ..., 316. Furthermore, the MATARA 300 comprises a digital interface chip (DIG) 130. Moreover, the MATARA 300 comprises a baseband, BB, processor 140. The MATARA 300 comprises one or two or more transceiver chips 110, 120 (e.g., a first transceiver chip 110 and optionally a second transceiver chip 120). The BB processor 140 is connected / connectable to the DIG 130. Furthermore, the DIG 130 is connected / connectable to the one or more transceiver chips 110, 120. Moreover, the one or two or more transceiver chips 110, 120 are connected / connectable to a respective antenna unit 301, 302, ..., 316. The MATARA (300) is comprisable in a wireless device (WD) 322 (shown in figure 8). Thus, in some embodiments, a WD 322 comprises the MATARA 300. Alternatively, a transceiver node (TNode) 397 (shown in figure 8) comprises the MATARA 300. Furthermore, the MATARA comprises spatial filters (for transmission and / or reception) 150. In some embodiments, the spatial filters 150 are used for digital beamforming. Moreover, in some embodiments, the DIG 130 comprises the spatial filters 150. Furthermore, the DIG 130 comprises one or more analog-to-digital converters (ADCs) and / or one or more digital-to-analog converters (DACs), e.g., the DIC 130 comprises one DAC and one ADC for each transceiver (chain) it is connected / connectable to. Alternatively, the DIC 130 comprises one ADC / DAC pair (comprising one DAC and one ADC) for each in-phase (I) component and one ADC / DAC pair (comprising one DAC and one ADC) for each quadrature (Q) component of the transceivers it is connected / connectable to. Moreover, the DIG 130 comprises a control unit (CU) 150. The DIG comprises one or more transmitter impairment compensation units (TICU) 151, 152, ..., 165, 166. The spatial filters 150 are connected / connectable to the TICUs 151, 152, ..., 165, 166 and / or to the DAOs (e.g., via the TICUs). Furthermore, the CU 150 is connected / connectable to the TICUs (e.g., for sending control signals and / or parameters to the TICUs). Moreover, the CU 100 may receive the output of one or more ADCs and / or one or more output from the spatial filters 150. Each transceiver chip 110, 120 comprises one or more, e.g., two, transceivers 20, 30, ..., 40. Each transceiver 20, 30, ..., 40 comprises a low pass filter (LPF), a mixer (MX), and a power amplifier (PA), and a low noise amplifier (LNA). As an example, each transceiver 20, 30, ..., 40 comprises (or functions as) a transmitter (chain) 20A, 30A, 40A and a receiver (chain) 20B, 30B, 40B. Each transmitter comprises an LPF, an MX, and a PA, and each receiver comprises an LPF, an MX, and an LNA (the LPF and the MX may be the same for both the transmitter and the receiver).

[0068] The control unit (CU) 100 is adapted / configured to determine (transmitter) impairment compensation parameters (ICPs) 70 for one or more transmitters / transceivers 20A, 30A, ..., 40A (which potentially has one or more or no impairments). The CU 100 is connectable / connected to the one or more transmitters / transceivers 20, 30, 40. Furthermore, the CU is connectable / connected to a first receiver (transceiver) 30B, 40B. The CU is adapted / configured to receive a first signal 10, e.g., from the BB processor 140 via the spatial filters 150, directly from a processor comprised in the DIG 130, or directly from a signal generation unit comprised in the DIG 130. Furthermore, the CU is adapted / configured to configure the transmitter (transceiver) 20A with a first transmitter configuration. Moreover, the CU is adapted / configured to configure / set the transmitter / transceiver 20A, 20 to transmit the first signal 10 with a first (information) bandwidth (BW) BW1 at / with a first carrier frequency (CF) CF1. The CU is adapted / configured to configure / set a first receiver / transceiver 30B, 30, 40B, 40 to receive a second signal with a second BW BW2, BW3 at a second CF CF1, CF2 (e.g., the LPF of the first receiver 30B is configured / set to BW2 and / or the LPF of the first / second receiver 40B is configured / set to BW3). Furthermore, the CU is adapted / configured to receive the second signal 50, 60 from the first receiver / transceiver 30B, 30, 40B, 40. Moreover, the CU is adapted / configured to determine the ICPs 70 based on the first and second signals 10, 50, 60 and based on the first transmitter configuration. The first BW BW1 is different from the second BW BW2 (in some embodiments, BW1 is smaller than BW2). Alternatively, or additionally, the first CF CF1 is different from the second CF CF2. As another alternative, the first BW BW1 is different from the second / third BW BW3 (in some embodiments, BW1 is larger than BW3). As yet another alternative, the first BW is equal to the second BW. As a further alternative, the first CF CF1 is equal to the second CF CF2.

[0069] In some embodiments, the CU 100 is configured to receive a third signal 10A. The CU is adapted / configured to configure the transmitter / transceiver 20A, 20 with a second transmitter configuration. Moreover, the CU 100 is adapted / configured to configure / set the transmitter / transceiver 20A, 20 to transmit the third signal 10A with a first bandwidth (BW) BW1 at / with a first carrier frequency (CF) CF1. The CU is adapted / configured to configure / set a first receiver / transceiver 30B, 30, 40B, 40 to receive a fourth signal 50A, 60A with a second BW BW2, BW3 at a second CF CF1, CF2. Furthermore, the CU 100 is adapted / configured to receive the fourth signal 50A, 60A from the first receiver / transceiver 30B, 30, 40B, 40. Moreover, the CU is adapted / configured to determine the ICPs 70 based on the first, second, third, and fourth signals 10, 50, 60, 10A, 50A, 60A and based on the first and second transmitter configurations. In some embodiments, the CU 100 is configured to receive further signals (e.g., one or more per transceiver), to configure further transmitters and / or receivers (e.g., all transmitters / transceivers), and determine further ICPs (e.g., one set of ICPs for each of the TICUs 151, 152, ..., 165, 166).

[0070] In some embodiments, the CU is adapted / configured to configure / set one or more transmitter impairment compensation units (TICU) 151, 152, 165, 166 with the determined ICPs 70. Each TICU 151, 152, ..., 165, 166 compensates for or is configured / adapted to compensate for one or more of a non-linear characteristic of the PA (of the corresponding transmitter / transceiver), a DC offset of / for / in the corresponding transmitter / transceiver 20, and a quadrature signal imbalance (an imbalance between in-phase and quadrature components or an imbalance in IQ) of the transmitter / transceiver 20. Each TICU 151, 152, ..., 165, 166 comprises one or more PA non-linearity compensation units. As an example, the / each PA non-linearity compensation unit is or comprises a (digital) non-linear (or predistortion) filter unit (for compensating a non-linear characteristic of the corresponding PA). As another example (or additionally to the previous example), the PA non-linearity compensation unit is directly connected to a corresponding transceiver 20, 30, 40 and sends a (positive or negative) bias signal or a control signal comprising the bias signal / value to the corresponding transceiver 20, 30, 40. The corresponding transceiver 20, 30, 40 adds or subtracts the bias value to the PA directly (at the PA) or indirectly (e.g., by adding or subtracting a bias to / from the MX, to / from the LPF or at the interconnection between the MX and the LPF). Thus, compensation can be performed by one or more of the PA non-linearity compensation unit / TICU 151, 152, ..., 165, 166 and the transceiver 20, 30, 40. Alternatively, or additionally, each TICU 151, 152, ..., 165, 166 comprises one or more DC offset compensation unit (for compensating for a DC offset of the corresponding transmitter / transceiver 20). As an example, the DC offset compensation unit is a (e.g., digital) filter having the first signal 10 as input and having a modified first signal (e.g., the first signal plus a bias value) as output to the corresponding DAC. As another example, the DC offset compensation unit is directly connected to a corresponding transceiver 20, 30, 40 and sends a (positive or negative) bias signal or a control signal comprising the bias signal / value to the corresponding transceiver 20, 30, 40. The corresponding transceiver 20, 30, 40 adds or subtracts the bias value to the PA directly (at the PA) or indirectly (e.g., by adding or subtracting a bias to / from the MX, to / from the LPF or at the interconnection between the MX and the LPF). As yet another example, the DC offset compensation unit is a (e.g., digital) filter and is directly connected to a corresponding transceiver 20, 30, 40 and sends a (positive or negative) bias signal or a control signal comprising the bias signal / value to the corresponding transceiver 20, 30, 40. Thus, compensation can be performed by one or more of the DC offset compensation unit / TICU 151, 152, ..., 165, 166 and the transceiver 20, 30, 40. As another alternative, or additionally, each TICU 151, 152, ..., 165, 166 comprises one or more IQ imbalance compensation unit (for compensating for a quadrature signal imbalance). As a first example, the IQ imbalance compensation unit is a (e.g., digital) filter having the first signal 10 as input and having a modified first signal (e.g., the first signal multiplied by a gain and / or plus a bias value) as output to the corresponding DAC. As a second example, the IQ imbalance compensation unit has the first signal 10 as input, separates the input signal 10 into I and Q components (101, 10Q), multiplies / combines each of the I and Q components with a gain (a, b, c, d) to produce scaled I and Q components (a*l, b*Q), combines (by addition or subtraction) the scaled I and Q components to a sum ([a*l]+[b*Q], [c*l]-[d*Q]), optionally adds a bias value to the sum, and outputs the sum (optionally with a bias value) to the corresponding DAC. As a third example, the IQ imbalance compensation unit is directly connected to a corresponding transceiver 20, 30, 40 and sends a (positive or negative) gain and / or bias signal or a control signal comprising the gain and / or bias signal / value to the corresponding transceiver 20, 30, 40. The corresponding transceiver 20, 30, 40 applies the gain and / or the bias value to the mixer directly or indirectly. As a fourth example, the IQ imbalance compensation unit is directly connected to a corresponding transceiver 20, 30, 40 and sends a (positive or negative) gain for each of the I and Q components and / or a bias signal or a control signal comprising the gain for each of the I and Q components and / or bias signal / value to the corresponding transceiver 20, 30, 40. The corresponding transceiver 20, 30, 40 applies the gain for each of the I and Q components and / or the bias value, e.g., as LPF gains for the corresponding I and Q branches. As yet a further example, the IQ imbalance compensation unit is a combination of two or more of the first, second, third, and fourth examples. Thus, compensation can be performed by one or more of the IQ imbalance compensation unit / TICU 151, 152, ..., 165, 166 and the transceiver 20, 30, 40. In some embodiments, each TICU 151, 152, ..., 165, 166 is implemented as one or more look-up tables (LUTs), e.g., a separate LUT for one or more of the PA nonlinearity compensation unit, the DC offset compensation unit, and the IQ imbalance compensation unit. Alternatively, or additionally, each TICU 151, 152, ..., 165, 166 is implemented as one or more polynomial algorithms, e.g., a separate polynomial algorithm for one or more of the PA non-linearity compensation unit, the DC offset compensation unit, and the IQ imbalance compensation unit. Thus, the compensation can be performed dynamically / adaptively (e.g., a new set of ICPs may be dependent upon the current and / or previous sets of ICPs). In some embodiments, the first transceiver chip 110 comprises the transmitter 20 and the first receiver 30. In these embodiments complexity is reduced.

[0071] Alternatively, the first transceiver chip 110 comprises the transmitter 20 and the second transceiver chip 120 comprises the first receiver 30. In these embodiments, more flexibility (e.g., in the measurements and / or in the compensation) is achieved.

[0072] Figure 2 illustrates the total output power of a power amplifier (PA) versus frequency according to some embodiments. As an example, the transmitted first signal 10 (transmitted by the transmitter 20) comprises one or more resource blocks (e.g., 1, 2, 5, 10, 50 resource blocks, RBs). Since there are normally 12 subcarriers (SC) e.g., in a 5G system, and the sub carrier spacing (SCS) may be 15, 30, 60, 120 and 240 kHz, as an example the RB BW (e.g., BW1) may be 14.4 MHz (with 120kHz, 12 SB, and 10 RBs). In some embodiments, the first BW (BW1) is smaller than the BW the LPF of the transmitter 20 is configured for (e.g., LPF configured for 50 MHz). Furthermore, a first carrier frequency (CF) CF1 is utilized for transmission of the first signal 10. The first CF CF1 is, in some embodiments, the center frequency of the system BW. The LPF of the first receiver 30B, 40B is configured with a second BW BW2. The second BW BW2 is larger than the first BW BW1. As an example, the second BW BW2 is (equal to) a bandwidth part BWP, such as 10 MHz, 20 MHz, or 50 MHz. As another example, the second BW BW2 is (equal to) a system BW, such as 100 MHz, 200 MHz, 400 MHz, or 800 MHz. Furthermore, the first receiver 30B, 40B (or the MX thereof) is configured with the first CF CF1. The first transmitter configuration comprises, in some embodiments, a first power configuration. The first power configuration comprises a first power level for the PA. The power level may be 5 dBm, 10 dBm, 12 dBm, or 15 dBm. Thus, leakage due to non-linear characteristic of the PA inside the second BW (BW2) can be measured. In some embodiments, the first transmitter configuration comprises, additionally or alternatively, settings for the LPF, the MX and / or the LNA. In some embodiments, the same, e.g., the first, transceiver chip 110 comprises the transmitter 20A and the first receiver 30B. In these embodiments, the first receiver is a receiver utilized for receiving regular radio signals (i.e., not a dedicated measurement receiver). Thus, complexity is reduced.

[0073] As another example, the transmitted first signal 10 (transmitted by the transmitter 20A) comprises one or more resource blocks (e.g., 1, 2, 5, 10, 50 resource blocks, RBs). The first (information) BW is (equal to) a (full) system BW, such as 100 MHz, 200 MHz, 400 MHz, or 800 MHz. Alternatively, the first (information) BW is (equal to) a (full) bandwidth part BWP, such as 10 MHz, 20 MHz, or 50 MHz. The first signal 10 is transmitted by the transmitter 20A at full system BW / BWP. Furthermore, the LPF of the transmitter 20A is configured for the full system BW / BWP. Moreover, the first signal 10 is transmitted at the first CF (CF1). The first CF is, in some embodiments, the center frequency of the system BW. The LPF of the first receiver 30B is configured with a second BW BW2. The second BW BW2 is equal to or different from the first BW BW1. As an example, the second BW BW2 is (full) bandwidth part (BWP), such as 10 MHz, 20 MHz, or 50 MHz. Alternatively, or additionally, the LPF of the first receiver 40B is configured with a second / third BW BW3. As seen in figure 2, the third BW BW3 is smaller than the first BW BW1. Furthermore, the first receiver 30B, 40B is configured to receive the second signal 50, 60 at the second CF (CF2, which is different from CF1), i.e., the MX of the first receiver 30B, 40B is configured with CF2. The first transmitter configuration comprises, in some embodiments, a first power configuration. The first power configuration comprises a first power level for the PA. The power level may be 5 dBm, 10 dBm, 12 dBm, or 15 dBm. Thus, leakage due to non-linear characteristics of the PA inside an adjacent frequency band can be measured. In some embodiments, the first transmitter configuration comprises, additionally or alternatively, settings for the LPF, the MX and / or the LNA. In some embodiments, the first transceiver chip 110 comprises the transmitter 20A and the second transceiver chip 120 comprises the first receiver 40B. In these embodiments, the first receiver 40B is a receiver utilized for receiving regular radio signals (i.e., not a dedicated measurement receiver). Thus, complexity is reduced. Furthermore, the same receiver (e.g., receiver 40B) may be utilized for measurements of different transmitters (e.g., transmitters 20A, 30A). Thus, complexity is reduced. Moreover, in some embodiments, a first receiver 30B is encapsulated together with and / or in the same chip (e.g., the first transceiver chip 110) as the transmitter 20A is utilized for in-band measurements, and a second receiver 40B in a chip different from the chip the transmitter is in (e.g., the second transceiver chip 120) is utilized for out-of-band measurements (e.g., by utilizing a CF for the receiver, which CF is different from the CF utilized for the transmitter), e.g., simultaneously with the in-band measurements. Thus, more flexibility (e.g., in the measurements and / or in the compensation) is achieved. Alternatively, the first receiver 30B is utilized for measurements of a first (frequency) band, and the second receiver 40B is utilized for measurements of a second (frequency) band (simultaneously). The second band is different (overlapping or non-overlapping; adjacent or with a gap in-between) from the first band. Thus, measurement can be obtained faster and / or measurements can be made over a larger frequency band.

[0074] Figures 3A-3C illustrate a BB signal to be transmitted (figure 3A), a transmitted BB signal (figure 3B), and a received BB signal (figure 3C) versus frequency according to some embodiments, e.g., embodiments involving determination of DC offset compensation and / or compensating for a DC offset. The transmitted first signal 10 (transmitted by the transmitter 20A) comprises zero, one, two, three (or more) resource blocks (e.g., 0, 1, 2, 3, 4, 5, 6 RBs). However, as seen in figure 3A, the RB allocation (the BB signal) is offset from the CF the transmitter is configured with, i.e., the first CF (CF1). Thus, as can be seen in figure 3B, a transmission direct current (DC) offset is generated at / by the transmitter (e.g., the transmitter 20A). The receiver 30B, 40B is configured with a second CF (CF2), which is different / offset from CF1 (e.g., CF2=CF1 plus / minus 100 / 200 / 500 / 1000 / 2000 kHz). The LPF of the first receiver 30B, 40B is configured with a second BW (BW2). Thus, as seen in figure 3C, a reception DC offset is generated (due to any DC offset impairment in the receiver). The reception DC offset is different from the transmission DC offset. Furthermore, the reception DC offset is located at a frequency different from the frequency where the transmission DC offset is located (i.e., the reception DC offset and the transmission DC offset are separated in frequency). This is due to the fact that the second CF CF2 is different from the first CF CF1. Furthermore, the transmission DC offset can be estimated at the frequency CF1 minus CF2 (CF1-CF2). Thus, DC offset compensation parameters (or ICPs 70) can be determined (from the estimated transmission DC offset). The CU 100 can then configure / set a respective TICU 151, 152, 165, 166 with the determined DC offset compensation parameters (or ICPs 70). By estimating the transmission DC offset at frequency CF1-CF2 (where the reception DC offset is not present, since the reception DC offset and the transmission DC offset are separated in frequency), higher accuracy in the estimation of the transmission DC offset is achieved, and thus a more accurate compensation is enabled / achieved.

[0075] Figures 4A-4C illustrate a BB signal to be transmitted (figure 4A), a transmitted BB signal (figure 4B), and a received BB signal (figure 4C) versus frequency according to some embodiments, e.g., embodiments involving determination of quadrature signal imbalance compensation and / or compensating for quadrature signal imbalance. The transmitted first signal 10 (transmitted by the transmitter 20A) comprises one, two, three (or more) resource blocks (e.g., 1, 2, 3, 4, 5, 6 RBs). However, as seen in figure 4A, the RB allocation (the information / BB signal) is offset from the CF the transmitter is configured with, i.e., the first CF (CF1). Thus, as can be seen in figure 4B, a transmission quadrature signal (or IQ) imbalance component is generated. The transmission quadrature signal imbalance component appears at a frequency mirrored around CF1 from the RB allocation (the information / BB signal). The receiver 30B, 40B is configured with a second CF (CF2), which is different / offset from CF1 (e.g., CF2=CF1 plus / minus 100 / 200 / 500 / 1000 / 2000 kHz). The LPF of the first receiver 30B, 40B is configured with a second BW (BW2). Thus, as seen in figure 4C, a reception quadrature signal (or IQ) imbalance component is generated (due to receiver impairment). The reception quadrature signal (or IQ) imbalance component is different from the transmission quadrature signal (or IQ) imbalance component. Furthermore, the reception quadrature signal imbalance component is located at a frequency different from the frequency where the transmission quadrature signal imbalance component is located. This is due to the fact that the second CF (CF2) is different from the first CF (CF1) (and that the transmission / reception quadrature signal imbalance components are mirrored around the different CFs CF1 and CF2). Furthermore, the transmission quadrature signal imbalance component can be estimated without interference from the reception quadrature signal imbalance component. Thus, quadrature signal imbalance compensation parameters (or ICPs 70) can be determined (from the estimated transmission quadrature signal imbalance component). The CU 100 can then configure / set a respective TICU 151, 152, 165, 166 with the determined transmission quadrature signal imbalance compensation parameters (or ICPs 70). By estimating the transmission quadrature signal imbalance component (where the reception quadrature signal imbalance component is not present), higher accuracy in the estimation of the quadrature signal imbalance component is achieved, and thus a more accurate compensation is enabled / achieved.

[0076] Figure 5 illustrates some method steps of a method 500 according to some embodiments. The method 500 is for determining (transmitter) impairment compensation parameters (ICPs) for one or more transmitters / transceivers 20. The method comprises receiving 510 a first signal 10 from a baseband (BB) processor 140. In some embodiments, a BB chip comprises the BB processor 140. Furthermore, the BB processor 140 generates (or is configured to generate the first signal 10. Alternatively, the DIC 130 (or a processor / signal generation unit thereof) generates (or is configured to generate the first signal 10). By generating the first signal 10 in / by the DIC 130 calibration / compensation of impairment can be performed faster and / or more efficiently, e.g., since calibration / compensation can then be performed without involving the (external) BB processor 140. The generated first signal 10 is sent to the CU 100 (e.g. via spatial filters 150). Furthermore, the method comprises configuring 520 the transmitter 20 with a first transmitter configuration. Moreover, the method comprises configuring the transmitter 20 to transmit the first signal 10 with a first bandwidth (BW) BW1 at a first carrier frequency (CF) CF1. The method comprises configuring 530 a first receiver 30, 40 to receive a second signal with a second BW BW2, BW3 at a second CF CF1, CF2. Furthermore, the method comprises receiving 540 the second signal 50, 60 from the first receiver 30,40. Moreover, the method comprises determining 550 the ICPs 70 based on the first and second signals 10, 50, 60 and based on the first transmitter configuration. The first BW BW1 is different from the second BW BW2. Alternatively, or additionally, first CF CF1 is different from the second CF CF2. In some embodiments, the method 500 comprises configuring 560 one or more transmitter impairment compensation units (TICUs) 151, 152, ..., 165, 166, preferably the TICU 151, with the determined ICPs 70. Furthermore, in some embodiments, the method 500 comprises repeating 570 one or more of the steps of receiving 510, configuring (T) 520, configuring (R) 530, receiving (S2) 540, and determining 550 (and optionally the step of configuring 560). As an example, the method 500 is repeated (the steps described above 510, 520, 530, 540, 550 and optionally 560 are repeated), with the only difference that during configuring 520 the transmitter 20 is configured with a second transmitter configuration (different from the first transmitter configuration) instead of with the first transmitter configuration. The second transmitter configuration may comprise a second power configuration (different from the first power configuration) comprising a second power level (different from the first power level) for the PA (and the method 500 may thereafter be repeated also for a third, fourth and / or fifth power level and all the signals and configuration may be taken into account when determining the ICPs 70). As another example (additionally or alternatively), the method 500 is repeated (the steps described above 510, 520, 530, 540, 550 and optionally 560 are repeated), with the only difference that during configuring 520, another transmitter, e.g., the transmitter 30, is configured instead of the transmitter 20 (and optionally with the difference that during configuring 560 the TICU 152 is configured instead of the TICU 151. As yet another example, the method 500 is repeated for all transmitters (with the optional difference that a respective TICU 151, 152, ..., 165, 166 is configured).

[0077] According to some embodiments, a computer program product comprising a non- transitory computer readable medium 600, 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, or a universal serial bus (USB) memory, is provided. Figure 6 illustrates an example computer readable medium in the form of a compact disc (CD) ROM 600. The computer readable medium has stored thereon, a computer program comprising program instructions. The computer program is loadable into a data processor (PROC) 620, which may, for example, be comprised in a computer or a computing device 610, any of the WDs 322, 323, ..., 328, or the CU 100 described herein in connection with figure 1. When loaded into the data processor 620, the computer program may be stored in a memory (MEM) 630 associated with or comprised in the data processor 620. According to some embodiments, the computer program may, when loaded into and run by the data processor 620, cause execution of method steps according to, for example, the method illustrated in figure 5, 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 5. 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 5.

[0078] Figure 7 illustrates actions / method steps (e.g., of the method 500 described above) implemented in the WD 322 (described herein), in a processor or controlling circuitry thereof, in the MATARA 300 (described herein) and / or in a control unit (CU) thereof, e.g., the CU 100, according to some embodiments. The MATARA 300 (or the CU 100 thereof) is configured to cause reception 710 of a first signal 10 from a baseband (BB) processor 140. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a first receiving unit (e.g., first receiving circuitry, or a first MATARA / CU receiver). Furthermore, the MATARA 300 (or the CU 100 thereof) is configured to cause configuration 720 of the transmitter 20 with a first transmitter configuration. Moreover, the MATARA 300 (or the CU 100 thereof) is configured to cause configuration of the transmitter 20A to transmit the first signal 10 with a first bandwidth (BW) BW1 at a first carrier frequency (CF) CF1. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a first configuring unit (e.g., first configuring circuitry, a first configurer, or a first processor). Moreover, the MATARA 300 (or the CU 100 thereof) is configured to cause configuration 730 of a first receiver 30B, 40B to receive a second signal with a second BW BW2, BW3 at a second CF CF1, CF2. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a second configuring unit (e.g., second configuring circuitry, a second configurer, or a second processor). The MATARA 300 (or the CU 100 thereof) is configured to cause reception 740 of the second signal 50, 60 from the first receiver 30B, 40B. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a second receiving unit (e.g., second receiving circuitry, or a second MATARA / CU receiver). Furthermore, the MATARA 300 (or the CU 100 thereof) is configured to cause determination 750 of the ICPs 70 based on the first and second signals 10, 50, 60 and based on the first transmitter configuration. The first BW BW1 is different from the second BW BW2. Alternatively, or additionally, first CF CF1 is different from the second CF CF2. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a first determining unit (e.g., first determining circuitry, a first determiner, or a third processor). In some embodiments, the MATARA 300 (or the CU 100 thereof) is configured to cause configuration 760 of one or more transmitter impairment compensation units (TICUs) 151, 152, ..., 165, 166, preferably at least the TICU 151, with the determined ICPs 70. To this end, the MATARA 300 or the CU 100 may be associated with (e.g., operatively connectable, or connected, to) a third configuring unit (e.g., third configuring circuitry, a third configurer, or a fourth processor). In some embodiments, the MATARA 300 (or the CU 100 thereof) is configured to cause repetition 770 of one or more of the actions / steps of reception 710, 740, configuration 720, 730, determination 750, and optionally configuration 760. To this end, the MATARA 300 (or the CU 100 thereof) may be associated with (e.g., operatively connectable, or connected, to) a first repetition unit (e.g., first repetition circuitry or a first repeater). Moreover, in some embodiments, the MATARA 300 (or the CU 100 thereof) is configured to cause actions corresponding to any other method step described herein.

[0079] Figure 8 illustrates a system 999. The system 999 may be a wireless / cellular communication system, a cellular network, a mobile network, a telecommunications network, a cellular radio system, a digital cellular network, a mobile phone network, a mobile phone cellular network, such as 1G, 2G, 3G, 4G, 5G, 6G, or an ad hoc / mesh NW, such as Bluetooth or Wi-Fi. Furthermore, the system 999 comprises one or more wireless devices (WD) 322, 323, ..., 328. Moreover, the system 999 comprises one or more transceiver nodes (TNodes) 396, 397, 398, 399, i.e., the system 999 comprises a set 395 of one or more TNodes 396, 397, 398, 399. The one or more TNodes 396, 397, 398, 399 may be base stations (gNBs, eNBs, RBS), remote radio units (RRUs), NTN units or remote wireless nodes. The WD 322 (as well as the WDs 323, ..., 328) is, in some embodiments, configured to communicate with (e.g., send / transmit and / or receive signals, such as radio (or wireless) signals, e.g., comprising baseband / information signals, to / from) one or more of the remote TNodes 396, 397, 398, 399. In some embodiments, some, or all of the communication between the WD 322 (as well as the WDs 323, ..., 328) and the remote TNodes 396, 397, 398, 399 is performed with radio signals in the mmW frequency range. Alternatively, or additionally, the communication between the WD 322 (as well as the WDs 323, ..., 328) and the remote TNodes 396, 397, 398, 399 is performed with radio signals in the emW frequency range. As another alternative, or additionally (to mmW and emW), (some of) the communication between the WD 322 (as well as the WDs 323, 328) and the remote TNodes 396, 397, 398, 399 is performed with radio signals in the FR1 frequency range. Each Tnode 396, 397, 398, 399 is, in some embodiments, connected to a central computing device via a backhaul, such as a fibre-based backhaul, a wireless point-to- point backhaul, a copper-based wireline, satellite communications and / or point-to-multipoint wireless technologies.

[0080] List of examples:

[0081] Example 1: A multi-antenna transmitter and receiver arrangement, MATARA, (300), the MATARA (300) comprising two or more antennas (301, 302, ..., 316), the DIG (130) as described herein, a baseband, BB, processor (140), a first transceiver chip (110), a second transceiver chip (120).

[0082] Example 2: The MATARA (300) of example 1, wherein the second transceiver chip (120) is different from the first transceiver chip (110).

[0083] Example 3: The MATARA (300) of example 2, wherein the first transceiver chip (110) comprises the transmitter (20) and the first receiver (30).

[0084] Example 4: The MATARA (300) of example 2, wherein the first transceiver chip (110) comprises the transmitter (20) and the second transceiver chip (120) comprises the first receiver (30).

[0085] Example 5: The MATARA (300) of example 1, wherein the second transceiver chip (120) is the same as the first transceiver chip (110).

[0086] Example 6: A wireless device, WD, (322) comprising the MATARA (300) of any of examples 1-5.

[0087] Example 7: A transceiver node, TNode, (397) comprising the MATARA (300) of any of examples 1-5.

[0088] Example 8: A chip comprising the control unit, CU, (100) as described herein.

[0089] 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 actions / 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.

[0090] List of some acronyms and abbreviations that may appear in the description

[0091] 3GPP - 3rd Generation Partnership Project

[0092] 5G - fifth generation

[0093] 5G - NR (5G - New Radio) is a new RAT developed by 3GPP for the 5G mobile network

[0094] ADC - analog-to-digital converter

[0095] AGC - automatic gain controller

[0096] BB - baseband

[0097] BF - beamforming

[0098] BW - bandwidth

[0099] BWP - bandwidth part

[0100] CF - carrier frequency

[0101] CSI - channel state information

[0102] CSI-RS - channel state information reference signal

[0103] CQI - Channel Quality Indicator

[0104] CU - control unit

[0105] DAC - digital-to-analog converter

[0106] DC - direct current

[0107] DCI - downlink control information

[0108] DIC - Digital Interface Chip

[0109] DL-PRS - downlink positioning reference signal

[0110] DM-RS - demodulation reference signal

[0111] DR - dynamic range

[0112] DS - down-sampling

[0113] FR1 - Frequency Range 1

[0114] FR1.5 - Frequency Range 1.5

[0115] FR2 - Frequency Range 2

[0116] Fe - Front end

[0117] FWA - Fixed Wireless Access

[0118] GNSS - Global navigation satellite system

[0119] GPS - Global Positioning System

[0120] ICP - impairment compensation parameters IF - intermediate frequency

[0121] I / O - input / output

[0122] LI - Layer 1

[0123] LNA - Low Noise Amplifier

[0124] LO - Local Oscillator

[0125] LoS - Line of Sight

[0126] LTE - Long-Term Evolution

[0127] LUT - look-up table

[0128] MAC - Medium Access Control

[0129] MATARA - multi-antenna transmitter and receiver arrangement

[0130] MIMO - multiple input, multiple output mmW - millimetre wave

[0131] MX - Mixer

[0132] NAS - Non-access Stratum nLoS - non-Line of Sight

[0133] OFDM - orthogonal frequency-division multiplexing

[0134] PA - power amplifier

[0135] PBCH - Physical Broadcast Channel

[0136] PCB - printed circuit board

[0137] PCell - primary cell

[0138] PDCCH - physical downlink control channel

[0139] PDP - Power delay profile

[0140] PDSCH - physical downlink shared channel

[0141] PHY - Physical Layer

[0142] PLL - phase locked loop

[0143] PSCell - primary secondary cell

[0144] PSS - primary synchronization signal

[0145] PT-RS - Phase Tracking Reference signal

[0146] PUCCH - physical uplink control channel

[0147] PUSCH - physical uplink shared channel

[0148] QCL - quasi co-located QoS - quality of service

[0149] RAT - radio access technology

[0150] RB - Resource block

[0151] RRC - radio resource control

[0152] RSRP - Reference Signal Received Power

[0153] RSRQ - Reference Signal Received Quality

[0154] RSS - Received Signal Strength

[0155] RSSI - Received Signal Strength Indicator

[0156] SCell - Secondary Cell

[0157] SNR - Signal-to-noise ratio

[0158] SS - Snapshot

[0159] SSB - Synchronization Signal Block

[0160] SRS - sounding reference signal

[0161] SSS - secondary synchronization signal

[0162] STEF - spatio-temporal filter

[0163] STF - spatial transmission filter

[0164] TCI - Transmission Configuration Indicator

[0165] TICU - transmitter impairment compensation unit

[0166] TNode - transceiver node

[0167] UE - user equipment

[0168] VGA - variable gain amplifier

[0169] WD - wireless device

Claims

CLAIMS1. A control unit, CU, (100) for determining impairment compensation parameters, ICPs, (70) for a transmitter (20), wherein the CU (100) is connectable to the transmitter (20) and to a first receiver (30, 40) and configured to: receive a first signal (10); configure the transmitter (20) with a first transmitter configuration and to transmit the first signal (10) with a first bandwidth, BW, (BW1) at a first carrier frequency, CF, (CF1); configure a first receiver (30, 40) to receive a second signal with a second BW (BW2, BW3) at a second CF (CF1, CF2); receive the second signal (50, 60) from the first receiver (30,40); and determine the ICPs (70) based on the first and second signals (10, 50, 60) and based on the first transmitter configuration, wherein the first BW (BW1) is different from the second BW (BW2).

2. The control unit of claim 1, further configured to: receive a third signal (10A) to be transmitted by the transmitter (20); configure the transmitter (20) with a second transmitter configuration and to transmit the third signal (10A) with the first bandwidth, BW, (BW1) at the first CF (CF1); configure the first receiver (30, 40) to receive a fourth signal (50A, 60A) with the second BW (BW2, BW3) at the second CF (CF1, CF2); receive the fourth signal (50A, 60A) from the first receiver (30,40); and wherein the CU (100) is configured to determine the ICPs (70) further based on the third and fourth signals (10A, 50A, 60A) and the second transmitter configuration.

3. The control unit of any of claims 1 or 2, further configured to: configure a transmitter impairment compensation unit, TICU, (151, 152, ..., 165, 166) with the determined ICPs (70).

4. The control unit of claim 3, wherein the transmitter (20) comprises a power amplifier, PA, and wherein the TICU (151, 152, ..., 165, 166) compensates for one or more of: a non-linear characteristic of the PA; a DC offset of the transmitter (20); and an IQ-imbalance of the transmitter (20).

5. The control unit of any of claims 3-4, wherein the TICU (151, 152, ..., 165, 166) comprises one or more of: a non-linear filter unit;a DC offset compensation unit; and an IQ imbalance compensation unit.

6. The control unit of any of claims 1-5, wherein the first CF (CF1) is different from the second CF (CF2).

7. The control unit of any of claims 1-6, wherein a first transceiver chip (110) comprises the transmitter (20) and the first receiver (30).

8. The control unit of any of claims 1-6, wherein a first transceiver chip (110) comprises the transmitter (20) and a second transceiver chip (120) comprises the first receiver (40).

9. A digital interface chip, DIC, (130) comprising one or more spatial filters, and the control unit (100) of claim8, wherein the DIC (130) is connected to the first and second transceiver chips (110, 120) and to a baseband, BB, processor (140).

10. A multi-antenna transmitter and receiver arrangement, MATARA, (300), the MATARA (300) comprising two or more antennas (301, 302, ..., 316), the DIC (130) of claim 9, a baseband, BB, processor (140), a first transceiver chip (110), and a second transceiver chip (120).

11. The MATARA (300) of claim 10, wherein the second transceiver chip (120) is different from the first transceiver chip (110).

12. The MATARA (300) of claim 11, wherein the first transceiver chip (110) comprises the transmitter (20) and the first receiver (30).

13. The MATARA (300) of claim 11, wherein the first transceiver chip (110) comprises the transmitter (20) and wherein the second transceiver chip (120) comprises the first receiver (30).

14. The MATARA (300) of claim 10, wherein the second transceiver chip (120) is the same as the first transceiver chip (110).

15. A wireless device, WD, (322) comprising the MATARA (300) of any of claims 10-14.

16. A transceiver node, TNode, (397) comprising the MATARA (300) of any of claims 10-14.

17. A chip comprising the control unit, CU, (100) of any of claims 1-8.

18. A method (200) for determining transmitter impairment compensation parameters, ICPs, for a transmitter (20), the method comprising: receiving (210) a first signal (10) from a baseband, BB, processor; configuring (220) the transmitter (20) with a first transmitter configuration, and to transmit the first signal (10) with a first bandwidth, BW, (BW1) at a first carrier frequency, CF, (CF1);configuring (230) a first receiver (30, 40) to receive a second signal with a second BW (BW2, BW3) at a second CF (CF1, CF2); receiving (240) the second signal (50, 60) from the first receiver (30,40); and determining (250) the ICPs (70) based on the first and second signals (10, 50, 60) and based on the first transmitter configuration, wherein the first BW (BW1) is different from the second BW (BW2).

19. 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 claim 18.

20. 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 claim 18.

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