Modulation order adaptation for MIMO

Abstract

An apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

Description

Modulation Order Adaptation For MIMO RELATED APPLICATION

[0001] This application claims priority to FI Application No. 20245778 filed June 18, 2024, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The examples and non-limiting example embodiments relate generally to communications and, more particularly, to modulation order adaptation for MIMO. BACKGROUND

[0003] It is known for a communication device to gain access to a communication network via an access network node. SUMMARY

[0004] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

[0005] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determine a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulate and decode the downlink data based on the determined MCS.

[0006] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectralefficiency and a number of at least one transmission layer selected for a transmission of uplink data; and transmit, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS.

[0007] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; determine a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data; and demodulate and decode the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0008] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determine a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0009] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determine a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determine a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulate and decode the downlink data, based on the modulation order and the transport block size.

[0010] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for thetransmission; determine a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmit, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0011] In accordance with an aspect, an apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; determine a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determine a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulate and decode the uplink data, based on the modulation order and the transport block size. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing aspects and other features are explained in the following description, taken in connection with the accompanying drawings.

[0013] FIG.1 is a block diagram of one possible and non-limiting system in which the example embodiments may be practiced.

[0014] FIG.2 shows an example MCS index table for PDSCH.

[0015] FIG.3 shows an example MCS index table for PDSCH.

[0016] FIG. 4 shows an example of an MCS table with more than one overlapping entry for modulation switching.

[0017] FIG.5 shows an example MCS index table 1 for rank=1.

[0018] FIG.6 shows an example MCS index table 1A for rank=2.

[0019] FIG.7 shows an example MCS index table 1B for rank=3.

[0020] FIG.8 shows an example MCS index table 1C for rank=4.

[0021] FIG.9 shows an example modulation order mapping.

[0022] FIG.10 shows an example flow chart for the operation of Alt.2 for PDSCH operation.

[0023] FIG.11 shows an example flow chart for the operation of Alt.2 for PUSCH operation.

[0024] FIG.12 shows a signaling flow chart for the operation of Alt.3 for PDSCH operation.

[0025] FIG.13 shows an example flow chart for the operation of Alt.3 for PUSCH operation.

[0026] FIG. 14 is an example apparatus configured to implement the examples described herein.

[0027] FIG. 15 shows a representation of an example of non-volatile memory media used to store instructions that implement the examples described herein.

[0028] FIG.16 is an example method, based on the examples described herein.

[0029] FIG.17 is an example method, based on the examples described herein.

[0030] FIG.18 is an example method, based on the examples described herein.

[0031] FIG.19 is an example method, based on the examples described herein.

[0032] FIG.20 is an example method, based on the examples described herein.

[0033] FIG.21 is an example method, based on the examples described herein.

[0034] FIG.22 is an example method, based on the examples described herein.

[0035] FIG.23 is an example method, based on the examples described herein. DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0036] Turning to FIG.1, this figure shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. In the example of FIG.1, the user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or controlbuses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, comprising one of or both parts 140-1 and / or 140-2, which may be implemented in a number of ways. The module 140 may be implemented in hardware as module 140-1, such as being implemented as part of the one or more processors 120. The module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[0037] The RAN node 170 in this example is a base station that provides access for wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for example, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface (such as connection 131) to a 5GC (such as, for example, the network element(s) 190). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface (such as connection 131) to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU 195 may include or be coupled to and control a radio unit (RU). The gNB-CU 196 is a logical node hosting radio resource control (RRC), SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that control the operation of one or more gNB-DUs. The gNB-CU 196 terminates the F1 interface connected with the gNB-DU 195. The F1 interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU 195 is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU 196. One gNB-CU 196 supports one or multiple cells. One cell may be supported with one gNB-DU195, or one cell may be supported / shared with multiple DUs under RAN sharing. The gNB-DU 195 terminates the F1 interface 198 connected with the gNB-CU 196. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of a RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station or node.

[0038] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / W I / F(s)) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, one or more memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory / memories and processor(s), and / or other hardware, but these are not shown.

[0039] The RAN node 170 includes a module 150, comprising one of or both parts 150-1 and / or 150-2, which may be implemented in a number of ways. The module 150 may be implemented in hardware as module 150-1, such as being implemented as part of the one or more processors 152. The module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 150 may be implemented as module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[0040] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more gNBs 170 may communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interface for other standards.

[0041] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiberoptics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH / DU 195, and the one or more buses 157 could be implemented in part as, for example, fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB- CU 196) of the RAN node 170 to the RRH / DU 195. Reference 198 also indicates those suitable network link(s).

[0042] A RAN node / gNB can comprise one or more TRPs to which the methods described herein may be applied. FIG.1 shows that the RAN node 170 comprises TRP 51 and TRP 52, in addition to the TRP represented by transceiver 160. Similar to transceiver 160, TRP 51 and TRP 52 may each include a transmitter and a receiver. The RAN node 170 may host or comprise other TRPs not shown in FIG.1.

[0043] A relay node in NR is called an integrated access and backhaul node. A mobile termination part of the IAB node facilitates the backhaul (parent link) connection. In other words, the mobile termination part comprises the functionality which carries UE functionalities. The distributed unit part of the IAB node facilitates the so called access link (child link) connections (i.e. for access link UEs, and backhaul for other IAB nodes, in the case of multi-hop IAB). In other words, the distributed unit part is responsible for certain base station functionalities. The IAB scenario may follow the so called split architecture, where the central unit hosts the higher layer protocols to the UE and terminates the control plane and user plane interfaces to the 5G core network.

[0044] It is noted that the description herein indicates that “cells” perform functions, but it should be clear that equipment which forms the cell may perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For example, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single base station’s coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So if there are three 120 degree cells per carrier and two carriers, then the base station has a total of 6 cells.

[0045] The wireless network 100 may include a network element or elements 190 that mayinclude core network functionality, and which provides connectivity via a link or links 181 with a further network, such as a telephone network and / or a data communications network (e.g., the Internet). Such core network functionality for 5G may include location management functions (LMF(s)) and / or access and mobility management function(s) (AMF(S)) and / or user plane functions (UPF(s)) and / or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (mobility management entity) / SGW (serving gateway) functionality. Such core network functionality may include SON (self-organizing / optimizing network) functionality. These are merely example functions that may be supported by the network element(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to the network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an S1 interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / W I / F(s)) 180, interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. Computer program code 173 may include SON and / or MRO functionality 172.

[0046] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, or a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[0047] The computer readable memories 125, 155, and 171 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, non-transitory memory, transitory memory, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) andprocessors based on a multi-core processor architecture, as non-limiting examples. The processors 120, 152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, network element(s) 190, and other functions as described herein.

[0048] In general, the various example embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback devices having wireless communication capabilities, internet appliances including those permitting wireless internet access and browsing, tablets with wireless communication capabilities, head mounted displays such as those that implement virtual / augmented / mixed reality, as well as portable units or terminals that incorporate combinations of such functions. The UE 110 can also be a vehicle such as a car, or a UE mounted in a vehicle, a UAV such as e.g. a drone, or a UE mounted in a UAV. The user equipment 110 may be terminal device, such as mobile phone, mobile device, sensor device etc., the terminal device being a device used by the user or not used by the user.

[0049] UE 110, RAN node 170, and / or network element(s) 190, (and associated memories, computer program code and modules) may be configured to implement (e.g. in part) the methods described herein. Thus, computer program code 123, module 140-1, module 140-2, and other elements / features shown in FIG.1 of UE 110 may implement user equipment related aspects of the examples described herein. Similarly, computer program code 153, module 150-1, module 150-2, and other elements / features shown in FIG.1 of RAN node 170 may implement gNB / TRP related aspects of the examples described herein. Computer program code 173 and other elements / features shown in FIG. 1 of network element(s) 190 may be configured to implement network element related aspects of the examples described herein.

[0050] Having thus introduced a suitable but non-limiting technical context for the practice of the example embodiments, the example embodiments are now described with greater specificity.

[0051] The examples described herein relate to link adaptation and MCS selection for UL and DL multi-stream MIMO operation, either in 6G or in Rel-19+ version of 5G. Specifically, the trade-off between selected modulation and coding rate for a multi-stream MIMO SCH operation.

[0052] MCS (Modulation and Coding Scheme) selection in NR:

[0053] The link adaptation for cellular mobile communications is based on selecting an appropriate MCS for the UL or DL shared channel, applied for 3G HSPA, 4G / LTE and NR. For this purpose, MCS tables are defined which contain combinations of the applied modulation and coding rate, which then define the applied modulation and transport block size of the UL and DL-SCH according. The related procedures for NR for DL-SCH are described in Sec. 5.1.3, 5.1.3.1 and 5.1.3.2 and for the UL-SCH in Sec. 6.1.3, 6.1.3.1 and 6.1.3.1. of TS38.214. For 5G / NR several different MCS tables are defined:

[0054] For DL-SCH / PDSCH they can be found in Sec. 5.1.3.1, and the following different MCS tables are defined (1-4): 1) Table 5.1.3.1-1 - MCS index table 1 for PDSCH: (baseline) MCS table for modulation up to 64QAM, 2) Table 5.1.3.1-2 - MCS index table 2 for PDSCH: MCS table for modulation up to 256QAM, 3) Table 5.1.3.1-3 - MCS index table 3 for PDSCH: Low-spectral efficiency MCS table (up to 64QAM), 4) Table 5.1.3.1-4 - MCS index table 4 for PDSCH: MCS table for modulation order up to 1024QAM.

[0055] For UL-SCH / PUSCH similar separate tables are defined and used, which can be found in Sec. 6.1.3.1 (1-2): 1) For OFDM based PUSCH (transform precoding disabled), the MCS index table 1, 2 and 3 for PDSCH (i.e. Table 5.1.3.1-1, Table 5.1.3.1-2 and Table 5.1.3.1-3) are reused for operation, 2) For DFT-S-OFDM based PUSCH (i.e. transform precoding enabled), the following MCS tables are used (i-iii): i) Table 6.1.4.1-1 – (baseline) MCS table with modulation up to 64QAM, ii) Table 6.1.4.1-2 – Low-spectral efficiency MCS table with modulation up to 64QAM, iii) For modulation order up to 256QAM, the respective table for PDSCH (Table 5.1.3.1-2 / MCS index table 2) is reused.

[0056] FIG.2 shows an example MCS index table for PDSCH, which is also shown below as Table 5.1.3.1-1). Table 5.1.3.1-1: MCS index table 1 for PDSCH MCS Index Modulation Order Target Spectral IMCS Qm code Rate R x

[1024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.87707 2 526 1.0273 8 2 602 1.1758 9 2 679 1.3262 10 4 340 1.3281 11 4 378 1.4766 12 4 434 1.6953 13 4 490 1.9141 14 4 553 2.1602 15 4 616 2.4063 16 4 658 2.5703 17 6 438 2.5664 18 6 466 2.7305 19 6 517 3.0293 20 6 567 3.3223 21 6 616 3.6094 22 6 666 3.9023 23 6 719 4.2129 24 6 772 4.5234 25 6 822 4.8164 26 6 873 5.1152 27 6 910 5.3320 28 6 948 5.5547 29 2 Reserved 30 4 Reserved 31 6 Reserved

[0057] FIG.3 shows an example MCS index table for PDSCH, which is also shown below as Table 5.1.3.1-2. Table 5.1.3.1-2: MCS index table 2 for PDSCH MCS Index Modulation Order CS mTarget code Rate Spectral IMQ R x

[1024] efficiency 0 2 120 0.2344 1 2 193 0.3770 2 2 308 0.6016 3 2 449 0.8770 4 2 602 1.1758 5 4 378 1.4766 6 4 434 1.6953 7 4 490 1.9141 8 4 553 2.1602 9 4 616 2.4063 10 4 658 2.5703 11 6 466 2.7305 12 6 517 3.0293 13 6 567 3.322314 6 616 3.6094 15 6 666 3.9023 16 6 719 4.2129 17 6 772 4.5234 18 6 822 4.8164 19 6 873 5.1152 20 8 682.5 5.3320 21 8 711 5.5547 22 8 754 5.8906 23 8 797 6.2266 24 8 841 6.5703 25 8 885 6.9141 26 8 916.5 7.1602 27 8 948 7.4063 28 2 reserved 29 4 reserved 30 6 reserved 31 8 reserved

[0058] Referring to FIG. 2 and FIG. 3, when looking at the MCS tables for NR (example the baseline 64QAM table below), the following can be noted (1-4): 1) The entries are ordered in increasing modulation order and spectral efficiencies, 2) There is a fixed switching point from a certain modulation order to the next higher modulation order, 3) For some modulation order switching point, there may be (one or more) entries with similar spectral efficiencies defined to allow for more adaptation of similar spectral efficiencies but with different modulation orders (examples shown as items 202 and 204 in FIG. 2, where item 202 includes table entries corresponding to MCS indexes 9 and 10, and where item 204 includes table entries corresponding to MCS indexes 16 and 17), 4) For some modulation order switching points, the next higher modulation order starting immediately with a higher spectral efficiency than the lower modulation order (examples shown as items 302, 304, and 306 in FIG.3, where item 302 includes table entries corresponding to MCS indexes 4 and 5, where item 304 includes table entries corresponding to MCS indexes 10 and 11, and where item 306 includes table entries corresponding to MCS indexes 19 and 20).

[0059] The configured MCS table (and related entries) are applicable for the UL-SCH / DL- SCH channel operation independently of the applied MIMO transmission rank, i.e. the same MCS table is applicable for 1 to 4 layer multi-stream MIMO operation.

[0060] The modulation order switching points (from lower to higher modulation order) have been identified based on performance evaluations for single-stream (rank1) operation.

[0061] Both in LTE and NR, up to 2 codewords (CWs) may be transmitted to the UE at the same PDSCH (i.e. PDSCH comprises two CWs). Both CWs are encoded separately, and have their own MCS indicated. The CWs are mapped / transmitted on different spatial layers. As an example, the first CW may be mapped across four spatial layers, and the second CW may be mapped only on two spatial layers. There can be considerable channel quality differences between the spatial layers, hence, using different MCS indexes for the CWs is advantageous and beneficial.

[0062] It has been shown that the performance of the NR multi-stream MIMO operation is basically limited by the channel quality of the weakest stream.

[0063] Part of this problem is coming from the following facts of the NR operation (1-2):

[0064] 1. A coded transport block is mapped onto up to four MIMO layers, as NR applies the following data mapping order: First within a resource element (RE) (a-b): a) first to the Modulation constellation, followed by b) MIMO streams / layers, second in frequency domain (in increasing number of REs) and third in the time domain (in increasing number of OFDM symbols of PUSCH / PDSCH)

[0065] 2. The combination order of (i) modulation order and (ii) spectral efficiency (given by the modulation order * target code rate R, that is the modulation order multiplied with the target code rate R) cannot be independently selected or adopted for different multi-stream MIMO rank, as this combination is hard coded through the MCS table.

[0066] Especially in the UL, the average (over the frequency domain of the resource allocation) channel quality of the different MIMO streams / layers can be very different with differences of up to 15dB between different UE antenna ports.

[0067] Most NR UEs on market use non-coherent UL MIMO with independent single antenna units with no synchronization between them, meaning that each MIMO layer is mapped to separate antenna port, using an MCS table that has been designed for the same average channel quality (over f-domain resource allocation) is clearly sub-optimal.

[0068] Short motivation for the solution described herein: For higher the MIMO transmission rank it would better to support for a certain spectral efficiency a higher modulation order combined with a lower coding rate in order to improve the detection reliability, as the lowercoding rate gives a better chance for the SCH decoder to recover the rather large channel quality differences of the different MIMO streams / layers of the same codeword.

[0069] Described herein is a method for the PUSCH / PDSCH link adaptation to support different modulation (and coding rate) adaptation for varying MIMO transmission ranks.

[0070] When looking at possible solutions, the following can be considered:

[0071] Alt. 1 – larger MCS table with more than one overlapping entry for the modulation switching point: Support for larger MCS tables, with larger ‘overlapping spectral efficiency areas’ for different modulation orders, enabling selection of different modulation order and code rate for the same spectral efficiency.

[0072] FIG. 4 shows an example of an MCS table with more than one overlapping entry for modulation switching from one modulation order to the next higher modulation order, which example MCS table is shown below, showing a modification of Table 5.1.3.1-1: Table 5.1.3.1-1: MCS index table 1 for PDSCH MCS Index Modulation Order Target code Rate R x [10 Spectral IMCS Qm 24] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 5A 4 190 0.7422 6 2 449 0.8770 6A 4 225 0.8789 7 2 526 1.0273 7A 4 263 1.0273 8 2 602 1.1758 8A 4 301 1.1758 9 2 679 1.3262 10 4 340 1.3281 11 4 378 1.4766 12 4 434 1.6953 ... ... ... ...

[0073] Referring to FIG.4, an example for additional entries is shown for the baseline 64QAM PDSCH table for the switching from QPSK to 16QAM. The additional table entries include entry 402 corresponding to the table row that includes MCS index 5A, entry 404 correspondingto the table row that includes MCS index 6A, entry 406 corresponding to the table row that includes MCS index 7A, and entry 408 corresponding to the table row that includes MCS index 8A. This increases the DCI overhead, as a larger MCS DCI field (e.g. 6bit) would need to be supported.

[0074] Distinguishing factors or properties from the legacy MCS table design include that for the MCS switching point from one modulation order to the next higher modulation order, more than one spectral efficiency value step is included for both modulation orders.

[0075] With reference to FIG.4, an overlapping spectral efficiency area 410 comprises spectral efficiencies 0.7402 and 0.7422. The overlapping spectral efficiency area 410 has overlapping spectral efficiencies at least because modulation order 2 corresponding to MCS index 5 multiplied with 1 plus target code rate (R x

[1024] ) of 379 corresponding to MCS index 5, or 380, is equal to 760, which is equal to modulation order 4 corresponding to MCS index 5A multiplied with target code rate (R x

[1024] ) of 190 corresponding to MCS index 5A. When spectral efficiencies (e.g. two or more) overlap within an overlapping spectral efficiency area, the spectral efficiencies within the overlapping spectral efficiency area are considered to be within the same spectral efficiency order.

[0076] Alt.2 – MIMO order specific MCS tables: For this case, different modulation order switching points depending on the MIMO rank / number of layers are used for link adaptation.

[0077] FIG.5 shows an example MCS index table 1 for rank=1, which MCS index table 1 for rank=1 is also shown below: MCS index table 1 for rank=1 (legacy table) MCS Index Modulation Order Spectra CS Qm Target code R l IM ate R x

[1024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.8770 7 2 526 1.0273 8 2 602 1.1758 9 2 679 1.326210 4 340 1.3281 11 4 378 1.4766 12 4 434 1.6953 ... ... ... ...

[0078] FIG.6 shows an example MCS index table 1A for rank=2, which MCS index table 1A for rank=2 is also shown below: MCS index table 1A for rank=2 MCS Index Modulation Order Target code Spectral IMCS Qm Rate R x

[1024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.8770 7 2 526 1.0273 8 2 602 1.1758 9 4 301 1.1758 9 2 679 1.3262 10 4 340 1.3281 11 4 378 1.4766 12 4 434 1.6953 ... ... ... ...

[0079] FIG.7 shows an example MCS index table 1B for rank=3, which example MCS index table 1B for rank=3 is also shown below: MCS index table 1B for rank=3 MCS Index Modulation Order Target code Rate R x [1 Spectral IMCS Qm 024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.8770 7 2 526 1.0273 8 4 263 1.0273 8 2 602 1.1758 9 4 301 1.1758 9 2 679 1.3262 10 4 340 1.328111 4 378 1.4766 12 4 434 1.6953 ... ... ... ...

[0080] FIG.8 shows an example MCS index table 1C for rank=4, which example MCS index table 1C for rank=4 is also shown below: MCS index table 1C for rank=4 MCS Index Modulation Order Tar Spectral IMCS Qm get code Rate R x

[1024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.3770 3 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.8770 7 4 225 0.8789 7 2 526 1.0273 8 4 263 1.0273 8 2 602 1.1758 9 4 301 1.1758 9 2 679 1.3262 10 4 340 1.3281 11 4 378 1.4766 12 4 434 1.6953 ... ... ... ...

[0081] FIG. 5, FIG. 6, FIG. 7 and FIG. 8 show examples for the case of table 5.1.3.1, where the modulation order switching points for increasing MIMO order are moved to lower spectral efficiencies. E.g. for rank=1, the legacy table is used (switching point with overlap 502 on MCS indexes 9 and 10 for the switch from QPSK to 16QAM at MCS index 10). For rank=2, the switching point is to happen at the spectral efficiency of MCS index 9 (switching point with overlap 602 on MCS indexes 8 and 9), for rank=3 at MCS index 8 (switching point with overlap 702 on MCS indexes 7 and 8), and rank=4 at MCS index 7 (switching point with overlap 802 on MCS indexes 6 and 7).

[0082] The changes on top of (or made to) the legacy table are shown within FIG. 6, FIG. 7, FIG. 8, and FIG. 9 as underlining and strikethrough, where text that is underlined refers to an addition, and text having strikethrough corresponds to a removal. For example, as shown in FIG. 6, the entry 610 with newly added MCS index 9 has a modulation order of 4, where the removedentry corresponding to MCS index 9 previously had a modulation order of 2 (item 612). Thereby, the total number of entries in the MCS table is not increased and this correspondingly does not increase the DCI overhead (i.e. the MCS DCI field size is not changed).

[0083] FIG.6 shows the overlap 602 of a spectral efficiency 1.1758 that corresponds to MCS index 8 and a spectral efficiency 1.1758 that corresponds to MCS index 9 (in Table 1A of FIG. 6, the switching point now corresponds to MCS index 9 rather than MCS index 10). FIG. 7 shows the overlap 702 of a spectral efficiency 1.0273 that corresponds to MCS index 7 and a spectral efficiency 1.0273 that corresponds to MCS index 8 (in Table 1B of FIG.7, the switching point now corresponds to MCS index 8 rather than MCS index 10). FIG. 8 shows the overlap 802 of a spectral efficiency 0.08770 that corresponds to MCS index 6 and a spectral efficiency 0.8789 that corresponds to MCS index 7 (in Table 1C of FIG. 8, the switching point now corresponds to MCS index 7 rather than MCS index 10).

[0084] In FIG. 5, FIG. 6, FIG. 7, and FIG.8, the spectral efficiency for an index is computed as the modulation order QMfor the index multiplied with the target code rate R divided by 1024. For example, in FIG. 5, for MCS index 0, the spectral efficiency is computed as 2 * 120 / 1024 = 0.2344 rounded to the nearest ten-thousandth.

[0085] There could be a fixed mapping of the multiple tables for certain transmission ranks (as given above), or alternatively, the applicable Tables 1, 1A, 1B and 1C could be associated to a transmission rank by gNB indication (RRC configuration or MAC CE).

[0086] In a signaling variant, gNB does not need to resort to predefined MCS tables. Instead, gNB could indicate preferred MCS switching points for different modulation orders, and both gNB and UE generate modified MCS table per rank according to predefined rules. Let’s denote modulation order column in a MCS table with Qm, Q’m, Q’’mand Q’’’mfor rank=1, 2, 3 and 4, correspondingly (or the association of a modulation column to a rank could be indicated by the gNB through RRC signaling, MAC and / or DCI signaling). For example, considering MCS table associated to rank 2, the gNB would e.g. indicate as the switching points X’={X’(1),X’(2),…X’(m),…X’(M-1)} for Q’mfor M supported modulation orders {q1, q2, ..., qM} (e.g. M=3 with {2,4,6} corresponding to {QPSK, 16QAM, 64QAM} for the MCS table Table 5.1.3.1-1), the modulation order Q’m(a) and the rate R’(a) for MCS index a would be given as: o Q’m(a) = q1 and R’(a)=R(a) for a=0...X’(1)-1,o For m=2...M, o E’(m)= X’(m)-1, E’(M)=L-M-1; % last MCS table entry E for m-th modulation order o Q’m(a) = qm for a=X’(m-1)…E’(m) o If qm*R(X(m-1)) = qm-1*R(X(m-1)-1) or qm-1*(R(X(m-1)-1)+1) % identify if overlapping entries for rank 1 (i.e. baseline) table for the switching point from modulation order qm-1to qmo R’(a) = ceil(R(a-1)*qm-1 / qm) for a=X’(m-1)… X(m-1)-1 %insert overlapping entry and spectral efficiency entries up to the switching point of the baseline table o R’(a)=R(a) for a=X(m-1)… E’(m), % insert same entries as for baseline table for MCS indexes being the same or larger than the switching point of the baseline table o otherwise o R’(a)= ceil(R(a)* Q’m(a) / Qm(a)) for a=X’(m-1)....E’(m)

[0087] Distinguishing factors and / or properties from legacy MCS table operation include: Different MCS table applicable for different transmission ranks, and the tables for different transmission ranks differ at least, that the switching point from one modulation order to the next higher one for higher transmission ranks is at the same or lower spectral efficiency values when compared to lower transmission ranks. Furthermore, for a switching point from one modulation order to the next, at least one spectral efficiency value step for both modulation orders may be included.

[0088] Alt.3 – Rank dependent modulation order override: For this case, the legacy MCS is used to define the transport block size (TBS), but the modulation order given in the MCS table would not be applicable for higher transmission ranks / larger number of layers.

[0089] The UE would apply the MCS table together with the MCS index to determine the TBS (as in case of legacy), but when determining the modulation for transmission, a different (modified) modulation can be applied. The modified modulation order is also used to determine the number of coded bits after rate matching for the CW / transport block (TB).

[0090] An example is shown below for the modulation order columns Qm, Q’m, Q’’mand Q’’m again for the MCS entries of the legacy MCS table for 64QAM (with same range as for Alt. 1 and Alt.2)

[0091] The applicable modulation order columns of Qm, Q’m, Q’’mand Q’’’mcould be directly associated with rank=1, 2, 3 and 4, respectively – or the association to ranks could be indicated by the gNB (through RRC signaling, MAC and / or DCI signaling).

[0092] Alternatively, the mapping from Qm to Q’m (for rank=2), Q’’m (for rank=3) and Q’’’m (for rank=4) (i.e. the mapping table below) could be defined by RRC configuration (or MAC CE, DCI signaling). Either the overall table columns for Q’m, Q’’m and Q’’’m are configurable or alternatively, the gNB could just indicate the MCS index / entry for which the change to a higher modulation order would be done. If the gNB would for the example of rank=2 e.g. indicate as the switching points for Q’m{X’(1),X’(2), X’(M-1)} for M supported modulation orders {q1, q2, ..., qM} (e.g. M=3 with {q1, q2, q3}={2,4,6} corresponding to {QPSK, 16QAM, 64QAM} for the MCS table Table 5.1.3.1-1), the modulation order Q’m(a) for MCS index a for rank=2 would be given as: • Q’m(a)=q1 for a=0...X’(1)-1, • Q’m(a) = qm for a=X’(m-1)…X’(m)-1 and m=2...M-1 • Q’m(a)=qMfor a=X’(M-1)...last non reserved MCS entry (26, 27, 28 or 29), • Q’m(L-M+m-1)=qm for m=1..M % this keeps the same modulation order for the last reserved entries • where X’(m) is the modulation switching points for the consecutive modulation orders from modulation order qm to qm+1., i.e. the first MCS index with modulation order qm+1. Note: the last non-reserved entry for the modulation table is usually given by the L-M-1, where L is the size of the MCS table (e.g. L=32 for the 5-bits NR tables)

[0093] FIG. 9 shows an example modulation order mapping, where underlining shows a change to a modulation order and / or to a switching point from the table for rank = 1. The modulation order mapping shown in FIG.9 is also shown below. Modulation order mapping MCS Modulation Modulation Modulation Modulation Index Order Order Order Order IMCS Qm Q’m Q’’m Q’’’m 0 2 2 2 2 1 2 2 2 2 2 2 2 2 23 2 2 2 2 4 2 2 2 2 5 2 2 2 2 6 2 2 2 4 7 2 2 4 4 8 2 4 4 4

[0094] For the 9 2 4 4 4 example table 10 4 4 4 4 shown in 11 4 4 4 4 FIG. 9, 12 4 4 4 4 for the switch ... ... ... ... ... from QPSK to 16QAM the gNB would indicate (MCS entry) X’(1)={8} for Q’m, X’’(1)={7} for Q’’mand X’’’(1)={6} for Q’’’m.

[0095] This alternative does not increase the DCI overhead (i.e. MCS table size is not changed and the MCS DCI field size stays unchanged).

[0096] One (small) drawback of this operation compared to Alt.1 and 2 is, that ‘overlapping’ MCS entries with same or similar spectral efficiencies but with different modulation order are lost, as the modulation order switching point is moved but the spectral efficiencies are not correspondingly shifted (e.g. for entries 9 and 10 for the 64QAM table).

[0097] Distinguishing factors / properties from legacy MCS table operation include (1-3): 1) The MCS table is only used for TB size determination at least for more than one transmission layer, 2) The modulation order for the SCH transmission (including related rate-matching determination) is not defined by the MCS table itself but based on an additional table or signaling linking the MCS index to the applied modulation order at least for more than one transmission layer, 3) The properties of the modulation order table (or modulation order mapping such as the mapping shown in FIG. 9) include, that for a certain MCS index and / or spectral efficiency, the modulation order for a higher transmission rank is the same or higher compared to a lower transmission rank.

[0098] In the herein described embodiments, the rank refers to the number of layers used for transmission of single TB / CW. As used herein, “number of transmission layer” refers to the number of one or more transmission layers used to transmit a single CW / TB.

[0099] An example signaling flow-chart for PDSCH / DL-SCH operation for Alt. 2 is shown in FIG.10. The signaling exchanges shown in FIG.10 is between BS 170 and UE 110.

[0100] The example of Alt.2 for PDSCH operation has the following logical steps:

[0101] In step 1, the gNB determines the PDSCH transmission rank specific MCS-table. In case there is a fixed association from rank to the applicable MCS table, the gNB determines the association from the specification. Otherwise, in case the MCS table to apply can be chosen by the gNB, the gNB may determine the MCS table for PDSCH for higher transmission ranks (i.e. rank 2 to 4, note that although modified MCS tables or MCSs are provided in this and following examples from rank2 to rank4, in general the modified MCS tables or MCSs may be provided to any set of ranks above 1 e.g. only for rank2) for a PDSCH transmission. This may include to choose one from a set of fixed MCS tables (e.g. tables 1, 1B, 1C, 1D as discussed previously). This may alternatively for Alt.2A (where Alt.2A is an alternative to Alt.2) include to indicate modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M-1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1)} defining the MCS table for higher ranks based on the baseline (rank=1) MCS table with the modulation switching points given by X={X(1),X(2), X(M-1)}. The MCS table is the defined on the relation between the switching points. One example of a possible implementation with (a) retains the exact modulation order overlap for the same spectral efficiency has been presented previously.

[0102] In step 2, the gNB indicates the MCS table for the higher transmission ranks to the UE. This step is only needed, if there is not a direct association of fixed MCS tables for different transmission ranks to the MCS table. The signaling may involve indicating (a) the applicable table (from the set of fixed defined tables, e.g. Table 1, 1A, 1B, 1C for rank=2, 3 and 4), (b) signaling the modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M- 1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1)} for Alt. 2A. The signaling may be done by RRC, MAC CE and / or DCI / PHY signaling.

[0103] In step 3, the gNB constructs a PDSCH for transmission to the UE, where the applicable MCS is based on the MCS table associated with the chosen transmission rank of the PDSCH TB.

[0104] In step 4, the gNB transmits the PDSCH to the UE.

[0105] In step 5, the UE determines the MCS based on the MCS table associated to the transmission rank / number of layers of the PDSCH TB and indicated MCS index. The determination of the MCS table may be implicitly given by the specification (in case of fixed association) or depending on the received signaling in step 2. For the Alt.2A, the UE determines the MCS for the MCS index of the PDSCH based on the rank specific modulation orderswitching points as described previously.

[0106] In step 6, the UE decodes the PDSCH based on the MCS determined in step 5.

[0107] An example signaling flow-chart for the equivalent PUSCH operation for Alt. 2 is shown in FIG. 11. The signaling exchange shown in FIG. 11 is between the BS 170 and UE 110. The example of Alt.2 for PUSCH operation as shown in FIG.11 has the following logical steps:

[0108] In step 1, the gNB determines the PUSCH transmission rank specific MCS-table. In case there is a fixed association from rank to the applicable MCS table, the gNB determines the association from the specification. Otherwise, in case the MCS table to apply can be chosen by the gNB, the gNB may determine the MCS table for PUSCH for higher transmission ranks (i.e. rank 2 to 4) for a PUSCH transmission. This may include to choose one from a set of fixed MCS tables (e.g. tables 1, 1B, 1C, 1D as discussed previously). This may alternatively for Alt. 2A include to indicate modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M-1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1)} defining the MCS table for higher ranks based on the baseline (rank=1) MCS table with the modulation switching points given by X={X(1),X(2), X(M-1)}. The MCS table is the defined on the relation between the switching points. One example of a possible implementation with (a) retains the exact modulation order overlap for the same spectral efficiency has been presented herein.

[0109] In step 2, the gNB indicates the MCS table for the higher transmission ranks to the UE. This step is only needed, if there is not a direct association of fixed MCS tables for different transmission ranks to the MCS table. The signaling may involve indicating (a) the applicable table (from the set of fixed defined tables, e.g. Table 1, 1A, 1B, 1C for rank=2, 3 and 4), (b) signaling the modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M- 1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1)} for Alt. 2A. The signaling may be done by RRC, MAC CE and / or DCI / PHY signaling.

[0110] In step 3, the gNB indicates PUSCH scheduling grant, comprising PUSCH transmission rank and MCS index, to UE.

[0111] In step 4, the UE determines the MCS based on the MCS table associated to the transmission rank / number of layers of the PUSCH TB and indicated MCS index. The determination of the MCS table may be implicitly given by the specification (in case of fixedassociation) or depending on the received signaling in step 2. For the Alt.2A, the UE determines the MCS for the MCS index of the PUSCH based on the rank specific modulation order switching points as described previously.

[0112] In step 5, the UE constructs a PUSCH for transmission to the gNB based on the MCS determined in step 4.

[0113] In step 6, the UE transmits the PUSCH to the gNB.

[0114] In step 7, the gNB decodes the PUSCH based on the MCS indicated in step 3.

[0115] Alt.3 – Rank dependent modulation order override:

[0116] A signaling flow-chart for PDSCH operation for Alt. 3 is shown in FIG. 12. In FIG. 12, the signaling exchange is between the BS 170 and UE 110. The example of Alt.3 for PDSCH operation as shown in FIG.12 has the following logical steps:

[0117] In step 1, the gNB determines for PDSCH transmission rank specific modulation order switching points. In case there is a fixed table of rank specific modulation orders, the gNB determines the rank specific modulation order from the specification. Otherwise, this includes selecting a lower modulation order for certain MCS indexes for higher ranks as for lower transmission ranks of a PDSCH TB.

[0118] In step 2, the gNB indicates the rank-specific modulation switching points to the UE. This step is only needed, if there is not a fixed table of rank specific modulation orders. The signaling may involve indicating the modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M-1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1) }. The signaling may be done using RRC, MAC and / or DCI / PHY signaling.

[0119] In step 3, the gNB constructs a PDSCH for transmission to the UE. This includes determining the transport block size using the MCS of the MCS index value of the MCS table for PDSCH. The gNB determines the modulation order based on the applicable MCS index and the transmission rank together with the transmission rank specific modulation order switching point (details discussed for Alt. 3 previously). This further includes performing PDSCH modulation, rate-matching and resource element mapping based on the newly determined modulation order (which may be higher compared to the modulation order of the MCS index in the MCS table for higher rank transmissions).

[0120] In step 4, the gNB transmits the PDSCH to the UE.

[0121] In step 5, the UE determines the applicable modulation order based on transmission rank / number of layers of the PDSCH TB together with the transmission rank specific modulation order switching point and the MCS index value.

[0122] In step 6, the UE decodes the PDSCH based on the applicable PDSCH modulation order determined in step 5. This includes determining the transport block size using the MCS (modulation and coding rate) of the MCS index value of the MCS table for PDSCH. This includes using the determined modulation order of step 5, to perform RE de-mapping and modulation de-mapping to perform the TB decoding.

[0123] A signaling flow-chart for PUSCH operation for Alt. 3 is shown in FIG. 13. In FIG. 13, the signaling exchange is between the BS 170 and UE 110. The example of Alt.3 for PUSCH operation has the following logical steps:

[0124] In step 1, the gNB determines for PUSCH transmission rank specific modulation order switching points. In case there is a fixed table of rank specific modulation orders, the gNB determines the rank specific modulation order for an MCS index from the specification. Otherwise, this includes selecting a lower modulation order for certain MCS indexes for higher ranks as for lower transmission ranks of a PUSCH TB.

[0125] In step 2, the gNB indicates the rank-specific modulation order switching points to the UE. This step is only needed, if there is not a fixed table of rank specific modulation orders. The signaling may involve indicating the modulation switching points sets for rank2 to rank 4, i.e. X’={X’(1),X’(2), X’(M-1)}, X’’={X’’(1),X’’(2), X’’(M-1)} and X’’’={X’’’(1),X’’’(2), X’’’(M-1)}. The signaling may be done using RRC, MAC and / or DCI / PHY signaling.

[0126] In step 3, the gNB indicates PUSCH scheduling grant, comprising PUSCH transmission rank and MCS index, to UE.

[0127] In step 4, the UE determines the applicable modulation order based on transmission rank / number of layers of the PUSCH TB and the MCS index value of step 3. The UE determines the new, applicable modulation order based on the MCS index value and the transmission rank together with the transmission rank specific modulation switching point (details discussed for Alt.3 previously).

[0128] In step 5, the UE constructs a PUSCH for transmission to the gNB. This includes determining the transport block size using the MCS of the MCS index value of the MCS table for PUSCH. This further includes performing PUSCH modulation, rate-matching and resource element mapping based on the newly determined modulation order of step 4 (which may be higher compared to the modulation order of the MCS index in the MCS table for PUSCH for higher rank transmissions).

[0129] In step 6, the UE transmits the PUSCH to the gNB

[0130] In step 7, the gNB decodes the PUSCH based on the applicable rank-specific PUSCH modulation order. This includes determining the transport block size using the MCS (modulation and coding rate) of the MCS index value signaled in step 3 of the MCS table for PUSCH. The gNB determines the new applicable modulation order based on transmission rank / number of layers of the PUSCH TB and the MCS index value of step 3 (details discussed for Alt. 3, similarly as the UE in step 4). This includes using the determined modulation order, to perform RE de-mapping and modulation de-mapping to perform the PUSCH TB decoding.

[0131] In the previous examples, before step 1, the gNB or network may decide to use transmission rank specific MCS tables or modulation orders based on UE capability or measurements indicating significant imbalance between antenna ports or received MIMO layers.

[0132] For the examples described herein, there could be for example just 2 or 3 MCS tables defined for {1…4} layers (with one table being associated with more than one number of layers – for example 1 table for rank / layer=1, 1 table for rank / layer=2 and 1 table for rank / layer= 3 or 4). Similarly, there could be just 2 or 3 columns in the modulation order table defined for {1…4} layers (with one column being associated with more than one number of layers – for example 1 column for rank / layer=1, 1 column for rank / layer=2 and 1 column for rank / layer= 3 or 4).

[0133] In one embodiment, for DL the gNB transmits one set of switching points for a table corresponding to a number of one or more layers used for the transmission of the DL data, for example one of X’, or X’’, or X’’’, and not all of them. In another embodiment, in the UL case, the gNB transmits all of the switching points for all the tables corresponding to rank 2 or larger (each of X’, X’’, X’’’…) and then the UE derives a table corresponding to the number of transmission layer selected for the transmission of UL data.

[0134] Advantages and technical effects of the examples described herein include betteradaptability of modulation and spectral efficiency for multi-stream MIMO (rank>1) transmission of a single PDSCH or PUSCH transport block.

[0135] The herein described mechanisms improve 3GPP functionalities or communication functionalities in general. The examples described herein may be part of 3GPP specifications or communications specifications.

[0136] FIG. 14 is an example apparatus 1400, which may be implemented in hardware, configured to implement the examples described herein. The apparatus 1400 comprises at least one processor 1402 (e.g. an FPGA and / or CPU), one or more memories 1404 including computer program code 1405, the computer program code 1405 having instructions to carry out the methods described herein, wherein the at least one memory 1404 and the computer program code 1405 are configured to, with the at least one processor 1402, cause the apparatus 1400 to implement circuitry, a process, component, module, or function (implemented with control module 1406) to implement the examples described herein. The one or more memories 1404 may include a non-transitory memory, a transitory memory, a volatile memory (e.g. RAM), or a non-volatile memory (e.g. ROM).

[0137] Modulation order adaptation for MIMO 1430 implements the examples described herein.

[0138] The apparatus 1400 includes a display and / or I / O interface 1408, which includes user interface (UI) circuitry and elements, that may be used to display aspects or a status of the methods described herein (e.g., as one of the methods is being performed or at a subsequent time), or to receive input from a user such as with using a keypad, camera, touchscreen, touch area, microphone, biometric recognition, one or more sensors, etc. The apparatus 1400 includes one or more communication e.g. network (N / W) interfaces (I / F(s)) 1410. The communication I / F(s) 1410 may be wired and / or wireless and communicate over the Internet / other network(s) via any communication technique including via one or more links 1424. The link(s) 1424 may be the link(s) 131 and / or 176 from FIG.1. The link(s) 131 and / or 176 from FIG.1 may also be implemented using transceiver(s) 1416 and corresponding wireless link(s) 1426. The communication I / F(s) 1410 may comprise one or more transmitters or one or more receivers.

[0139] The transceiver 1416 comprises one or more transmitters 1418 and one or more receivers 1420. The transceiver 1416 and / or communication I / F(s) 1410 may comprise standard well-known components such as an amplifier, filter, frequency-converter, (de)modulator, andencoder / decoder circuitries and one or more antennas, such as antennas 1414 used for communication over wireless link 1426.

[0140] The control module 1406 of the apparatus 1400 comprises one of or both parts 1406-1 and / or 1406-2, which may be implemented in a number of ways. The control module 1406 may be implemented in hardware as control module 1406-1, such as being implemented as part of the one or more processors 1402. The control module 1406-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module 1406 may be implemented as control module 1406-2, which is implemented as computer program code (having corresponding instructions) 1405 and is executed by the one or more processors 1402. For instance, the one or more memories 1404 store instructions that, when executed by the one or more processors 1402, cause the apparatus 1400 to perform one or more of the operations as described herein. Furthermore, the one or more processors 1402, the one or more memories 1404, and example algorithms (e.g., as flowcharts and / or signaling diagrams), encoded as instructions, programs, or code, are means for causing performance of the operations described herein.

[0141] The apparatus 1400 to implement the functionality of control 1406 may be UE 110, RAN node 170 (e.g. a gNB or base station), or one or more network element(s) 190 (e.g. LMF 190). Thus, processor 1402 may correspond to processor(s) 120, processor(s) 152 and / or processor(s) 175, memory 1404 may correspond to one or more memories 125, one or more memories 155 and / or one or more memories 171, computer program code 1405 may correspond to computer program code 123, computer program code 153, and / or computer program code 173, control module 1406 may correspond to module 140-1, module 140-2, module 150-1, and / or module 150-2, and communication I / F(s) 1410 and / or transceiver 1416 may correspond to transceiver 130, antenna(s) 128, transceiver 160, antenna(s) 158, N / W I / F(s) 161, and / or N / W I / F(s) 180. Alternatively, apparatus 1400 and its elements may not correspond to either of UE 110, RAN node 170, or network element(s) 190 and their respective elements, as apparatus 1400 may be part of a self-organizing / optimizing network (SON) node or other node, such as a node in a cloud.

[0142] The apparatus 1400 may also be distributed throughout the network (e.g.100) including within and between apparatus 1400 and any network element (such as a network control element (NCE) 190 and / or the RAN node 170 and / or UE 110).

[0143] Interface 1412 enables data communication and signaling between the various items of apparatus 1400, as shown in FIG.14. For example, the interface 1412 may be one or more buses such as address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. Computer program code (e.g. instructions) 1405, including control 1406 may comprise object-oriented software configured to pass data or messages between objects within computer program code 1405, or computer program code (e.g. instructions) 1405, including control 1406 may include functional, scripting, or procedural code. The apparatus 1400 need not comprise each of the features mentioned, or may comprise other features as well. The various components of apparatus 1400 may at least partially reside in a common housing 1428, or a subset of the various components of apparatus 1400 may at least partially be located in different housings, which different housings may include housing 1428.

[0144] FIG. 15 shows a schematic representation of non-volatile memory media 1500a (e.g. computer / compact disc (CD) or digital versatile disc (DVD)) and 1500b (e.g. universal serial bus (USB) memory stick) and 1500c (e.g. cloud storage for downloading instructions and / or parameters 1502 or receiving emailed instructions and / or parameters 1502) storing instructions and / or parameters 1502 which when executed by a processor allows the processor to perform one or more of the steps of the methods described herein. Instructions and / or parameters 1502 may represent a computer readable medium.

[0145] FIG.16 is an example method 1600 based on the examples described herein. At 1610, the method includes determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data. At 1620, the method includes transmitting, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS. Method 1600 may be performed with RAN node 170 or apparatus 1400.

[0146] FIG.17 is an example method 1700 based on the examples described herein. At 1710, the method includes receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer. At 1720, the method includes determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data. At 1730, the method includes demodulating and decoding the downlink data based on the determined MCS. Method 1700 may be performed with UE 110 or apparatus 1400.

[0147] FIG.18 is an example method 1800 based on the examples described herein. At 1810, the method includes determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of uplink data. At 1820, the method includes transmitting, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS. Method 1800 may be implemented with UE 110 or apparatus 1400.

[0148] FIG.19 is an example method 1900 based on the examples described herein. At 1910, the method includes receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer. At 1920, the method includes determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data. At 1930, the method includes demodulating and decoding the uplink data with the number of at least one transmission layer, based on the determined MCS. Method 1900 may be performed with RAN node 170 or apparatus 1400.

[0149] FIG.20 is an example method 2000 based on the examples described herein. At 2010, the method includes determining a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission. At 2020, the method includes determining a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission. At 2030, the method includes transmitting, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size. Method 2000 may be performed with RAN node 170 or apparatus 1400.

[0150] FIG.21 is an example method 2100 based on the examples described herein. At 2110, the method includes receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer. At 2120, the method includes determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission. At 2130, the method includes determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission. At 2140, the method includes demodulating and decoding the downlink data, based on the modulation order and the transport block size. Method 2100 may be implemented with UE 110 or apparatus 1400.

[0151] FIG.22 is an example method 2200 based on the examples described herein. At 2210, the method includes determining a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission. At 2220, the method includes determining a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission. At 2230, the method includes transmitting, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size. Method 2200 may be implemented with UE 110 or apparatus 1400.

[0152] FIG.23 is an example method 2300 based on the examples described herein. At 2310, the method includes receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer. At 2320, the method includes determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission. At 2330, the method includes determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission. At 2340, the method includes demodulating and decoding the uplink data, based on the modulation order and the transport block size. Method 2300 may be performed with RAN node 170 or apparatus 1400.

[0153] The following examples are provided and described herein.

[0154] Example 1. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

[0155] Example 2. The apparatus of example 1, wherein the determining the MCS comprises selecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

[0156] Example 3. The apparatus of example 2, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmissionlayer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiency corresponding to a modulation switching point of the second table.

[0157] Example 4. The apparatus of example 3, wherein the apparatus is further caused to: determine another MCS selected from the first table for another transmission of other downlink data, based on: the spectral efficiency corresponding to the modulation switching point of the first table, and one of the at least one number of at least one transmission layer associated with the first table; wherein the MCS determined based on the spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data is selected from the second table, wherein the spectral efficiency used to determine the MCS corresponds to the spectral efficiency corresponding to the modulation switching point of the second table, and wherein the number of at least one transmission layer selected for the transmission of the downlink data corresponds to one of the at least one number of at least one transmission layer associated with the second table; and transmit, to the user equipment, the other downlink data with the one of the at least one number of at least one transmission layer associated with the first table using the determined another MCS.

[0158] Example 5. The apparatus of any of examples 2 to 4, wherein the apparatus is further caused to: configure the user equipment with the plurality of MCS tables using at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0159] Example 6. The apparatus of example 5, wherein an MCS table configuration that depends on a number of at least one transmission layer is based on a capability of the user equipment.

[0160] Example 7. The apparatus of any of examples 2 to 6, wherein the apparatus is further caused to: transmit, to the user equipment, the number of at least one transmission layer, wherein the plurality of MCS tables is preconfigured at the user equipment.

[0161] Example 8. The apparatus of any of examples 1 to 7, wherein the apparatus is further caused to: transmit, to the user equipment, an MCS index indicating an entry in an MCS table which is associated with the number of at least one transmission layer.

[0162] Example 9. The apparatus of any of examples 1 to 8, wherein the apparatus is further caused to: construct a physical downlink shared channel (PDSCH) for the transmission of the downlink data with the number of at least one transmission layer, based on the determined MCS.

[0163] Example 10. The apparatus of any of examples 1 to 9, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate different modulation orders in an alternative manner.

[0164] Example 11. The apparatus of example 10, wherein the MCS selected for the transmission of the downlink data for the number of at least one transmission layer has a higher or equal modulation order than the MCS selected for the transmission of the downlink data for another number of at least one transmission layer for a spectral efficiency order, wherein the number of at least one transmission layer is higher than the another number of at least one transmission layer.

[0165] Example 12. The apparatus of any of examples 1 to 11, wherein the apparatus is further caused to: determine another MCS different from the MCS for another transmission of other downlink data, based on another spectral efficiency and another number of at least one transmission layer selected for the another transmission of the other downlink data; wherein the another number of at least one transmission layer is higher than the number of at least one transmission layer, and the another spectral efficiency is lower than the spectral efficiency; and transmit, to the user equipment, the other downlink data with the another number of at least one transmission layer using the determined another MCS.

[0166] Example 13. The apparatus of any of examples 1 to 12, wherein there is a reference table for a transmission associated with one transmission layer, and MCS tables associated with at least one number of a plurality of transmission layers are indicated to the user equipment by indicating modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers.

[0167] Example 14. The apparatus of example 13, wherein a spectral efficiency corresponding to each switching point of the MCS tables associated with at least one number of a plurality of switching points decreases with an increasing number of transmission layers.

[0168] Example 15. An apparatus including: at least one processor; and at least one memorystoring instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determine a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulate and decode the downlink data based on the determined MCS.

[0169] Example 16. The apparatus of example 15, wherein the determining the MCS comprises selecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

[0170] Example 17. The apparatus of example 16, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmission layer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiency corresponding to a modulation switching point of the second table.

[0171] Example 18. The apparatus of example 17, wherein the apparatus is further caused to: receive, from the network entity, another transmission of other downlink data with one of the at least one number of at least one transmission layer associated with the first table; determine another MCS selected from the first table, based on: the spectral efficiency corresponding to the modulation switching point of the first table, and the one of the at least one number of at least one transmission layer associated with the first table; and demodulate and decode the other downlink data based on the determined another MCS; wherein the MCS determined based on the spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data is selected from the second table, wherein the spectral efficiency used to determine the MCS corresponds to the spectral efficiency corresponding to the modulation switching point of the second table, and wherein the number of at least one transmission layer with which the downlink data is received corresponds to one of the at least one number of at least one transmission layer associated with the second table.

[0172] Example 19. The apparatus of any of examples 16 to 18, wherein the apparatus is further caused to: receive, from the network entity, a configuration comprising information related to the plurality of MCS tables; wherein the configuration comprising the information related to theplurality of MCS tables is received from the network entity with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0173] Example 20. The apparatus of example 19, wherein an MCS table configuration that depends on a number of at least one transmission layer is based on a capability of the apparatus.

[0174] Example 21. The apparatus of any of examples 16 to 20, wherein the apparatus is further caused to: receive, from the network entity, the number of at least one transmission layer, wherein the plurality of MCS tables is preconfigured at the apparatus.

[0175] Example 22. The apparatus of any of examples 15 to 21, wherein the apparatus is further caused to: receive, from the network entity, an MCS index indicating an entry in an MCS table which is associated with the number of at last one transmission layer; wherein the MCS and the spectral efficiency used to demodulate and decode the downlink data with the number of at least one transmission layer are determined from the entry in the MCS table indicated with the MCS index received from the network entity.

[0176] Example 23. The apparatus of any of examples 15 to 22, wherein the downlink data is received in a physical downlink shared channel (PDSCH).

[0177] Example 24. The apparatus of any of examples 15 to 23, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate different modulation orders in an alternative manner.

[0178] Example 25. The apparatus of example 24, wherein the MCS selected for the demodulating and decoding the downlink data with the number of at least one transmission layer has a higher or equal modulation order than the MCS selected for the demodulating and decoding the downlink data with another number of at least one transmission layer for a spectral efficiency order, wherein the number of at least one transmission layer is higher than the another number of at least one transmission layer.

[0179] Example 26. The apparatus of any of examples 15 to 25, wherein the apparatus is further caused to: receive, from the network entity, another transmission of other downlink data with another number of the at least one transmission layer; determine another MCS different from theMCS, based on another spectral efficiency and the another number of at least one transmission layer used for the another transmission of the other downlink data; and demodulate and decode the other downlink data with the another number of at least one transmission layer, based on the determined another MCS; wherein the another number of at least one transmission layer is higher than the number of at least one transmission layer, and the another spectral efficiency is lower than the spectral efficiency.

[0180] Example 27. The apparatus of any of examples 15 to 26, wherein the apparatus is further caused to: receive, from the network entity, an indication of MCS tables associated with at least one number of a plurality of transmission layers, wherein the indication of the MCS tables associated with at least one number of a plurality of transmission layers comprises an indication of modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers; and derive one MCS table associated with at least one number of a plurality of transmission layers from: a reference table for a transmission associated with one transmission layer, and a set of modulation switching points for the one MCS table associated with at least one number of a plurality of transmission layers; wherein the set of modulation switching points for the one MCS table associated with at least one number of a plurality of transmission layers is among the modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers received within the indication from the network entity; wherein the MCS used to demodulate and decode the downlink data is selected from the derived one MCS table associated with at least one number of a plurality of transmission layers.

[0181] Example 28. The apparatus of example 27, wherein a spectral efficiency corresponding to each switching point for the MCS tables associated with at least one number a plurality of transmission layers decreases with an increasing number of transmission layers.

[0182] Example 29. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of uplink data; and transmit, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS.

[0183] Example 30. The apparatus of example 29, wherein the determining the MCS comprisesselecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

[0184] Example 31. The apparatus of example 30, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmission layer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiency corresponding to a modulation switching point of the second table.

[0185] Example 32. The apparatus of example 31, wherein the apparatus is further caused to: determine another MCS selected from the first table for another transmission of other uplink data, based on: the spectral efficiency corresponding to the modulation switching point of the first table, and one of the at least one number of at least one transmission layer associated with the first table; wherein the MCS determined based on the spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data is selected from the second table, wherein the spectral efficiency used to determine the MCS corresponds to the spectral efficiency corresponding to the modulation switching point of the second table, and wherein the number of at least one transmission layer selected for the transmission of the uplink data corresponds to one of the at least one number of at least one transmission layer associated with the second table; and transmit, to the network entity, the other uplink data with the one of the at least one number of at least one transmission layer associated with the first table using the determined another MCS.

[0186] Example 33. The apparatus of any of examples 30 to 32, wherein the apparatus is further caused to: receive, from the network entity, a configuration comprising information related to the plurality of MCS tables with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0187] Example 34. The apparatus of any of examples 30 to 33, wherein the apparatus is further caused to: receive, from the network entity, the number of at least one transmission layer, wherein the plurality of MCS tables is preconfigured at the apparatus.

[0188] Example 35. The apparatus of any of examples 29 to 34, wherein the apparatus is further caused to: receive, from the network entity, an MCS index indicating an entry in an MCS tablewhich is associated with the number of at least one transmission layer; wherein the MCS used for the transmission of the uplink data with the number of at least one transmission layer is determined from the entry in the MCS table indicated with the MCS index.

[0189] Example 36. The apparatus of any of examples 29 to 35, wherein the apparatus is further caused to: construct a physical uplink shared channel (PDSCH) for the transmission of the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0190] Example 37. The apparatus of any of examples 29 to 36, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate different modulation orders in an alternative manner.

[0191] Example 38. The apparatus of example 37, wherein the MCS selected for the transmission of the uplink data for the number of at least one transmission layer has a higher or equal modulation order than the MCS selected for the transmission of the uplink data for another number of at least one transmission layer for a spectral efficiency order, wherein the number of at least one transmission layer is higher than the another number of at least one transmission layer.

[0192] Example 39. The apparatus of any of examples 29 to 38, wherein the apparatus is further caused to: determine another MCS different from the MCS for another transmission of other uplink data, based on another spectral efficiency and another number of at least one transmission layer selected for the another transmission of the other uplink data; wherein the another number of at least one transmission layer is higher than the number of at least one transmission layer, and the another spectral efficiency is lower than the spectral efficiency; and transmit, to the network entity, the other uplink data with the another number of at least one transmission layer using the determined another MCS.

[0193] Example 40. The apparatus of any of examples 29 to 39, wherein the apparatus is further caused to: receive, from the network entity, an indication of MCS tables associated with at least one number of a plurality of transmission layers, wherein the indication of the MCS tables associated with at least one number of a plurality of transmission layers is comprises an indication of modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers; and derive one MCS table associated with at least one number of a plurality of transmission layers from a reference table for a transmission associatedwith one transmission layer, from the modulation switching points for the one MCS table associated with at least one number of plurality of transmission layers; wherein the set of modulation switching points for the one MCS table associated with at least one number of a plurality of transmission layers is among the modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers received within the indication from the network entity; wherein the MCS determined for the transmission of the uplink data with the number of at least one transmission layer is selected from the derived one MCS table associated with at least one number of a plurality of transmission layers.

[0194] Example 41. The apparatus of example 40, wherein a spectral efficiency corresponding to each switching point of the MCS tables associated with at least one number of a plurality of switching points decreases with an increasing number of transmission layers.

[0195] Example 42. The apparatus of any of examples 29 to 41, wherein an MCS table configuration that depends on a number of at least one transmission layer is based on a capability of the apparatus.

[0196] Example 43. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a user equipment, a transmission of uplink data with a number of at least one transmission layer and with a channel; determine a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data; and decode and demodulate the channel used for the transmission of the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0197] Example 44. The apparatus of example 43, wherein the determining the MCS comprises selecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

[0198] Example 45. The apparatus of example 44, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmission layer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiencycorresponding to a modulation switching point of the second table.

[0199] Example 46. The apparatus of example 45, wherein the apparatus is further caused to: receive, from the user equipment, another transmission of other uplink data with one of the at least one number of at least one transmission layer associated with the first table and with the channel; determine another MCS selected from the first table, based on: the spectral efficiency corresponding to the modulation switching point of the first table, and the one of the at least one number of at least one transmission layer associated with the first table; and decode and demodulate the channel used for the transmission of the other uplink data, based on the determined another MCS; wherein the MCS determined based on the spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data is selected from the second table, wherein the spectral efficiency used to determine the MCS corresponds to the spectral efficiency corresponding to the modulation switching point of the second table, and wherein the number of at least one transmission layer with which the uplink data is received corresponds to one of the at least one number of at least one transmission layer associated with the second table.

[0200] Example 47. The apparatus of any of examples 44 to 46, wherein the apparatus is further caused to: configure the user equipment with the plurality of MCS tables using at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0201] Example 48. The apparatus of any of examples 44 to 47, wherein the apparatus is further caused to: transmit, to the user equipment, the number of at least one transmission layer, wherein the plurality of MCS tables is preconfigured at the user equipment.

[0202] Example 49. The apparatus of any of examples 43 to 48, wherein the apparatus is further caused to: transmit, to the user equipment, an MCS index indicating an entry in an MCS table which is associated with the number of at least one transmission layer.

[0203] Example 50. The apparatus of any of examples 43 to 49, wherein the channel with which the uplink data is received comprises a physical uplink shared channel (PUSCH).

[0204] Example 51. The apparatus of any of examples 43 to 50, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate differentmodulation orders in an alternative manner.

[0205] Example 52. The apparatus of example 51, wherein the MCS selected for the decoding and demodulating of the channel used for the transmission of the uplink data with the number of at least one transmission layer has a higher or equal modulation order than the MCS selected for the decoding and demodulating of the channel used for the transmission of the uplink data with another number of at least one transmission layer for a spectral efficiency order, wherein the number of at least one transmission layer is higher than the another number of at least one transmission layer.

[0206] Example 53. The apparatus of any of examples 43 to 52, wherein the apparatus is further caused to: receive, from the user equipment, another transmission of other uplink data with another number of the at least one transmission layer; determine another MCS different from the MCS, based on another spectral efficiency and the another number of at least one transmission layer used for the another transmission of the other uplink data; decode and demodulate the channel used for the transmission of the other uplink data with the another number of at least one transmission layer, based on the determined another MCS; wherein the another number of at least one transmission layer is higher than the number of at least one transmission layer, and the another spectral efficiency is lower than the spectral efficiency.

[0207] Example 54. The apparatus of any of examples 43 to 53, wherein there is a reference table for a transmission associated with one transmission layer, and MCS tables associated with at least one number of a plurality of transmission layers are indicated to the user equipment by indicating modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers.

[0208] Example 55. The apparatus of example 54, wherein a spectral efficiency corresponding to each switching point for the MCS tables associated with at least one number a plurality of transmission layers decreases with an increasing number of transmission layers.

[0209] Example 56. The apparatus of any of examples 43 to 55, wherein an MCS table configuration that depends on a number of at least one transmission layer is based on a capability of the user equipment.

[0210] Example 57. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at leastto: determine a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determine a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0211] Example 58. The apparatus of example 57, wherein the modulation order is selected based on the modulation and coding scheme index of a table, wherein the table comprises a plurality of modulation and coding scheme indexes, each of the modulation and coding scheme indexes comprises an indication of modulation order, and the modulation and coding scheme index is selected from the plurality of modulation and coding scheme indexes.

[0212] Example 59. The apparatus of example 58, wherein: the table comprises a plurality of modulation order columns, each of the plurality of the modulation order columns is associated with a number of at least one transmission layer, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the transmission of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the plurality of modulation order columns of the table, wherein the modulation order column is associated with the number of at least one transmission layer selected for the transmission.

[0213] Example 60. The apparatus of any of examples 58 to 59, wherein: an association of modulation order columns of the table to a number of at least one transmission layer is indicated by the apparatus with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the transmission of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the table, wherein the modulation ordercolumn is associated with the number of at least one transmission layer selected for the transmission.

[0214] Example 61. The apparatus of any of examples 58 to 60, wherein: the table comprises a mapping from a first modulation order column associated with a first number of at least one transmission layer to a second modulation order column associated with the number of at least one transmission layer selected for the transmission that is higher than the first number of at least one transmission layer, and each entry of the first modulation order column and the second modulation order column comprises an association between a modulation and coding scheme index and a modulation order, and information about the mapping is indicated by the apparatus with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, and wherein determining the modulation order for the transmission of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation and coding scheme and from the second modulation order column which is associated with the number of at least one transmission layer selected for the transmission and the mapping.

[0215] Example 62. The apparatus of any of examples 59 to 61, wherein the apparatus is further caused to: determine at least one modulation switching point, wherein each of the at least one modulation switching point indicates a change of modulation order in the table, and each of the at least one modulation switching point is associated with a modulation and coding scheme index and a modulation order column associated with a number of at least one transmission layer; and transmit, to the user equipment, information associated with the at least one modulation switching point.

[0216] Example 63. The apparatus of example 62, wherein each of the at least one modulation switching point indicates an increase of modulation order, and modulation and coding scheme indexes associated with the at least one modulation switching point that correspond to the same modulation order in the table decrease as the number of at least one transmission layer associated with the modulation order column increases.

[0217] Example 64. The apparatus of any of examples 62 to 63, wherein the information associated with the at least one modulation switching point is transmitted using at least one of: aradio resource control message, a medium access control control element, or downlink control information signaling.

[0218] Example 65. The apparatus of any of examples 57 to 64, wherein the apparatus is further caused to: construct a physical downlink shared channel for the transmission of the downlink data, based on the modulation order and the transport block size.

[0219] Example 66. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determine a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determine a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulate and decode the downlink data, based on the modulation order and the transport block size.

[0220] Example 67. The apparatus of example 66, wherein the modulation order is selected based on the modulation and coding scheme index of a table, wherein the table comprises a plurality of modulation and coding scheme indexes, each of the modulation and coding scheme indexes comprises an indication of modulation order, and the modulation and coding scheme index is selected from the plurality of modulation and coding scheme indexes.

[0221] Example 68. The apparatus of example 67, wherein: the table comprises a plurality of modulation order columns, each of the plurality of the modulation order columns is associated with a number of at least one transmission layer, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the demodulating and decoding of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer received with the transmission comprises selecting the modulation order for the downlink data reception based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the plurality of modulation order columns of the table, wherein the modulation order column is associated with the number of at least one transmission layer received with the transmission.

[0222] Example 69. The apparatus of any of examples 67 to 68, wherein: an association of modulation order columns of the table to a number of at least one transmission layer is receivedby the apparatus with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the demodulating and decoding of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer received with the transmission comprises selecting the modulation order for the downlink data reception based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the table, wherein the modulation order column is associated with the number of at least one transmission layer received with the transmission.

[0223] Example 70. The apparatus of any of examples 67 to 69, wherein: the table comprises a mapping from a first modulation order column associated with a first number of at least one transmission layer to a second modulation order column associated with the number of at least one transmission layer received with the transmission that is higher than the first number of at least one transmission layer, and each entry of the first modulation order column and the second modulation order column comprises an association between a modulation and coding scheme index and a modulation order, and information about the mapping is received by the apparatus with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, and wherein determining the modulation order for the demodulating and decoding of the downlink data based on the modulation and coding scheme index and the number of at least one transmission layer received with the transmission comprises selecting the modulation order for the downlink data reception based on the modulation and coding scheme index determining the modulation and coding scheme and from the second modulation order column which is associated with the number of at least one transmission layer received with the transmission and the mapping.

[0224] Example 71. The apparatus of any of examples 68 to 70, wherein the apparatus is further caused to: receive, from the network entity, information associated with at least one modulation switching point, wherein each of the at least one modulation switching point indicates a change of modulation order in the table, and each of the at least one modulation switching point is associated with a modulation and coding scheme index and a modulation order column associated with a number of at least one transmission layer.

[0225] Example 72. The apparatus of example 71, wherein each of the at least one modulationswitching point indicates an increase of modulation order, and modulation and coding scheme indexes associated with the at least one modulation switching point that correspond to the same modulation order in the table decrease as the number of at least one transmission layer associated with the modulation order column increases.

[0226] Example 73. The apparatus of any of examples 71 to 72, wherein the information associated with the at least one modulation switching point is received with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0227] Example 74. The apparatus of any of examples 66 to 73, wherein the downlink data is received in a physical downlink shared channel (PDSCH).

[0228] Example 75. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determine a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmit, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0229] Example 76. The apparatus of example 75, wherein the modulation order is selected based on the modulation and coding scheme index of a table, wherein the table comprises a plurality of modulation and coding scheme indexes, each of the modulation and coding scheme indexes comprises an indication of modulation order, and the modulation and coding scheme index is selected from the plurality of modulation and coding scheme indexes.

[0230] Example 77. The apparatus of example 76, wherein: the table comprises a plurality of modulation order columns, each of the plurality of the modulation order columns is associated with a number of at least one transmission layer, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the transmission of the uplink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation andcoding scheme and from a modulation order column of the plurality of modulation order columns of the table, wherein the modulation order column is associated with the number of at least one transmission layer selected for the transmission.

[0231] Example 78. The apparatus of any of examples 76 to 77, wherein the apparatus is caused to: receive, from the network entity, an indication of an association of modulation order columns of the table to a number of at least one transmission layer with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the transmission of the uplink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the table, wherein the modulation order column is associated with the number of at least one transmission layer selected for the transmission.

[0232] Example 79. The apparatus of any of examples 76 to 78, wherein: the table comprises a mapping from a first modulation order column associated with a first number of at least one transmission layer to a second modulation order column associated with the number of at least one transmission layer selected for the transmission that is higher than the first number of at least one transmission layer, and each entry of the first modulation order column and the second modulation order column comprises an association between a modulation and coding scheme index and a modulation order, and information about the mapping is received from the network entity with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling, and determining the modulation order for the transmission of the uplink data based on the modulation and coding scheme index and the number of at least one transmission layer selected for the transmission comprises selecting the modulation order for the transmission based on the modulation and coding scheme index determining the modulation and coding scheme and from the second modulation order column which is associated with the number of at least one transmission layer selected for the transmission and the mapping.

[0233] Example 80. The apparatus of any of examples 77 to 79, wherein the apparatus is further caused to: receive, from the network entity, information associated with at least one modulationswitching point, wherein each of the at least one modulation switching point indicates a change of modulation order in the table, and each of the at least one modulation switching point is associated with a modulation and coding scheme index and a modulation order column associated with a number of at least one transmission layer.

[0234] Example 81. The apparatus of example 80, wherein each of the at least one modulation switching point indicates an increase of modulation order, and modulation and coding scheme indexes associated with the at least one modulation switching point that correspond to the same modulation order in the table decrease as the number of at least one transmission layer associated with the modulation order column increases.

[0235] Example 82. The apparatus of any of examples 80 to 81, wherein the information associated with the at least one modulation switching point is received with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0236] Example 83. The apparatus of any of examples 75 to 82, wherein the apparatus is further caused to: construct a physical uplink shared channel for the transmission of the uplink data, based on the modulation order and the transport block size.

[0237] Example 84. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; determine a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determine a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulate and decode the uplink data, based on the modulation order and the transport block size.

[0238] Example 85. The apparatus of example 84, wherein the modulation order is selected based on the modulation and coding scheme index of a table, wherein the table comprises a plurality of modulation and coding scheme indexes, each of the modulation and coding scheme indexes comprises an indication of modulation order, and the modulation and coding scheme index is selected from the plurality of modulation and coding scheme indexes.

[0239] Example 86. The apparatus of example 85, wherein: the table comprises a plurality ofmodulation order columns, each of the plurality of the modulation order columns is associated with a number of at least one transmission layer, wherein each entry of a modulation order column comprises an association between a modulation and coding scheme index and a modulation order, wherein determining the modulation order for the demodulating and decoding of the uplink data based on the modulation and coding scheme index and the number of at least one transmission layer received with the transmission comprises selecting the modulation order for the uplink data reception based on the modulation and coding scheme index determining the modulation and coding scheme and from a modulation order column of the plurality of modulation order columns of the table, wherein the modulation order column is associated with the number of at least one transmission layer received with the transmission.

[0240] Example 87. The apparatus of example 86, wherein the apparatus is further caused to: determine at least one modulation switching point, wherein each of the at least one modulation switching point indicates a change of modulation order in the table, and each of the at least one modulation switching point is associated with a modulation and coding scheme index and a modulation order column associated with a number of at least one transmission layer; and transmit, to the user equipment, information associated with the at least one modulation switching point.

[0241] Example 88. The apparatus of example 87, wherein each of the at least one modulation switching point indicates an increase of modulation order, and modulation and coding scheme indexes associated with the at least one modulation switching point that correspond to the same modulation order in the table decrease as the number of at least one transmission layer associated with the modulation order column increases.

[0242] Example 89. The apparatus of any of examples 87 to 88, wherein the information associated with the at least one modulation switching point is transmitted with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

[0243] Example 90. The apparatus of any of examples 84 to 89, wherein the uplink data is received in a physical uplink shared channel (PUSCH).

[0244] Example 91. A method including: determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmitting, to a user equipment, the downlink data with thenumber of at least one transmission layer using the determined MCS.

[0245] Example 92. A method including: receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulating and decoding the downlink data based on the determined MCS.

[0246] Example 93. A method including: determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of uplink data; and transmitting, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS.

[0247] Example 94. A method including: receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer and with a channel; determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data; and decoding and demodulating the channel used for the transmission of the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0248] Example 95. A method including: determining a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determining a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmitting, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0249] Example 96. A method including: receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulating and decoding the downlink data, based on the modulation order and the transport block size.

[0250] Example 97. A method including: determining a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determining a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmitting, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0251] Example 98. A method including: receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulating and decoding the uplink data, based on the modulation order and the transport block size.

[0252] Example 99. An apparatus including: means for determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and means for transmitting, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

[0253] Example 100. An apparatus including: means for receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; means for determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and means for demodulating and decoding the downlink data based on the determined MCS.

[0254] Example 101. An apparatus including: means for determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of uplink data; and means for transmitting, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS.

[0255] Example 102. An apparatus including: means for receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer and with a channel; means for determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data;and means for decoding and demodulating the channel used for the transmission of the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0256] Example 103. An apparatus including: means for determining a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; means for determining a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and means for transmitting, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0257] Example 104. An apparatus including: means for receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; means for determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; means for determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and means for demodulating and decoding the downlink data, based on the modulation order and the transport block size.

[0258] Example 105. An apparatus including: means for determining a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; means for determining a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and means for transmitting, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0259] Example 106. An apparatus including: means for receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; means for determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; means for determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and means for demodulating and decoding the uplink data, based on the modulation order and the transport block size.

[0260] Example 107. A computer readable medium including instructions stored thereon forperforming at least the following: determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmitting, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

[0261] Example 108. A computer readable medium including instructions stored thereon for performing at least the following: receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulating and decoding the downlink data based on the determined MCS.

[0262] Example 109. A computer readable medium including instructions stored thereon for performing at least the following: determining a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of uplink data; and transmitting, to network entity, the uplink data with the number of at least one transmission layer using the determined MCS.

[0263] Example 110. A computer readable medium including instructions stored thereon for performing at least the following: receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer and with a channel; determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the uplink data; and decoding and demodulating the channel used for the transmission of the uplink data with the number of at least one transmission layer, based on the determined MCS.

[0264] Example 111. A computer readable medium including instructions stored thereon for performing at least the following: determining a transport block size for a transmission of downlink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determining a modulation order for the transmission of the downlink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmitting, to a user equipment, the downlink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0265] Example 112. A computer readable medium including instructions stored thereon forperforming at least the following: receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulating and decoding the downlink data, based on the modulation order and the transport block size.

[0266] Example 113. A computer readable medium including instructions stored thereon for performing at least the following: determining a transport block size for a transmission of uplink data, based on a modulation and coding scheme and a number of at least one transmission layer selected for the transmission; determining a modulation order for the transmission of the uplink data based on a modulation and coding scheme index and the number of at least one transmission layer selected for the transmission; and transmitting, to a network entity, the uplink data with the number of at least one transmission layer, based on the modulation order and the transport block size.

[0267] Example 114. A computer readable medium including instructions stored thereon for performing at least the following: receiving, from a user equipment, a transmission of uplink data with a number of at least one transmission layer; determining a transport block size, based on a modulation and coding scheme and the number of at least one transmission layer received with the transmission; determining a modulation order, based on a modulation and coding scheme index and the number of at least one transmission layer received with the transmission; and demodulating and decoding the uplink data, based on the modulation order and the transport block size.

[0268] References to a ‘computer’, ‘processor’, etc. should be understood to encompass not only computers having different architectures such as single / multi-processor architectures and sequential or parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGAs), application specific circuits (ASICs), signal processing devices and other processing circuitry. References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor or firmware such as, for example, the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device etc.

[0269] The memories as described herein may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, non-transitory memory, transitory memory, fixed memory and removable memory. The memories may comprise a database for storing data.

[0270] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0271] As used herein, the term ‘circuitry’ may refer to the following: (a) hardware circuit implementations, such as implementations in analog and / or digital circuitry, and (b) combinations of circuits and software (and / or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s) / software including digital signal processor(s), software, and memories that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. As a further example, as used herein, the term ‘circuitry’ would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The term ‘circuitry’ would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

[0272] It should be understood that the foregoing description is only illustrative. Various alternatives and modifications may be devised by those skilled in the art. For example, features recited in the various dependent claims could be combined with each other in any suitable combination(s). In addition, features from different example embodiments described above could be selectively combined into a new example embodiment. Accordingly, this description is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

[0273] The following acronyms and abbreviations that may be found in the specification and / or the drawing figures are given as follows (the abbreviations and acronyms may be appended / combined with each other or with other characters using e.g. a dash, hyphen, slash,letter, or number, and may be case insensitive): 3G third generation 3GPP third generation partnership project 4G fourth generation 5G fifth generation 5GC 5G core network 6G sixth generation Alt. alternative AMF access and mobility management function ASIC application-specific integrated circuit BS base station CD compact / computer disc CE control element CPU central processing unit CU central unit or centralized unit CW codeword DC dual connectivity DCI downlink control information DFT-S-OFDM discrete Fourier transform spread orthogonal frequency division multiplexing DL downlink DSP digital signal processor DU distributed unit DVD digital versatile disc eNB evolved Node B (e.g., an LTE base station) EN-DC E-UTRAN new radio – dual connectivity en-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as a secondary node in EN-DC E-UTRA evolved UMTS terrestrial radio access, i.e., the LTE radio access technology E-UTRAN E-UTRA network F1 interface between the CU and the DU f-domain frequency domainFPGA field-programmable gate array gNB generalized node B, base station for 5G / NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC HSPA high speed packet access IAB integrated access and backhaul I / F interface I / O input / output LA link adaptation LMF location management function LTE long term evolution (4G) MAC medium access control MAC CE medium access control control element MCS modulation and coding scheme MIMO multiple-input multiple-output MME mobility management entity MRO mobility robustness optimization NCE network control element ng or NG new generation ng-eNB new generation eNB NG-RAN new generation radio access network NR new radio N / W network OFDM orthogonal frequency division multiplexing PDA personal digital assistant PDCP packet data convergence protocol PDSCH physical downlink shared channel PHY physical layer PostEQ post equalizer PUSCH physical uplink shared channel QAM quadrature amplitude modulation QPSK quadrature phase shift keying RAM random access memory RAN radio access networkRE resource element Rel release RLC radio link control ROM read-only memory RRC radio resource control RU radio unit Rx receive, or receiver, or reception SCH shared channel SDAP service data adaptation protocol Sec. section SGW serving gateway SINR signal to interference plus noise ratio SMF session management function SON self-organizing / optimizing network TB transport block TBS transport block size TPUT throughput TRP transmission reception point TS technical specification Tx transmit, or transmitter, or transmission UAV unmanned aerial vehicle UE user equipment (e.g., a wireless, typically mobile device) UI user interface UL uplink UMTS Universal Mobile Telecommunications System UPF user plane function USB universal serial bus X2 network interface between RAN nodes and between RAN and the core network Xn network interface between NG-RAN nodes

Claims

CLAIMS What is claimed is:

1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determine a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulate and decode the downlink data based on the determined MCS.

2. The apparatus of claim 1, wherein the determining the MCS comprises selecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

3. The apparatus of claim 2, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmission layer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiency corresponding to a modulation switching point of the second table.

4. The apparatus of claim 2 or 3, wherein the apparatus is further caused to: receive, from the network entity, a configuration comprising information related to the plurality of MCS tables; wherein the configuration comprising the information related to the plurality of MCS tables is received from the network entity with at least one of: a radio resource control message,a medium access control control element, or downlink control information signaling.

5. The apparatus of claim 4, wherein an MCS table configuration that depends on a number of at least one transmission layer is based on a capability of the apparatus.

6. The apparatus of any of claims 2 to 5, wherein the apparatus is further caused to: receive, from the network entity, the number of at least one transmission layer, wherein the plurality of MCS tables is preconfigured at the apparatus.

7. The apparatus of any of claims 1 to 6, wherein the apparatus is further caused to: receive, from the network entity, an MCS index indicating an entry in an MCS table which is associated with the number of at last one transmission layer; wherein the MCS and the spectral efficiency used to demodulate and decode the downlink data with the number of at least one transmission layer are determined from the entry in the MCS table indicated with the MCS index received from the network entity.

8. The apparatus of any of claims 1 to 7, wherein the downlink data is received in a physical downlink shared channel (PDSCH).

9. The apparatus of any of claims 1 to 8, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate different modulation orders in an alternative manner.

10. The apparatus of claim 9, wherein the MCS selected for the demodulating and decoding the downlink data with the number of at least one transmission layer has a higher or equal modulation order than the MCS selected for the demodulating and decoding the downlink data with another number of at least one transmission layer for a spectral efficiency order, wherein the number of at least one transmission layer is higher than the another number of at least one transmission layer.

11. The apparatus of any of claims 1 to 10, wherein the apparatus is further caused to: receive, from the network entity, an indication of MCS tables associated with at least one number of a plurality of transmission layers, wherein the indication of the MCS tablesassociated with at least one number of a plurality of transmission layers comprises an indication of modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers; and derive one MCS table associated with at least one number of a plurality of transmission layers from: a reference table for a transmission associated with one transmission layer, and a set of modulation switching points for the one MCS table associated with at least one number of a plurality of transmission layers; wherein the set of modulation switching points for the one MCS table associated with at least one number of a plurality of transmission layers is among the modulation switching points for the MCS tables associated with at least one number of a plurality of transmission layers received within the indication from the network entity; wherein the MCS used to demodulate and decode the downlink data is selected from the derived one MCS table associated with at least one number of a plurality of transmission layers.

12. The apparatus of claim 11, wherein a spectral efficiency corresponding to each switching point for the MCS tables associated with at least one number a plurality of transmission layers decreases with an increasing number of transmission layers.

13. A method comprising: receiving, from a network entity, a transmission of downlink data with a number of at least one transmission layer; determining a modulation and coding scheme (MCS) based on a spectral efficiency and the number of at least one transmission layer used for the transmission of the downlink data; and demodulating and decoding the downlink data based on the determined MCS.

14. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least oneprocessor, cause the apparatus at least to: determine a modulation and coding scheme (MCS) based on a spectral efficiency and a number of at least one transmission layer selected for a transmission of downlink data; and transmit, to a user equipment, the downlink data with the number of at least one transmission layer using the determined MCS.

15. The apparatus of claim 14, wherein the determining the MCS comprises selecting the MCS from an MCS table among a plurality of MCS tables based on the number of at least one transmission layer, wherein each of the plurality of MCS tables is associated with at least one number of at least one transmission layer.

16. The apparatus of claim 15, wherein the plurality of MCS tables comprises a first MCS table and a second MCS table, and the at least one number of at least one transmission layer associated with the first table is higher than the at least one number of at least one transmission layer associated with the second table, and wherein a spectral efficiency corresponding to a modulation switching point of the first table is lower than a spectral efficiency corresponding to a modulation switching point of the second table.

17. The apparatus of claim 15 or 16, wherein the apparatus is further caused to: send, to the user equipment, a configuration comprising information related to the plurality of MCS tables.

18. The apparatus of claim 17, wherein the configuration is sent with at least one of: a radio resource control message, a medium access control control element, or downlink control information signaling.

19. The apparatus of any of claims 14 to 18, wherein the apparatus is further caused to: send, to the user equipment, the number of at least one transmission layer.

20. The apparatus of any of claims 14 to 19, wherein the MCS is determined from an MCS table, wherein MCS indexes of the MCS table are ordered in increasing spectral efficiency, and multiple consecutive MCS indexes of the MCS table indicate different modulation orders in an alternative manner.

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