Interleaving of codewords

Abstract

Examples of the invention relate to interleaving of a codeword being a Reed-Muller codeword or being derived from a Reed- Muller codeword. Thus, a first communication device (100) interleaves a codeword (formula) comprising number of bits to obtain an interleaved codeword comprising bits, wherein the codeword is derived from a Reed-Muller codeword of rth order or is a Reed-Muller codeword of rth order, wherein N ≥ 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword (formula) is a codeword derived from a Reed-Muller codeword of the rth order or is a Reed- Muller codeword of rth order. The interleaved codeword (formula) is truncated to obtain a truncated codeword f which is transmitted to a second communication device (300) in a communication signal (510). The communication signal (510) may be a wake-up signal. Furthermore, examples of the invention also relate to corresponding methods and a computer program.

Description

[0001] INTERLEAVING OF CODEWORDS

[0002] TECHNICAL FIELD

[0003] Examples of the invention relate to interleaving a codeword being a Reed-Muller codeword or being derived from a Reed-Muller codeword. Furthermore, examples of the invention also relate to corresponding methods and a computer program.

[0004] BACKGROUND

[0005] The 3rdGeneration Partnership Project (3GPP) is developing solutions to reduce the power consumption for certain User Equipment (UE) categories having limited energy sources, e.g., loT sensors and actuators powered by non-rechargeable coinsize batteries, or wearable devices such as smart watches, rings, eHealth related and medical monitoring devices.

[0006] When there is no data traffic, most of the UE energy is spent for monitoring the downlink control channel for incoming data communication requests. In order to reduce UE power consumption, the Discontinuous Reception (DRX) method has been introduced in 4G and 5G networks. DRX suspends UE control channel monitoring for a configured period of time by putting the UE in a sleep mode. With DRX, the power consumption depends on the length of wake-up periods. To meet battery life requirements, long DRX cycles are necessary. However, long DRX cycles would cause too high latency for services with requirements of both long battery life and low latency.

[0007] 3GPP is specifying a new downlink Wake-Up Signal (WUS) for UEs equipped with an ultra-low power Wake-Up Receiver (WUR). In these UEs, the main transceiver (TRX) is switched off most of the time. The WUR monitors a predefined set of time-frequency resources for presence of a UE-specific or UE-group specific WUS. When the UE detects a WUS carrying its own ID or a group ID, the WUR switches on the TRX so as to resume control channel monitoring and perform data communication.

[0008] SUMMARY

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

[0010] Another objective of examples of the invention is to present an interleaving solution resulting in improved performance compared to conventional solutions.

[0011] The above and further objectives are solved by the subject matter of the independent claims.

[0012] Further examples of the invention can be found in the dependent claims.

[0013] According to a first aspect of the invention, the above-mentioned and other objectives are achieved with a first communication device configured to:

[0014] interleave a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder;

[0015] truncate the interleaved codeword d to obtain a truncated codeword f; and

[0016] transmit a communication signal to a second communication device, the communication signal indicating the truncated codeword f.An advantage of the first communication device according to the first aspect is that it allows to increase the minimum distance between the truncated codewords by a careful choice of the interleaver, thereby allowing the decoder of the second communication device to reach larger decoding error correction / detection capability compared to conventional solutions.

[0017] In an implementation form of a first communication device according to the first aspect, the truncated codeword f comprises E number of bits and the codeword d is generated by encoding K number of input bits, where E > K.

[0018] An advantage with this implementation form is that E must be at least as large as K in order to avoid loss of transmitted information.

[0019] In an implementation form of a first communication device according to the first aspect, the K number of input bits represents a subgroup identity of second communication devices.

[0020] An advantage with this implementation form is that the subgroup identities are more reliably transmitted, thereby providing fewer missed detections compared to conventional solutions.

[0021] In an implementation form of a first communication device according to the first aspect, K = 3,4 or 5 and N = 32.

[0022] An advantage with this implementation form is that it is capable of encoding 3GPP NR subgroup identities, and can use a 3GPP NR short block code of length 32.

[0023] In an implementation form of a first communication device according to the first aspect, r = 1.

[0024] An advantage with this implementation form is that it uses a code of the same type as the 3GPP NR short block length code for encoding the subgroup identities.

[0025] In an implementation form of a first communication device according to the first aspect, the codeword d is generated according to the 3GPP standard specification TS 38.212, section 5.3.3.3-1.

[0026] An advantage with this implementation form is that it uses the 3GPP NR short block length code for encoding the subgroup identities.

[0027] In an implementation form of a first communication device according to the first aspect, the first communication device is configured to:

[0028] transmit a control message to the second communication device, the control message indicating at least one of E and a subgroup identity.

[0029] The subgroup identity can be represented with K number of bits.

[0030] An advantage with this implementation form is that the second communication device can use the information about the truncated codeword and / or the subgroup identity length in order to produce better decoded words compared to blindly decoding the same received codeword.

[0031] In an implementation form of a first communication device according to the first aspect, the communication signal is a wakeup signal.An advantage with this implementation form is that it fulfils the objective of waking up the second communication devices belonging to a subgroup.

[0032] In an implementation form of a first communication device according to the first aspect,

[0033] the N / 2 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder; and / or

[0034] the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder.

[0035] An advantage with this implementation form is that, when the targeted truncated codeword lengths are E = N / 2 and E = N / 4, the implementation achieves the same minimum distances as those achieved by a Reed-Muller code of length N / 2 or N / 4 and order r, which are large minimum distances. A similar advantage is obtained when the targeted truncated codeword lengths are E = N / 4 and E = N / 8.

[0036] In an implementation form of a first communication device according to the first aspect, the interleaving of the codeword d comprises:

[0037] rearrange the N bits of the codeword d such that any two bits of the N / 2 first bits of the interleaved codeword d is obtained based on two different sequences of generator coefficients.

[0038] An advantage with this implementation form is that there are no repeated bits in the N / 2 first bits of the codeword. This helps to achieve a larger minimum distance.

[0039] In an implementation form of a first communication device according to the first aspect, the different sequences of generator coefficients differ in at least one generator coefficient.

[0040] This helps to achieve a larger minimum distance.

[0041] In an implementation form of a first communication device according to the first aspect, the first communication device is a network access node and the second communication device is a client device.

[0042] An advantage with this implementation form is that it allows a wireless network to wake up client devices in a subgroup of client devices.

[0043] According to a second aspect of the invention, the above-mentioned and other objectives are achieved with a second communication device configured to:

[0044] receive a communication signal from a first communication device, the communication signal indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E > K', receive a control message from a first communication device, the control message indicating at least one of E and a subgroup identity; and

[0045] determine a wake-up command based on the control message and the truncated codeword f.The reception of the communication signal and the control message may be performed in any order. Thus, the communication signal may be received before the control message, or the control message may be received before the communication signal.

[0046] An advantage of the second communication device according to the second aspect is that it allows to increase the minimum distance between the truncated codewords by a careful choice of the interleaver, thereby allowing the decoder of the second communication device to reach larger decoding error correction / detection capability compared to conventional solutions.

[0047] In an implementation form of a second communication device according to the second aspect, the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder.

[0048] In an implementation form of a second communication device according to the second aspect,

[0049] the N / 2 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder; and / or

[0050] the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder.

[0051] An advantage with this implementation form is that, when the targeted truncated codeword lengths are E = N / 2 and E = N / 4, the implementation achieves the same minimum distances as those achieved by a Reed-Muller code of length N / 2 or N / 4 and order r, which are large minimum distances. A similar advantage is obtained when the targeted truncated codeword lengths are E = N / 4 and E = N / 8.

[0052] In an implementation form of a second communication device according to the second aspect, r = 1.

[0053] An advantage with this implementation form is that it uses a code of the same type as the 3GPP NR short block length code for encoding the subgroup identities.

[0054] In an implementation form of a second communication device according to the second aspect, the K number of input bits represents a subgroup identity of second communication devices.

[0055] An advantage with this implementation form is that the subgroup identities are more reliably transmitted, thereby providing fewer missed detections compared to conventional solutions.

[0056] In an implementation form of a second communication device according to the second aspect, K = 3, 4 or 5 and N = 32.

[0057] An advantage with this implementation form is that it is capable of encoding 3GPP NR subgroup identities, and can use a 3GPP NR short block code of length 32.

[0058] In an implementation form of a second communication device according to the second aspect, the codeword d is generated according to the 3GPP standard specification TS 38.212, section 5.3.3.3-1.An advantage with this implementation form is that it uses the 3GPP NR short block length code for encoding the subgroup identities.

[0059] In an implementation form of a second communication device according to the second aspect, the communication signal is a wake-up signal.

[0060] An advantage with this implementation form is that it fulfils the objective of waking up the second communication devices belonging to a subgroup.

[0061] In an implementation form of a second communication device according to the second aspect, the first communication device is a network access node and the second communication device is a client device.

[0062] An advantage with this implementation form is that it allows a wireless network to wake up client devices in a subgroup of client devices.

[0063] 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:

[0064] interleaving a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder;

[0065] truncating the interleaved codeword d to obtain a truncated codeword f; and

[0066] transmitting a communication signal to a second communication device, the communication signal indicating the truncated codeword f.

[0067] 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.

[0068] 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.

[0069] 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:

[0070] receiving a communication signal from a first communication device, the communication signal indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E >

[0071]

[0072] receiving a control message from a first communication device, the control message indicating at least one of E and a subgroup identity; and

[0073] determining a wake-up command based on the control message and the truncated codeword f.

[0074] 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.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.

[0075] Examples 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 examples of the invention. Further, examples 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.

[0076] Further applications and advantages of examples of the invention will be apparent from the following detailed description.

[0077] BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The appended drawings are intended to clarify and explain different examples of the invention, in which:

[0079] - Fig. 1 shows a first communication device according to examples of the invention;

[0080] - Fig. 2 shows a flow chart of a method for a first communication device according to examples of the invention; - Fig. 3 shows a second communication device according to examples of the invention;

[0081] - Fig. 4 shows a flow chart of a method for a second communication device according to examples of the invention; - Fig. 5 shows a communication system according to examples of the invention;

[0082] - Fig. 6 shows a block diagram of a rate matching block of a transmitter of a first communication device according to examples of the invention;

[0083] - Fig. 7 and 8 show block diagrams of a processing block of a receiver of a second communication device according to examples of the invention;

[0084] - Fig. 9 shows a signaling diagram according to examples of the invention;

[0085] - Fig. 10 shows minimum distance of rate matched NR RM code vs. rate matching output length E: and

[0086] - Figs. 11 to 13 shows performance results for examples of the invention.

[0087] DETAILED DESCRIPTION

[0088] 3GPP RANI has agreed that the WUS will carry UE subgroup ID and that there will be 31 or less UE subgroups in each cell, plus an ID reserved for waking up all the low-power UEs in the cell. As the maximum number of subgroup IDs is 32, it is expected that there will be no more than 5 information bits per subgroup ID.

[0089] The NR code for small block lengths defined in section 5.3.3.3 of 3GPP TS 38.212 has a fixed codeword length of N = 32 bits. Whether the corresponding codewords for LP-WUS will be rate-matched so as to obtain a shorter codeword length is not agreed yet but is considered in RANI, since preliminary performance evaluations show that a codeword length of 32 bits may be unnecessarily long in order to meet the coverage performance targets. NR rate matching (r.m.) for short block length codewords keeps the initial E bits of the 32-bit codeword and discards the rest. This method is also called head truncation.

[0090] The minimum distance of the rate-matched code, and hence the performance of the corresponding transmission, depends on the codeword bits arrangement. Rearranging the codeword bits suitably can result in truncated codewords with increased minimum distances, hence better error correction performance, which ultimately can allow additional shortening of the codewords while still achieving the target performance, which is a missed detection rate (MDR) of not larger than 1% at -3 dB SNR.A 3GPP RANI contribution shows that NR rate-matched Reed-Muller (RM) coded transmission with rate-matched codeword length E = 22 bits achieve the missed detection rate (MDR) target of 1% at -3 dB SNR. That performance is obtained by using the conventional NR RM code and NR rate matching.

[0091] Examples of the invention however discloses a novel rate matching method for improving the performances of rate-matched RM coded transmission of UE subgroup IDs in a wake-up signal among other things. Compared to the method in the NR specification, the present solution produces larger minimum distances, therefore better performance.

[0092] Fig. 1 shows a first communication device 100 according to examples of the invention. In the example 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.

[0093] 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 and devices, such as e.g., the processor 102 and the transceiver 104, configured to perform the actions.

[0094] According to examples of the invention, the first communication device 100 is configured to: interleave a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a RM codeword of rthorder or is a RM codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a RM codeword of the rthorder or is a RM codeword of rthorder; truncate the interleaved codeword d to obtain a truncated codeword f; and transmit a communication signal 510 to a second communication device 300, the communication signal 510 indicating the truncated codeword f.

[0095] Furthermore, in an example of the invention, the first communication device 100 comprises a processor configured to: interleave a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a RM codeword of rthorder or is a RM codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a RM codeword of the rthorder or is a RM codeword of rthorder; truncate the interleaved codeword d to obtain a truncated codeword f. The first communication device 100 comprises a transceiver configured to: transmit a communication signal 510 to a second communication device 300, the communication signal 510 indicating the truncated codeword f.Moreover, in yet another example 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: interleave a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a RM codeword of rthorder or is a RM codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a RM codeword of the rthorder or is a RM codeword of rthorder; truncate the interleaved codeword d to obtain a truncated codeword f; and transmit a communication signal 510 to a second communication device 300, the communication signal 510 indicating the truncated codeword f.

[0096] 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: interleaving 202 a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a RM codeword of rthorder or is a RM codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a RM codeword of the rthorder or is a RM codeword of rthorder; truncating 204 the interleaved codeword d to obtain a truncated codeword f; and transmitting 206 a communication signal 510 to a second communication device 300, the communication signal 510 indicating the truncated codeword f.

[0097] N / 2 first bits may be understood such that, in a codeword d = (d0,

[0098]

[0099] of length N bits, the N / 2 first bits are (d0,..., dNj2-i )■ In other words, in a codeword d of length N bits, the N / 2 first bits are the bits having indices smaller than + Anin ■ where Iminis the smallest index value. Equivalently, the N / 4 first bits of the codeword d = (d0,...,dN-1) are (d0,..., djv / 4-i ete-

[0100] Fig. 3 shows a second communication device 300 according to examples of the invention. In the example 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.

[0101] 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 and devices, such as e.g., the processor 302 and the transceiver 304, configured to perform the actions.

[0102] According to examples of the invention the second communication device 300 is configured to: receive a communication signal 510 from a first communication device 100, the communication signal 510 indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E > K', receive a control message 520 froma first communication device 100, the control message 520 indicating at least one of E and a subgroup identity; and determine a wake-up command based on the control message 520 and the truncated codeword f.

[0103] Furthermore, in an example of the invention, the second communication device 300 comprises a transceiver configured to: receive a communication signal 510 from a first communication device 100, the communication signal 510 indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E >

[0104]

[0105] and receive a control message 520 from a first communication device 100, the control message 520 indicating at least one of E and a subgroup identity. The second communication device 300 comprises a processor configured to: determine a wake-up command based on the control message 510 and the truncated codeword f.

[0106] Moreover, in yet another example 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 communication signal 510 from a first communication device 100, the communication signal 510 indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E >

[0107]

[0108] receive a control message 520 from a first communication device 100, the control message 520 indicating at least one of E and a subgroup identity; and determine a wake-up command based on the control message 510 and the truncated codeword f.

[0109] 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 communication signal 510 from a first communication device 100, the communication signal 510 indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E >

[0110]

[0111] receiving 404 a control message 520 from a first communication device 100, the control message 520 indicating at least one of E and a subgroup identity; and determining 406 a wake-up command based on the control message 510 and the truncated codeword f.

[0112] Fig. 5 shows a communication system or a communication network 500 according to an example of the invention. The communication system 500 in the disclosed example comprises a first communication device 100 and a second communication device 300 configured to communicate and operate in the communication system 500. In this particular example, the first communication device 100 is configured as a network access node, such as a base station, while the second communication device 300 is configured as a client device, such as a UE. The network access node may be part of a radio access network (RAN) and can include a communication interface for communication with a network (NW) such as a core network (CN). The communication between the first communication device 100 and the second communication device 300 may be performed using channels in the downlink (DL) and the uplink (UL). Thus, it is shown in Fig. 5 how the first communication device 100 transmits a communication signal 510 according to examples of the invention in DL to the second communication device 300.

[0113] Further details related to examples of the invention will fully or partially be described in a 3GPP context. Thus, 3GPP terminology, definitions, expressions and system architecture may be used. Especially, the first communication device 100 according to the invention may in these examples be configured to perform any of the described functions of a 3GPP gNB. Correspondingly, the second communication device 300 according to the invention may in these examples be configured to perform any of the described functions of a 3GPP UE. It may however be noted that examples of the invention are not limited thereto.RM codes are a general class of structured error correction codes parameterized by two positive integers: m (any positive integer) and 0 < r < m. A RM code is denoted RM(r, m), where parameter r is the RM code order and the codeword length is N = 2mbits. The RM(r,m) code has 2Kcodewords, where K = Σi=0bits is the encoder’s input sequence length. Its minimum distance is dmin= 2m~rbits1. In particular, a 1storder (r = 1) RM code is a low-rate2code - it has input length

[0114]

[0115] K = m + 1 bits and minimum distance is half its codeword length, that is: dmin= 2m-1= N / 2 bits.

[0116] In general, encoding is represented by the following equation

[0117] d = cG (1) where, according to conventional coding theory notation, d and c are binary row vectors of length N bits and K bits, respectively, and G is a binary matrix of size K x N called generator matrix.

[0118] The generator matrix of any 1storder RM code is a (m + 1) x N matrix with all ones in the 1strow. In the remaining part of the matrix (m bottom rows), the columns contain the binary representations of all integers between 0 and m — 1. As an example, the generator matrix of RM (1,3) is shown here:

[0119] 1 1 1 1 1 1 1 1 r -10 1 0 1 0 1 0 1 0 0 1 1 0 0 (2) -1 1 1 1 0 0 0 0- It is easy to verify that the following recursive relation holds for 1storder RM codes:

[0120]

[0121] (3)

[0122] 11...1 oo...o J’ Eq. (3) implies that any codeword of a 1storder RM code is a concatenation of two replicas / copies of a codeword of a shorter 1storder RM code, where the first replica may have its bits inverted. Here, inverted means that all ‘0’s are transformed into ‘ 1 ’s and all ‘ l’s are transformed into ‘0’s. According to a more general construction, the generator matrix of code RM(r, m) can be written as follows:

[0123] (4)

[0124]

[0125] 00...0 ]'

[0126] The above equation establishes a recursive relation that allows to construct RM generator matrices, and therefore corresponding RM codes, of any length and order by combining shorter RM codes of same and lower orders. Eq. (4) implies that any codeword of a rthorder RM code is a concatenation of two replicas / copies of a codeword of a shorter rthorder RM code, where the first replica may have some or all its bits inverted in the positions corresponding to the ‘1 ’s of a codeword of a shorter (r — l)thorder RM codeword. In another interpretation, the above recursive construction reveals that there is a length N / 2 RM code nested within a length N RM code. In turn, the length N / 2 RM code has a length N / 4 RM code nested in itself, which in turn has a nested code of length N / 8, etc.

[0127] In the NR specification, a code of length N = 32 for encoding small block lengths is specified in Section 5.3.3.3 of 3GPP TS 38.212. In that section, Table 5.3.3.3-1 specifies the generator coefficients that are used to encode the input bits so as to obtain the coded bits. The encoding is done according to the following equation:

[0128] 1The minimum distance of a code is the minimum number of differences between any pair of codewords.

[0129] 2The code rate is defined as the ratio K / N.di= Ick^i,k I mod 2, i = 0,..., N — 1 (5)

[0130]

[0131] \fc=0 ' where c = (c0,..., cK-1) is the encoder input word and d = (d0,..., dN-1) is the codeword.

[0132] Eq. (5) is equivalent to Eq. (1) above if G = MT, where M = [Mt k] is the matrix with elements Ml kfrom Table 5.3.3.3-1 of 3GPP TS 38.212 and (-)Tdenotes matrix transposition.

[0133] It can be noticed that the matrix formed by the leftmost six columns of Table 5.3.3.3-1 can be derived from

[0134]

[0135] by rearranging the rows. Thus, when K < 6, the codewords of the above code are derived from the 1storder RM code of length IV = 32 bits by rearrangement of its elements (i.e., bits). We denote the matrix formed by the leftmost six columns of Table 5.3.3.3-1 as M = (M0,..., M5) where Mi= (M0 i, M1 i,..., MN-1,i)T, i = 0,...,5, is the column vector corresponding to the elements in column I from Table 5.3.3.3-1 of 3GPP TS 38.212.

[0136] For LP-WUS, the number of information bits is K < 5, thus only the leftmost 5 columns are combined to generate a LPWUS codeword d, thus the codeword d is a codeword derived from a 1storder RM codeword by rearranging the bits.

[0137] After encoding, NR performs rate matching by truncation / extension so as to obtain a rate-matched codeword f = (f0,..., fE-1) of length E bits. Rate matching is done according to the following equation:

[0138] fk (k mod

[0139]

[0140] E — 0,..., E — 1. (6)

[0141] where N = 32 bits. In the above scheme with reference to Fig. 6, the information message c = (c0,..., cK-1) of length K = 3,...,5 bits is encoded by the NR small block length encoder 120. The message c may optionally be zero-padded by one bit so as to obtain a zero-padded encoder input word c' = (0, c0,..., cK-1) in the optional zero padding block 122 in Fig. 6. NR small block length encoding may be performed as specified in Sec. 5.3.3.3 of 3GPP TS 38.212. At the NR encoder 120 output in Fig.

[0142] 6, a codeword d = (d0,...,dN-1) of length IV = 32 bits is obtained according to Eq. (5). The codeword d is interleaved so as to obtain an interleaved codeword d = (d0,...,dN-1) in the interleaver block 132 in Fig. 6 where di= dπ. Here, (πi)i=0N-1is a permutation.

[0143] The interleaved codeword d is rate-matched according to the conventional NR method from Sec. 5.4.3 of 3GPP TS 38.212 in the NR rate matching block 134 in Fig. 6, so as to obtain a rate matched codeword denoted truncated codeword f = (f0,..., fE-1) of arbitrary length E bits where E > K. NR rate matching is defined by the following equation:

[0144] fk (k mod

[0145]

[0146] E — 0,..., E — 1. (7)

[0147] Thus, the truncated codeword f comprises E number of bits and the codeword d is generated by encoding K number of input bits, where E > K.

[0148] The truncated codeword f is sent to the modulator block 140 and transmitted by the antenna 110 in a communication signal 510 to one or more receivers as shown in Fig. 6.

[0149] An objective of examples of the invention is achieved by an interleaver configured to rearrange the bits in its input word according to permutation

[0150]

[0151] i=0,...,N-1 that is designed to produce increased minimum distances of the rate-matched code.A property of any 1storder RM code generator matrix G (see Eq. (3)) is that the submatrix obtained by removing the all-1 row (first row) contains in its columns all the unique (i.e., not repeated) binary sequences of m bits. The generator matrix produces a code with minimum distance which is half the codeword length: dmin= N / 2. Obtaining a minimum distance which is as close as possible to half the length of the rate-matched codeword is a target.

[0152] In order to achieve large minimum distance in a set of codewords, there should be no bit repetition, where two (or more) bits form a repetition if, in each codeword, these bits have the same value. A repetition occurs when two (or more) codeword bits - say dt and dj, with i j - are determined, based on the encoding Eq. (5), using the same set of generator coefficients, that is: Ml k= MJ k, for all k = 0,..., K — 1. For example, when K = 4 bits and N = 32, encoding according to Eq. (5) produces a repetition of coded bits d0and d5as the corresponding generator coefficients are the same: (M00, M01, M02, M03) = (M50, M5 1, M52, M53) = (1, 1,0,0): and similar observations reveal that bits d1and d11form a repetition, as well as bits d2and d12. In order to avoid repetitions in the rate-matched codeword when its length is E = N / 2, the interleaver block 132 has to rearrange the RM codeword so that each of the N / 2 bits dt= dn,i = 0,..., — 1, in the first half of the interleaved codeword d - the N / 2 first bits of d - is obtained based on a different set of coefficients Mπ 0,..., Mπ, K-1. In other words, in order to avoid repetitions, there must be no pair of indices p,q between 0 and N / 2 — 1 such that

[0153]

[0154] =

[0155]

[0156] ■■■>, / <- i )■ Note that, since Ml 0= 1 for all i, such an arrangement exists only when K > log2N. A possible algorithm for generating a permutation that satisfies the above approach / principle is the following algorithm denoted algorithm 1:

[0157] ALGORITHM!:

[0158] fc = 0;

[0159] n = 0;

[0160] while k < N do:

[0161] if Mk 0: K-1≠ Mz 0: K-1for all non-negative integers z < k:

[0162] nn= fc;

[0163] n = n + 1;

[0164] end if

[0165] k = k + 1;

[0166] end while

[0167] Fill the remaining part of the permutation with the values that haven’t been assigned to the permutation in the steps above.

[0168]

[0169] Hence, in examples of the invention, the interleaving of the codeword d comprises rearranging the N bits of the codeword d such that any two bits of the N / 2 first bits of the interleaved codeword d is obtained based on two different sequences of generator coefficients. It may further be noted that the different sequences of generator coefficients may differ in at least one generator coefficient in such examples.

[0170] In the above algorithm 1 and further on in the present disclosure, notation Mk 0: K-1is a compact notation used to denote the vector of elements at row k and columns 0 to K — 1 of matrix M, that is (Mk 0, Mk 1,..., Mk, K-1)- By applying the above algorithm to matrix M derived from the table in 5.3.3.3 of 3GPP TS 38.212, we obtain the permutation in Table 1 (see also alternative representation in Table 2). The gains in terms of minimum distance are evaluated in the following disclosure.Table 1. Interleaver permutation - first option.

[0171] i 7T, i 7T, i 7T, i 7T,

[0172] 0 0 8 8 16 11 24 23

[0173] 1 1 9 9 17 12 25 25

[0174] 2 2 10 10 18 15 26 26

[0175] 3 3 11 13 19 17 27 27

[0176] 4 4 12 14 20 18 28 28

[0177] 5 5 13 16 21 20 29 29

[0178] 6 6 14 19 22 21 30 30

[0179] 7 7 15 24 23 22 31 31

[0180]

[0181] Table 2. Interleaver permutation - first example. Alternative representation.

[0182] i 0...10 11 12 13 14 15 16 17 18 19 20 21:24 22 23 24 25...31ni 0...10 13 14 16 19 24 11 12 15 17 18 20:23 21 22 23 25...31

[0183]

[0184] With the above permutation, we note that the interleaved codeword d of length N bits contains, in its first half, a codeword that can be derived from the 1storder RM code of length N / 2 by a permutation of its bits. Similarly, the second half of the interleaved codeword d comprises a derived codeword from a 1storder RM code of length N / 2. More generally, the herein disclosed interleaving may be formulated such that the N / 2 first bits of the interleaved codeword d is a codeword derived from a RM codeword of rthorder or a RM codeword of rthorder and the IV / 4 first bits of the interleaved codeword d is a codeword derived from a RM codeword of rthorder or a RM codeword of rthorder. As an alternative or in a combination of the previous statement, the IV / 4 first bits of the interleaved codeword d is a codeword derived from a RM codeword of rthorder or a RM codeword of rthorder and the IV / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a RM codeword of rthorder.

[0185] It has been noted above that, since the first generator column Mi 0= 1 for all i, a permutation that avoids repetitions in the first half of the interleaved codeword exists only when K > log2N. By zero-padding the input word c so as to obtain c' = (0, c0,..., cK-1) at the encoder input, the first generator column is no longer used for encoding as its corresponding input bit is Cg = 0. Based on the structure of M, it then follows that a repetition avoiding permutation as above exists when K > log2N — 1, thus providing benefits for smaller values of K. A corresponding permutation generator algorithm would be the same as Algorithm 1 above, where Mk 0: K-1is replaced by Mfc 1: Kand Mz 0: K-1is replaced by MZ 1. K.

[0186] More in general, depending on how the generator coefficients are arranged in the original generator matrix, zero-padding the input word to the encoder at given positions may be beneficial. Thus, the input word c can be zero-padded at multiple positions - say (p0,...,pK’ _■ / )'. where 0 < p0< p, < ••• < pK’-1< K + K' - so as to obtain a zero-padded encoder input word c' = (c'0,..., c'K+K'-1) of length K + K' where c'p0= c'p1= ··· = c'pK'= 0. The remaining bits of the zero-padded word c' are obtained from the input word c. Therefore, in examples of the invention, the codeword d is obtained by encoding the zero-padded word c' according to Eq. (5) above, wherein ckis replaced by c'kand the summation runs from k = 0 to K + K' — 1.

[0187] Thus, the encoding may be done according to ( the following equation:

[0188] K+K’-I \

[0189] ckMi kj mod 2, i = 0,...,1V — 1. (8)

[0190]

[0191] k=0 / In a second approach, we target to obtain an interleaved codeword d of length N bits that comprises, in its first quarter, a codeword that can be derived from the 1storder RM code of length N / 4 by a permutation of its bits. Moreover, the interleaved codeword d comprises, in its first half, a codeword that can be derived from the 1storder RM code of length N / 4 by a permutation of its bits. In that way, we expect to achieve minimum distance improvements when the rate-matched codeword length is E = N / 4 as well as when E = N / 2. A possible algorithm for generating a permutation according to the above approach is the following algorithm denoted algorithm 2:

[0192] ALGORITHM 2:

[0193] fc = 0;

[0194] n = 0;

[0195] while k < N do:

[0196] if Mk 0: K-2≠ Mz 0: K-2for all non-negative integers z < k:

[0197] nn= fc;

[0198] n = n + 1;

[0199] end if

[0200] k = k + 1;

[0201] end while

[0202] k = 0;

[0203] while k < N do:

[0204] if Mk 0: K-1≠ Mz 0: K-1for all non-negative integers z < k and k ≠ πqfor all non-negative integers q < n:

[0205] nn= fc;

[0206] n = n + 1;

[0207] end if

[0208] k = k + 1;

[0209] end while

[0210] Fill the remaining part of the permutation with the values that haven’t been assigned to it in the steps above.

[0211]

[0212] The 2ndpermutation obtained by the above algorithm is reported in Table 3.

[0213] Table 3. Interleaver permutation - second example.

[0214] i 0...4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21:24 25...31ni 0...4 6 8 14 5 7 9 10 13 16 19 24 11 12 15 17 18 20:23 25...31

[0215]

[0216] When zero-padding the encoder input, the above Algorithm 2 has to be updated as follows: replace Mk 0: K-2≠ Mz 0: K-2by M

[0217]

[0218] fc,i: K-i replace Mk 0: K-1≠ Mz 0: K-1by Mk 1: K≠ Mz 1: K.

[0219] One further option is to generate a permutation based on the above algorithm and then modify the permutation by exhaustive search (e.g., computer-based search), targeting performance improvements for specific truncated codeword lengths E or input word length K. An example of permutation that performs better than the one in Table 3 for K = 5 is shown in Table 4, which is obtained based on the permutation of Table 3 by modifications in the initial 13 elements.Table 4. Interleaver permutation - variant of second example.

[0220] i 0...4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21:24 25...31ni 0...4 14 10 8 7 9 6 13 5 16 19 24 11 12 15 17 18 20:23 25...31

[0221]

[0222] A 3rdpermutation is defined in Table 5. This permutation rearranges the codeword bits so that the corresponding rows of M form a transposed RM generator matrix in canonical form, that is: π(M) =

[0223]

[0224] G5, where Π denotes a row re-arrangement.

[0225] Table 5. Interleaver permutation - third example.

[0226] i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31ni 30 29 18 17 16 28 15 14 27 26 13 12 11 10 25 19 24 9 8 7 23 6 5 22 4 3 21 2 1 20 0 31

[0227]

[0228] The receiver of the second communication device 300 receiving the communication signal 510 may process the received communication signal 510 in two different ways when the communication signal 510 is a wake-up signal.

[0229] Fig. 7 shows a block diagram of a first example of processing in the receiver of a UE 300. The decoder in the wake-up receiver may operate according to the following steps:

[0230] 1. Receive a truncated codeword f comprised in a communication signal 510;

[0231] 2. Rearrange the received bits of the received truncated codeword f so as to match the original arrangement at the encoder output, and fill with zeros the positions of the bits that have not been transmitted in a de-rate matching block 330 comprising a NR de-rate matching block 332 at its input connected in series with a de-interleaver block 334 at its output;

[0232] 3. Decode the received truncated codeword f in the NR decoder block 344 so as to obtain a decoded message c;

[0233] which is a (possibly corrupted) version of the transmitted information message c;

[0234] 4. Obtain a transmitted subgroup ID from the decoded message c and compare it with a preconfigured subgroup ID, stored in the memory block 340, in the comparator block 342; and

[0235] 5. If the transmitted subgroup ID and the preconfigured subgroup ID match (i.e., the same subgroup ID) the comparator block 342, generate a wake-up command for the main transceiver (TRX) block 360. Else, the main TRX 360 continues in sleep mode.

[0236] Fig. 8 shows a block diagram of a second example of processing in the receiver of a UE 300. According to an alternative operation mode, the wake-up receiver performs the following steps:

[0237] 1. Receive a truncated codeword f which possibly is a corrupted version of a transmitted truncated codeword f;

[0238] 2. Compare the received truncated codeword f with a stored truncated codeword, from a memory block 350, that was generated when the network configured the subgroup ID in the UE 300 in the comparator block 352; and 3. If the received truncated codeword and the stored truncated codeword match, generate a wake-up command for the main TRX block 360. As the received truncated codeword may be corrupted by interference or noise, the two truncated codewords may differ in bits in a small number of positions but still be considered to match each other. The number of positions wherein the two truncated codewords may differ while being considered to match may be at most less than half the minimum distance of the truncated code. Else, the main TRX 360 continues in sleep mode.Fig. 9 shows control signaling according to examples of the invention. In this example, the signaling is performed from a gNB 100 to a UE 300.

[0239] In order to be able to decode the WUS and generate a wake-up command to the main transceiver, the WUR in the UE 300 needs to know the WUS starting time and its length, and its own subgroup ID. Moreover, the WUR may benefit from knowing the number of subgroups in the cell. The WUS starting time is obtained by a dedicated synchronization signal which is already agreed by 3GPP. The WUS length can be pre-configured in the UE 300, the rate-matched codeword length E before the main transceiver is sent to sleep mode.

[0240] In these examples, the codeword d may be generated according to the 3GPP standard specification TS 38.212, section 5.3.3.3-1. Thus, the K number of input bits represents a subgroup identity of UEs. Especially, the parameters have the following values: K = 3,4 or 5 and N = 32, and r = 1.

[0241] In step I in Fig. 9, the gNB 100 transmits a control message 520 to the UE 300. The control message 520 indicates at least one subgroup ID and optionally a code parameter E. The indication of a subgroup ID may implicitly indicate a subgroup ID length K. The control message 520 may be defined according to NR standards and protocols. Thus, the control message 520 may be transmitted in a Physical Downlink Control Channel (PDCCH) in the form of a Downlink Control Information (DCI) to the UE 300.

[0242] In step II in Fig. 9, the gNB 100 transmits a sleep command to the UE 300 according to NR standard.

[0243] In step III in Fig. 9, the UE 300 switches off the main transceiver (TRX) upon reception of the sleep command from the gNB 100.

[0244] In step IV in Fig. 9, the gNB 100 transmits a communication signal 510 to the UE 300. As previously mentioned, the communication signal 510 indicates a truncated codeword f according to examples of the invention, and is in this particular example a wake-up signal.

[0245] In step V in Fig. 9, the UE 300 wakes up the main transceiver if the K number of input bits represents a subgroup identity of the UE 300.

[0246] In general, the arrangement of codeword bits is irrelevant to the minimum distance of the code itself, as interleaving rearranges the bits without changing their values. However, when rate matching is used in order to shorten (or extend) the codewords, the arrangement of codeword bits has an impact on the minimum distance of the rate-matched code.

[0247] Based on the recursive construction of Eq. (3), it can be seen that a 1storder RM code of length 32 bits generated by GRM(1followed by rate matching by truncation so as to have r.m. output length E = 16 bits produces a 1storder RM code of length 16 whose minimum distance is dmin= 8.

[0248] On the other hand, evaluations show that the code generated by M, when rate matched by truncation to length E = 16 bits, has smaller minimum distance: dmin= 6 when K = 4,5 bits; dmin= 7 when K = 3. The minimum distance of rate matched NR RM code vs. rate matching output length is shown in Fig. 10, where it is highlighted that, for E = 16 bits (see vertical dotted line), the minimum distances of the rate matched codes are smaller than 8.An at-a-glance comparison between NR and the novel rate matching minimum distances performance (using 1stpermutation) is shown in Fig. 11 and Table 4.

[0249] In Fig. 11, a representative case - K = 4 bits - is shown. It can be seen that the new rate matching produces minimum distance same or better than NR. Zero-padding further increases the minimum distance gain compared to NR, except for E = 5 bits.

[0250] Table 4. Comparison of minimum distance obtained with new r.m. with 1stpermutation compared to NR r.m. Legend: “=” cells indicate same minimum distance. Positive / negative values indicate better / worse than NR minimum distance. K\E 12 13 14 15 16 17 18 19 20 21 22 23 24 25...32 3 -1 -1 = = 1 = = 1 1 = 1 1 = =

[0251] 4 2 2 2 1 = 1 1 = 1 =

[0252] 5 1 = 1 1 = 1 =

[0253]

[0254] For the rate matching output lengths E = 16,19,22 bits, the new rate matching provides minimum distance improvements for all values of K = 3, 4, 5 bits needed for LP-WUS.

[0255] A comparison between NR and new rate matching minimum distances performance, where new r.m. uses the 2ndpermutation, is shown in Fig. 12. It can be seen that the new r.m. with second permutation produces larger minimum distances compared to NR. Usage of zero padding can further increase the minimum distance for certain rate matching output lengths.

[0256] Fig. 13 shows that the second permutation produces better minimum distances than NR for several values of E in the range between 5 and 16 bits, when the number of input bits is K = 7, thus producing a derived 2ndorder RM code. The variant of second permutation produces even larger minimum distances for E = 7,..., 11 bits.

[0257] Table 7 shows the missed detection rate (MDR) performance evaluations for K = 5 bits, respectively, obtained with the first permutation. For given information word length K| bi ts ] and rate matched codeword length E [bits], the table indicates if the corresponding scheme achieves the performance target of MDR < 1% at SNR=-3dB. The last column in the tables shows the corresponding SNR gain at MDR = 1%. It can be seen that new rate matching achieves the performance with rate matched codeword length E = 19 bits, while NR rate matching requires a longer codeword: E = 20 bits.

[0258] Table 7. Rate matching output lengths that meet the target performance of MDR < 1% at SNR=-3dB; corresponding SNR gain@MDR=l° / o of new r.m. compared to NR. K=5 info bits.

[0259] E [bits] NR r. m. New r. m.

[0260] 18 No No

[0261] 19 No Yes

[0262] 20 Yes Yes

[0263]

[0264] Moreover, 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 3GPPrelated long term evolution (LTE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR) and their evolutions such as mobile networks for the future, as well as in IEEE related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and their evolutions.

[0265] 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, and 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 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 LTE, LTE-advanced, 5G wireless systems, such as NR, and their evolutions such as mobile networks for the future, as well as in IEEE related Wi-Fi, WiMAX and their evolutions.

[0266] Furthermore, any method according to examples 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.

[0267] Moreover, it should be realized that the first communication device 100 and the second communication device 300 comprise any necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing or implementing examples 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.

[0268] Therefore, the processor(s) 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 a plurality 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.

[0269] Finally, it should be understood that the invention is not limited to the examples described above, but also relates to and incorporates all examples within the scope of the appended independent claims.

Claims

CLAIMS1. A first communication device (100) configured to:interleave a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a / V / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder;truncate the interleaved codeword d to obtain a truncated codeword f; andtransmit a communication signal (510) to a second communication device (300), the communication signal (510) indicating the truncated codeword f.

2. The first communication device (100) according to claim 1, wherein the truncated codeword f comprises E number of bits and the codeword d is generated by encoding K number of input bits, where E > K.

3. The first communication device (100) according to claim 2, wherein the K number of input bits represents a subgroup identity of second communication devices.

4. The first communication device (100) according to claim 2 or 3, wherein K = 3, 4 or 5 and N = 32.

5. The first communication device (100) according to claim 4, wherein r = 1.

6. The first communication device (100) according to claim 4 or 5, wherein the codeword d is generated according to the 3GPP standard specification TS 38.212, section 5.3.3.3-1.

7. The first communication device (100) according to any one of claims 2 to 6, configured to:transmit a control message (520) to the second communication device (300), the control message (520) indicating at least one of E and a subgroup identity.

8. The first communication device (100) according to any one of the preceding claims, wherein the communication signal (510) is a wake-up signal.

9. The first communication device (100) according to any one of the preceding claims, whereinthe N / 2 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder; and / orthe N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the / V / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder.

10. The first communication device (100) according to any one of the preceding claims, wherein the interleaving of the codeword d comprises:rearrange the N bits of the codeword d such that any two bits of the N / 2 first bits of the interleaved codeword d is obtained based on two different sequences of generator coefficients.

11. The first communication device (100) according to claim 9, wherein the different sequences of generator coefficients differ in at least one generator coefficient.

12. The first communication device (100) according to any one of the preceding claims, wherein the first communication device (100) is a network access node and the second communication device (300) is a client device.

13. A second communication device (300) configured to:receive a communication signal (510) from a first communication device (100), the communication signal (510) indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E > Kreceive a control message (520) from a first communication device (100), the control message (520) indicating at least one of E and a subgroup identity; anddetermine a wake-up command based on the control message (510) and the truncated codeword f.

14. The second communication device (300) according to claim 13, wherein the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a N / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder.

15. The second communication device (300) according to claim 14, whereinthe N / 2 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder; and / orthe N / 4 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder and the N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of rthorder or a Reed-Muller codeword of rthorder.

16. The second communication device (300) according to claim 15, wherein r = 1.

17. The second communication device (300) according to any one of claims 14 to 16, wherein the K number of input bits represents a subgroup identity of second communication devices.

18. The second communication device (300) according to any one of claims 14 to 17, wherein K = 3,4 or 5 and N = 32.

19. The second communication device (300) according to claim 18, wherein the codeword d is generated according to the 3GPP standard specification TS 38.212, section 5.3.3.3-1.

20. The second communication device (300) according to any one of claims 14 to 19, wherein the communication signal (510) is a wake-up signal.

21. The second communication device (300) according to any one of claims 14 to 20, wherein the first communication device (100) is a network access node and the second communication device (300) is a client device.

22. A method (200) for a first communication device (100), the method (200) comprising:interleaving (202) a codeword d comprising N number of bits to obtain an interleaved codeword d comprising N bits, wherein the codeword d is derived from a Reed-Muller codeword of rthorder or is a Reed-Muller codeword of rthorder, wherein N > 16, and wherein at least one of a N / 2 first bits, or a / V / 4 first bits, or a N / 8 first bits of the interleaved codeword d is a codeword derived from a Reed-Muller codeword of the rthorder or is a Reed-Muller codeword of rthorder;truncating (204) the interleaved codeword d to obtain a truncated codeword f; andtransmitting (206) a communication signal (510) to a second communication device (300), the communication signal (510) indicating the truncated codeword f.

23. A method (400) for a second communication device (300), the method (400) comprising:receiving (402) a communication signal (510) from a first communication device (100), the communication signal (510) indicating a truncated codeword f comprising E number of bits, the truncated codeword f being derived from an interleaved codeword d, the interleaved codeword d being derived from a codeword d generated by encoding K number of input bits, where E > E;receiving (404) a control message (520) from a first communication device (100), the control message (520) indicating at least one of E and a subgroup identity; anddetermining (406) a wake-up command based on the control message (510) and the truncated codeword f.

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

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