Data transmissions according to reception capability

Abstract

Embodiments of the invention relate to a first communication device (100) and a second communication device (300) for data transmission according to the reception capability of a receiver. The second communication device (300) informs the first communication device (100) about the reception capability of its transceiver in reception mode. The first communication device (100) uses the information about the reception capability of the second communication device (300) for determining a transmission mode which is used by the first communication device (100) for a subsequent data transmission from the first communication device (100) to the second communication device (300). Furthermore, the invention also relates to corresponding methods and a computer program.

Description

[0001] DATA TRANSMISSIONS ACCORDING TO RECEPTION CAPABILITY

[0002] TECHNICAL FIELD

[0003] Embodiments of the invention relate to a first communication device and a second communication device for data transmissions by a transmitter according to reception capability of a receiver. Furthermore, embodiments of the invention also relate to corresponding methods and a computer program.

[0004] BACKGROUND

[0005] Power efficiency (PE) of radio frequency (RF) circuits such as of a power amplifier (PA) is very important. This is especially the case for a user equipment (UE) having a limited battery capacity. Due to the high peak average power ratio (PAPR) in orthogonal Frequency Division Multiplexing (OFDM) based systems, which require a high back-off ratio for a PA to work in the linear region, the PE of PA is typically low. Traditional techniques such as digital pre-distortion (DPD) and crest factor clipping (CFR) can significantly enhance the PE, but the efficiency is still far from satisfying.

[0006] Thus, there are strong motivations to improve the PE of PA in 5G-NR and communication networks of the future from different perspectives such as in order to support satellite communication and non-terrestrial network (NTN) systems, and improve the energy efficiency (EE) in future communication networks aiming for a peak rate of lOOGbps (Giga bits per second) or ITbps (Terra bits per second). Increasing the PE of PA is also beneficial to enhance the coverage of high frequency bands, such as upper 6GHz (U6G) and mmWave bandwidths, by transmitting with a higher power to compensate the high path-loss and power attenuation.

[0007] Besides, there is also a trend to increase the modulation-order from 256-QAM to 1K-QAM and 4K-QAM, also known as Super- QAM, for high throughputs. With Super-QAM, the error vector magnitude (EVM) can degrade the performance significantly and therefore has to be reduced compared to low-order modulations. This however, put a stringent requirement on the linearity of the PA and front-end circuits. In order to meet such stringent EVM limits, more expensive circuits and components are needed in the transceiver, which increases the manufacturing cost of such transceivers.

[0008] SUMMARY

[0009] An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

[0010] Another objective of embodiments of the invention is to provide a solution with increased PE of RF circuits in communication devices.

[0011] The above and further objectives are solved by the subject matter of the independent claims. Further embodiments of the invention can be found in the dependent claims.

[0012] According to a first aspect of the invention, the above mentioned and other objectives are achieved with a first communication device configured to: transmit a first message to a second communication device, the first message indicating a request for a reception capability of a transceiver of the second communication device; receive a second message from the second communication device, the second message indicating the reception capability of the transceiver of the second communication device; determine a transmission mode of a transceiver of the first communication device based on the indicated reception capability of the transceiver of the second communication device; and perform a data transmission to the second communication device via the transceiver of the first communication device in the determined transmission mode.

[0013] An advantage of the first communication device according to the first aspect is that since the transmission mode of the first communication device can be adapted to the reception capability of the second communication device, the PA of the transceiver of the first communication device can work more efficiently. Further, the adaptation of the transmission mode to the reception capability opens up the possibility of non-conventional operation of the transceiver of the transmitter such as operating in the non-linear region of the PA. Thus, improved PE is possible, and also the ability to support higher frequency bands with better coverage, and higher modulation schemes such as Super-QAM.

[0014] In an implementation form of a first communication device according to the first aspect, the reception capability of the transceiver of the second communication device is a reception capability among a plurality of possible reception capabilities.

[0015] An advantage with this implementation form is that since there is a plurality of possible reception capabilities available the corresponding transmission mode may be adapted accordingly for improved PE of the PA and / or the performance of the data transmission.

[0016] In an implementation form of a first communication device according to the first aspect, the determined transmission mode is a transmission mode among a plurality of transmission modes.

[0017] An advantage with this implementation form is that since there is a plurality of possible transmission modes, the determined or selected transmission mode may be adapted to the reception capability signaled by the second communication device for improved PE of the PA and / or the performance of the data transmission.

[0018] In an implementation form of a first communication device according to the first aspect, each transmission mode is associated with an allowed error vector magnitude, EVM, constraint value for the transceiver of the first communication device.

[0019] An advantage with this implementation form is that each transmission mode is clearly defined by its EVM constraint value for exact operation of the transceiver of the first communication device.

[0020] In an implementation form of a first communication device according to the first aspect, each EVM constraint value is associated with a non-linear distortion operation of the transceiver of the first communication device.

[0021] An advantage with this implementation form is that the transmit power at the first communication device can be reduced due to the introduction of the non-linear distortion operation. This also means that this implementation form is useful in satellite communications and in NTN systems where the transmit power generally is limited.

[0022] In an implementation form of a first communication device according to the first aspect, each EVM constraint value is associated with a modulation type.

[0023] An advantage with this implementation form is that the operation of the transceiver of the first communication device can also be adapted to the modulation scheme used in the data transmission.

[0024] In an implementation form of a first communication device according to the first aspect, different transmission modes correspond to different EVM constraint values. In an implementation form of a first communication device according to the first aspect, each transmission mode is associated with one or more transceiver operation parameters in a group comprising: a predefined power amplifier model, a saturation level, a peak average power ratio, and a back-off ratio.

[0025] An advantage with this implementation form is that important operation parameters are defined for the operation of the transceiver of the first communication device so as to improve the PE of the PA and / or the performance of the data transmission.

[0026] In an implementation form of a first communication device according to the first aspect, the first communication device being configured to: transmit a third message to the second communication device previous to performing the data transmission to the second communication device, the third message indicating the one or more transceiver operation parameters associated with the determined transmission mode.

[0027] An advantage with this implementation form is that these parameters can help the second communication device to prepare its transceiver for the reception of the data transmission in the determined transmission mode by the first communication device.

[0028] In an implementation form of a first communication device according to the first aspect, the first communication device is configured to: transmit a non-linear reference signal to the second communication device previous to receiving the second message.

[0029] An advantage with this implementation form is that the second communication device can estimate the parameters of the nonlinear distortion operation at transmit side and / or the received quality of the non-linear reference signal for further use in the present transmission / reception scheme.

[0030] In an implementation form of a first communication device according to the first aspect, the first communication device being configured to: receive a fourth message from the second communication device, the fourth message indicating a received quality of the non-linear reference signal; and wherein the first communication device is configured to: determine the transmission mode of the transceiver of the first communication device further based on the received quality of the non-linear reference signal.

[0031] An advantage with this implementation form is that by also considering the received quality of the non-linear reference signal the determination of a transmission mode among a plurality of transmission modes can be improved for improved PE of the PA and / or the performance of the data transmission.

[0032] In an implementation form of a first communication device according to the first aspect, the first communication device being configured to: transmit a fifth message to the second communication device previous to performing the data transmission to the second communication device, the fifth message indicating the determined transmission mode.

[0033] An advantage with this implementation form is that the information about the determined transmission mode for the data transmission can help the second communication device to configure its transceiver for the reception of the data transmission.

[0034] In an implementation form of a first communication device according to the first aspect, the fifth message is a downlink control information message, a radio resource control message, or a medium access control, MAC, control element, CE, message. According to a second aspect of the invention, the above mentioned and other objectives are achieved with a second communication device configured to: receive a first message from a first communication device, the first message indicating a request for a reception capability of a transceiver of the second communication device; and transmit a second message to the first communication device, the second message indicating the reception capability of the transceiver of the second communication device.

[0035] An advantage of the second communication device according to the second aspect is that since the transmission mode of the first communication device can be adapted to the reception capability of the second communication device, the PA of the transceiver of the first communication device can work more efficiently. Further, the adaptation of the transmission mode to the reception capability opens up the possibility of non-conventional operation of the transceiver of the transmitter such as operating in the non-linear region of the PA. Thus, improved PE is possible, and also the ability to support higher frequency bands with better coverage, and higher modulation schemes such as Super-QAM.

[0036] In an implementation form of a second communication device according to the second aspect, the reception capability of the transceiver of the second communication device is a reception capability among a plurality of possible reception capabilities.

[0037] An advantage with this implementation form is that since there is a plurality of possible reception capabilities available the corresponding transmission mode may be adapted accordingly for improved PE of the PA and / or the performance of the data transmission.

[0038] In an implementation form of a second communication device according to the second aspect, the second communication device being configured to: receive a data transmission from the first communication device via the transceiver of the second communication device, the data transmission being performed in a transmission mode of a transceiver of the first communication device.

[0039] In an implementation form of a second communication device according to the second aspect, the second communication device being configured to: receive a third message from the first communication device previous to receiving the data transmission, the third message indicating one or more transceiver operation parameters associated with the transmission mode of the transceiver of the first communication device in a group comprising: a predefined power amplifier model, a saturation level, a peak average power ratio, and a back-off ratio; and receive the data transmission from the first communication device based on the one or more transceiver operation parameters associated with the transmission mode of the transceiver of the first communication device.

[0040] An advantage with this implementation form is that these parameters can help the second communication device to prepare its transceiver for the reception of the data transmission in the determined transmission mode by the first communication device.

[0041] In an implementation form of a second communication device according to the second aspect, the second communication device being configured to: receive a non-linear reference signal from the first communication device previous to transmitting the second message; estimate a received quality of the non-linear reference signal based on the non-linear reference signal; and transmit a fourth message to the first communication device, the fourth message indicating the received quality of the non-linear reference signal.

[0042] An advantage with this implementation form is that by also considering the received quality of the non-linear reference signal the determination of a transmission mode among a plurality of transmission modes can be improved for improved PE of the PA and / or the performance of the data transmission.

[0043] In an implementation form of a second communication device according to the second aspect, the second communication device being configured to: receive a fifth message from the first communication device previous to receiving the data transmission from the first communication device, the fifth message indicating the transmission mode for the data transmission.

[0044] An advantage with this implementation form is that the information about the determined transmission mode for the data transmission can help the second communication device to configure its transceiver for the reception of the data transmission.

[0045] In an implementation form of a second communication device according to the second aspect, the fifth message is a downlink control information message, a radio resource control message, or a MAC CE message.

[0046] According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a first communication device, the method comprises: transmitting a first message to a second communication device, the first message indicating a request for a reception capability of a transceiver of the second communication device; receiving a second message from the second communication device, the second message indicating the reception capability of the transceiver of the second communication device; determining a transmission mode of a transceiver of the first communication device based on the indicated reception capability of the transceiver of the second communication device; and performing a data transmission to the second communication device via the transceiver of the first communication device in the determined transmission mode.

[0047] The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the first communication device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the first communication device.

[0048] The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the first communication device according to the first aspect.

[0049] According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a second communication device, the method comprises: receiving a first message from a first communication device, the first message indicating a request for a reception capability of a transceiver of the second communication device; and transmitting a second message to the first communication device, the second message indicating the reception capability of the transceiver of the second communication device. The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the second communication device according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the second communication device.

[0050] The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the second communication device according to the second aspect.

[0051] Embodiments of the invention also relate to a computer program, characterized in program code, which when run by at least one processor causes the at least one processor to execute any method according to embodiments of the invention. Further, embodiments of the invention also relate to a computer program product comprising a computer readable medium and the mentioned computer program, wherein the computer program is included in the computer readable medium, and may comprises one or more from the group of: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.

[0052] Further applications and advantages of embodiments of the invention will be apparent from the following detailed description.

[0053] BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

[0055] - Fig. 1 shows a first communication device according to an embodiment of the invention;

[0056] - Fig. 2 shows a flow chart of a method for a first communication device according to an embodiment of the invention;

[0057] - Fig. 3 shows a second communication device according to an embodiment of the invention;

[0058] - Fig. 4 shows a flow chart of a method for a second communication device according to an embodiment of the invention;

[0059] - Fig. 5 shows a communication system according to an embodiment of the invention;

[0060] - Fig. 6 shows a signaling diagram of an embodiment of the invention; and

[0061] - Fig. 7 shows a signaling diagram of an embodiment of the invention.

[0062] DETAILED DESCRIPTION

[0063] Generally, critical modeling of the PA of a transceiver is the error vector magnitude (EVM) and the adjacent channel power ratio (ACPR). The EVM represents the in-band amplifier distortion, while the ACPR represents the out-of-band distortion of the PA. Both leads to nonlinear (NL) distortion in the PA. The NL response directly affects the signal demodulation and the bit error rate, and also causes spectral regrowth which creates interference in the frequency bands outside the channel of interest for data transmissions.

[0064] The NL distortion effects can result from many different sources such as: nonlinear PA, quantization effects in the Digital-to- Analog Conversion (DAC), clipping to reduce the PAPR, carrier-frequency offset (CFO), phase noise, in phase and quadrature (IQ) imbalance, as well as other factors.

[0065] In 3 GPP standards and in 5G-NR systems it is required to quantify the NL distortion in the system to ensure that the communication device meets performance specifications and follows strict 5G EVM and ACPR standards.

[0066] It has been observed that the NL distortion can either be good or bad for receivers depending on their NL distortion resolving capability. However, since there is no information exchange between transmitter and receiver about the NL distortion, the transmitter therefore always assumes that NL distortion is bad for the receiver and therefore tries to eliminate the NL distortion as much as possible. Nevertheless, NL distortion can boost the PA efficiency at the transmitter by reducing the back-off ratio of the PA, which can be important for enhancing the power-efficiency of the PA. Therefore, it is herein disclosed to exploit the capabilities of receivers to e.g., cope with NL distortion, and thus to enhance the current 5G-NR and networks of the future. This may e.g., be achieved by relaxing EVM constraints by exploiting the capability of the receiver to cope with NL distortion.

[0067] Fig. 1 shows a first communication device 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1, the first communication device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The first communication device 100 may be configured for wireless and / or wired communications in a communication system. The wireless communication capability may be provided with an antenna or antenna array 110 coupled to the transceiver 104, while the wired communication capability may be provided with a wired communication interface 112 e.g., coupled to the transceiver 104.

[0068] The processor 102 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, or one or more chipsets. The memory 106 may be a read-only memory, a random access memory (RAM), or a non-volatile RAM (NVRAM). The transceiver 104 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices, such as network nodes and network servers. The transceiver 104, memory 106 and / or processor 102 may be implemented in separate chipsets or may be implemented in a common chipset. That the first communication device 100 is configured to perform certain actions can in this disclosure be understood to mean that the first communication device 100 comprises suitable means, such as e.g., the processor 102 and the transceiver 104, configured to perform the actions.

[0069] According to embodiments of the invention, the first communication device 100 is configured to: transmit a first message 510 to a second communication device 300, the first message 510 indicating a request for a reception capability of a transceiver 304 of the second communication device 300; receive a second message 520 from the second communication device 300, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300; determine a transmission mode of a transceiver 104 of the first communication device 100 based on the indicated reception capability of the transceiver 304 of the second communication device 300; and perform a data transmission 560 to the second communication device 300 via the transceiver 104 of the first communication device 100 in the determined transmission mode.

[0070] Furthermore, in an embodiment of the invention, the first communication device 100 for a communication system 500 comprises a transceiver configured to: transmit a first message 510 to a second communication device 300, the first message 510 indicating a request for a reception capability of a transceiver 304 of the second communication device 300; receive a second message 520 from the second communication device 300, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300. The first communication device 100 comprises a processor configured to: determine a transmission mode of a transceiver 104 of the first communication device 100 based on the indicated reception capability of the transceiver 304 of the second communication device 300. The transceiver being further configured to perform a data transmission 560 to the second communication device 300 via the transceiver 104 of the first communication device 100 in the determined transmission mode.

[0071] Moreover, in yet another embodiment of the invention, the first communication device 100 for a communication system 500 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to: transmit a first message 510 to a second communication device 300, the first message 510 indicating a request for a reception capability of a transceiver 304 of the second communication device 300; receive a second message 520 from the second communication device 300, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300; determine a transmission mode of a transceiver 104 of the first communication device 100 based on the indicated reception capability of the transceiver 304 of the second communication device 300; and perform a data transmission 560 to the second communication device 300 via the transceiver 104 of the first communication device 100 in the determined transmission mode.

[0072] Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a first communication device 100, such as the one shown in Fig. 1. The method 200 comprises: transmitting 202 a first message 510 to a second communication device 300, the first message 510 indicating a request for a reception capability of a transceiver 304 of the second communication device 300; receiving 204 a second message 520 from the second communication device 300, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300; determining 206 a transmission mode of a transceiver 104 of the first communication device 100 based on the indicated reception capability of the transceiver 304 of the second communication device 300; and performing 208 a data transmission 560 to the second communication device 300 via the transceiver 104 of the first communication device 100 in the determined transmission mode.

[0073] Fig. 3 shows a second communication device 300 according to an embodiment of the invention. In the embodiment shown in Fig. 3, the second communication device 300 comprises a processor 302, a transceiver 304 and a memory 306. The processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 known in the art. The second communication device 300 may be configured for wireless and / or wired communications in a communication system. The wireless communication capability may be provided with an antenna or antenna array 310 coupled to the transceiver 304, while the wired communication capability may be provided with a wired communication interface 312 e.g., coupled to the transceiver 304.

[0074] The processor 302 may be referred to as one or more general-purpose CPUs, one or more DSPs, one or more ASICs, one or more FPGAs, one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, one or more chipsets. The memory 306 may be a read-only memory, a RAM, or a NVRAM. The transceiver 304 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices. The transceiver 304, the memory 306 and / or the processor 302 may be implemented in separate chipsets or may be implemented in a common chipset. That the second communication device 300 is configured to perform certain actions can in this disclosure be understood to mean that the second communication device 300 comprises suitable means, such as e.g., the processor 302 and the transceiver 304, configured to perform the actions.

[0075] According to embodiments of the invention, the second communication device 300 is configured to: receive a first message 510 from a first communication device 100, the first message 510 indicating request for a reception capability of a transceiver 304 of the second communication device 300; and transmit a second message 520 to the first communication device 100, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300.

[0076] Furthermore, in an embodiment of the invention, the second communication device 300 for a communication system 500 comprises a transceiver configured to: receive a first message 510 from a first communication device 100, the first message 510 indicating request for a reception capability of a transceiver 304 of the second communication device 300; and transmit a second message 520 to the first communication device 100, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300. Moreover, in yet another embodiment of the invention, the second communication device 300 for a communication system 500 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to: receive a first message 510 from a first communication device 100, the first message 510 indicating request for a reception capability of a transceiver 304 of the second communication device 300; and transmit a second message 520 to the first communication device 100, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300.

[0077] Fig. 4 shows a flow chart of a corresponding method 400 which may be executed in a second communication device 300, such as the one shown in Fig. 3. The method 400 comprises receiving 402 a first message 510 from a first communication device 100, the first message 510 indicating a request for a reception capability of a transceiver 304 of the second communication device 300; and transmitting 404 a second message 520 to the first communication device 100, the second message 520 indicating the reception capability of the transceiver 304 of the second communication device 300.

[0078] Fig. 5 shows a communication system 500 according to an embodiment of the invention. The communication system 500 in the disclosed embodiment comprises a first communication device 100 and a second communication device 300 configured to communicate and operate in the communication system 500. For simplicity, the shown communication system 500 only comprises one first communication device 100 and one second communication device 300. However, the communication system 500 may comprise any number of first communication devices 100 and any number of second communication devices 300 without deviating from the scope of the invention.

[0079] The communication system 500 may be any suitable communication system such as 3GPP 5G, any communication networks in the future, satellite communications and non-terrestrial network (NTN) systems. Thus, the first communication device 100 may be any suitable transmitting device acting in such systems, and the second communication device 300 may be any suitable receiving device acting in such systems.

[0080] In the shown example of Fig. 5, the first communication device 100 act as a network access node, such as a gNB, while the second communication device 300 act as a client device, such as a UE. However, the reverse case is possible, i.e., that the first communication device 100 act as a client device, while the second communication device 300 act as a network access node. After the network access node 100 and the client device 300 have exchanged the first 510 and second messages 520 between each other, the network access node 100 performs a data transmission 560 to the client device 300 by using its transceiver operating in a determined transmission mode.

[0081] Further details related to embodiments of the invention will now be described in a 3GPP context. Thus, 3GPP terminology, definitions, expressions and system architecture will be used. Especially, the first communication device 100 according to the invention may in these embodiments be configured to perform any of the described functions of a gNB 100. Correspondingly, the second communication device 300 according to the invention may in these embodiments be configured to perform any of the described functions of a UE 300. It may however be noted that embodiments of the invention are not limited thereto as previously stated.

[0082] Fig. 6 and 7 show signaling diagrams of further embodiments of the invention. The major signaling related to the herein disclosed solution is shown in Fig. 6, while Fig. 7 shows additional signaling and aspects according to further embodiments of the invention.

[0083] In step I in Fig. 6, the gNB 100 transmits a first message 510 to the UE 300. The first message 510 indicates a request for a reception capability of a transceiver 304 of the UE 300. The indicating of the request for the reception capability may be explicit e.g., by using one or more information bits dedicated for such purpose. The indicating of the request may also be given implicit e.g., be derived based on other control information transmitted by the gNB 100. The first message 510 may also be denoted a first control message and may be a radio resource control (RRC) message, a medium access control (MAC) control element (CE) message, or a downlink control information (DCI) message.

[0084] In embodiments of the invention, the reception capability of the transceiver 304 of the UE 300 is a reception capability among a plurality of possible reception capabilities. This means that different receivers may have different reception capabilities. However, advanced receives may also be able to operate in two or more different reception modes. In such cases each reception mode would correspond to a certain reception capability which may be denoted reception capability type.

[0085] In step III in Fig. 6, the UE 300 transmits a second message 520 to the gNB 100 in response to the reception of the first message 510. The second message 520 indicates the reception capability of the transceiver 304 of the UE 300. The second message 520 may be denoted a second control message and may be comprised in an uplink control information (UCI). Also, the indication of the reception capability may be explicit or implicit given.

[0086] In step IV in Fig. 6, the gNB 100 receive the second message 520 from the UE 300. The gNB 100 demodulates and decodes the second message 520 so as to derive the information enclosed therein. The second message 520 as aforementioned indicates the reception capability of the transceiver 304 of the UE 300. Therefore, the gNB 100 will know the reception capability of the UE 300 for the subsequent data transmission to come.

[0087] Based on the second message 520, i.e., the indicated reception capability of the transceiver 304 of the UE 300, the gNB 100 determines a transmission mode of its transceiver 104 based on the indicated reception capability of the transceiver 304 of the UE 300. For good performance the transmission mode should match the indicated reception capability. Therefore, the matching or mapping between transmission mode and reception capability may be given as one or more predetermined tables which may be standardized. Examples of such proposed tables are given below in the following disclosure.

[0088] From the above reasoning it may be derived that the determined transmission mode may be a transmission mode among a plurality of transmission modes. More in detail, each transmission mode among the plurality of transmission modes may be associated with an allowed EVM constraint value for the transceiver 104 of the gNB 100. That the EVM constraint value is an allowed EVM constraint value may be understood such that the gNB 100 should follow the EVM constraint value given in the table when performing the data transmission to the UE 300.

[0089] In embodiments of the invention, each EVM constraint value is associated with a NL distortion operation of the transceiver 104 of the gNB 100, and may further also be associated with a modulation type. Thus, different transmission modes may correspond to different EVM constraint values. Exemplary EVM constraint values are given in the exemplary tables 1 and 2.

[0090] Table 1 lists EVM constraint values depending on the modulation scheme and the UE type or rather the reception capability type of the UE 300. For example, with BPSK modulation and reception capability (RC) type of the UE equal to 0, the EVM constraint value is given as EVM_00. The RC type equal to 0 is the same as the current 5G-NR which means that EVM_00 is the same as the value given in the 5G-NR standard. On the other hand, if the RC type equals to 1 , the EVM constraint value is EVM_00 which means that the transmission mode allows NL operation of the transceiver and its PA. Further, if the modulation is 64QAM and the RC type is M, the EVM constraint value is EVM_M2, and so on. Thus, RC type 0 is the same as the current 5G-NR, RC type 1 is an advanced UE that can deal with NL distortion and RC type M is the most advanced UE that also can deal with NL distortion. It may be noted that the EVM constraint values in Table 1 satisfies the relationship: EVM_0X < EVM_1X < ... < EVM_MX, i.e., when the RC type increases from 0 to M, the EVM limit also increases accordingly. In other words, a higher RC type corresponds to a higher EVM limit which in turn can support more NL distortion.

[0091] Table 1: EVM constraint values

[0092] Table 2 is a simplified table compared to Table 1, since the number of total EVM constraint values is reduced according to a rule that when the RC type is 1 -level higher, the EVM value is also 1 -level higher for the same modulation-order.

[0093] Table 2: EVM constraint values

[0094] In step V in Fig. 6, the gNB 100 performs a subsequent data transmission 560 to the UE 300 via its transceiver 104 in the previously determined transmission mode. The data transmission 560 may relate to any suitable data transmission such as transmission of pay load, control information, etc.

[0095] In step VI in Fig. 6, the UE 300 receives the data transmission 560 from the gNB 100 via its transceiver 304. The received data transmission 560 has been performed in the determined transmission mode of the transceiver 104 of the gNB 100. The UE 300 demodulates and decodes the received data transmission 560 to obtain the information content of the data transmission 560 for further processing. This may be performed according to conventional processing techniques for reception of data transmissions.

[0096] Moreover, in embodiments of the invention as illustrated in Fig. 7 further aspects of the invention are introduced such as the use of reference signals, exchange of critical parameters etc. for improved performance of the data transmission from the gNB 100 to the UE 300.

[0097] In step III in Fig. 7, the gNB 100 further transmits one or more NL reference signals 570 to the UE 300 previous to receiving the second message 520. This can be a new type of reference signals that is designed and adapted for estimating the parameters of NL distortions, and / or determining the reception quality, or the reference signal can be an existing reference signal in 5G such as phase-tracking reference signal (PTRS) but serving the new purpose of estimating NL parameters.

[0098] In step IV in Fig. 7, the UE 300 receives the one or more NL reference signals 570 from the gNB 100 previous to transmitting the second message 520. The UE 300 performs measurements on the received NL reference signals 570. Based on the measurements of the received NL reference signals 570, the UE 300 may estimate a received quality of the NL reference signal 570. The received quality may relate to an indication whether the NL reference signal can be detected with a satisfying quality.

[0099] In step V in Fig. 7, the UE 300 transmits a fourth message 540 to the gNB 100. The fourth message 540 indicates the received quality of the NL reference signal 570 estimated in the previous step and may also be denoted a fourth control message. As previously mentioned, the indication of the received quality may be explicit or implicit and may be comprised in UCI signaling.

[0100] In step VI in Fig. 7, the gNB 100 receives the fourth message 540 from UE 300. The gNB 100 demodulates and decodes the fourth message 540 to derive the information therein.

[0101] Steps VII and VIII in Fig. 7 are more or less the same as steps III and IV in Fig. 6, i.e., the UE 300 transmits the second message 520 which is received by the gNB 100, etc. However, the gNB 100 may use the quality of the NL reference signal 570 indicated in the fourth message 540 from the UE 300 for determining the transmission mode of its transceiver 104. This means that additional considerations may be used in the determination of the suitable transmission mode for the coming data transmission. The determination or selection of the transmission mode is important since by correctly matching the transmission mode with the reception capability, the performance of the subsequent data transmission 560 can be optimized. In step IX in Fig. 7, the gNB 100 transmits a fifth message 550 to the UE 300 previous to performing the data transmission 560. The fifth message 550 indicates the determined transmission mode that will be used by the gNB 100 when performing the data transmission 560 and may be denoted a fifth control message. In embodiments of the invention, the fifth message 550 may be any of: a DCI message, a RRC message, or a MAC CE message.

[0102] In step X in Fig. 7, the UE 300 receives the fifth message 550 from the gNB 100 previous to receiving the data transmission 560. The UE 300 demodulates and decodes the fifth message 550 so as to derive the information disclosed therein. The UE 300 may use the fifth message 550 indicating the transmission mode for preparing for the coming data transmission 560 by choosing or designing a suitable receiving algorithm according to the fifth message 550.

[0103] In step XI in Fig. 7, the gNB 100 further transmits a third message 530 to the UE 300 previous to performing the data transmission 560. The third message 530 indicates the one or more transceiver operation parameters associated with the determined transmission mode and may also be denoted a third control message. It is therefore realized that each transmission mode of the gNB 100 may be associated with one or more transceiver operation parameters in a group comprising: a predefined power amplifier model, a saturation level, a peak average power ratio, and a back-off ratio. These parameters can be utilized as prior information for the receiver to design a suitable receiving algorithm to detect the data in the coming data transmission 560.

[0104] In step XII in Fig. 7, the UE 300 receives the third message 530 from the gNB 100 previous to receiving the data transmission 560. The UE 300 demodulates and decodes the third message 530 so as to derive the information disclosed therein. The UE 300 may use any of the messages mentioned in this disclosure for preparing for the coming data transmission 560. These transceiver operation parameters may be used to estimate or model the NL distortion of the signal, and may thus be used to design an appropriate receiving algorithm to detect data from the distorted and received signal. Hence, the transceiver operation parameters may be used as input parameters to such a receiving algorithm for processing the received signal of the data transmission at the UE 300.

[0105] In step XIII in Fig. 7, the gNB 100 performs the data transmission 560 to the UE 300 as previously mentioned.

[0106] In step XIV in Fig. 7, the UE 300 receives the data transmission 560 from the gNB 100 and may use the one or more transceiver operation parameters associated with the transmission mode of the transceiver of the gNB 100 for configuring its transceiver 304 for the reception of the data transmission 560. The UE 300 may process the received data transmission 560 according to conventional techniques so as to derive the data therein.

[0107] A network access node herein may also be denoted as a radio network access node, an access network access node, an access point (AP), or a base station (BS), e.g., a radio base station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the standard, technology and terminology used. The radio network access node may be of different classes or types such as e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby the cell size. The radio network access node may further be a station, which is any device that contains an IEEE 802.11 -conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The radio network access node may be configured for communication in 3GPP related long term evolution (LTE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR) and their evolutions, as well as in IEEE related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and their evolutions.

[0108] A client device herein may be denoted as a user device, a user equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and / or a mobile terminal, or any communication apparatus (e.g. chip or chipset) that is configured to and / or is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in this context may be, for example, portable, pocket-storable, hand-held, computer- comprised, or vehicle-mounted mobile devices, enabled to communicate voice and / or data, via a radio access network (RAN), with another communication entity, such as another receiver or a server. The UE may further be a station, which is any device that contains an IEEE 802.11 -conformant MAC and PHY interface to the WM. The UE may be configured for communication in 3GPP related LEE, LTE-advanced, 5G wireless systems, such as NR, and their evolutions, as well as in IEEE related Wi-Fi, WiMAX and their evolutions.

[0109] Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as previously mentioned a ROM, a PROM, an EPROM, a flash memory, an EEPROM, or a hard disk drive.

[0110] Moreover, it should be realized that the first communication device 100 and the second communication device 300 comprise the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing or implementing embodiments of the invention. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

[0111] Therefore, the processors) of the first communication device 100 and the second communication device 300 may comprise, e.g., one or more instances of a CPU, a processing unit, a processing circuit, a processor, an ASIC, a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising aplurality of processing circuits, such as e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

[0112] Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

CLAIMS1. A first communication device (100) configured to: transmit a first message (510) to a second communication device (300), the first message (510) indicating a request for a reception capability of a transceiver (304) of the second communication device (300); receive a second message (520) from the second communication device (300), the second message (520) indicating the reception capability of the transceiver (304) of the second communication device (300); determine a transmission mode of a transceiver (104) of the first communication device (100) based on the indicated reception capability of the transceiver (304) of the second communication device (300); and perform a data transmission (560) to the second communication device (300) via the transceiver (104) of the first communication device (100) in the determined transmission mode.

2. The first communication device (100) according to claim 1, wherein the reception capability of the transceiver (304) of the second communication device (300) is a reception capability among a plurality of possible reception capabilities.

3. The first communication device (100) according to claim 1 or 2, wherein the determined transmission mode is a transmission mode among a plurality of transmission modes.

4. The first communication device (100) according to claim 3, wherein each transmission mode is associated with an allowed error vector magnitude, EVM, constraint value for the transceiver (104) of the first communication device (100).

5. The first communication device (100) according to claim 4, wherein each EVM constraint value is associated with a non-linear distortion operation of the transceiver (104) of the first communication device (100).

6. The first communication device (100) according to claim 4 or 5, wherein each EVM constraint value is associated with a modulation type.

7. The first communication device (100) according to any one of claims 4 to 6, wherein different transmission modes correspond to different EVM constraint values.

8. The first communication device (100) according to any one of the preceding claims, wherein each transmission mode is associated with one or more transceiver operation parameters in a group comprising: a predefined power amplifier model, a saturation level, a peak average power ratio, and a back-off ratio.

9. The first communication device (100) according to claim 8, configured to: transmit a third message (530) to the second communication device (300) previous to performing the data transmission (560) to the second communication device (300), the third message (530) indicating the one or more transceiver operation parameters associated with the determined transmission mode.

10. The first communication device (100) according to any one of the preceding claims, configured to: transmit a non-linear reference signal (570) to the second communication device (300) previous to receiving the second message (520).

11. The first communication device (100) according to claim 10, configured to: receive a fourth message (540) from the second communication device (300), the fourth message (540) indicating a received quality of the non-linear reference signal (570); and wherein the first communication device (100) is configured to: determine the transmission mode of the transceiver (104) of the first communication device (100) further based on the received quality of the non-linear reference signal (570).

12. The first communication device (100) according to any one of the preceding claims, configured to: transmit a fifth message (550) to the second communication device (300) previous to performing the data transmission (560) to the second communication device (300), the fifth message (550) indicating the determined transmission mode.

13. The first communication device (100) according to claim 12, wherein the fifth message (550) is a downlink control information message, a radio resource control message, or a medium access control, MAC, control element, CE, message.

14. A second communication device (300) configured to: receive a first message (510) from a first communication device (100), the first message (510) indicating a request for a reception capability of a transceiver (304) of the second communication device (300); and transmit a second message (520) to the first communication device (100), the second message (520) indicating the reception capability of the transceiver (304) of the second communication device (300).

15. The second communication device (300) according to claim 14, wherein the reception capability of the transceiver (304) of the second communication device (300) is a reception capability among a plurality of possible reception capabilities.

16. The second communication device (300) according to claim 14 or 15, configured to: receive a data transmission (560) from the first communication device (100) via the transceiver (304) of the second communication device (300), the data transmission (560) being performed in a transmission mode of a transceiver (104) of the first communication device (100).

17. The second communication device (300) according to claim 16, configured to: receive a third message (530) from the first communication device (100) previous to receiving the data transmission (560), the third message (530) indicating one or more transceiver operation parameters associated with the transmission mode of the transceiver (104) of the first communication device (100) in a group comprising: a predefined power amplifier model, a saturation level, a peak average power ratio, and a back-off ratio; and receive the data transmission (560) from the first communication device (100) based on the one or more transceiver operation parameters associated with the transmission mode of the transceiver of the first communication device (100).

18. The second communication device (300) according to any one of claims 14 to 17, configured to: receive a non-linear reference signal (570) from the first communication device (100) previous to transmitting the second message (520); estimate a received quality of the non-linear reference signal (570) based on the non-linear reference signal (570); and transmit a fourth message (540) to the first communication device (100), the fourth message (540) indicating the received quality of the non-linear reference signal (570).

19. The second communication device (300) according to any one of claims 16 to 18, configured to: receive a fifth message (550) from the first communication device (100) previous to receiving the data transmission (560) from the first communication device (100), the fifth message (550) indicating the transmission mode for the data transmission (560).

20. The second communication device (300) according to claim 19, wherein the fifth message (550) is a downlink control information message, a radio resource control message, or a MAC CE message.

21. A method (200) for a first communication device (100), the method (200) comprising: transmitting (202) a first message (510) to a second communication device (300), the first message (510) indicating a request for a reception capability of a transceiver (304) of the second communication device (300); receiving (204) a second message (520) from the second communication device (300), the second message (520) indicating the reception capability of the transceiver (304) of the second communication device (300); determining (206) a transmission mode of a transceiver (104) of the first communication device (100) based on the indicated reception capability of the transceiver (304) of the second communication device (300); and performing (208) a data transmission (560) to the second communication device (300) via the transceiver (104) of the first communication device (100) in the determined transmission mode.

22. A method (400) for a second communication device (300), the method (400) comprising: receiving (402) a first message (510) from a first communication device (100), the first message (510) indicating a request for a reception capability of a transceiver (304) of the second communication device (300); and transmitting (404) a second message (520) to the first communication device (100), the second message (520) indicating the reception capability of the transceiver (304) of the second communication device (300).

23. A computer program with a program code for performing a method according to claim 21 or 22 when the computer program runs on a computer.17

Images