Method for polar coded modulation

Abstract

The present invention provides methods, apparatus and systems for constructing and modulating polar codes. Such procedures may involve: identifying inhomogeneous channel conditions; selecting a modulation order; configuring multiple component codes and delta ratios for unequal error protection (UEP); identifying initial code construction parameters for each component code; calculating modified code construction parameters based on the delta ratios for UEP; and encoding the component polar codes according to the modified construction parameters. Each component code may include multiple input bits. The initial code construction parameters and the modified code construction parameters may include a number of unfrozen input bits and a number of frozen input bits, and identifying the number of unfrozen input bits and the number of frozen input bits may involve calculating and comparing reliability values ​​for each bit. Calculating and comparing reliability values ​​for each bit may involve applying a polarization weight (PW) based method.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 900,173, filed September 13, 2019, the contents of which are incorporated herein by reference. Background Art

[0003] Polar codes may be the first channel code type that has been analytically demonstrated to achieve capacity. Polar codes may exhibit comparable performance to conventional LDPC codes or turbo codes with low or no error floor, with the aid of an embedded CRC, especially for small to medium block lengths. Polar codes with continuous cancellation decoding may require relatively low encoding and decoding complexity. However, decoding complexity may increase proportionally with the list size when CRC-assisted list decoding is employed and with the block length of the codeword. The increased complexity may become a central issue, especially in medium to large block lengths, and limit the adoption of polar codes in high throughput scenarios including 5G NR eMBB data rates (~20 Gbps) and above. Summary of the invention

[0004] Methods, apparatus, and systems for constructing and modulating polar codes are provided. Such procedures may involve: identifying inhomogeneous channel conditions; selecting a modulation order; configuring multiple component codes and delta ratios for unequal error protection (UEP); identifying initial code construction parameters for each component code; calculating modified code construction parameters based on the delta ratios for UEP; and encoding the component polar codes according to the modified construction parameters. Each component code may include multiple input bits. The initial code construction parameters and the modified code construction parameters may include a number of unfrozen input bits and a number of frozen input bits, and identifying the number of unfrozen input bits and the number of frozen input bits may involve calculating and comparing reliability values ​​for each bit. Calculating and comparing reliability values ​​for each bit may involve applying a polarization weight (PW) based method. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0006] Figure 1A is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B It is shown that according to one embodiment, Figure 1A A system diagram of an exemplary wireless transmit / receive unit (WTRU) for use within the communication system shown;

[0008] Figure 1C It is shown that according to one embodiment, Figure 1A a system diagram of an exemplary radio access network (RAN) and an exemplary core network (CN) used within the illustrated communication system; and

[0009] Figure 1D is a diagram according to one embodiment which can be Figure 1A A system diagram of another exemplary RAN and another exemplary CN used within the communication system shown.

[0010] Figure 2 is a diagram of an exemplary polar code encoder with codeword block length N=8.

[0011] Figure 3 is a diagram illustrating an exemplary process for both a bit interleaved coded modulation (BICM) transmitter and a BICM receiver.

[0012] Figure 4 is a flow chart of an exemplary scheme for polar code construction and modulation according to one or more embodiments described herein.

[0013] Figure 5 is a diagram of an example of polar code construction using a reliability sequence.

[0014] Figure 6 is a diagram of an example of identifying the number of unfrozen bits in a component polar code.

[0015] Figure 7 is a diagram of an example of a code construction for each component polar code.

[0016] Figure 8 is a graph of an exemplary comparison of frame / bit error performance in AWGN.

[0017] Fig. 9 is a graph of an exemplary comparison of frame / bit error performance in fast fading.

[0018] Fig.10 is a diagram of an example of a sequence of original code constructs.

[0019] Fig.11 is a diagram of an example of generating a new code construction sequence through biasing.

[0020] Fig.12 is a diagram of an example of a higher precision code construction sequence. DETAILED DESCRIPTION

[0021] Figure 1A1 is a schematic diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0022] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a station (STA)) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0023] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an evolved NodeB (eNB), a Home NodeB, a Home evolved NodeB, a next generation NodeB such as a gNodeB (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0024] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0025] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0026] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0028] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using NR.

[0029] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0030] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), GSM Enhanced Data Rates for Evolution (EDGE), GSM EDGE (GERAN), etc.

[0031] Figure 1A The base station 114b in the may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, the base station 114 b may have a direct connection to the Internet 110. Therefore, the base station 114 b may not need to access the Internet 110 via the CN 106.

[0032] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, delay requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the specification, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0033] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0035] Figure 1B is a system diagram illustrating an exemplary WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0036] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0037] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via an air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive RF and light signals. It should be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0038] Although the transmit / receive element 122 is Figure 1B 1 as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0039] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0040] The processor 118 of the WTRU 102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0041] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0042] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0043] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, Module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. Peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geographic location sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor, humidity sensor, etc.

[0044] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0045] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As described above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0046] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0047] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0048] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0049] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0050] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-evolved Node-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0051] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0052] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0053] Although the WTRU Figures 1A to 1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0054] In a representative embodiment, the other network 112 may be a WLAN.

[0055] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and leading to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be sent to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be sent by the AP, for example, wherein the source STA may send traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be sent between the source and destination STAs (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

[0056] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may transmit a beacon on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0057] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0058] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz and / or 80MHz channels can be formed by combining continuous 20MHz channels. A 160MHz channel can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For the 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be transmitted by transmitting STA. At the receiver of the receiving STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be sent to the medium access control (MAC).

[0059] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0060] WLAN systems that can support multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only the 1MHz operating mode) is transmitting to the AP, all available frequency bands may be considered busy even if most of the available frequency bands remain idle.

[0061] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0062] Figure 1D 1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0063] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0064] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable parameter sets. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0065] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while also not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate or connect with the gNBs 180a, 180b, 180c while also communicating or connecting with other RANs, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more evolved Node-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the evolved Node-Bs 160a, 160b, 160c may serve as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0066] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR, and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0067] Figure 1DThe illustrated CN 106 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0068] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services used by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for MTC access, etc. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0069] The SMF 183a, 183b may be connected to the AMF 182a, 182b via the N11 interface in the CN 106. The SMF 183a, 183b may also be connected to the UPF 184a, 184b via the N4 interface in the CN 106. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0070] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, etc.

[0071] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the DNs 185a, 185b via the UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0072] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0073] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, the one or more simulation devices may perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or perform testing using over-the-air wireless communications.

[0074] The one or more simulation devices may perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device may be used in a test scenario in a test lab and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. The one or more simulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which may include one or more antennas) may be used by the simulation device to transmit and / or receive data.

[0075] In one or more embodiments, a device (such as a WTRU or a base station) may perform one or more processes to send a transmission. For example, one or more transport blocks may be delivered to a physical layer of the device where the transport blocks may undergo processing. Typically, channel coding may be performed as part of a physical layer process. There are many types of channel coding, such as low density parity check (LDPC) codes, turbo codes, and polar codes.

[0076] Polar codes may be the first channel coding type that has been analytically demonstrated to achieve capacity. Polar codes may exhibit comparable performance to conventional LDPC codes or turbo codes with low or no error floor, aided by an embedded CRC, especially for small to medium block lengths. Polar codes with continuous cancellation decoding may require relatively low encoding and decoding complexity. However, decoding complexity may increase proportionally with the list size when CRC-assisted list decoding is employed and with the block length of the codeword. The increased complexity may become a central issue, especially in medium to large block lengths, and limit the adoption of polar codes in high throughput scenarios (such as 5G NR eMBB) with high data rates (e.g., 20 Gbps and above).

[0077] Due to its excellent performance in small block lengths, polar codes can be used as channel coding schemes for forward error correction (FEC) operations in control channels. Polar code encoding can be defined as follows:

[0078]

[0079] Polar code The codeword vector of is generated by the product of the input vector N and the generator matrix G. and are binary vectors of length N = 2 n , where N represents the codeword block length. The generator matrix G N can be defined by the Kronecker power of ;

[0080]

[0081] where represents the n-th Kronecker power of (). In Arikan's original paper, where B N represents the bit-reversal matrix, and it changes the order of the elements in . The bit-reversal operation is further described below.

[0082] Generally, it can be assumed that certain input bits of the polar code can have fixed values (e.g., zero), in which case they are called "frozen bits". The input indices for the frozen bits can be represented by the set and if i < j, then the remaining part of the input bits of the polar code can carry variable information bits, and they are called "unfrozen bits". The input indices of the unfrozen bits can be represented by the set A = {a1, a2, a3…, a K} and if i < j, then a i < a j . The number of information bits and / or unfrozen bits can be defined as K and the number of frozen bits can be N - K. The coding rate R of the polar code can be defined as

[0083] The process of determining the input bit indices of the frozen bits and unfrozen bits can be called the "code construction" of the polar code, and several code construction methods can be adopted. Generally speaking, these methods can initially involve calculating the reliability of each input bit index, and thus having an order of bit index reliability before starting the encoding operation. According to the obtained reliability order, the least reliable input bits can be assigned as frozen bits, and the remaining bits can be assigned as unfrozen / information bits. The ratio of frozen bits to unfrozen bits can be determined according to the desired coding rate. In the case where the positions of the frozen bits and unfrozen bits are available, the encoding operation is as shown in the example of Figure 2 .

[0084] Figure 2 is a diagram of an exemplary polar encoder with a codeword block length N = 8. As shown in Figure 2As shown, the polar encoder may be represented by node 201, wherein the node may be represented by (i, j), i=1, ..., N and j=0, ..., n. The vertical axis 202 and the horizontal axis may be represented by (i, j), respectively.

[0085] Generally speaking, decoding algorithms for polar codes can be classified into two types: decoding based on continuous cancellation (SC) and decoding based on belief propagation (BP). SC polar decoding is a sequential decoding method that calculates the log-likelihood ratio (LLR) values ​​of the input bits in a serial manner. SC polar decoding can be based on the assumption that the previously decoded bits are correct and they can be used to decode the current bit. Continuous cancellation list (SCL) decoding can involve the use of several candidate path lists to improve the performance of SC decoding. The best list can be selected based on the results of the LLR calculation. CRC-assisted continuous cancellation list (CA-SCL) decoding can use embedded CRC as a tool for selecting the list. Through CA-SCL decoding, polar codes can achieve error performance comparable to or superior to conventional LDPC codes or turbo codes.

[0086] Bit-interleaved coded modulation (BICM) is one method that can be used to combine channel codes with modulation. For example, the output code bits of a channel encoder can be interleaved, and the interleaved bits can be mapped to modulation symbols in a BICM transmitter.

[0087] Figure 3 300 may begin with receiving an information payload 301 (e.g., from an upper layer). Channel coding 302 (e.g., polar code coding) may then be performed on the received information payload, and the coded bits may then be interleaved and subsequently modulated. In the BICM receiver process, at 310, the received channel symbols may be demodulated 311 and LLR values ​​corresponding to each code bit calculated 312. After the LLR calculation, the values ​​may be deinterleaved 313 for channel decoding 314.

[0088] The BICM method can flexibly combine channel coding and modulation while providing maximum diversity under fading channels to show better error performance. The Gray mapping rule can be considered as the best mapping method for BICM. BICM can be used to integrate polar codes with modulation in the uplink channel, and Gray-mapped QAM can be further used for modulation. The modulation order can be defined as m=log2M when considering M-ary QAM (or constellation). For example, under this assumption, the modulation order of 16QAM is 4.

[0089] Polar codes may be one candidate channel coding scheme for high throughput communications.High order modulation may be a key enabler for high throughput, and thus high order modulation operations are combined with polar codes.

[0090] In some cases, for polar code construction, it can be assumed that each coded bit experiences the same or very similar aggregate channel effects or conditions at the receiver. Under such an assumption, the aggregate channel effects or conditions imply not only the physical channel, but also the effects of multiple transmitter-receiver operations (such as MIMO demultiplexing, successive cancellation, etc.). For each polar code bit, the aggregate channel effects or conditions (simply denoted as channel conditions for convenience) may include the effects or modifications of the basic polar code (e.g., 16QAM or fading channels, etc.) by other additional schemes (e.g., channel interleavers or MIMO transmitters, etc.) through BPSK / QPSK modulation under additive white Gaussian noise (AWGN) channels.

[0091] However, similarly, when polar codes are combined with high-order modulation, this assumption of identical or very similar channel effects and / or conditions may not be retained, and each received LLR value of each code position may have differences in channel conditions from each other. This makes it possible to have problems when using polar codes in some cases. In some specific implementations, polar codes can utilize a channel interleaver to average these differences caused by high-order modulation to improve bit error rate performance. However, even after the interleaving operation, the channel interleaver may not provide enough channel condition uniformity, which may result in a performance gap between the interleaver operation and the ideal case with uniform aggregate channel conditions. This gap can be further increased with the increase of the modulation order.

[0092] Therefore, there is a need to address the problems described above (e.g., changing channel conditions). Specifically, as described herein, there may be one or more methods, systems, and / or devices for using an unequal protection (UEP) method with component polarity codes (e.g., for high-order modulation systems). The UEP method may affect one or more processes of transmission. For example, again referring to Figure 3 As an example, the UEP method may introduce a process involving a polar encoder 322a (eg, as it relates to code construction 322b) and a modulator 325.

[0093] Typically, the polar code system may employ the BICM method. In the UEP method, the input bits to the polar encoder may be divided into P groups. Each of the P groups may be continuous in the field of the input bit index. The length of the group is defined by the number of bits in the group. For the case where the group starts with a power-of-two input index (e.g., assuming the index numbering starts at 1), the bits in the group may correspond to the input bits of a particular component polar code. The number of unfrozen bits in each component polar code may be determined by K0. ′ ,K1 ′,…,K P-1 'Definition, where

[0094]

[0095] There may be one or more ways to determine the UEP parameters. Taking into account that the received code bits may experience different (e.g., binary) channel conditions, the UEP process may enhance performance when applied to component polar codes (e.g., in scenarios that also include high-order modulation).

[0096] Figure 4 A flow chart of an exemplary polar code scheme is shown. At a high level, the flow chart runs through the process of code construction as it relates to the polar code scheme; the process is described in further detail herein. In general, in this example, the process may begin at some point in the transmission process (e.g., when a transport block / information to be sent has been delivered from a higher layer to the physical layer - see, for example, Figure 3 320 of ). At 401, the device may identify parameters of inhomogeneous channel conditions (e.g., modulation orders, such as 16QAM, 32QAM, etc.). Next, at 402, the number of component codes P may be determined; or in other words, how many component codes may be selected when redesigning the polar code for the UEP scenario. Typically, a polar code may be a combination of different / same component codes by construction; for the purposes of this example, the polar code may be considered a recursive code. In some cases, a Δ parameter may also be determined at 402, where each Δ parameter may be a ratio of frozen bits to unfrozen bits for a given component code (e.g., if starting from 0, each component code is up to P-1). At 403, an overall polar code may be constructed based on the number of component codes and the Δ parameter. At 404, based on the overall code construction, the number of unfrozen bits used for inhomogeneous channel conditions before UEP may be identified. At 405, the difference between the original polar code and the polar code constructed at 403 may be calculated based on the identification made at 404. At 406, the number of unfrozen bits may be identified after UEP based on the difference determined at 405. Once this process is completed, codes may be constructed for each component code by selecting / changing unfrozen / frozen bits. In some cases, the process of changing frozen / unfrozen bits may be referred to as a UEP technique / process.

[0097] In one example, the number of groups or the number of component codes P obtained from the input bits can be determined based on a trade-off between complexity and performance according to a conditional parameter (e.g., modulation order). Note that, as discussed herein, the input bits may refer to all component codes in a polar encoder, while the number of component codes may refer to a specific component code. For example, when the modulation order is greater than 2 (=QPSK), P may take a value greater than 1. In some cases, when P=1, this value may correspond to a conventional polar code construction without UEP.

[0098] In another example, we can assume that δ0, δ1, …, δ P-1 is the ratio of unfrozen bits to be updated for each component polarity code (e.g., component code 0, component code 1, ... component code P-1). These ratios (also known as Δ) can be determined using the number of component codes. The parameters can take negative values, which correspond to a decrease in the unfrozen bits in the component code after the update, while positive values ​​mean an increase in the number of unfrozen bits. These parameters can be obtained by calculations based on polar code construction (e.g., calculations based on density evolution or polarization weights (PW), while including the modulation order in the code construction calculation), or by detailed simulations. According to the enumerated methods, the optimal code construction according to the modulation order can be obtained, and it can be compared with the code construction obtained under the assumption of equal channel conditions for each code bit. According to the difference in the component polarity code rates between the two constructions, δ can be obtained by averaging or approximating p Note that as a result of changing the frozen / unfrozen bits, the bit rate will also change. Specifically, as disclosed herein, bit rate = number of unfrozen bits / (number of unfrozen bits + number of frozen bits).

[0099] δ p It can be defined by the following formula, where K p ' and K p Corresponding to the number of unfrozen bits in the component polar codes before and after UEP, respectively.

[0100]

[0101] For example, P=2 for QAM with modulation orders higher than 2 (QPSK) may result in δ0≈-0.0556 when randomly interleaved (e.g., or applying an NR channel interleaver). The optimal coding rate for each component code can be determined, for example, by using Equation 9, and δ0 can be derived therefrom.

[0102] Polar code construction may include a process of determining input bit indices of frozen / unfrozen bits to provide to a polar encoder. One of the simplest ways to determine frozen and unfrozen bits is to use a reliability sequence.

[0103] Figure 5 An example of polar code construction using reliability sequences is shown, where N = 1024. Figure 5As shown, the construction code sequence (also referred to as reliability sequence 500 or 510) may have integer values ​​in bins indicating input bit indices of the polar encoder, and the position of the bin indicates its relative reliability. In this example, the reliability of the input bit indices may increase from the top of the list to the bottom of the list (e.g., reliability order 501). This top-to-bottom reliability orientation may be applicable to other exemplary figures described herein. The bit indices 502 in the last K bins from the bottom may determine the unfrozen bits. The remaining input bit indices may be selected as frozen bits.

[0104] The number of unfrozen bits in the component polar code (K0 ′ ,K1 ′ ,…,K P-1 ') can be obtained from the total polar code construction before applying the UEP process. For each input field of each component polar code (eg, each block of input bits equally partitioned by P), the number of unfrozen bits can be identified (eg, counted).

[0105] Figure 6 It shows that when P = 2, K0 ′ +K1 ′ =K=512 and N=1024. The code construction / reliability sequence is shown at 610, and the selection of frozen / unfrozen bits is shown at 602. In this example, there may be , where this represents the selection 602 of unfrozen bits from the bottom of the code structure. The first group 603 may range from 0 to 511, while the second group 604 may range from 512 to 1023. Figure 6 As shown, in the first group 603, 139 unfrozen bits can be determined, and 373 unfrozen bits can be determined in the second group 604. Therefore, the coding rate of the first component polar code (e.g., the first group 603) is 139 / 512 and the coding rate of the second component polar code (e.g., the second group 604) is 373 / 512.

[0106] As described herein, for each component polar code, there may be one or more processes for code construction. In one example, the number of unfrozen bits after applying the UEP process to each input bit group may be defined as K0, K1, ..., K P-1 . By dividing from δ0,δ1,…,δ P-1 The differential unfrozen bits obtained by the value include K′0, K′1, …, K′ to the unfrozen bits P-1 , the modified code construction can be configured to provide unequal error protection. The number of differentially unfrozen bits per input bit group (ΔK0, ΔK1, …, ΔK P-1 ) can be calculated by the following formula:

[0107] ΔK p =[K′ p ×δ p ],p=0,1,…,P-1

[0108] The number of unfrozen bits of each component polar code after the UEP process can be given by:

[0109] K p =K′ p +ΔK p ,p=0,1,…,P-1 Formula 5

[0110] The number of frozen bits of each component polar code after the UEP process is:

[0111] N p -K p =N p -K′ p -ΔK p ,p=0,1,…,P-1 Formula 6

[0112] It can be assumed that the total unfrozen bits after the UEP process are also K and k can be automatically determined by this assumption p For example, if we choose p = P-1, the last component polar code is:

[0113]

[0114] exist Figure 6 In the example of , the 8-bit index with the minimum reliability between unfrozen bits in the first group 603 (e.g., input bit indexes from 0 to 511) can be converted from unfrozen bits to frozen bits. Similarly, the 8-bit index with the maximum reliability between frozen bits in the second group 604 (e.g., input bit indexes from 512 to 1023) can be converted to unfrozen bits. These processes can start with the last selected unfrozen bit index in the overall (e.g., original) polar code construction. From the last index selected in the original code construction, the decision of the index value of each bin in the graph (when deciding whether it is the first group or the second group according to two directions (e.g., up, down)) can be checked until all differential unfrozen bits or frozen bits of each component code are determined.

[0115] Figure 7 An example of code construction for each component polar code is shown. This example can be followed with Figure 4 The same process as described in , where the bits are identified before UEP 701 and after UEP 702. This example is also similar to Figure 6, using the same values ​​for demonstration purposes (e.g., the first group is shown at 703, and the second group is shown at 704). In this example, P = 2, K'0 = 139, K'1 = 373, K'0 + K'1 = K = 512, and N = 1024. For δ0 ≈ -0.0556, ΔK0 = [139 × (-0.0556)] = 8, K0 = K'0 + ΔK0 = 131, and K1 = K-K0 = 381.

[0116] The proposed scheme can be evaluated under the conditions shown in Table 1.

[0117] parameter value N 1024 K 512 (including CRC) Coding rate 496 / 1024＝0.484 CRC 16CRC Decoding scheme CA-SCL, list size = 8 Code Structure 3GPP NR polar code sequence modulation 3GPP NR Gray Mapping 256QAM UEP Parameters <![CDATA[P=2,δ0=-0.0556]]> Channel Interleaver Random Interleaver Channel AWGN, fast fading Counting the smallest bit errors 100 block errors

[0118] Table 1: Evaluation conditions

[0119] Figure 8 An exemplary comparison of frame / bit error performance in an additive white Gaussian noise (AWGN) channel is provided for demonstration purposes related to the effectiveness of the techniques described herein. Frame error rate (FER) / bit error rate (BER) may be shown in vertical axis 811, and symbol power (ES) / noise power (No) Es / No may be shown in horizontal axis 812. In this example, the proposed UEP may be compared over 10 -4 The coding gain is 0.3 dB at a BER / FER of 1.

[0120] Fig. 9 An exemplary comparison of frame / bit error performance in a fast fading channel is provided for demonstration purposes related to the effectiveness of the techniques described herein. FER / BER may be shown in vertical axis 911, and Es / No may be shown in horizontal axis 912. Here, the proposed UEP may be compared at 2×10 -5 For higher order modulations such as 512QAM and 1024QAM, even greater performance gains can be expected.

[0121] In some cases, an adaptive polar code construction sequence can be configured. By introducing different code construction sequences, the same effect as UEP can be achieved. In the case where the received bits experience different aggregate channel conditions, in one option, a different code construction sequence for each event can be used at the encoder.

[0122] As an example of a change in aggregate channel conditions, such as when modulation orders greater than 2 (QPSK) are combined with polar codes, different code construction sequences may be applied depending on the modulation order selected at the transmitter, thereby presenting a trade-off between complexity and performance. That is, for the purpose of illustrating this example, a different code construction sequence for each modulation order may be assumed. In a simpler example, a single code construction sequence for modulation orders above 2 may be used.

[0123] In addition to the original code construction sequence, various methods of configuring the code construction sequence can also be used. For example, the code construction sequence can be generated by offline calculation. Depending on the channel conditions, offline calculations optimized for the corresponding channel conditions can be performed. In this case, and when assuming K different code constructions, it may be necessary to save the total size of kN sequences in memory.

[0124] One offline calculation method is to generate a code construction sequence based on polarization weight (PW). In this method, the reliability of each input index of each polarity code bit under uniform channel conditions can be calculated by the following formula:

[0125]

[0126] Here, θ(j) may represent the reliability value of the jth input bit index. s Represents the sth binary digit value when j is represented in binary digital form. According to the provided formula, the reliability values ​​of all bit indices can be obtained, and the code construction sequence based on these reliability values ​​can also be created by sorting the values ​​of θ(j) (j=0,1,…,N-1).

[0127] In one option, the reliability value calculation formula given in Formula 8 can be modified to generate code construction sequences for different modulation orders. For example:

[0128]

[0129] Using the modified formula, large a and the corresponding α(l) coefficients can be used to design more complex code construction sequences. A simple example would be to choose a=1 and α(0)=0.255 for all QAM modulation orders above 2 (QPSK). By modifying θ new(j) By sorting, a new code construction sequence for high-order modulation can be obtained.

[0130] In some cases, a new code sequence can be generated by modifying the original code construction sequence. For example, if additional memory is required to save the new sequence, this may be advantageous. In this case, modifying the original code construction can result in a more relaxed memory requirement relative to generating the new sequence.

[0131] Fig.10 An example of an original code construction sequence modified according to a method described herein is shown. In this example, a bias can be assigned to the reliability value of each component polarity code. For illustrative purposes, the reliability bias can be added to Fig.10 The code construction sequence shown in , for example, N=16.

[0132] In this example, each table 1010 and 1020 has reliabilities in the left column (1011, 1021) and input indices in the right column (1012, 1022). For example, input bit index 10 has a 9th reliability order. The selection of the second component code is shown in 1020 by gray shading. For each component polarity code or each group, a bias can be applied. p (p=0, 1, . . . , P-1) to generate a new code construction sequence for adaptive code construction. For example, o0=0 and o1=5 can be applied to 1010 and 1020.

[0133] Fig.11 An exemplary process of generating a new code structure by biasing is shown. At 1110 and 1120, the bias is added to the input bit index of the second component code (e.g., the second group), and 1130 shows the final new code structure sequence after sorting. Fig.10 As shown, the selection of the second component code is shown by gray shading, and each list may have a right column showing reliability (1111, 1121, 1131) and a left column for inputting indexes (1112, 1122, 1132). The new code construction sequence may have a reliability order different from the original sequence so that the second component polarity code has a higher reliability. When another code construction is needed, another bias value can be used, and similar multiple code construction sequences can be obtained. For the new code construction sequence, frozen bit indexes and unfrozen bit indexes (e.g., using one or more techniques described herein) can be selected, as shown in gray shading. For example, the most reliable K bits may be selected as unfrozen bits, and the remaining bits may be selected as frozen bits.

[0134] The code construction sequence described herein may represent the reliability order by an ordered sequence of integers (e.g., 0, 1, ..., N-1) that increments by a value of one, which may not show the relative reliability value of each input index. Therefore, when a new sequence is generated based on a bias, the reliability order of the new sequence may not simply correspond to the same value as the biased version of the original reliability order. To overcome this, the reliability of each input bit index may be described with higher precision to obtain a more accurate generation of the new sequence.

[0135] Fig.12An example of describing the reliability of the input bit index with higher precision is shown. By applying a bias based on the high-precision reliability order (e.g., Fig.11 ), a new code construction sequence can be generated without the distortion caused by simply incrementing the value by one (e.g., Fig.12 As shown, reliability 1201 does not increase by one. In some cases, the basis of the increment can be a bias value; depending on the bias value, the increment can be any value. In this case, the bias value can have a higher precision than the previous example. Higher precision can be obtained by quantizing the probability value in the probability calculation result (e.g., by density evolution code construction) or polarization weights.

[0136] Generally speaking, any technique disclosed herein with respect to polar encoding may also be applicable to the corresponding decoding process.

[0137] Once the modified code construction parameters are determined based on the increment ratio, the corresponding component code has a new code construction sequence, so some frozen bits can be converted to unfrozen bits or vice versa according to these new parameters. Using the new code construction sequence, the component code continues the standard polar encoding process to obtain the encoded bits.

[0138] In one case, the device may perform a process of channel coding using polar codes. The device may identify non-uniform channel condition parameters. The device may determine multiple component codes and multiple increment ratios for component codes based on non-uniform channel condition parameters to perform unequal error protection (UEP), wherein the component code includes multiple input bits. The device may determine initial code construction parameters based on uniform conditions for multiple component codes, wherein the initial code construction parameters may include an initial number of unfrozen input bits or an initial number of frozen input bits. Then, the device may determine modified code construction parameters based on increment ratios or multiple component codes, wherein the modified code construction parameters include a modified number of unfrozen input bits and a modified number of frozen input bits. Then, the device may encode multiple information bits using multiple component codes for transmission to be transmitted under non-uniform channel conditions according to the modified code construction parameters. This encoding may occur in an encoder. The operation in the disclosed encoder may result in a modification of the order of the encoded bit stream, which may be identified by comparing such bit streams produced by other encoding methods. In addition, the operational details for code construction can be determined by studying various test input (e.g., uncoded) bit streams and their corresponding coded bit stream results. Once encoded, the device can send transmission. In some cases, the non-uniform channel condition is the modulation order, and / or the modulation order can be based on the non-uniform channel condition. In some cases, the initial code construction parameters may be before the UEP. In some cases, the modified code construction parameters may be after the UEP. In some cases, the modified code construction parameters may further include a reliability sequence. In some cases, determining the initial code construction parameters may include calculating and comparing the reliability values ​​of each input bit in the component code. In some cases, calculating and comparing the reliability values ​​of each input bit in the component code may be performed according to a method based on polarization weights. In some cases, calculating and comparing the reliability values ​​of each input bit in the component code may be performed by further assigning a bias to each reliability value. In some cases, the device may be a wireless transmit receive unit (WTRU), a base station, a new radio network node, a network function entity, an access point, a site, an eNodeB or a gNodeB.

[0139] Although features and elements are described above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method for performing channel coding implemented by a device, the method comprising: Selecting a modulation order based on non-uniform channel conditions; determining modified code construction parameters for the plurality of component codes based on the selected modulation order, wherein the modified code construction parameters include a modified number of unfrozen input bits and a modified number of frozen input bits; encoding a plurality of information bits for transmission to be transmitted using the selected modulation order according to the modified code construction parameters and using the plurality of component codes; as well as The transmission is sent with a plurality of coded information bits.

2. The method of claim 1 , wherein the modified code construction parameters are further based on initial code construction parameters, wherein the initial code construction parameters are determined for the multiple component codes based on uniform channel conditions for the multiple component codes, wherein the initial code construction parameters include an initial number of unfrozen input bits and an initial number of frozen input bits, and wherein the uniform channel conditions are different from the non-uniform channel conditions.

3. The method of claim 1, wherein the non-uniform channel condition is determined from a channel experiencing varying conditions at a transceiver of the device.

4. The method of claim 2, wherein the uniform channel condition is determined from channels experiencing the same or similar conditions at a transceiver of the device.

5. The method of claim 3, wherein a set of modified code construction parameters is determined for each of a plurality of inhomogeneous channel conditions. The method according to claim 1 , wherein the modified code construction parameters further include a reliability sequence.

7. The method of claim 2, wherein each of the plurality of component codes comprises a plurality of input bits, wherein determining the initial code construction parameters comprises calculating and comparing reliability values ​​for each of the plurality of input bits in a component code. 8 . The method of claim 7 , wherein calculating and comparing the reliability value for each of the plurality of input bits in a component code is performed according to a polarization weight based method.

9. The method of claim 7, wherein calculating and comparing the reliability value for each of the plurality of input bits in the component code is performed by further assigning a bias to each reliability value.

10. The method of claim 1, wherein the device is a wireless transmit receive unit (WTRU), a base station, a new radio network node, a network function entity, an access point, a station, an eNodeB, or a gNodeB.

11. A device for performing channel coding, the device comprising: a processor operatively coupled to the transceiver, the processor and transceiver configured to select a modulation order based on non-uniform channel conditions; The processor and transceiver are configured to determine modified code construction parameters for a plurality of component codes based on the selection of the modulation order, wherein the modified code construction parameters include a modified number of unfrozen input bits and a modified number of frozen input bits; The processor and transceiver are configured to encode a plurality of information bits for transmission to be transmitted using the selected modulation order according to the modified code construction parameters and using the plurality of component codes; as well as The processor and transceiver are configured to send the transmission with a plurality of encoded information bits.

12. The device according to claim 11, wherein the modified code construction parameters are further based on initial code construction parameters, wherein the initial code construction parameters are determined for the plurality of component codes based on a uniform channel condition for the plurality of component codes, wherein the initial code construction parameters include an initial number of unfrozen input bits and an initial number of frozen input bits; and Wherein the uniform channel condition refers to a channel over which the transmission is to be sent experiencing the same or similar conditions at a transceiver of the device and wherein the uniform channel condition is different from the non-uniform channel condition.

13. The apparatus of claim 11, wherein the non-uniform channel condition is determined from a channel experiencing varying conditions at a transceiver of the apparatus, and a set of modified code construction parameters is determined for each of a plurality of non-uniform channel conditions.

14. The apparatus of claim 11, wherein the apparatus is a wireless transmit receive unit (WTRU), a base station, a new radio network node, a network function entity, an access point, a station, an eNodeB, or a gNodeB.

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