Waveform-based data integrity checking and error correction

Abstract

To obtain efficient data integrity check, EC, or ED for ZT, UW, and CP-based waveforms that increase reliability, provide flexibility, maintain high coding rates, and are adaptable to different device types.SOLUTION: A radio transmit / receive unit (WTRU) may receive a unique word-error check (UW-EC) coded signal. The pre-decoder data check entity can check for errors on the basis of the EC bits and systematic and parity bits from the UW-EC coded signal. When no errors are detected by the pre-decoder data check entity, error-free data can be signaled to a 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 word (UW) are candidates for wireless waveforms. ZT or UW can be used as a more resource-rich and energy-efficient alternative to redundancy schemes such as cyclic prefix (CP) or null subcarriers. Waveforms using ZT or UW can achieve high reliability, low peak-to-average power ratio (PAPR) characteristics, low out-of-band (OOB) leakage, very high data rates, and can result 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. Also, ED or EC systems may 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 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 enhances 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 prior to 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 / unsuccess condition. [Brief description 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] FIG. 1 illustrates an example communication system in which one or more embodiments may be implemented. [Figure 1B] 1B is a diagram of an example wireless transmit / receive unit (WTRU) used within the communications 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. [Diagram 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. [Diagram 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 can use non-zero redundant symbols. [Diagram 5] Transmitter for Unique Word Error Check (UW-EC) waveform. [Figure 6] This is a receiver for checking UW-EC signal data. [Figure 7] UW-EC Cyclic Redundancy Check (CRC) (UW-EC-CRC) Transmitter for signal diversity. [Figure 8] This is a receiver for the UW-EC-CRC diversity system. [Figure 9] This is a transmitter for the UW-EC on CRC signal. [Figure 10] UW-EC on CRC signal data check for receiver. [Figure 11] FIG. 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. 13 is a process diagram for generating and transmitting a UW-EC waveform. [Figure 15] FIG. 13 is a process diagram for receiving and demodulating a UW-EC waveform. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] For the methods and processes described below, the recited steps may be performed in any order out of sequence, and sub-steps 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 may have 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 be extended to longer lists as well. 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 be extended to longer lists as well with the same aforementioned 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 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] As shown in FIG. 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 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 the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 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, and the like.

[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 eNode B, a home Node B, a home eNode B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated 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 the 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). The 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), etc.

[0020] The base station 114b in FIG. 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may use any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a 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 via the core network 106.

[0021] The RAN 104 may communicate with a 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 the 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 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 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 networks 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 to communicate 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, which may use a cellular-based radio technology, and a base station 114b, which may use an IEEE 802 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. Although 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, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and receive both RF 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, for example, UTRA and IEEE 802.11.

[0029] The processor 118 of the WTRU 102 may be coupled to and 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. Additionally, 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 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, or the like. 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, which may be configured to provide location information (e.g., longitude and latitude) regarding a 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 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 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, and the like.

[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] Although the RAN 104 includes eNodeBs 140a, 140b, 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, 140c may each include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNodeBs 140a, 140b, 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 over 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 attachment 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, and may facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0040] The core network 106 may facilitate communications 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 communications between the WTRUs 102a, 102b, 102c and traditional land-line communications 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 networks 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 on 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 prior to 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 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 the fifth generation (5G) radio access network 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 as they may allow for simpler or one tap equalization per subchannel at the receiver or transceiver. A variant of OFDM, DFT-s-OFDM, improves on 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 inter-symbol interference (ISI) that may occur due to different channel delay spreads and to maintain symbol cyclicity. The length of the CP may be fixed and based on the maximum delay spread of the channel or cell for system simplification. As a result, when the delay spread of the channel is smaller than the CP duration, spectral efficiency may be lost. This efficiency loss may be significant with a large variance in the root mean square (RMS) delay spread of the channel. For example, in mmWave channels, the delay spread may be less than 4 nanoseconds (ns) for line-of-sight (LOS) conditions and up to 70 ns for indoor non-line-of-sight (NLOS) conditions for indoor channels. Systems configured with or supporting multiple different CP sizes may add processing complexity for fixed subframe durations or time intervals, since changing the CP size may change the number of OFDM symbols in a subframe.

[0046] Zero-tailed (ZT) DFT-s-OFDM or unique word (UW) OFDM waveforms may be configured to efficiently accommodate or handle variable CP sizes, variable channel delay spreads, variable cell sizes, etc. Also, the ZT DFT-s-OFDM waveform may be decoupled from the channel characteristics in some configurations, and the duration of ZT may be dynamically adapted to the channel delay spread without any change to the OFDM symbol duration. Finally, ZT may 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 h Zero (204) and N in the tail t The data (203) can be generated by adding zero as zero (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 inverse fast Fourier transform (IFFT) component or function 212 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 perfect 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 loss of the desirable cyclic property of the OFDM signal and larger ISI. Correspondingly, for some data types, the 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 symbol 300 at the transmitter 302, the tail or head of each OFDM block or symbol may have substantially zero, perfect zero, near-zero, or zero samples. The UW 301 may use a constant tail for each block or symbol so that the channel may be transformed from a linear convolution to a circular convolution, allowing for a 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 to 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 to 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 summing 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. The transmission by transmitter 302 may proceed over channel H to receiver 318 and be received by antenna 320. The signal received by receiver 318 may be processed by S / P component or function 322 to generate parallel information streams that 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 possibly distortion due to equalization errors. The permutation matrix P components or functions 306 may be optimized by changing or shifting the positions of the redundant subcarriers to reduce the large values ​​of the redundant subcarriers r and signal distortion. The reduction and optimization of the 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, shifting all subcarriers to generate ZT may result in a more complicated receiver structure at the receiver 318.

[0053] FIG. 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, the 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 redundant symbols at either or both ends of the DFT spreading block 415, non-zero redundant symbols may be used to suppress leakage energy in the tail 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, since 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 may be decoded by any DFT-s-OFDM receiver. Thus, a DFT-s-OFDM receiver or transceiver may in part decode the UW DFT-s-OFDM waveform or the DFT-s-OFDM waveform together.

[0055] In the transmitter 401, the 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 tail of one or more DFT-s-OFDM symbols using a tail suppression component or function 410. Similarly, suppressed DFT-s-OFDM symbols at the head 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 UW u 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 matrices D 1416 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. 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 may be used to generate M1.

[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 coupled to a receiver shaping matrix B for shaping and then 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] A despreading block 442 generates a 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

[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 when a packet is successfully detected by the pre-decoder, data or data integrity check channel decoding may be bypassed. If packet decoding is unsuccessful by the pre-decoder, data integrity checking, 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 / unsuccess condition.

[0068] The generic pre-decoder data integrity checking 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 checking 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. Additionally, error checking or error checking bits may be configured to be incorporated into the UW-EC waveform. The UW-EC may be a sequence including orthogonal that may carry some EC bits or 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. A Zadoff-Chu sequence with a cyclic shift may be used to transmit the EC sequence. 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. A sequence other than the Zadoff-Chu sequence with or without a cyclic shift may be used to transmit the EC sequence 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. In the transmitter 502, it may be desirable to use a UW for error checking 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 extended 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 data packets, control packets, or any combination thereof related to transmission in any combination of a data channel, a control channel, a broadcast channel, etc., in the UL or DL. 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 using 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. The systematic or data bits without a CRC may be signaled to an EC bit generator 516 to generate EC bits to add EC functionality. 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] FIG. 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 may be detected by the UW-E codeword detection component or function 610 using a UW-EC codebook component or function 612. The receiver 602 may 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. Additionally, the codebook may be predefined or configured such 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 prior to channel decoding by a Raw 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 the channel decoding may reduce complexity, power consumption, and latency at the receiver 602. Instead, the error-free data 624 may be signaled to the source decoder 622 to 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, and the like.

[0077] If the RawBER pre-decoder data check component or function 616 is unable to successfully detect the packet or channel data, then 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 coded BER 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. In the first layer, if no errors are detected, 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. Additionally, 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 above 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, unsuccessful, etc. 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 SINR values, etc. When the CQI value is substantially within the range, the pre-decoder data check may be performed. Otherwise, the pre-decoder and post-decoder data checks may be used or the 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 the 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, and then generate or recover the 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 probability of passing or succeeding the data check, a low CQI range to indicate unfavorable or undesirable channel conditions and a low probability of passing or succeeding the data check, and a very low CQI range to indicate substantially worst channel conditions in which 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 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 the output data 626. If the measured CQI is substantially within the low CQI range, a 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, and then generate or recover the 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 when 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 successful data packets, data blocks, data segments, 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 a 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 errors, 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 such that HARQ latency and power consumption are reduced when bypassing channel decoding and CRC checking, and the second layer HARQ may include a post-decoder data integrity check and maintain backward compatibility to 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, so that diversity may be achieved and if one check fails, the other may be used for error checking. Furthermore, both error checking procedures may be used for extended protection. This may be desirable for critical data or control communications such as 911, emergency, etc.

[0087] The CRC, when combined with UW-EC, may improve performance by increasing robustness and diversity for error-vulnerable 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 that generates systematic bits with CRC and parity bits. The channel encoder 710 may be, but is not limited to, a polar code, a systematic polar code, an LDPC, 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 that 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, the transmitter 401, etc. 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 at 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. Additionally, 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 by 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 the erroneous data 818 to the channel decoder 820. The channel decoded systematic bits may be signaled to the CRC check component or function 822 to detect errors and output a signal for the source decoder 824. The source decoder 824 may output the data 828 by using the CRC checked output of the CRC check component or function 822.

[0092] For communication 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 reduce the code or sequence length at the expense of possible reduced cyclicity that 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 that 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 that generates systematic bits with CRC and parity bits. The channel encoder 910 may use a polar code, a systematic polar code, an LDPC, 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 that 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 the transmitter 302, the 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 the 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 check. The UW-EC on CRC scheme may be implemented in at least two steps. At the transmitter, a CRC may be fed to the input of an EC generation block using an ECF function to generate EC or UW-EC bits that may be used to generate a UW-EC code or sequence. At the receiver, at least two steps may 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 may detect the UW-EC sequence from the received signal 1004 at a UW-EC waveform component or function 1006. The UW-EC codeword c may 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 on 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 to output data 1025. The channel decoder 1020 may be configured to perform turbo decoding, convolutional decoding, LDPC channel decoding, polar decoding, block decoding, and the like.

[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 results 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 act as an additional layer to detect errors and output 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 since the CRC length may generally be shorter than the data. Thus, 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 cyclicity and coherent detection of the signal 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. A packet 1104 may include a code block #n 1106 having a CRC #n 1108. The 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 a coded block 1114. The per TTI transmission of the coded block 1114 is divided into M transmission sub-blocks 11160-1116. M-1 Each sub-block may include one or more symbols, such as OFDM symbols. Each sub-block may be appended with 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 to 1116 are M-1 If any of the VCRCs matches the VCRC, reception of the data packet may be successful. When successful, channel decoding, such as turbo decoding, LDPC decoding, polar decoding, etc., may be bypassed or skipped to increase performance and reduce complexity.

[0102] M transmission subblocks 11160 to 1116 M-1When the VCRCs of any of the sub-blocks do not match, channel decoding may be performed. To increase speed and reduce power usage, the sub-blocks that match the VCRCs may be used as prior knowledge or information to 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 in the UW-EC sequence. The sub-block VCRC structure may be applied to code blocks or non-coded blocks. Similarly, parity check bits or repetitions of data in the sub-blocks generated by a parity check function such as an exclusive OR (XOR) operation may be carried or embedded in 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, UW-DFT-OFDM, etc. In UW-OFDM or UW-DFT-s-OFDM, when the VCRC is indicated by the UW-EC sequence, the detected UW-EC sequence or the VCRC may be used for error detection of the transmit code sub-blocks. 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, special communications, etc., 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 overlap (RCIC) encoder 1202. Systematic bits b may be generated at output 1214 based on a multiplexer 1204 that multiplexes systematic bits b 1203 and dummy bits d 1205 to create stream T. Stream T may be interleaved by an interleaver 1206 to create an interleaved stream X, which may be encoded by a systematic convolutional encoder 1208 that outputs X and coded outputs p1 and p2 1212. The 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 signal is:

[0107]

number

[0108] It can be expressed as: A UW-DFT-s-OFDM signal, such as that generated by the 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. Thus, 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] In the above formula,

[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 a tail suppression operation, and the third term M 22 u may represent how the UW-EC sequence is generated. 22 is a complete matrix, say N tail ≦N r If u = u , then any UW sequence over vector u can be generated. Furthermore, the UW-EC sequence can be generated over vector u by M 22 It can be generated by u or c.

[0127] A given set of orthogonal sequences

[0128]

number

[0129] If serves 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 by:

[0133]

number

[0134] After an error check bit operation such as 516, 714 or 914, a sequence or codeword c may be selected from the UW-EC codebook components or functions 520, 718 or 918. By inserting c or adjusting u, a UW-EC sequence may 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 turbo codes, convolutional codes, LDPC codes, polar codes, block codes, etc. In generation component or function 1302, UW-EC may be added by UW-EC component or function 1314 using EC bits provided by EC bits component or function 1312 in the frequency domain.

[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 redundant subcarriers r and elements of the data vector d 1304 to 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] Systematic block codes can be represented as G = [I|P], where I is the identity matrix. Systematic block codes can include systematic Reed-Solomon (RS) codes and systematic cyclic codes, and G is represented by the following formula.

[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 the above formula, where ε is the BER probability, 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 can be 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 is equal to L. Two distinct sets of sequences

[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, cyclic shift codes, etc. 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 of the detected UW-EC codes to generate UW-EC bits and use the UW-EC bits 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 conditions are 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 errors are found, the data may be sent for channel decoding by the channel decoder 618. If no errors are 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 may be used. After detection of v, v to W may 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 may be an interleaving pattern or a pseudorandom code. For a given W, the data may be decoded. For control-aided UW multi-user approaches, the control may be decoded to obtain a UW-EC, which may then be used to error check against a CRC and determine v using the UW-EC, or to determine W using the one-to-one mapping of v to W.

[0171] FIG. 14 is 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 of 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] FIG. 15 is 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 if an error is present. If no errors are 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). Additional error checks on the channel decoded data (1514) may also be performed.

[0173] Although features and elements are described above in certain combinations, one skilled in the art will understand that each feature or element may 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 over 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 generate a block of data for transmission; the processor is configured to determine a block cyclic redundancy check (CRC) and append the determined block CRC to the block of data; the processor is configured to divide the block of data and the appended block CRC into a plurality of transmission sub-blocks, one of the transmission sub-blocks including the appended block CRC; For each of the transmitted sub-blocks, the processor determines a sub-block CRC as a respective determined sub-block CRC; and configured to attach the respective determined sub-block cyclic redundancy check to a transmitted sub-block; The processor is further configured to generate an Orthogonal Frequency Division Multiplexing (OFDM) signal derived from the plurality of transmission sub-blocks and the attached sub-block CRC, wherein at least the block of data and the attached block CRC are Low Density Parity Check (LDPC) coded; the transceiver is configured to transmit the OFDM signal; The transceiver is configured to receive feedback including an indication of whether to retransmit data for the block of data, the indication being received in response to the transmission of the sub-block CRC. W.T.R.U.

2. 10. The WTRU of claim 1, wherein the indication of whether to retransmit data for the block of data is not received in response to the transmitted appended block CRC.

3. The WTRU of claim 1 , wherein the indication of whether to retransmit data for the block of data is received further in response to the transmitted appended block CRC.

4. 2. The WTRU of claim 1, wherein the transceiver is configured to receive, in addition to the received feedback, a further type of feedback including an indication of whether to retransmit data of the block of data in response to successful decoding of the block of data.

5. 1. A method in a wireless transmit / receive unit (WTRU), comprising: generating a block of data for transmission; determining a block cyclic redundancy check (CRC) and appending said determined block CRC to said block of data; dividing the block of data and the appended block CRC into a plurality of transmission sub-blocks, one of the transmission sub-blocks including the appended block CRC; determining a sub-block CRC for each of the transmitted sub-blocks as a respective determined sub-block CRC; attaching each determined sub-block CRC to a transmitted sub-block; generating an Orthogonal Frequency Division Multiplexing (OFDM) signal derived from the plurality of transmission sub-blocks and the attached sub-block CRC, where at least the blocks of data and the attached sub-block CRC are Low Density Parity Check (LDPC) coded; transmitting said OFDM signal; receiving feedback including an indication of whether to retransmit data for the block of data, the indication being received in response to the transmission of the sub-block CRC; A method for providing the above.

6. 6. The method of claim 5, wherein the indication of whether to retransmit data for the block of data is not received in response to the transmitted appended block CRC.

7. 6. The method of claim 5, wherein the indication of whether to retransmit data for the block of data is received further in response to the transmitted appended block CRC.

8. receiving, in addition to the received feedback, a further type of feedback in response to successful decoding of the block of data, including an indication of whether to retransmit the data of the block of data. The method of claim 5 further comprising:

9. 1. A wireless transmit / receive unit (WTRU), comprising: A processor; a transceiver operably coupled to the processor; the processor is configured to receive an Orthogonal Frequency Division Multiplexing (OFDM) signal derived from a plurality of sub-blocks and an attached sub-block Cyclic Redundancy Check (CRC), the plurality of sub-blocks being divisions of a block of data and an attached block CRC, one of the sub-blocks including the attached block CRC, at least the block of data and the attached block CRC being Low Density Parity Check (LDPC) coded; The processor is configured to generate an indication of whether to retransmit data for the block of data based on the received sub-block CRC; the processor is configured to generate feedback including the indication of whether to retransmit data for the block of data; The transceiver is further configured to transmit the feedback. W.T.R.U.

10. 10. The WTRU of claim 9, wherein the indication of whether to retransmit data for the block of data is generated based on information other than the received appended block CRC.

11. 10. The WTRU of claim 9, wherein the indication of whether to retransmit data for the block of data is generated further based on the received appended block CRC.

12. 10. The WTRU of claim 9, wherein the processor is configured to determine not to generate the indication of whether to retransmit data for the block of data based on the received appended block CRC.

13. The processor is further configured to generate an indication of whether to retransmit data of the block of data based on successful decoding of the block of data; the processor is further configured to generate a further type of feedback including the indication of whether to retransmit data for the block of data; The transceiver is further configured to transmit the further type of feedback in addition to the transmitted feedback. The WTRU of claim 9.

14. A method in a wireless transmit / receive unit (WTRU), receiving an Orthogonal Frequency Division Multiplexing (OFDM) signal derived from a plurality of sub-blocks and an attached sub-block Cyclic Redundancy Check (CRC), the plurality of sub-blocks being divisions of a block of data and an attached block CRC, one of the sub-blocks including the attached block CRC, and at least the block of data and the attached block CRC being Low Density Parity Check (LDPC) coded; generating an indication of whether to retransmit data for the block of data based on the received sub-block CRC; generating feedback including the indication of whether to retransmit data for the block of data; sending said feedback; A method for providing the above.

15. 15. The method of claim 14, wherein the indication of whether to retransmit data for the block of data is generated based on information other than the received and appended block CRC.

16. 15. The method of claim 14, wherein the indication of whether to retransmit data for the block of data is generated further based on the received and appended block CRC.

17. determining not to generate the indication of whether to retransmit data for the block of data based on the received appended block CRC; The method of claim 14 further comprising:

18. generating an indication of whether to retransmit data for the block of data based on successful decoding of the block of data; generating a further type of feedback including the indication of whether to retransmit data for the block of data; transmitting said further type of feedback in addition to said transmitted feedback; The method of claim 14 further comprising:

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