Waveform-based data integrity checking and error correction

Abstract

It is desirable to have an efficient data integrity check, EC, or ED for ZT, UW, and CP based waveforms that increases reliability, provides flexibility, maintains a high coding rate, and is adaptable to different device types.SOLUTION: A wireless transmit / receive unit (WTRU) may receive a unique word-error check (UW-EC) encoded signal. A pre-decoder data check entity may check for errors based on EC bits and systematic and parity bits from a UW-EC encoded signal. If no errors are detected at the pre-decoder data check entity, error-free data may be signaled to the source decoder without channel decoding.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to waveform-based data integrity checking and error correction. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 273,966, filed December 31, 2015, the contents of which are incorporated herein by reference.

[0003] Frequency division multiple access (FDMA) or orthogonal frequency division multiplexing (OFDM) waveforms using zero-tailed (ZT) or unique words (UW) are candidate wireless waveforms. ZT or UW can be used as a more resource-rich and energy-efficient alternative to redundancy schemes such as cyclic prefixes (CP) or null subcarriers. Waveforms using ZT or UW can achieve high reliability, low peak-to-average power ratio (PAPR), low out-of-band (OOB) leakage, and very high data rates, resulting in better quality of service (QoS).

[0004] Systems configured with waveforms using ZT, UW, or CP will require error detection (ED) or error checking (EC) to meet the reliability requirements of next-generation devices while maintaining high throughput or coding rates. ED or EC systems may also need to be flexible to handle different devices and corresponding frame structures, such as machine-to-machine (M2M), machine-type communication (MTC), wearable devices, and the Internet of Things (IoT).

[0005] Therefore, it is desirable to have an efficient data integrity check, EC, or ED, for ZT-, UW-, and CP-based waveforms that enhances reliability, provides flexibility, maintains high coding rates, and is adaptable to different device types. Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable to have an efficient data integrity check, EC, or ED, for ZT-, UW-, and CP-based waveforms that increases reliability, provides flexibility, maintains high coding rates, and is adaptable to different device types. [Means for solving the problem]

[0007] Error detection may be performed on the received waveform before channel decoding so that channel decoding may be bypassed when a packet is successfully detected by the predecoder data check. If packet decoding is unsuccessful by the predecoder data check, channel decoding and error checking may be performed. The predecoder data check may use existing or derived signals that may explicitly or implicitly indicate an error check pass / success or fail / fail condition. [Brief explanation of the drawings]

[0008] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which:

[0009] [Figure 1A] 1 is a diagram of an exemplary communication system in which one or more embodiments may be implemented. [Figure 1B] 1B is a diagram of an exemplary wireless transmit / receive unit (WTRU) used within the communication system of FIG. 1A. [Figure 1C] 1B is a system diagram of an example radio access network and core network used within the communication system of FIG. 1A. [Figure 2] FIG. 1 is a diagram of a zero-tailed (ZT) discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (s-OFDM) (DFT-s-OFDM) transmitter. [Figure 3] FIG. 1 is a diagram of a unique word (UW)-OFDM transmitter and receiver. [Figure 4] FIG. 1 is a diagram of a UW DFT-s-OFDM transmitter and receiver that may use non-zero redundant symbols. [Figure 5] Transmitter for unique word error check (UW-EC) waveform. [Figure 6] This is a receiver for checking UW-EC signal data. [Figure 7] Transmitter for UW-EC Cyclic Redundancy Check (CRC) (UW-EC-CRC) signal diversity. [Figure 8] This is a receiver for the UW-EC-CRC diversity system. [Figure 9] A transmitter for UW-EC on CRC signals. [Figure 10] UW-EC on CRC signal data check for receiver. [Figure 11] 1 is a diagram of a sub-block virtual CRC (VCRC) structure. [Figure 12] This is a systematic rate-compatible insertion convolutional (RCIC) encoder. [Figure 13] FIG. 1 is a diagram of UW-EC waveform generation. [Figure 14] FIG. 1 is a process diagram for generating and transmitting a UW-EC waveform. [Figure 15] FIG. 1 is a process diagram for receiving and demodulating a UW-EC waveform. DETAILED DESCRIPTION OF THE INVENTION

[0010] For the methods and processes described below, the recited steps may be performed in any order out of sequence, and substeps not explicitly described or shown may be performed. Additionally, "coupled," "operably coupled," "communicating," and the like may mean that entities are linked or in communication, but that there may be zero or more intermediate entities between the linked entities. Also, any combination of the disclosed features / elements may be used in one or more embodiments. When referring to "A or B," it may include A, B, or A and B, and may similarly be extended to longer lists. When using the notation X / Y, it may include X or Y. When using the notation X / Y, it may also include X and Y. The notation X / Y may similarly be extended to longer lists with the same foregoing logic.

[0011] Elements shown in the figures or described herein may be implemented by one or more functions or components in hardware, software, firmware, etc. Additionally, in the examples herein, a transmitter may be a transceiver or part of multi-component hardware if desired. A receiver may be a transceiver or part of multi-component hardware if desired. Finally, the term data or information in the examples herein may include control data, control information, control packets, user data, user information, payload data, payload information, data packets, general data, or general information.

[0012] 1A is a diagram of an example 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, broadcasts, etc., to multiple wireless users. The communication system 100 may enable the multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may use 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), etc.

[0013] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, and 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, WTRUs 102a, 102b, 102c, and 102d may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, consumer electronics devices, etc.

[0014] The communications system 100 may also include a base station 114a and a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d and facilitate access to one or more communications networks, such as the core network 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 Node B, an eNodeB, a Home Node B, a Home eNodeB, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each shown as a single element, it should be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0015] The base station 114a may be part of the RAN 104, which may include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals within a particular geographic area, sometimes referred to as a cell (not shown). A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In another embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology and thus may use multiple transceivers for each sector of the cell.

[0016] 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 communications link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0017] More specifically, as noted above, the communications system 100 may be a multiple-access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a and the WTRUs 102a, 102b, 102c in the RAN 104 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using Wideband CDMA (W-CDMA). W-CDMA may include communications protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0018] In another 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 Enhanced LTE (LTE-A).

[0019] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as 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), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0020] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may use any suitable RAT for facilitating wireless connectivity in a local area, such as a business, home, vehicle, campus, etc. 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 another 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 use a cellular-based RAT (e.g., W-CDMA, cdma2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 through the core network 106.

[0021] The RAN 104 may communicate with the core network 106, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it should be understood that the RAN 104 and / or core network 106 may communicate directly or indirectly with other RANs that use the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be using E-UTRA radio technology, the core network 106 may also communicate with another RAN (not shown) that uses GSM radio technology.

[0022] The core network 106 may also serve 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 providing 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 Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another core network connected to one or more RANs that may use the same RAT as the RAN 104 or a different RAT.

[0023] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities, i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may use a cellular-based radio technology and a base station 114b that may use an IEEE 802.11 radio technology.

[0024] 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include 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 other peripherals 138. It should be understood that the WTRU 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0025] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple 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) circuit, 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 functionality that enables 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. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it should be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0026] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) over the 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 another embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR signals, UV signals, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and receive both RF signals and light signals. It should be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0027] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use 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.

[0028] 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 UTRA and IEEE 802.11, for example.

[0029] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 133. The non-removable memory 130 may include random access memory (RAM), 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, etc. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0030] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components within 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 batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0031] The processor 118 may also be coupled to a GPS chipset 136 that may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (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 should be understood that the WTRU 102 may acquire location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0032] Additionally, the processor 118 may be coupled to other peripherals 138, which may include one or more software 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 (e-compass), a satellite transceiver, a digital camera (for photos or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, etc.

[0033] 1C is a system diagram of the RAN 104 and the core network 106 according to one embodiment. As noted above, the RAN 104 may use E-UTRA radio technology and communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the core network 106.

[0034] While the RAN 104 includes eNodeBs 140a, 140b, and 140c, it should be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 140a, 140b, and 140c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNodeBs 140a, 140b, and 140c may implement MIMO technology. Thus, for example, the eNodeB 140a may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0035] Each of the eNodeBs 140a, 140b, 140c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users on the uplink and / or downlink, etc. As shown in FIG. 1C, the eNodeBs 140a, 140b, 140c may communicate with one another via an X2 interface.

[0036] 1C may include a mobility management entity gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146. Although each of the foregoing elements is shown as part of the core network 106, it should be understood that any one of these elements may be owned and / or operated by an entity other than the core network operator.

[0037] The MME 142 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 142 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 142 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that use other radio technologies such as GSM or W-CDMA.

[0038] The serving gateway 144 may be connected to each of the eNodeBs 140a, 140b, 140c in the RAN 104 via an S1 interface. The serving gateway 144 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The serving gateway 144 may also perform other functions such as anchoring the user plane during inter-eNodeB handover, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0039] The serving gateway 144 may also be connected to a PDN gateway 146, 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.

[0040] The core network 106 may facilitate communication with other networks. For example, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, and may facilitate communication between the WTRUs 102a, 102b, 102c and traditional landline communication devices. For example, the core network 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the core network 106 and the PSTN 108. Additionally, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to networks 112, which may include other wired or wireless networks owned and / or operated by other service providers.

[0041] Additionally, the other network 112 may be connected to an IEEE 802.11-based wireless local area network (WLAN) 160. The WLAN 160 may include an access router 165. The access router may include a gateway function. The access router 165 may communicate with multiple access points (APs) 170a, 170b. Communication between the access router 165 and the APs 170a, 170b may be via wired Ethernet (IEEE 802.3 standard) or any type of wireless communication protocol. The AP 170a communicates wirelessly with the WTRU 102d over the air interface.

[0042] To save power, reduce complexity, and reduce latency, channel decoding may be skipped or bypassed in a receiver or transceiver if a received packet, frame, or channel transmitted over a generic or unique word-error checking (UW-EC) waveform is successfully detected for the examples given herein. Channel decoding may also be skipped or bypassed if an error is detected before channel decoding for the examples given herein.

[0043] Wireless applications and devices may require gigabit-per-second throughput, simple architecture, operation in high-traffic-density areas, very low latency, and very low power consumption. Such applications or devices may include tactile Internet, Internet of Things (IoT), sensors, mission-critical communications (MTC), millimeter-wave (mmWave) systems, highly reliable and low-latency communications (URLLC), enhanced mobile broadband (eMBB), etc. To meet this requirement, enhancements to fifth-generation (5G) radio access networks include new radio waveforms.

[0044] Orthogonal frequency division multiplexing (OFDM) is used in networks such as LTE, Wi-Fi, and 802.11x due to its ability to transform frequency-selective channels into smaller, flat-fading subchannels. Flat-fading subchannels may be desirable because they may allow for simpler, or one-tap, equalization per subchannel at the receiver or transceiver. A variant of OFDM, DFT-s-OFDM, improves the peak-to-average power ratio (PAPR) of OFDM by spreading the data sequence with a DFT before the spreading signal is added to the subchannel.

[0045] Both OFDM and discrete Fourier transform spread OFDM (DFT-s-OFDM) may use a cyclic prefix (CP) to prevent or reduce intersymbol interference (ISI) that can occur due to different channel delay spreads and maintain symbol cyclicity. For system simplicity, the length of the CP may be fixed and based on the maximum delay spread of the channel or cell. As a result, spectral efficiency may be lost when the channel delay spread is smaller than the CP duration. This efficiency loss can be significant with large variance in the root-mean-square (RMS) delay spread of the channel. For example, in mmWave channels, the delay spread can be less than 4 nanoseconds (ns) under line-of-sight (LOS) conditions and up to 70 ns under indoor non-line-of-sight (NLOS) conditions for indoor channels. Because changing the CP size can change the number of OFDM symbols in a subframe, systems configured with or supporting multiple different CP sizes may add processing complexity due to a fixed subframe duration or time interval.

[0046] Zero-tailed (ZT) DFT-s-OFDM or unique word (UW) OFDM waveforms can be configured to efficiently accommodate or handle variable CP sizes, variable channel delay spreads, variable cell sizes, etc. Also, ZT DFT-s-OFDM waveforms can be decoupled from channel characteristics in some configurations, and the duration of ZT can be dynamically adapted to the channel delay spread without any change to the OFDM symbol duration. Finally, ZT can be used as a gap for beam switching, uplink (UL) / downlink (DL) switching, interference measurements in mmWave channels, etc.

[0047] 2 is a diagram of a ZT DFT-s-OFDM transmitter 202. In ZT DFT-s-OFDM, ZT is the number of N at the head of the DFT spreading component or function 208. h as zero (204) and N in the tail t The data (203) can be generated by adding zeros as the zeros (206). d =MNt -N h The bits output by the DFT spreading component or function 208 may be mapped to subcarriers by the subcarrier mapping component or function 210. The size of the DFT spreading component or function 208 may be represented as M, and the size of the inverse fast Fourier transform (IFFT) component or function 212 may be represented as N_IFFT. Correspondingly, at the output of the IFFT component or function 212, there may be M data symbols 214 and (N_IFFT / M-1) interpolated samples. For this configuration, a zero input to the DFT spreading component or function 208 results in a head N of data symbols 214 at the output of the IFFT component or function 212. Zh Zero (216) and tail N Zt It can be distributed over zero (218).

[0048] The tails may not be exactly or substantially perfectly zero due to sample interpolation. Also, because the interpolated samples may be data-dependent, the zero tails may vary between DFT-s-OFDM symbols, resulting in a loss of the desirable cyclic property of the OFDM signal and greater ISI. Correspondingly, for some data types, a ZT DFT-s-OFDM signal may have a bit error rate (BER) floor at high signal-to-noise ratios (SNRs) in high delay spread channels.

[0049] 3 is a diagram of a unique word (UW)-OFDM transmitter 302 and receiver 318. By adding a UW 301 to the data symbols 300 at the transmitter 302, the tail or head of each OFDM block or symbol may have substantially zeros, perfect zeros, near-zeros, or zero samples. The UW 301 may use a constant tail for each block or symbol so that the channel may be transformed from linear to circular convolution, allowing for simpler receiver / transceiver structure and operation. Additionally, the UW 301 may be used as a training field at the receiver to track phase drift, multipath delay, etc.

[0050] In the transmitter 302, data 303 may be converted into a parallel stream by a serial-to-parallel (S / P) converter component or function 304. A data vector d may be output by the S / P component or function 304 and signaled or provided to a permutation matrix P component or function 306. The data vector d may also be signaled or provided to a zero-tail generator component or function 305 to create redundant subcarriers r and generate zero, perfect zero, near-zero, or zero samples at the tails of the OFDM block or symbol. The redundant subcarriers r may be modulated with values ​​generated by the zero-tail generator component or function 305. The permutation matrix P component or function 306 may map the redundant subcarriers r and elements of the data vector d to be transformed into the time domain by an inverse DFT component or function 308 to create an output signal x.

[0051] A fixed UW vector u generated by UW component or function 310 may be added to the tail of output signal x by summation component or function 309 to produce signal t. Signal t may be parallel-to-serial converted by parallel-to-serial (P / S) component or function 312 and then transmitted using antenna 314. Transmissions by transmitter 302 may proceed over channel H to receiver 318 and be received by antenna 320. Signals received by receiver 318 may be processed by S / P component or function 322 to generate parallel information streams, which are transformed to the frequency domain by DFT component or function 324 and equalized in the frequency domain by frequency-domain equalizer (FDE) component or function 326. The UW may be output by UW component or function 329 and subtracted from the output signal of FDE component or function 326 by subtraction components or functions 327, 328. An inverse permutation matrix component or function 330 may use the outputs of the subtraction components or functions 327, 328 to recover the data vector d and the signal X 331. The data vector d is converted to a serial stream 334 by a P / S component or function 332.

[0052] In some configurations, the norm of the redundant subcarriers r may be large for a UW OFDM signal or waveform, resulting in high power consumption at the transmitter 302 and possible distortion due to equalization errors. The permutation matrix P components or functions 306 may be optimized by changing or varying the positions of the redundant subcarriers to reduce large values ​​of the redundant subcarriers r and signal distortion. Reduction and optimization of large values ​​may also be achieved through heuristic algorithms for the permutation matrix P components or functions 306 and adjustments to all allocated subcarriers to generate ZT for the output signal x. However, varying all subcarriers to generate ZT may result in a more complex receiver structure at the receiver 318.

[0053] 4 is a diagram of a UW DFT-s-OFDM transmitter 401 and receiver 402 that may use non-zero redundant symbols. The UW DFT-s-OFDM waveform may use pulse shaping to reduce the energy consumption caused by the UW. Similar to the ZT DFT-s-OFDM, data symbols in the UW DFT-s-OFDM may also be mapped to the central portion of the DFT spreading block 415. Furthermore, rather than placing zero-redundancy symbols at either end or both ends of the DFT spreading block 415, non-zero redundant symbols may be used to suppress leakage energy in the tails of the waveform at the transmitter 401.

[0054] The UW DFT-s-OFDM waveform may consume very low energy to null the tail, which may result in lower ISI, lower PAPR, and lower out-of-band (OOB) emissions in high-multipath distortion environments. Furthermore, because the UW may be inserted at the input DFT-spreading block 415, the receiver 402 may be able to remove the UW and data symbols without extra operations, with reduced complexity. As a result, the UW DFT-s-OFDM waveform can be decoded by any DFT-s-OFDM receiver. Therefore, a DFT-s-OFDM receiver or transceiver may, in part, both decode the UW DFT-s-OFDM waveform or the DFT-s-OFDM waveform.

[0055] In the transmitter 401, data 404 may be transformed by an S / P component or function 406 to generate a data vector d. The transmitter 401 may generate suppressed DFT-s-OFDM symbols at the tails of one or more DFT-s-OFDM symbols using a tail suppression component or function 410. Similarly, suppressed DFT-s-OFDM symbols at the heads of one or more DFT-s-OFDM symbols may be placed or configured by the transmitter 401 on the data 404.

[0056] The suppression signal s may be combined with the UW by summing component or function 414 to generate a suppression vector r that provides a zero tail to the data vector d. The UWu may be generated by the UW component or function 412. In the transmitter 401, N d represents the number of modulation symbols, and N r may be usable dimensions for the tail suppression component or function 410.

[0057] The permutation matrix P components or functions 408 permutes the elements of the modulation symbols and suppression vector r from the sub-spreading matrix D 1 416 to D K 418 to the input of the DFT spreading block 415. K 418 may modulate the data symbols using the values ​​produced by the tail suppression component or function 410. The lower-end DFT sub-spreading matrix D K 418 is M header,K and M tail,K Using M K The upper-end DFT sub-spreading matrix D1416 can be configured to generate M header,1 and M tail,1 M1 can be generated using

[0058] The output of DFT spreading block 415 may be shaped in the frequency domain by a shaping matrix component or function 420 to construct a matrix B for different pulse shapes and converted to the time domain by an inverse DFT component or function 422. An output signal x is generated and, after parallel-to-serial conversion by a P / S component or function 424, transmitted using antenna 426.

[0059] The UW-DFT-s-OFDM receiver 402 may perform substantially the inverse operation of the transmitter 401 while taking into account the effects of the communication channel. An antenna 428 receives the transmission by the transmitter 401. The received signal is serial-to-parallel converted by an S / P component or function 430 to produce a vector y, which is processed by a DFT F component or function 432. The output of the DFT F component or function 432 is then fed to a receiver shaping matrix B for shaping and subsequent equalization by an FDE component or function 436. H 434. The FDE component or function 436 may use any one of minimum mean square error (MMSE), zero forcing, best linear least unbiased estimator (BLUE), or similar functions.

[0060] The despreading block 442 uses the matrix S to despread the output of the FDE component or function 436. H The sub-despreading matrix D1 H 440 to D K H 438. The despreading block 442 may include the data vector

[0061]

number

[0062] and signal

[0063]

number

[0064] To recover the matrix P H The result is communicated to the inverse or receiver permutation matrix 444 using the data vector

[0065]

number

[0066] may be parallel-to-serial converted by a P / S component or function 446 to produce data 447 .

[0067] In the following example, error detection may be performed on the received waveform before channel decoding so that data or data integrity check channel decoding may be bypassed when a packet is successfully detected by the pre-decoder. If packet decoding is unsuccessful by the pre-decoder, data integrity check, channel decoding, and error checking may be performed. The pre-decoder data integrity check may use existing or derived signals that may explicitly or implicitly indicate an error check pass / success or fail / fail condition.

[0068] The generic pre-decoder data integrity check mechanism may be used for data packets, control packets, data channels, control channels, broadcast channels, etc., or any combination thereof. The generic pre-decoder data integrity check mechanism may be applied to the UL channel or the DL channel.

[0069] Also in the following examples, codebook-based error checking or error checking encoding may be used. The codebook may use spreading codes, masking, orthogonal codes, etc. to add EC bits to the UW waveform and generate a UW-EC waveform. Furthermore, error checking or error check bits may be configured to be incorporated into the UW-EC waveform. The UW-EC may be an orthogonal-containing sequence that carries some EC bits or may be embedded within the UW waveform.

[0070] The UW-EC sequence may be selected according to an error checking function (ECF). The ECF may generate EC bits from systematic bits by adding an EC function to the data, CRC, or data and CRC as desired. The ECF may use a parity check function, a CRC function, etc. The UW-EC may be transmitted in a UW-based waveform. The UW or UW-based waveform may be one or any combination of UW-OFDM, ZT-OFDM, ZT FDMA, UW DFT-s-OFDM, or similar waveforms.

[0071] Codebook-based error checking or pre-decoder data integrity check may also be applicable to CP-based OFDM or DFT-s-OFDM waveforms, where EC sequences may be transmitted as a fixed or known set of sequences. For example, a reference signal may be used to transmit EC sequences as a fixed or known set of sequences in, but not limited to, a CP-based OFDM or DFT-s-OFDM waveform. Zadoff-Chu sequences with a cyclic shift may be used to transmit EC sequences. The reference signal may be a dedicated reference signal, a demodulation reference signal (DMRS), a sounding reference signal (SRS), a beam reference signal (BRS), a mobility reference signal (MRS), etc. Sequences other than Zadoff-Chu sequences, with or without a cyclic shift, may also be used to transmit EC sequences or EC bits.

[0072] FIG. 5 is a diagram of a transmitter 502 for a UW-EC waveform. An error check function (ECF) may be predefined or configured to generate EC bits from systematic bits by adding an EC function to the data. It may be desirable to use a UW for error checking in the transmitter 502 instead of a CRC because the UW may already be available and may reduce overhead if the UW is used to replace or assist the CRC for error checking. Codebook-based UW-EC may also be desirable because error checking may be performed before decoding, so that decoding latency may be reduced or eliminated at the receiver or transceiver. Furthermore, if a UW is used in addition to the CRC for enhanced error checking, backward compatibility with existing CRC checks may be maintained, which is desirable.

[0073] Data 504 may be signaled to a source encoder 506 and to a channel encoder 508 to generate systematic bits 514. The data 504 may be a data packet, a control packet, or any combination thereof, related to transmission in the UL or DL ​​via any combination of a data channel, a control channel, a broadcast channel, etc. In the transmitter 502, the systematic bits 514 may be generated without a cyclic redundancy check (CRC) or parity bit. The systematic bits 514 may be generated by a channel encoder 508. The channel encoder 508 may be a channel encoder that uses a systematic channel code, such as a systematic polar code, a low-density parity check (LDPC), a turbo code, a convolutional code, a block code, or any combination thereof. EC functionality may be added by signaling the systematic or data bits without a CRC to an EC bit generator 516 to generate EC bits. The EC bits may be used in a UW-EC codeword selection component or function 522 to select a UW-EC codeword, such as u or c, from a UW-EC codebook component or function 520 .

[0074] A UW waveform generator component or function 512 may generate a UW waveform based on the systematic and parity bits 510 from the channel encoder 508. The UW waveform may be generated as described for transmitter 302, transmitter 401, etc. A UW-EC codeword may be selected to generate a UW-EC sequence that may be added by a UW-EC component or function 524 to the signal at the UW waveform generator component or function 512 by inserting c or adjusting u. When adjusting u, the condition in equation (1) may be required. M 22 u=c formula (1) The UW-EC waveform may be generated by a UW-EC waveform component or function 526 to be sent as a transmit signal 528 .

[0075] 6 is a diagram of a receiver 602 for UW-EC signal data checking. A received signal 604 is processed by a UW-EC waveform component or function 606 to detect the UW-EC sequence and provide a signal to a data demodulation component or function 608. The UW-EC waveform component or function 606 also provides a signal to a UW-EC codeword detection component or function 610. The UW-EC codeword c can be detected by the UW-EC codeword detection component or function 610 using a UW-EC codebook component or function 612. The receiver 602 can communicate with the transmitter 502 such that the UW-EC codebook component or function 612 is synchronized with the UW-EC codebook component or function 520. Furthermore, the codebook can be predefined or configured so that the receiver 602 decodes the received signal 604 using a blind detection algorithm.

[0076] EC bits are generated from the codeword c by an EC bit recovery component or function 614. If a successful packet or channel data can be detected before channel decoding by a low bit error rate (BER) pre-decoder data check component or function 616 using the EC bits and systematic bits without the CRC and parity bits signaled or provided by the data demodulation component or function 608, processing by the channel decoder 618 may be bypassed. For any of the examples given herein, the pre-decoder data check may be used interchangeably with the pre-decoder data integrity check. Skipping or bypassing channel decoding may reduce complexity, power consumption, and latency at the receiver 602. Instead, error-free data 624 may be signaled to the source decoder 622, which may output data 626. The channel decoder 618 may be configured to perform turbo decoding, convolutional decoding, LDPC channel decoding, polar decoding, systematic polar decoding, block decoding, etc.

[0077] If the RawBER pre-decoder data check component or function 616 is unable to successfully detect the packet or channel data, channel decoding or additional error checking may be required at the receiver 602. The demodulated data by the data demodulation component or function 608 may be signaled as systematic bits without CRC and parity bits and used by the RawBER pre-decoder data check component or function 616 to signal erroneous data 617 to the channel decoder 618. The channel decoded data is signaled to a codedBER-based EC check component or function 620, which uses the EC bits to output a signal for the source decoder 622 to process and output the source decoded data 626.

[0078] The receiver 602 may be configured to use multi-layer data error checking. For example, when using two layers, the first-layer data error check may include a coarse data error check. If no errors are detected in the first layer, the receiver 602 may bypass processing by the channel decoder 618 and skip the second-layer or fine data error check. Correspondingly, error-free data 624 is signaled to the source decoder 622. If the first-layer or coarse data error check is unsuccessful, the receiver 602 may perform channel decoding and the second-layer or fine data error check.

[0079] The first layer or coarse data error checking may be performed by the RawBER pre-decoder data check component or function 616. The second layer or fine data error checking may be performed by the codedBER EC check component or function 620 after channel decoding by the channel decoder 618. The second layer or fine data error checking may not be used unless there are data errors detected by the first, or coarse layer data error checking. Furthermore, using the codedBER EC check component or function 620 after channel decoding may improve packet error rate (PER) or block error rate (BLER) performance when data errors are detected by the RawBER pre-decoder data check component or function 616.

[0080] The receiver 602 may use a channel quality indicator (CQI) or signal-to-interference-and-noise ratio (SINR) pre-decoder data check. The CQI or SINR may be used to indicate or determine the channel conditions experienced by the received signal 604. For a CQI-based receiver, if the CQI value is substantially high or exceeds a threshold, better channel conditions may be inferred, and the probability of passing the error check may be higher. Furthermore, the CQI pre-decoder data check may be configured without link adaptation at the receiver 602, so that the CQI may be used to indicate the pass, success, failure, or unsuccessful status of the error check without maintaining the PER or BLER at a fixed, set, or predetermined value.

[0081] A CQI range may be used for the CQI pre-decoder data check. The CQI range may be predetermined, signaled, negotiated with the transmitter, predefined, indexed in a CQI table, etc. Also, the CQI range or associated threshold may be based on simulation, dynamic, adjustable, based on system throughput, based on BLER, based on buffer occupancy, based on buffer status, determined using an SINR value, etc. When the CQI value is substantially within the range, the pre-decoder data check may be performed. Otherwise, pre-decoder and post-decoder data checks may be used, or data may be discarded before channel decoding.

[0082] As an example, the receiver 602 may be configured to use two CQI ranges. A high CQI range may be defined to indicate favorable or desirable channel conditions, and a low CQI range may be defined to indicate unfavorable or undesirable channel conditions. If the measured CQI is substantially within the high CQI range, the receiver 602 may perform a coarse or first-tier pre-decoder data check without channel decoding in the channel decoder 618, signal error-free data 624 to the source decoder 622, and generate or recover output data 626. If the measured CQI is substantially within the low CQI range, fine or second-tier channel decoding may be performed in the channel decoder 618 and error checking in the coded BER EC check component or function 620, followed by generating or recovering output data 626.

[0083] As another example, the receiver 602 may be configured to use three CQI ranges: a high CQI range to indicate favorable or desirable channel conditions and a very high likelihood of passing or succeeding the data check; a low CQI range to indicate unfavorable or undesirable channel conditions and a low likelihood of passing or succeeding the data check; and a very low CQI range to indicate substantially worst-case channel conditions where the data check cannot be passed or succeeded. If the measured CQI is substantially within the high CQI range, the receiver 602 may perform a coarse or first-layer pre-decoder data check without channel decoding in the channel decoder 618, signal error-free data 624 to the source decoder 622, and generate or recover output data 626. If the measured CQI is substantially within the low CQI range, fine or second-layer channel decoding may be performed in the channel decoder 618 and error checking may be performed in the coded BER EC check component or function 620, followed by generating or recovering output data 626. If the measured CQI is substantially within a very low CQI range, the receiver 602 may discard the packet. The examples given herein for using CQI may work similarly if SINR is used as the metric for determining when to perform channel decoding.

[0084] The receiver 602 may provide high-speed or low-latency hybrid automatic repeat request (HARQ) by bypassing or skipping channel decoding at the channel decoder 618. A pre-decoder data check may also lead to early detection of a successful data packet, data block, data segment, etc., so that HARQ latency may be reduced. As an example, multi-layer HARQ data checks may be configured. In the receiver 602, a pre-decoder error check may be performed by a UW-EC data check at the RawBER pre-decoder data check component or function 616 when a data packet is received. If the pre-decoder error check is passed or successful, the receiver 602 may trigger a first-layer HARQ without channel decoding or further (e.g., second-layer) HARQ processing. An acknowledgement (ACK) may also be communicated to the transmitter 502. If the pre-decoder error check is unsuccessful or fails due to an error, the receiver 602 may perform channel decoding at the channel decoder 618 and perform a second-layer HARQ. The receiver 602 may then feed back an acknowledgement (ACK) or a negative acknowledgement (NACK) to the transmitter 502 based on the CRC check.

[0085] The first layer HARQ may be configured or designed as a fast HARQ pre-decoder data check so that HARQ latency and power consumption are reduced when bypassing channel decoding and CRC check, and the second layer HARQ may include a post-decoder data integrity check to maintain backward compatibility with legacy HARQ procedures if an error is detected by the pre-decoder data check entity.

[0086] 7 is a diagram of a transmitter 702 for UW-EC-CRC signal diversity. The transmitter 702 may use both CRC and UW-EC error checking, thereby achieving diversity; if one check fails, the other may be used for error checking. Furthermore, both error checking procedures may be used for extended protection, which may be desirable for critical data or control communications, such as 911, emergencies, etc.

[0087] When combined with UW-EC, the CRC can improve performance by increasing robustness and diversity for error-sensitive or high-interference channels. Data 704 may pass from source encoder 706 to a CRC component or function 708, where a CRC may be appended. The output of the CRC component or function 708 may be signaled to a channel encoder 710, which generates systematic bits with CRC and parity bits. Channel encoder 710 may be, but is not limited to, a polar code, a systematic polar code, an LDPC code, a turbo code, etc. The systematic bits, which may include the data with the CRC appended, may be signaled to an EC bit generation component or function 714, which adds an EC function for the data or the CRC and the data. The EC bits are used by a UW-EC codeword selection component or function 716 to select a UW-EC codeword u or c from a UW-EC codebook component or function 718.

[0088] The UW waveform generator component or function 712 may generate a UW waveform based on systematic bits, which may include data appended with a CRC, output from the channel encoder 710. The UW waveform may be generated by a component such as the transmitter 302 or the transmitter 401. The UW-EC codeword may be used to generate a UW-EC sequence, which may be added to the UW waveform generated by the UW waveform generation component or function 712 by inserting c or adjusting u in the addition component or function 720. The adjustment of u may be performed by satisfying the condition, i.e., M 22 u=c formula (2) The UW-EC waveform may be generated by a UW-EC waveform component or function 722 and communicated as a transmit signal 724 .

[0089] 8 is a diagram of a receiver 802 for the UW-EC-CRC diversity scheme. The receiver 802 may detect a UW-EC sequence from a received signal 804 at a UW-EC waveform component or function 806. The UW-EC codeword c may be detected by a UW-EC codeword detection component or function 810 using a UW-EC codebook component or function 812. The receiver 802 may communicate with the transmitter 702 such that the UW-EC codebook component or function 812 may be synchronized with the UW-EC codebook component or function 718. Furthermore, as will be appreciated by those skilled in the art, two codebooks may be predefined or configured such that the receiver 802 may decode the received signal 804 using a blind detection algorithm.

[0090] The EC bits may be generated from the codeword c by the EC bit recovery component or function 814. If the packet or channel data can be successfully detected by the UW-EC-CRC pre-decoder data check component or function 816 using the EC bits, the CRC output, and / or the systematic bits with the CRC and parity bits generated by the data demodulation component or function 808, processing by the channel decoder 820 may be bypassed. Instead, the error-free output data 826 is signaled to the source decoder 824, which outputs data 828. The channel decoder 820 may be configured to perform turbo decoding, convolutional decoding, LDPC channel decoding, polar decoding, block decoding, etc.

[0091] If the UW-EC-CRC pre-decoder data check component or function 816 cannot successfully detect the packet or channel data using the EC bits, the CRC output, and / or the systematic bits with CRC and parity bits, channel decoding or additional error checking may be required at the receiver 802. The demodulated data by the data demodulation component or function 808 is signaled as systematic bits with CRC and parity bits and used by the UW-EC-CRC pre-decoder data check component or function 816 to signal erroneous data 818 to the channel decoder 820. The channel decoded systematic bits may be signaled to a CRC check component or function 822 to detect errors and output a signal for the source decoder 824. The source decoder 824 may output data 828 by using the CRC checked output of the CRC check component or function 822.

[0092] For communications between the transmitter 702 and the receiver 802, substantially the same UW-EC sequence may be used for every symbol of a transmission time interval (TTI). This configuration may be desirable to maintain cyclicity within the TTI. As another example, the UW-EC or CRC may be split across multiple symbols within the TTI. This configuration may reduce the complexity of blind detection at the receiver 802 by reducing some codes or sequences, or may reduce code or sequence length at the expense of possible reduced cyclicity, which may require advanced signal processing.

[0093] FIG. 9 is a diagram of a transmitter 902 for a UW-EC on CRC signal. Data 904 may pass from a source encoder 906 and a CRC component or function 908 to a channel encoder 910, which generates systematic bits with CRC and parity bits. The output of the CRC component or function 908 may be signaled to a channel encoder 910, which generates systematic bits with CRC and parity bits. The channel encoder 910 may use a polar code, a systematic polar code, an LDPC code, a turbo code, etc. The systematic bits, which may include the data with the CRC appended, may be signaled to an EC bit generator component or function 914, which adds an EC function to the CRC portion. The EC bits may be used by a UW-EC codeword selection component or function 916 to select a UW-EC codeword u or c from a UW-EC codebook component or function 918.

[0094] The UW waveform generator component or function 912 may generate a UW waveform based on the systematic and parity bits from the channel encoder 910. The UW waveform may be generated by a component such as transmitter 302, transmitter 401, etc. The UW-EC codeword may be used to generate a UW-EC sequence that is added to the UW waveform generated in the UW waveform generation component or function 912 by inserting c or adjusting u in an addition component or function 920. The adjustment of u may be performed by satisfying the condition, i.e., M 22 u=c formula (3) The UW-EC waveform may be generated by a UW-EC waveform component or function 922 and communicated as a transmit signal 924 .

[0095] FIG. 10 is a diagram of a receiver 1002 for UW-EC-on-CRC signal data checking. The UW-EC-on-CRC scheme can be implemented in at least two steps. At the transmitter, a CRC can be fed to the input of an EC generation block using an ECF function to generate EC bits or UW-EC bits that can be used to generate a UW-EC code or sequence. At the receiver, at least two steps can be implemented by using the UW-EC to check the explicit CRC bits and, if successful / passing, using the passed explicit CRC bits to check the data. The receiver 1002 can detect the UW-EC sequence from the received signal 1004 at a UW-EC waveform component or function 1006. The UW-EC codeword c can be detected by a UW-EC codeword detection component or function 1010 using a UW-EC codebook component or function 1012. The receiver 1002 may communicate with the transmitter 902 such that the UW-EC codebook component or function 1012 may be synchronized with the UW-EC codebook component or function 918. Additionally, as will be appreciated by those skilled in the art, the two codebooks may be predefined or configured such that the receiver 1002 may decode the received signal 1004 by using a blind detection algorithm.

[0096] EC bits may be generated from the codeword c by an EC bit recovery component or function 1014. A UW-EC on CRC pre-decoder data check component or function 1016 uses the EC bits to perform an error check against the CRC generated by the demodulation component or function 1008 to detect data errors. If successful, such as based on a correct CRC, a data integrity check may be performed on the systematic bits for a CRC error check using the "correct CRC" by a CRC check component or function 1026. If the CRC check is successful, channel decoding by the channel decoder 1020 may be bypassed and error-free data 1028 is signaled to the source decoder 1024, which outputs data 1025. The channel decoder 1020 may be configured to perform turbo decoding, convolutional decoding, LDPC channel decoding, polar decoding, block decoding, etc.

[0097] If the CRC error check by the CRC check component or function 1026 is unsuccessful, such as based on an incorrect or failed data integrity check, channel decoding or additional error checking may be required at the receiver 1002. The demodulated data generated by the data demodulation component or function 1008 is signaled as systematic bits with CRC and parity bits and used by the UW-EC on CRC pre-decoder data check component or function 1016 to signal erroneous data 1018 to the channel decoder 1020. In addition to the systematic bits with CRC and parity bits, the channel decoder 1020 may use the unsuccessful error check result from the CRC check component or function 1026 to decode and then signal to the CRC check component or function 1022. The CRC check component or function 1022 may function as an additional layer for detecting errors and outputting a signal for the source decoder 1024. The source decoder 1024 may output data 1025 by using the CRC checked output of the CRC check component or function 1022 .

[0098] The configuration of the transmitter 902 and receiver 1002 may enable error checking on an explicit CRC instead of data bits by using UW-EC. Using UW-EC on CRC may ensure the correctness of the CRC before error checking is performed on the data. This may reduce the UW-EC sequence length because the CRC length may generally be shorter than the data. Therefore, fewer UW-EC sequences may be required for communication. For some applications, UW-EC on CRC may significantly reduce detection complexity and detection errors at the receiver 1002.

[0099] Furthermore, substantially the same UW-EC sequence for symbols within a TTI may be used for communication between the transmitter 902 and the receiver 1002. This configuration may be desirable to maintain signal cyclicity and coherent detection at the receiver 1002.

[0100] Any of the transmitters 302, 401, 502, 702, or 902 may be configured to operate or be part of the WTRU 102, the base station 114a, the base station 114b, or the eNodeBs 140a-140c. Similarly, any of the receivers 318, 402, 602, 802, or 1002 may be configured to operate or be part of the WTRU 102, the base station 114a, the base station 114b, or the eNodeBs 140a-140c.

[0101] 11 is a diagram of a sub-block VCRC structure that may be used by transmitter 702 or 902, if desired. Packet 1104 may include code block #n 1106 with CRC #n 1108. Packet 1104 may be processed by a channel encoder component or function 1110 and then provided to a rate match component or function 1112 to generate coded block 1114. Transmission of coded block 1114 per TTI may be divided into M transmission sub-blocks 11160-1116. M-1 Each sub-block may contain one or more symbols, such as OFDM symbols. Each sub-block may be accompanied by a virtual CRC (VCRC) 1120, 1124, or 1128 to transmit bit symbols 1118, 1122, or 1126, respectively. At the receiver, M transmit sub-blocks 11160 through 1116 are M-1 If any of the VCRCs matches the VCRC, the data packet may be successfully received. When successful, channel decoding, such as turbo decoding, LDPC decoding, polar decoding, etc., may be bypassed or skipped, increasing performance and reducing complexity.

[0102] M transmission sub-blocks 11160 to 1116 M-1When any of the VCRCs do not match, channel decoding may be performed. To increase speed and reduce power usage, the sub-blocks with matching VCRCs may be used as prior knowledge or information for the channel decoder. The sub-block VCRCs may be decoded by a low-latency channel decoder, a low-latency turbo decoder, a low-latency LDPC, a low-latency polar code, etc. Furthermore, the VCRCs may be carried or embedded within the UW-EC sequence. The sub-block VCRC structure may be applied to code blocks or non-coded blocks. Similarly, parity-check bits generated by a parity-check function such as an exclusive-OR (XOR) operation or repetitions of data within a sub-block may be carried or embedded within the UW-EC sequence.

[0103] Furthermore, the sub-block VCRC may use a systematic rate-compatible insertion convolutional encoder and a UW waveform such as UW-OFDM or UW-DFT-OFDM. In UW-OFDM or UW-DFT-s-OFDM, when the VCRC is indicated by a UW-EC sequence, the detected UW-EC sequence or VCRC may be used for error detection of the transmit code sub-block. If the transmit code sub-blocks pass the VCRC using the UW-EC sequence at a receiver such as receiver 802 or 1002, those transmit code sub-blocks may bypass the channel decoder 820 or 1020, respectively.

[0104] The transmit code block may include systematic code bits b. The starting point for systematic code bits b may be required at the beginning of a circular buffer. However, for smaller packet sizes, such as control channel transmissions in LTE, downlink control information (DCI) communications, uplink control information (UCI) communications, and special communications, a channel encoder such as 508, 710, 910, or 1110 may use convolutional coding instead of turbo coding for better performance.

[0105] 12 is a diagram of a systematic rate compatible insertion and superposition (RCIC) encoder 1202. Systematic bits b may be generated at output 1214 based on multiplexer 1204, which multiplexes systematic bits b 1203 and dummy bits d 1205 to create stream T. Stream T may be interleaved by interleaver 1206 to create interleaved stream X, which may be encoded by systematic convolutional encoder 1208, which outputs X and coded outputs p1 and p2 1212. RCIC encoder 1202 may achieve coding rates similar to those of the 3rd Generation Partnership Project (3GPP) LTE or LTE-A standard and may use VCRC.

[0106] For waveform generation, such as with UW-OFDM, the transmitter 302 receives the signal:

[0107]

number

[0108] It can be expressed as: A UW-DFT-s-OFDM signal, such as that generated by transmitter 402,

[0109]

number

[0110] It can be expressed as:

[0111] Equations (4) and (5) are substantially similar except for the DFT spreading matrix S. Therefore, the generic expression for UW waveforms such as UW-OFDM and UW-DFT-s-OFDM is

[0112]

number

[0113] where:

[0114]

number

[0115]

number

[0116] and N tail may be the number of samples in the tail. The non-tail and tail portions of the symbol are then

[0117]

number

[0118] and in the above equation,

[0119]

number

[0120] and

[0121]

number

[0122] and r=s+u. Variable x tail teeth,

[0123]

number

[0124] or

[0125]

number

[0126] It can also be expressed as: The first two terms in equation (8), M 21 d+M 22 s may represent the tail suppression operation, and the third term M 22 u may represent how the UW-EC sequence is generated. M 22 is a complete matrix, say N tail ≦N r If M, any UW sequence can be generated via vector u. Furthermore, the UW-EC sequence can be generated via M 22 It can be generated by u or c.

[0127] a predetermined set of orthogonal sequences

[0128]

number

[0129] acts as a UW-EC sequence, generating a UW-EC sequence is

[0130]

number

[0131] In equation (10), the following relationship may be desired: M 22 u i =c i , where i=1,2,...M Equation (11)

[0132] Furthermore, the vector u in the frequency domain can be adjusted to generate a UW-EC sequence in time as given below:

[0133]

number

[0134] After an error check bit operation such as 516, 714 or 914, a sequence or codeword c can be selected from the UW-EC codebook component or function 520, 718 or 918. By inserting c or adjusting u, a UW-EC sequence can be generated. When adjusting u, M 22 The condition u=c may be desirable.

[0135] 13 is an example of UW-EC waveform generation by generation component or function 1302. For generation component or function 1302, a UW-EC waveform may be generated based on systematic bits. The systematic encoder may use a turbo code, a convolutional code, an LDPC code, a polar code, a block code, etc. In generation component or function 1302, UW-EC may be added by UW-EC component or function 1314 in the frequency domain using EC bits provided by EC bits component or function 1312.

[0136] In the generation component or function 1302, a data vector d 1304 may be input to a tail suppression component or function 1308 to produce a sequence s that is combined with vector u by an addition component or function 1310 to produce redundant subcarriers r. A permutation matrix P component or function 1306 may map the elements of the data vector d 1304 and redundant subcarriers r, which will be transformed to the time domain by an inverse DFT component or function 1316, to produce an output signal x 1318. The output signal x 1318 may be expressed as follows:

[0137]

number

[0138] In Equation 13, c can be a UW-EC code, a UW-EC sequence, etc. in the time domain.

[0139] A systematic block code can be represented as G = [I|P], where I is the identity matrix. The systematic block code can include a systematic Reed-Solomon (RS) code and a systematic cyclic code, and G is represented as follows.

[0140]

Number

[0141] When CRC is used, if the CRC length c is given, when m < c, m errors can be detected. If the m-error vector is divisible by the CRC polynomial, the error may not be detected. When the CRC length is equal to c, the CRC operation may not detect m >= c burst bit errors, where m can represent consecutive bit errors.

[0142] CRC performance can be measured based on any one of the undetected error probability P ud , the packet length n, the CRC length c, the generator characteristics, or the BER. P ud is generally

[0143]

Number

[0144] can be determined by, where ε is the BER probability in the above formula, d min is the minimum number of non-zero elements in any non-zero codeword, and d max is the maximum number of non-zero elements in any non-zero codeword. In some configurations, the BER is about 10 -1 or less, and the generator CRC can be assumed to be optimal.

[0145] A set of UW-based mutually orthogonal codes or sequences may be desirable. A set of M sequences

[0146]

Number

[0147] where c i The length of each of the sequences is equal to L.

[0148]

number

[0149] ,

[0150]

number

[0151] teeth,

[0152]

number

[0153] are said to be mutually orthogonal if ∀i≠j and i,j∈{1,...,M}, where

[0154]

number

[0155] teeth,

[0156]

number

[0157] and

[0158]

number

[0159] A mutually orthogonal set of sequences can be constructed by complementary sequences, such as Golay complementary sequences. Other codes, such as Zadov-Chu (ZC) sequences, constant amplitude zero autocorrelation waveform (CAZAC) sequences, and cyclic shift codes, may also be used.

[0160] The number of sequences in the set, M, may decrease with the interference-free window (IFW) or zero correlation zone (ZCZ) length. For example,

[0161]

number

[0162] ,

[0163]

number

[0164] The (L=16, M=8, ZCZ=1) code can be expressed as follows:

[0165]

number

[0166] The pre-decoder data check provided in the receiver 602, 802, or 1002 may be configured for multi-user support and multiplexing. In this configuration, each user may be assigned a code according to a UW-EC generated from the data, from an explicit CRC, or from both the data and the CRC. In a single-user configuration, each user device, such as the WTRU 102, detects the code. In a multi-user configuration, each user device may detect several UW-EC codes substantially simultaneously.

[0167] Also, for a multi-user configuration, each user device, such as the WTRU 102, may use each detected UW-EC code to generate a UW-EC bit and use the UW-EC bit to check for data errors. A user device may use all detected UW-EC codes and UW-EC bits if desired. In one configuration, in the case of multi-user detection, received data may be designated as pass when only one UW-EC code is successfully detected.

[0168] 5, the transmitter 502 may be configured to use N UW-EC bits based on the data 504. A UW-EC sequence v from the K sequences may be selected for the data if the UW-EC K sequences are orthogonal and may have substantially low correlation sequences, and / or the following condition is met: K=2 N Formula (16) The UW-EC codebook size may be set to K.

[0169] 6, at the receiver 602, v may be detected from the received data d of the received signal 604. The UW-EC bits may be reconstructed according to v. Error checking may be performed on the received data d. If an error is found, the data may be sent for channel decoding by the channel decoder 618. If no error is found, the channel decoding may be bypassed or skipped, and the data may be sent directly to the source decoder 622.

[0170] For multi-user detection, superposition can be used. After detecting v, v to W can be used as a one-to-one mapping to determine W, where W is a diagonal matrix with the diagonal being a random sequence. The random sequence for W can be an interleaved pattern or a pseudorandom code. For a given W, the data can be decoded. For control-assisted UW multi-user approaches, the control can be decoded to obtain UW-EC, which can then be used to error check against a CRC and determine v using UW-EC, or to determine W using the one-to-one mapping of v to W.

[0171] 14 illustrates a process 1400 for generating and transmitting a UW-EC waveform. Data or a signal may be channel encoded (1402). EC bits may be generated from systematic bits generated by channel encoding the data or signal (1404). A UW-EC codeword may be selected from a UW-EC codebook using the generated EC bits (1406). The generated UW-EC sequence and systematic and parity bits may be signaled to a UW waveform generator (1408). A UW-EC waveform may then be generated and transmitted (1410).

[0172] Figure 15 illustrates a process 1500 for receiving and demodulating a UW-EC signal or waveform. A UW-EC waveform based on the received signal is signaled to a UW-EC codeword detector and data demodulator (1502). The UW-EC codeword and EC bits are detected (1504). A pre-decoder data check may use the EC bits and systematic and parity bits (1506) to determine whether an error is present. If no error is detected, the check is successful (1508), error-free data is signaled to the source decoder, and the channel decoder is bypassed (1510). If an error is detected, the check is unsuccessful (1511), and erroneous data is signaled to the channel decoder (1512). An additional error check (1514) on the channel-decoded data may also be performed.

[0173] Although features and elements are described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. Furthermore, the methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) 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 internal hard disks and removable disks, magneto-optical media, optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. 1. A wireless transmit / receive unit (WTRU), comprising: a processor; a transceiver operably coupled to the processor; the processor is configured to divide the data into a plurality of data blocks; the processor is further configured to generate and apply a cyclic redundancy check (CRC) to each of the plurality of data blocks; the processor is further configured to low-density parity check (LDPC) encode the plurality of data blocks and the appended CRC into a plurality of LDPC blocks and the appended CRC; the processor is further configured to concatenate the plurality of LDPC blocks and the appended CRC; the processor is further configured to generate information associated with the error check; the processor is further configured to generate a codeword using a codebook, the codeword being based on the information associated with the error check; the processor is further configured to generate an orthogonal frequency division multiplexing (OFDM) signal by mapping the codeword and the concatenated plurality of LDPC blocks and appended CRC to resource elements of the OFDM signal; The processor and the transceiver are further configured to transmit the generated OFDM signal. WTRU.

2. The WTRU of claim 1 , wherein the processor is further configured to generate an additional CRC in addition to the appended CRC, the generated OFDM signal including the additional CRC.

3. The WTRU of claim 1 , wherein the codewords are mapped to a single OFDM signal.

4. The WTRU of claim 1 , wherein the codeword is mapped to a plurality of OFDM signals.

5. The WTRU of claim 1 , wherein the generated OFDM signal includes one or more OFDM symbols.

6. The WTRU of claim 1 , wherein the LDPC coding is a low-delay LDPC coding.

7. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: Dividing the data into a plurality of data blocks; generating and appending a cyclic redundancy check (CRC) to each of the plurality of data blocks; low-density parity check (LDPC) encoding the plurality of data blocks and the appended CRC into a plurality of LDPC blocks and the appended CRC; concatenating the plurality of LDPC blocks and the appended CRC; generating information associated with the error check; generating a codeword using a codebook, said codeword being based on said information associated with said error checking; generating an orthogonal frequency division multiplexing (OFDM) signal by mapping the codeword and the concatenated LDPC blocks and appended CRC to resource elements of the OFDM signal; transmitting the generated OFDM signal; A method for providing

8. The method of claim 7 , further comprising generating an additional CRC in addition to the appended CRC, wherein the generated OFDM signal includes the additional CRC.

9. The method of claim 7 , wherein the codewords are mapped onto a single OFDM signal.

10. The method of claim 7 , wherein the codewords are mapped to multiple OFDM signals.

11. The method of claim 7 , wherein the generated OFDM signal comprises one or more OFDM symbols.

12. The method of claim 7 , wherein the LDPC coding is low-delay LDPC coding.

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