WO2022036679A1 - Techniques de codage de fenêtre glissante pour des systèmes de communication sans fil - Google Patents

Techniques de codage de fenêtre glissante pour des systèmes de communication sans fil Download PDF

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Publication number
WO2022036679A1
WO2022036679A1 PCT/CN2020/110474 CN2020110474W WO2022036679A1 WO 2022036679 A1 WO2022036679 A1 WO 2022036679A1 CN 2020110474 W CN2020110474 W CN 2020110474W WO 2022036679 A1 WO2022036679 A1 WO 2022036679A1
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WIPO (PCT)
Prior art keywords
source symbols
symbols
sliding window
source
pool
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PCT/CN2020/110474
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English (en)
Inventor
Kangqi LIU
Changlong Xu
Ruiming Zheng
Jian Li
Liangming WU
Hao Xu
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Qualcomm Incorporated
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Priority to PCT/CN2020/110474 priority Critical patent/WO2022036679A1/fr
Publication of WO2022036679A1 publication Critical patent/WO2022036679A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1657—Implicit acknowledgement of correct or incorrect reception, e.g. with a moving window
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0041—Arrangements at the transmitter end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1614—Details of the supervisory signal using bitmaps
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/1887—Scheduling and prioritising arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L2001/0092—Error control systems characterised by the topology of the transmission link
    • H04L2001/0093—Point-to-multipoint

Definitions

  • the following relates to wireless communications, including sliding window coding techniques for wireless communications systems.
  • Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) .
  • Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems.
  • 4G systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems
  • 5G systems which may be referred to as New Radio (NR) systems.
  • a wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .
  • UE user equipment
  • Some wireless communications systems may support broadcasting of data from a transmitting device to receiving devices.
  • the transmitting device may refrain from transmitting subsequent data until each receiving device successfully receives and decodes the prior data, which may result in inefficient communications in the system.
  • a base station may identify a pool of source symbols for broadcast transmission to one or more user equipments (UEs) .
  • the base station may encode a portion of the pool of source symbols within a window.
  • the base station may identify a first set of source symbols included in a sliding window.
  • the base station may encode the first set of source symbols to obtain a first set of encoded symbols, using a network coding scheme, based on the first set of source symbols being within the sliding window.
  • the base station may transmit the first set of encoded symbols to the one or more UEs.
  • the base station may adjust the sliding window based on transmitting the first set of encoded symbols that correspond to the first set of source symbols.
  • the base station may adjust the sliding window based on feedback received from the one or more UEs. For example, the base station may identify a symbol of the first set of source symbols that corresponds to a minimum acknowledgment sequence number of a set of acknowledgment sequence numbers reported from the one or more UEs. Each UE may report an acknowledgement sequence number which represents the sequence number of a first unsuccessfully-received symbol for that UE or a last successfully received symbol for that UE. The minimum acknowledgement sequence number is the smallest sequence number of those received from all of the UEs.
  • the minimum acknowledgment sequence number may indicate a quantity of the first set of source symbols that are associated with acknowledgments (ACKs) from each of the UEs.
  • the identified symbol may be the symbol subsequent to the quantity of symbols with ACKs from each of the UEs (e.g., the first symbol in the first set of symbols that has not received an ACK from each of the UEs) .
  • the base station may adjust the sliding window such that the identified symbol is a first symbol of the adjusted window for an additional transmission. Additionally or alternatively, the base station may adjust the sliding window automatically (e.g., the base station may adjust the sliding window a preconfigured quantity of symbols) .
  • the base station may include one or more symbols of the first set of source symbols in a subsequent transmission based on the feedback from the one or more UEs (e.g., one or more source symbols of the first set of source symbols that are associated with negative acknowledgment messages may be included in the subsequent transmission) .
  • Such window adjustment techniques may result in more efficient communications (e.g., additional source symbols may be sent even if a receiving devices fails to recover a portion of the first set of source symbols) while ensuring reliable communications, among other advantages.
  • a method of wireless communications at a base station may include identifying a pool of source symbols for groupcast transmission via a network coding scheme, encoding, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmitting the first set of encoded symbols to one or more UEs via groupcast transmission, receiving, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjusting the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory.
  • the instructions may be executable by the processor to cause the apparatus to identify a pool of source symbols for groupcast transmission via a network coding scheme, encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmit the first set of encoded symbols to one or more UEs via groupcast transmission, receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the apparatus may include means for identifying a pool of source symbols for groupcast transmission via a network coding scheme, encoding, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmitting the first set of encoded symbols to one or more UEs via groupcast transmission, receiving, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjusting the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • a non-transitory computer-readable medium storing code for wireless communications at a base station is described.
  • the code may include instructions executable by a processor to identify a pool of source symbols for groupcast transmission via a network coding scheme, encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmit the first set of encoded symbols to one or more UEs via groupcast transmission, receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • adjusting the sliding window may include operations, features, means, or instructions for receiving, from the one or more UEs, a set of acknowledgment sequence numbers as part of the feedback, each acknowledgment sequence number associated with a respective UE of the one or more UEs, and adjusting the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols such that an initial symbol of the second set of source symbols may be a symbol of the first set of source symbols corresponding to a smallest acknowledgment sequence number of the set of acknowledgment sequence numbers.
  • adjusting the sliding window further may include operations, features, means, or instructions for including a contiguous subset of the pool of source symbols as the second set of source symbols, beginning at the initial symbol.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the portion of the first set of source symbols based on the received feedback, where the portion of the first set of source symbols includes one or more source symbols of the first set of source symbols for which at least one negative acknowledgement was received from the one or more UEs.
  • symbols of the second set of source symbols may be not contiguous within the pool of source symbols.
  • receiving the feedback may include operations, features, means, or instructions for receiving a bitmap corresponding to the first set of source symbols, the bitmap indicating a set of negative acknowledgement bits, each negative acknowledgement bit of the set of negative acknowledgement bits corresponding to the portion of the first set of source symbols.
  • adjusting the sliding window may include operations, features, means, or instructions for automatically adjusting the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols a predefined number of source symbols from an initial symbol of the first set of source symbols, the predefined number of source symbols being less than a number of source symbols in the sliding window.
  • the portion of the first set of source symbols included within the second set of source symbols includes an overlapping portion of the first set of source symbols arising from the sliding window being adjusted the predefined number of source symbols less than the number of source symbols in the sliding window, the portion of the first set of source symbols also including any source symbols within the predefined number of source symbols for which a negative acknowledgement was received.
  • adjusting the sliding window may include operations, features, means, or instructions for receiving, from an upper layer of the base station, the additional source symbols sequentially to the first set of source symbols, where automatically adjusting the sliding window may be based on receiving the additional source symbols.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for encoding, in accordance with the network coding scheme, the second set of source symbols from the pool of source symbols, the second set of source symbols being within the sliding window and being encoded into a second set of encoded symbols, and transmitting the second set of encoded symbols to the one or more UEs via groupcast transmission.
  • the network coding scheme includes a fountain coding scheme, a raptor coding scheme, a gaussian elimination process scheme, a belief propagation scheme, or a combination thereof.
  • the base station communicates with the one or more UEs via a multicast radio bearer or dual radio bearer.
  • FIG. 1 illustrates an example of a system for wireless communications that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIG. 2 illustrates an example of a wireless communications system that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIGs. 3–6 illustrates examples of window adjustment coding schemes that support sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIG. 7 illustrates an example of a process flow that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIGs. 8 and 9 show block diagrams of devices that support sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIG. 10 shows a block diagram of a communications manager that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIG. 11 shows a diagram of a system including a device that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • FIGs. 12 and 13 show flowcharts illustrating methods that support sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • Some wireless communication systems may support broadcast services (e.g., a multicast/broadcast service (MBS) ) where a transmitting device broadcasts (e.g., in addition or alternative to unicasting) data to one or more receiving devices.
  • the transmitting device and the receiving device may be examples of network nodes that exchange data packets via communications links.
  • a network node such as a user equipment (UE) , a base station, an integrated access and backhaul (IAB) relay node, or another wireless device, may encode symbols before transmission to improve reliability of a destination node successfully receiving the transmitted information.
  • encoded symbols may provide redundancy, which may be used to correct errors that result from the transmission environment (e.g., errors due to path loss or obstacles, among other examples of relatively poor channel conditions) .
  • a transmitting device broadcasts encoded symbols associated with a first set of source symbols to one or more receiving devices, then each receiving device may obtain a different quantity of symbols such that a receiving device experiencing a high channel quality may successfully receive and decode the first set of source symbols before a receiving device having a low channel quality.
  • the transmitting device may refrain from encoding and transmitting a second set of source symbols until each receiving device successfully recovers the first set of source symbols (e.g., the transmitting device may retransmit the first set of encoded symbols until feedback from the one or more UEs indicates the first set of source symbols were successfully recovered) .
  • Such examples may result in relatively inefficient communications, for example, due to one or more receiving devices with poor channel conditions failing to successfully receive the first set of source symbols for a relatively long time. Additionally or alternatively, some receiving devices may fail to decode the source symbols (e.g., rateless codes may stall due to missing or corrupt packets) , which may lead to an increase in an amount of encoded packets used for a successful recovery of the set of source packets.
  • rateless codes may stall due to missing or corrupt packets
  • devices in a wireless communications system may implement one or more window adjustment coding techniques to decode or encode source symbols, which may result in improved efficiency for communications while ensuring reliable communications, among other advantages.
  • a base station may identify a pool of source symbols for transmission to one or more UEs.
  • the base station may obtain one or more sets of encoded symbols from the source symbols using a network coding scheme (e.g., using a rapid tornado (Raptor) code, among other examples of coding schemes) .
  • the base station may encode a first set of source symbols within a sliding window (i.e., the sliding window may include the first set of source symbols) .
  • the base station may transmit the first set of encoded symbols to the one or more UEs.
  • the one or more UEs may provide feedback for one or more symbols of the first set of source symbols (e.g., acknowledgment messages and/or negative acknowledgment messages for the one or more symbols) .
  • the base station may poll the UEs for feedback and receive a set of acknowledgment sequence numbers in response to the polling.
  • the base station may adjust the sliding window. For example, the base station may adjust the sliding window based on the feedback received from the one or more UEs. As an illustrative example, the base station may identify a symbol of the first set of source symbols that corresponds to minimum acknowledgment sequence number of the set of acknowledgment sequence numbers from the one or more UEs. Each UE may report an acknowledgement sequence number which represents the sequence number of a first unsuccessfully-received symbol for that UE or a last successfully received symbol for that UE. The minimum acknowledgement sequence number is the smallest sequence number of those received from all of the UEs.
  • the minimum acknowledgment sequence number may indicate a quantity of the first set of source symbols that are associated with acknowledgments (ACKs) from each of the UEs.
  • the identified symbol may be the symbol subsequent to the quantity of symbols with ACKs from each of the UEs (e.g., the first symbol in the first set of symbols that has not received an ACK from each of the UEs) .
  • the base station may adjust the sliding window such that the identified symbol is an initial symbol of the adjusted window for an additional transmission.
  • the base station may adjust the sliding window automatically (e.g., the base station may slide the sliding window a preconfigured quantity of symbols) .
  • the base station may include one or more symbols of the first set of source symbols in a subsequent transmission based on the feedback from the one or more UEs. For example, if the base station receives a negative acknowledgment for one or more symbols of the first set of source symbols, such symbols may be included in the subsequent transmission along with a second set of source symbols (e.g., a portion of the first set of source symbols, additional source symbols from the pool of source symbols, or a combination thereof) included in the adjusted window.
  • a second set of source symbols e.g., a portion of the first set of source symbols, additional source symbols from the pool of source symbols, or a combination thereof.
  • Such window adjustment techniques may result in more efficient communications (e.g., additional source symbols may be sent even if a receiving devices fails to recover a portion of the first set of source symbols) while ensuring reliable communications, among other advantages.
  • aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further described in the context of window adjustment coding schemes and a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to window adjustment coding techniques for wireless communications systems.
  • FIG. 1 illustrates an example of a wireless communications system 100 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130.
  • the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network.
  • LTE Long Term Evolution
  • LTE-A LTE-Advanced
  • LTE-A Pro LTE-A Pro
  • NR New Radio
  • the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.
  • ultra-reliable e.g., mission critical
  • the base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities.
  • the base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125.
  • Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125.
  • the coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.
  • the UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times.
  • the UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1.
  • the UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.
  • network equipment e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment
  • the base stations 105 may communicate with the core network 130, or with one another, or both.
  • the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) .
  • the base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both.
  • the backhaul links 120 may be or include one or more wireless links.
  • One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or other suitable terminology.
  • a base transceiver station a radio base station
  • an access point a radio transceiver
  • a NodeB an eNodeB (eNB)
  • eNB eNodeB
  • a next-generation NodeB or a giga-NodeB either of which may be referred to as a gNB
  • gNB giga-NodeB
  • a UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples.
  • a UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer.
  • PDA personal digital assistant
  • a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.
  • WLL wireless local loop
  • IoT Internet of Things
  • IoE Internet of Everything
  • MTC machine type communications
  • the UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.
  • devices such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.
  • the UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers.
  • the term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125.
  • a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) .
  • BWP bandwidth part
  • Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling.
  • the wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation.
  • a UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration.
  • Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.
  • FDD frequency division duplexing
  • TDD time division duplexing
  • Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) .
  • MCM multi-carrier modulation
  • OFDM orthogonal frequency division multiplexing
  • DFT-S-OFDM discrete Fourier transform spread OFDM
  • a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related.
  • the number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) .
  • a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.
  • Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) .
  • Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .
  • SFN system frame number
  • Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration.
  • a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots.
  • each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing.
  • Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) .
  • a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.
  • a subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) .
  • TTI duration e.g., the number of symbol periods in a TTI
  • the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .
  • Physical channels may be multiplexed on a carrier according to various techniques.
  • a physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques.
  • a control region e.g., a control resource set (CORESET)
  • CORESET control resource set
  • a control region for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier.
  • One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115.
  • one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner.
  • An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size.
  • Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.
  • a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110.
  • different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105.
  • the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105.
  • the wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.
  • the wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof.
  • the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications.
  • the UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions) .
  • Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT) , mission critical video (MCVideo) , or mission critical data (MCData) .
  • MCPTT mission critical push-to-talk
  • MCVideo mission critical video
  • MCData mission critical data
  • Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications.
  • the terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein.
  • a UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol) .
  • D2D device-to-device
  • P2P peer-to-peer
  • One or more UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105.
  • Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105.
  • groups of the UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group.
  • a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs 115 without the involvement of a base station 105.
  • the core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions.
  • the core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) .
  • EPC evolved packet core
  • 5GC 5G core
  • MME mobility management entity
  • AMF access and mobility management function
  • S-GW serving gateway
  • PDN Packet Data Network gateway
  • UPF user plane function
  • the control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130.
  • NAS non-access stratum
  • User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions.
  • the user plane entity may be connected to the network operators IP services 150.
  • the network operators IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.
  • Some of the network devices may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) .
  • Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) .
  • Each access network transmission entity 145 may include one or more antenna panels.
  • various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .
  • the wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) .
  • the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length.
  • UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors.
  • the transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.
  • HF high frequency
  • VHF very high frequency
  • the wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands.
  • the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band.
  • LAA License Assisted Access
  • LTE-U LTE-Unlicensed
  • NR NR technology
  • an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band.
  • devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance.
  • operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) .
  • Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.
  • a base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming.
  • the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming.
  • one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower.
  • antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations.
  • a base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115.
  • a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.
  • an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.
  • the base stations 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing.
  • the multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas.
  • Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords) .
  • Different spatial layers may be associated with different antenna ports used for channel measurement and reporting.
  • MIMO techniques include single-user MIMO (SU-MIMO) , where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , where multiple spatial layers are transmitted to multiple devices.
  • SU-MIMO single-user MIMO
  • Beamforming which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device.
  • Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference.
  • the adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device.
  • the adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .
  • the wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack.
  • communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based.
  • a Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels.
  • RLC Radio Link Control
  • a Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels.
  • the MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency.
  • the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or a core network 130 supporting radio bearers for user plane data.
  • RRC Radio Resource Control
  • transport channels may be mapped to physical channels.
  • the UEs 115 and the base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully.
  • Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link 125.
  • HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) .
  • FEC forward error correction
  • ARQ automatic repeat request
  • HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions) .
  • a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.
  • devices of the wireless communications system 100 may implement mixed broadcast and unicast transmissions, for example, on a physical downlink shared channel (PDSCH) (e.g., with LTE single-cell point to multipoint (SC-PTM) as a baseline, the LTE SC-PTM associated with single cell broadcast, broadcast over PDSCH addressed with a G-RNTI, etc. ) .
  • PDSCH physical downlink shared channel
  • SC-PTM LTE single-cell point to multipoint
  • a mixed broadcast (MB) and unicast layer may receive a MB quality of service (QoS) flow over a MB-N3 tunnel, and the MB QoS flow may be mapped to a multicast radio bearer (MRB) or a data radio bearer (DRB) .
  • MRB multicast radio bearer
  • DRB data radio bearer
  • Such examples may have a relatively close synergy with unicast (e.g., a device may be enabled with flexible switching between DRB and MRB, unicast assistance to MRB in lower layers, etc. ) .
  • the wireless communications system may support one or more interfaces (e.g., N2 interface for control signaling for MB flow setup or modification, MB-N3 interface as a user plane interface for MB flow delivery over a GPRS tunneling protocol (GTP) , etc. ) .
  • GTP GPRS tunneling protocol
  • the wireless communications system 100 may support broadcast services where a transmitting device (e.g., a base station 105) broadcasts one or more symbols to one or more receiving devices (e.g., UEs 115) .
  • the base station 105 may encode (i.e., using a network coding technique) symbols before transmission to improve reliability of a destination node successfully receiving the transmitted information.
  • a base station 105 may implement window adjustment coding techniques. For example, a base station 105 may identify a set of source symbols for broadcast transmission. The base station 105 may obtain one or more sets of encoded symbols from the source symbols using a network coding scheme.
  • the base station 105 may obtain the encoded symbols using a window adjustment coding technique where the base station 105 uses a first set of source symbols within a sliding window to obtain a first set of encoded symbols.
  • the base station 105 may adjust the sliding window, for example, based on feedback received from one or more UEs 115.
  • the base station 105 may obtain a second set of encoded symbols using a second set of source symbols (e.g., the second set of source symbols may include additional source symbols within the adjusted window, a portion of the first set of source symbols included in the window or identified from the received feedback, or a combination thereof) . Accordingly, the base station 105 may adjust the sliding window to obtain additional sets of encoded symbols. Implementing such window adjustment coding techniques may allow for an increased reliability of a broadcast services in the wireless communications system 100.
  • FIG. 2 illustrates an example of a wireless communications system 200 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the wireless communications system 200 may implement one or more aspects of a wireless communications system 100.
  • the wireless communications system 200 may include a UE 115-a, a UE 115-b, and a UE 115-c which may be examples of a UE 115 as described with reference to FIG. 1.
  • the wireless communications system 200 may also include a base station 105-a which may be an example of a base station 105 as described with reference to FIG. 1.
  • the base station 105-a may be associated with a cell which provides wireless communications service with a coverage area 110-a.
  • the wireless communications system 200 may support network coding techniques, such as encoding algorithms with error correcting codes (e.g., forward error correction codes such as erasure correction codes) .
  • error correcting codes e.g., forward error correction codes such as erasure correction codes
  • Some examples of encoding algorithms with erasure correcting codes include fountain codes, such as Luby transform (LT) codes or Raptor codes.
  • a fountain code may be an example of a rateless code, where a set of source symbols (e.g., K symbols) may be encoded as any quantity of encoding symbols (e.g., a quantity of symbols greater than K symbols) .
  • a device e.g., a base station 105, a UE 115, etc.
  • Encoding the source symbols may include combining one or more source symbols into each encoding symbol.
  • An encoding process may include using a degree distribution, where the degree distribution represents a probability mass function of a set of degrees d i (e.g., d 1 , d 2 , d 3 , etc. ) .
  • ⁇ (i) may represent the probability that an index of an encoding symbol (e.g., the degree of the ith symbol represented as di) is equal to a degree d.
  • the degree d i may represent the quantity of source symbols which may be combined into a given encoding symbol.
  • a Raptor code may use a small average degree.
  • a device may perform a decoding process to recover a set of source symbols from a set of encoded symbols.
  • the decoding process may include identifying an encoding symbol associated with a single source symbol (i.e., has a degree of one) .
  • the device may perform a logical exclusive OR (XOR) operation between the identified encoding symbol and each encoding symbol associated with the source symbol.
  • the device may repeat the decoding process until each source symbol of the set of source symbols has been recovered.
  • the device may recover the set of source symbols from a set of encoded symbols if an amount of encoded symbols is greater than the amount of source symbols.
  • the device may fail to recover the set of source symbols if the device cannot identify an encoding symbol associated with a single source symbol.
  • Such a decoding scheme may be referred to as a belief propagation scheme. Additionally or alternatively, a device may perform a different decoding process, such as a gaussian elimination process (i.e., a gaussian elimination scheme) , among other examples.
  • a gaussian elimination process i.e., a gaussian elimination scheme
  • a transmitting device 230 may encode a set of K source symbols 220 using one or more network coding techniques.
  • the transmitting device 230 may encode the K source symbols 220 using a rateless code (e.g., a fountain code, an LT code, a Raptor code, etc. ) .
  • Encoding the K source symbols 220 may yield a set of N encoded symbols 225, which the transmitting device 230 may transmit to one or more receiving devices 235 (e.g., UEs 115-a, 115-b, and 115-c) .
  • a receiving device 235 may receive a set of L encoded symbols 215.
  • L may be less than or equal to N based on, for example, channel conditions experienced by the receiving device 235. If the L is greater than K, that is, if the set of L encoded symbols 215 is larger than the set of K source symbols 220, the receiving device 235 may successfully recover the set of source symbols 220.
  • the wireless communications system 200 may support MBS communications services where the base station 105-a, which may be an example of a transmitting device 230, transmits encoded symbols to the UEs 115-a, 115-b, and 115-c which may be examples of receiving devices 235.
  • the base station 105-a may operate in RLC-UM, where the base station 105-a transmits encoded symbols without receiving feedback from the UEs 115-a, 115-b, or 115-c indicating whether the UEs 115-a, 115-b, or 115-c successfully recovered the source symbols. Accordingly, the base station 105-a may transmit a full set of encoded symbols.
  • the UEs 115-a, 115-b, and 115-c may recover the source symbols using different numbers of encoded symbols based on channel conditions experienced by each UE 115. That is, each of the UEs 115-a, 115-b, and 115-c may successfully decode the source symbols if the number of successfully received symbols is greater than the number of source symbols (K) , but may unsuccessfully decode the source symbols if the number of successfully received symbols is less than the number of source symbols (K) . In such cases, depending on channel conditions and decoding success, some UEs 115 may successfully decode the transmitted symbols, and others may not.
  • the base station 105-a may generate encoded symbols using a window adjustment coding technique.
  • the base station 105-a may identify a pool (i.e., a set) of data source symbols for transmission to one or more of the UEs 115-a, 115-b, or 115-c.
  • the base station 105-a may identify a window (e.g., a sliding window) including a set of the K source symbols 205 to be used for generating a respective set of encoded symbols 210.
  • the base station 105-a may identify a first set of source symbols included in the sliding window for a first transmission.
  • the base station 105-a may encode the first set of source symbols included in the window to obtain a first set of encoded symbols.
  • the base station 105-a may transmit the first set of encoded symbols to the UEs 115.
  • the base station 105-a may adjust the sliding window, for example, automatically and/or based on feedback from the UEs 115.
  • the base station 105-a may adjust the window a pre-configured quantity of source symbols to cover a second set of source symbols.
  • the base station 105-a may include one or more symbols of the first set of source symbols in the second set of source symbols (e.g., the base station 105-a may encode additional source symbols from adjusting the window and one or more symbols that were indicated to be unsuccessfully recovered by one or more UEs 115) . Additionally or alternatively, the base station 105-a may shift the sliding window such that an initial symbol of the second set of symbols included in the sliding window is a symbol associated with a threshold quantity of acknowledgment messages (e.g., for feedback type 1, the initial symbol may be identified based on a minimum acknowledgment sequence number as described herein) . The base station 105-a may encode the second set of source symbols to obtain a second set of encoded symbols. The base station 105-a may transmit the second set of source symbols, and repeat such operations until the pool of source symbols is successfully communicated to the UEs 115.
  • a threshold quantity of acknowledgment messages e.g., for feedback type 1
  • the base station 105-a may encode the second set of
  • window adjustment coding techniques may allow for an increased reliability of broadcast services in the communications system 200 and reduce an overall system latency.
  • the window adjustment techniques described herein may enable retransmission of unsuccessfully recovered source symbols while also sliding the window to include one or more additional source symbols (e.g., successfully recovered source symbols may not be transmitted and the additional source symbols may be transmitted instead) , which may reduce latency for communications between the base station 105-a and the UEs 115, among other advantages.
  • FIG. 3 illustrates an example of a window adjustment coding scheme 300 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the window adjustment coding scheme 300 may implement aspects of a wireless communications system 100 or 200 or any combination thereof as described with reference to FIGs. 1 and 2.
  • the window adjustment coding scheme 300 may be implemented by one or more base stations 105, one or more UEs 115, or any combination thereof.
  • the window adjustment coding scheme 300 may be implemented by a network node (e.g., a base station 105) to generate encoded symbols 320 from a set of source symbols 305 that are included in a sliding window 315.
  • a network node e.g., a base station 105
  • the base station 105 may identify a pool of source symbols 305 for transmission to one or more UEs 115 (e.g., a groupcast transmission to a plurality of UEs 115) . As illustrated, the base station 105 may identify a pool of source symbols 305-a through 305-l for communicating data to the UEs 115, although any quantity of source symbols 305 may be included in the pool of source symbols 305. The base station 105 may encode a portion of the pool of source symbols 305 based on a sliding window. For example, the base station 105 may identify a range of source symbols 305 included in the window 315. The base station 105 may encode the source symbols to obtain a set of encoded symbols 325, as described herein with reference to FIG. 2.
  • the base station 105-a may encode source symbol 305-d to source symbol 305-i included in the window 315 to obtain encoded symbols 320-a through 320-i.
  • the base station 105-a may transmit the set of encoded symbols 325 to one or more UEs 115.
  • the base station 105 may monitor for feedback from the UEs 115 in response to transmitting the set of encoded symbols 325 (e.g., feedback type 1 or feedback type 2) .
  • the base station 105 may receive feedback indicating that one or more of the source symbols 305 in the window 315 were unsuccessfully recovered.
  • a UE may transmit a negative acknowledgment (NACK) message or may fail to send an acknowledgment (ACK) message due to failing to recover one or more of the source symbols 305 (e.g., poor channel conditions may result in a threshold quantity of encoded symbols 320 to be lost and a UE 115 may be unable to identify corresponding source symbols 305) .
  • NACK negative acknowledgment
  • ACK acknowledgment
  • the base station 105 may retransmit the encoded symbols 325, for example, until each UE 115 has successfully recovered the source symbols 305 in the window 315, prior to adjusting the window 315 to transmit additional source symbols 305 (e.g., the out-of-window source symbols 310-b) .
  • additional source symbols 305 e.g., the out-of-window source symbols 310-b
  • the base station 105 may retransmit the same source symbols 305 multiple times if a UE 115 of multiple UEs 115 is unable to recover the source symbols 305, which may result in high signaling overhead and latency for delivering the pool of source symbols 305.
  • the base station 105 may implement a sliding window to improve communications efficiency. For example, the base station 105 may adjust the sliding window 315 using feedback from the UEs for the source symbols 305-d through 305-i. In some examples, the base station 105 may adjust the sliding window automatically. For example, the base station 105 may adjust the window 315 a pre-configured (e.g., pre-defined) quantity of source symbols to cover a second set of source symbols. As an illustrative example, the base station 105 may shift the window 315 to cover source symbols 305-f to 305-l. Additionally or alternatively, the base station 105-a may include one or more symbols of the first set of source symbols in the second set of source symbols.
  • the base station 105-a may include the symbol 305-d in addition to the symbols 305 in the adjusted window 315 based on the symbol 305-d being indicated to be unsuccessfully recovered by one or more UEs 115 (e.g., the feedback may indicate a NACK or a relatively small quantity of ACKs) .
  • the base station 105 may adjust the window 315 based on the received feedback from the UEs 115 (e.g., the feedback may trigger the window adjustment and the quantity of symbols that the sliding window 315 is shifted may be based on the feedback) .
  • the base station 105 may transmit a polling request (e.g., as part of a radio link control (RLC) polling procedure) to the one or more UEs 115.
  • the UEs may each report a respective ACK sequence number.
  • the ACK sequence number may be a field that indicates the sequence number of the next not received RLC service data unit (SDU) which is not reported as missing in the status packet data unit (PDU) .
  • the transmitting side of an AM RLC entity may interpret that all RLC SDUs up to but not including the RLC SDU with a sequence number equal to the received ACK sequence number have been received by its peer AM RLC entity, for example, excluding those RLC SDUs indicated in the status PDU with a NACK sequence number, portions of RLC SDUs indicated in the status PDU with a NACK sequence number, a segment offset (SO) start and SO end, RLC SDUs indicated in the status PDU with a NACK sequence number and NACK range, and portions of RLC SDUs indicated in the status PDU with a NACK sequence number, NACK range, SO start, and SO end, among other examples.
  • the ACK sequence number may indicate a contiguous quantity of the first set of source symbols that were successfully recovered. For example, an ACK sequence number of 5 may indicate that 5 of the source symbols 305 were successfully received and decoded by a respective UE 115. Accordingly, the base station 105-a may shift the sliding window such that an initial symbol of the second set of symbols included in the adjusted sliding window is a symbol associated with a minimum ACK sequence number received from the UEs 115.
  • the fourth source symbol 305 may be identified as the beginning source symbol 305 of the adjusted window.
  • the window 315 may be adjusted such that the beginning of the adjusted window 315 begins at source symbol 305-e and includes additional source symbol 305-j, based on the source symbol 305-e corresponding to the minimum ACK sequence number and/or a NACK message.
  • the base station 105 may adjust the sliding window for each transmission until the pool of source symbols 305 is successfully recovered by the group of UEs 115, which may reduce a latency of the system while ensuring reliable communications, among other advantages.
  • each source symbol 305 may correspond to an index value.
  • source symbol 305-a may be assigned an index value of 0, source symbol 305-b may be assigned an index value of 1, etc.
  • a UE 115 (or a base station 105) may be able to identify the index value of a source symbol 305, which may enable the UE 115 to transmit feedback for that source symbol.
  • a base station 105 may indicate the index value for each source symbol 305.
  • the base station 105 may include the source symbol 305-a in the set of source symbols 305 for encoding and transmission, as described herein (e.g., based on receiving a NACK for the source symbol 305-a from a prior transmission) .
  • the base station 105 may indicate an index for each source symbol 305 (e.g., the source symbol 305-a and the source symbols 305-d to 305-i included in the window 315) , which may enable UEs 115 to properly reconstruct the source symbols 305, among other examples.
  • FIG. 4 illustrates an example of a window adjustment scheme 400 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the window adjustment coding scheme 400 may implement aspects of a wireless communications system 100 or 200 or any combination thereof as described with reference to FIGs. 1 and 2.
  • the window adjustment coding scheme 400 may be implemented by one or more base stations 105, one or more UEs 115, or any combination thereof.
  • the window adjustment coding scheme 400 may be implemented by a network node (e.g., a base station 105) to generate encoded symbols from a set of source symbols 405 that are included in a sliding window 410.
  • a network node e.g., a base station 105
  • the base station 105 may identify a pool of source symbols 405 for transmission to one or more UEs 115, such as the source symbol 405-a through the source symbol 405-i, although any quantity of source symbols 405 may be used.
  • the base station 105 may determine that a first set of source symbols 405 (e.g., the source symbols 405-a through 405-e) are included in a sliding window 410-a.
  • the base station 105 may encode the first set of source symbols 405 into a first set of encoded symbols as described herein.
  • the base station 105 may transmit the first set of encoded symbols to one or more UEs 115 (e.g., via a groupcast transmission) .
  • the base station 105 may monitor for feedback from the UEs 115.
  • the UEs 115 may be configured with feedback type 1, feedback type 2, polling feedback techniques, or a combination thereof.
  • the base station 105 may monitor for ACK messages in accordance with a feedback type 1 scheme.
  • the base station 105 may transmit a polling request (e.g., as part of a RLC polling procedure) to the one or more UEs 115.
  • the UEs 115 may each report a respective ACK sequence number.
  • the ACK sequence number may indicate a contiguous quantity of the first set of source symbols that were successfully recovered.
  • an ACK sequence number of 3 may indicate that 3 of the source symbols 405 were successfully received and decoded by a respective UE 115. Accordingly, the base station 105-a may shift the sliding window such that an initial symbol of the second set of symbols included in the adjusted sliding window is a symbol associated with a minimum ACK sequence number received from the UEs 115. As an illustrative example, if the minimum ACK sequence number received from the UE 115 has a value of 3 (e.g., indicating that all of the UEs 115 successfully recovered the first 3 source symbols of the first set of source symbols) , the fourth source symbol 305 may be identified as the beginning source symbol 305 of the adjusted window.
  • the base station 105 may adjust the sliding window 410-a to the sliding window 410-b (e.g., the base station 105 may shift the window a quantity of source symbols 405 based on the feedback) .
  • the base station 105 may determine that the source symbol 405-c corresponds to a minimum ACK sequence number (e.g., the source symbols 405-a to 405-b were successfully received based on a value of the minimum ACK sequence number, and one or more UEs 115 have not reported an ACK for the source symbol 405-c as described herein) .
  • the base station 105 may adjust the window 410-a (e.g., slide the window 410-a) such that the window 410-b for encoding a subsequent transmission includes the source symbol 405-c as the initial source symbol 405 of a second set of source symbols (e.g., from the source symbol 405-c to the source symbol 405-g) .
  • the window 410-a may be moved to begin at a source symbol 405 associated with a minimum ACK sequence number received from the UEs 115.
  • the minimum ACK sequence number received from the UEs 115 may indicate that source symbols 405-a to 405-b were successfully received, and the base station 105 may shift the window 410-b such that the window begins with an initial source symbol 405-c based on the minimum ACK sequence number.
  • Such techniques may result in an improved recovery probability for one or more source symbols 405.
  • the base station 105 may transmit source symbols 405-c through 405-e in both the first transmission (e.g., associated with the window 410-a) and the second transmission (e.g., associated with the window 410-b) .
  • the overlapping portions of the window 410-a and the window 410-b may be recovered with higher probability due to the encoding and retransmission of the source symbols included in the overlapping portion.
  • FIG. 5 illustrates an example of a window adjustment scheme 500 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the window adjustment coding scheme 500 may implement aspects of a wireless communications system 100 or 200 or any combination thereof as described with reference to FIGs. 1 and 2.
  • the window adjustment coding scheme 500 may be implemented by one or more base stations 105, one or more UEs 115, or any combination thereof.
  • the window adjustment coding scheme 500 may be implemented by a network node (e.g., a base station 105) to generate encoded symbols from a set of source symbols 505 that are included in a sliding window 510.
  • a network node e.g., a base station 105
  • the base station 105 may identify a pool of source symbols 505 for communications to one or more UEs 115, such as the source symbol 505-a through the source symbol 505-h, although any quantity of source symbols 505 may be used.
  • the base station 105 may determine that a first set of source symbols 505 (e.g., the source symbols 505-a through 505-e) are included in a sliding window 510-a.
  • the base station 105 may encode the first set of source symbols 505 into a first set of encoded symbols for a first transmission 515-a to the one or more UEs 115, as described herein.
  • the base station 105 may monitor for feedback from the UEs 115.
  • the UEs 115 may be configured with feedback type 1, feedback type 2, polling feedback techniques, or a combination thereof.
  • the base station 105 may monitor for ACK messages in accordance with a feedback type 2 scheme.
  • the base station 105 may receive a bitmap from each UE 115 indicating that one or more source symbols 505 of the first set of source symbols 505 were successfully received (e.g., an ACK associated with each successfully received source symbol) , that a respective UE 115 failed to successfully receive one or more of the source symbols 505 (e.g., a NACK for each source symbol that was unable to be recovered) , or a combination thereof.
  • the base station 105 may adjust the sliding window 510-a to the sliding window 510-b for an additional groupcast transmission 515-b (e.g., the base station 105 may shift the window by a quantity of source symbols 505 based on the feedback) .
  • the base station 105 may adjust the window 510-a to the window 510-b such that the window 510-b for the additional transmission 515-b includes a second set of source symbols 505.
  • the second set of source symbols may be additional source symbols 505 included in the adjusted window 510-b (e.g., the source symbols 505-f through 505-h) .
  • the second set of source symbols may include one or more source symbols 505 from the first set of source symbols.
  • the base station 105 may include the source symbol 505-a and the source symbol 505-c in the second set of source symbols for the second transmission 515-b based on receiving at least one NACK for the source symbol 505-a and the source symbol 505-c, respectively.
  • source symbols 505 from the first set of source symbols corresponding to all ACK feedback from the set of UEs 115 may not be selected for the second transmission 515-b.
  • FIG. 6 illustrates an example of a window adjustment scheme 600 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the window adjustment coding scheme 600 may implement aspects of a wireless communications system 100 or 200 or any combination thereof as described with reference to FIGs. 1 and 2.
  • the window adjustment coding scheme 600 may be implemented by one or more base stations 105, one or more UEs 115, or any combination thereof.
  • the window adjustment coding scheme 600 may be implemented by a network node (e.g., a base station 105) to automatically adjust a sliding window 610 for generating encoded symbols from a set of source symbols 605 that are included in the sliding window 610.
  • a network node e.g., a base station 105
  • the base station 105 may identify a pool of source symbols 605 for transmission to one or more UEs 115, such as the source symbol 605-a through the source symbol 605-j.
  • the base station 105 may determine that a first set of source symbols 605 (e.g., the source symbols 605-a through 605-e) are included in a sliding window 610-a.
  • the base station 105 may encode the first set of source symbols 605 into a first set of encoded symbols for a first transmission 615-a to one or more UEs 115 (e.g., a groupcast transmission) .
  • the base station 105 may be configured to automatically adjust the sliding window 610-a. For example, the base station 105 may adjust the window 610-a two source symbols to the window 610-b, although the window may be adjusted any quantity of source symbols 605.
  • the base station may encode a second set of source symbols 605 for the second transmission 615-b (e.g., the source symbols 605-c through 605-g included in the adjusted window 610-b) .
  • the base station 105 may slide a window for encoding between transmissions 615 as the source symbols 605 are received sequentially from an upper layer.
  • the upper layer may provide a quantity of source symbols 605 for groupcast transmission between each transmission 615, and the base station 105 may shift a respective window 610 to include the provided quantity of source symbols 605 (e.g., two source symbols 605 as shown for illustrative clarity) .
  • the base station 105 may monitor for feedback from the UEs 115 for one or more of the transmissions 615.
  • the UEs 115 may be configured with feedback type 1, feedback type 2, polling feedback techniques, or a combination thereof.
  • the base station 105 may monitor for NACK messages subsequent to transmission 615-a.
  • transmission 615-a of a first set of encoded symbols may correspond to the first set of source symbols 605-a through 605-e.
  • the base station 105 may include one or more of the first set of source symbols 605 in the second set of source symbols for the transmission 615-b based on receiving feedback.
  • the base station 105 may include the source symbol 605-a in the second set of source symbols for the second transmission 615-b based on receiving at least one NACK for the source symbol 605-a.
  • source symbols 605 from the first set of source symbols corresponding to all ACK feedback from the set of UEs 115 may not be selected for the second transmission 615-b.
  • the second set of source symbols for encoding a second set of encoded symbols for the transmission 615-b may be selected based on being included in the window 610-b (e.g., a portion of the first set of source symbols 605-c through 605-e and additional source symbols from the pool of source symbols 605-f and 605-g) .
  • the second set of source symbols may include symbols not included in the window 610-b based on feedback (e.g., the source symbols 605-e may also be included) .
  • FIG. 7 illustrates an example of a process flow 700 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the process flow 700 may implement aspects of a wireless communications system 100 or 200, a window adjustment coding scheme 300, 400, 500, or 600, or any combination thereof as described with reference to FIGs. 1–6.
  • the process flow 700 may include a UE 115-d, a UE 115-e, and a base station 105-b which may be examples of the corresponding devices described herein.
  • Alternative examples of the following may be implemented where some processes are performed in a different order than described or not performed at all.
  • processes may include additional features not mentioned below, or further processes may be added.
  • the base station 105-b may identify a pool of source symbols for transmission.
  • the source symbols may include source symbols for groupcast or broadcast transmission.
  • the base station 105-b may encode source symbols included in a sliding window to obtain a set of encoded symbols.
  • a sliding window may include a first set of source symbols and the base station may encode the first set of source symbols into the first set of encoded symbols.
  • the base station 105-b may transmit the set of encoded symbols to the UEs 115-d and 115-e.
  • the UEs 115-d and 115-e may attempt to recover the source symbols associated with the set of encoded symbols.
  • the UE 115-d may recover a different amount of source symbols than the UE 115-e based on channel conditions experienced by each UE 115. For example, if the UE 115-d experiences a higher channel quality than the UE 115-e, the UE 115-d may successfully receive a larger amount of encoded symbols and so may recover a larger amount of source symbols.
  • the UE 115-d and/or the UE 115-e may send feedback to the base station 105-b.
  • the UE 115-d or the UE 115-e may report one or more ACK messages, NACK messages, or a combination thereof (e.g., in accordance with a feedback type 1 scheme using RLC polling techniques, a feedback type 2 scheme, etc. ) for one or more source symbols of the first set of source symbols.
  • the base station 105-b may adjust the sliding window.
  • the base station 105-b may adjust the sliding window automatically and/or based on the received feedback (e.g., the feedback may trigger the adjustment and the window may be shifted a quantity of source symbols based on the feedback) .
  • the base station 105-b may adjust the window a pre-configured quantity of source symbols to cover a second set of source symbols.
  • the base station 105-b may include one or more symbols of the first set of source symbols in the second set of source symbols (e.g., the base station 105-b may encode additional source symbols from adjusting the window, one or more symbols of the first set of source symbols associated with NACKs, or both) . Additionally or alternatively, the base station 105-b may shift the sliding window such that an initial symbol of the second set of symbols included in the sliding window is a symbol associated with a minimum ACK sequence number (e.g., a symbol indicated by the minimum ACK sequence number as being the first symbol that does not correspond to an ACK from each UE, among other examples) .
  • a minimum ACK sequence number e.g., a symbol indicated by the minimum ACK sequence number as being the first symbol that does not correspond to an ACK from each UE, among other examples
  • the base station 105-b may perform communications based on the window adjustment techniques. For example, the base station 105-b may encode the second set of source symbols, which may include source symbols within the adjusted window (e.g., a portion of the first set of source symbols, one or more additional source symbols, or both) , one or more source symbols that were unsuccessfully recovered from prior transmissions, or a combination thereof.
  • the communications may include the base station 105-b transmitting additional sets of encoded symbols obtained from source symbols within a sliding window covering varying ranges as described herein with reference to FIGs. 1–6.
  • the base station 105-b may repeat 710 through 725 until the entire pool of resources has been successfully communicated.
  • FIG. 8 shows a block diagram 800 of a device 805 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the device 805 may be an example of aspects of a base station 105 as described herein.
  • the device 805 may include a receiver 810, a communications manager 815, and a transmitter 820.
  • the device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sliding window coding techniques for wireless communications systems, etc. ) . Information may be passed on to other components of the device 805.
  • the receiver 810 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the receiver 810 may utilize a single antenna or a set of antennas.
  • the communications manager 815 may identify a pool of source symbols for groupcast transmission via a network coding scheme, encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission, receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the communications manager 815 may be an example of aspects of the communications manager 1110 described herein.
  • the communications manager 815 may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 815, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.
  • DSP digital signal processor
  • ASIC application-specific integrated circuit
  • FPGA field programmable gate array
  • the communications manager 815 may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components.
  • the communications manager 815, or its sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure.
  • the communications manager 815, or its sub-components may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.
  • I/O input/output
  • the communications manager 815 as described may be implemented to realize one or more potential advantages. Some implementations may allow the device 805 to implement a window adjustment coding technique for transmitting encoded symbols via a broadcast channel. Based on the window adjust coding techniques, the device 805 may support adjusting a sliding window as described herein to obtain one or more sets of encoded symbols such that receiving devices may successfully recover data. As such, the device 805 may realize reduced system latency, ensure reliability, or both, among other benefits.
  • the transmitter 820 may transmit signals generated by other components of the device 805.
  • the transmitter 820 may be collocated with a receiver 810 in a transceiver module.
  • the transmitter 820 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the transmitter 820 may utilize a single antenna or a set of antennas.
  • FIG. 9 shows a block diagram 900 of a device 905 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the device 905 may be an example of aspects of a device 805, or a base station 105 as described herein.
  • the device 905 may include a receiver 910, a communications manager 915, and a transmitter 945.
  • the device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sliding window coding techniques for wireless communications systems, etc. ) . Information may be passed on to other components of the device 905.
  • the receiver 910 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the receiver 910 may utilize a single antenna or a set of antennas.
  • the communications manager 915 may be an example of aspects of the communications manager 815 as described herein.
  • the communications manager 915 may include a symbol pool component 920, a coding component 925, a groupcast component 930, a feedback component 935, and a window adjustment component 940.
  • the communications manager 915 may be an example of aspects of the communications manager 1110 described herein.
  • the symbol pool component 920 may identify a pool of source symbols for groupcast transmission via a network coding scheme.
  • the coding component 925 may encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols.
  • the groupcast component 930 may transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission.
  • UEs user equipments
  • the feedback component 935 may receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols.
  • the window adjustment component 940 may adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the transmitter 945 may transmit signals generated by other components of the device 905.
  • the transmitter 945 may be collocated with a receiver 910 in a transceiver module.
  • the transmitter 945 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the transmitter 945 may utilize a single antenna or a set of antennas.
  • FIG. 10 shows a block diagram 1000 of a communications manager 1005 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the communications manager 1005 may be an example of aspects of a communications manager 815, a communications manager 915, or a communications manager 1110 described herein.
  • the communications manager 1005 may include a symbol pool component 1010, a coding component 1015, a groupcast component 1020, a feedback component 1025, a window adjustment component 1030, a portion component 1035, and a layer component 1040. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
  • the symbol pool component 1010 may identify a pool of source symbols for groupcast transmission via a network coding scheme.
  • the coding component 1015 may encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols.
  • the coding component 1015 may encode, in accordance with the network coding scheme, the second set of source symbols from the pool of source symbols, the second set of source symbols being within the sliding window and being encoded into a second set of encoded symbols.
  • the network coding scheme includes a fountain coding scheme, a raptor coding scheme, a gaussian elimination process scheme, a belief propagation scheme, or a combination thereof.
  • the base station communicates with the one or more UEs via a multicast radio bearer or dual radio bearer.
  • the groupcast component 1020 may transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission. In some examples, the groupcast component 1020 may transmit the second set of encoded symbols to the one or more UEs via groupcast transmission.
  • UEs user equipments
  • the feedback component 1025 may receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols.
  • the feedback component 1025 may receive a bitmap corresponding to the first set of source symbols, the bitmap indicating a set of negative acknowledgement bits, each negative acknowledgement bit of the set of negative acknowledgement bits corresponding to the portion of the first set of source symbols.
  • the window adjustment component 1030 may adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the feedback component 1025 may transmit, to the one or more UEs, a polling message associated with the feedback.
  • the feedback component 1025 may receive, from the one or more UEs, a set of acknowledgment sequence numbers as part of the feedback, each acknowledgment sequence number associated with a respective UE of the one or more UEs.
  • the window adjustment component 1030 may adjust the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols such that an initial symbol of the second set of source symbols is a symbol of the first set of source symbols corresponding to a smallest acknowledgment sequence number of the set of acknowledgment sequence numbers.
  • the window adjustment component 1030 may include a contiguous subset of the pool of source symbols as the second set of source symbols, beginning at the initial symbol.
  • the window adjustment component 1030 may adjust the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols such that an initial symbol of the second set of source symbols is a first symbol of the first set of source symbols for which a number of positive acknowledgements received from the one or more UEs is below a threshold. In some examples, the window adjustment component 1030 may automatically adjust the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols a predefined number of source symbols from an initial symbol of the first set of source symbols, the predefined number of source symbols being less than a number of source symbols in the sliding window.
  • the portion of the first set of source symbols included within the second set of source symbols includes an overlapping portion of the first set of source symbols arising from the sliding window being adjusted the predefined number of source symbols less than the number of source symbols in the sliding window, the portion of the first set of source symbols also including any source symbols within the predefined number of source symbols for which a negative acknowledgement was received.
  • the portion component 1035 may determine the portion of the first set of source symbols based on the received feedback, where the portion of the first set of source symbols includes one or more source symbols of the first set of source symbols for which at least one negative acknowledgement was received from the one or more UEs. In some examples, the portion component 1035 may symbols of the second set of source symbols are not contiguous within the pool of source symbols.
  • the layer component 1040 may receive, from an upper layer of the base station, the additional source symbols sequentially to the first set of source symbols, where automatically adjusting the sliding window is based on receiving the additional source symbols.
  • FIG. 11 shows a diagram of a system 1100 including a device 1105 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the device 1105 may be an example of or include the components of device 805, device 905, or a base station 105 as described herein.
  • the device 1105 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1110, a network communications manager 1115, a transceiver 1120, an antenna 1125, memory 1130, a processor 1140, and an inter-station communications manager 1145. These components may be in electronic communication via one or more buses (e.g., bus 1150) .
  • buses e.g., bus 1150
  • the communications manager 1110 may identify a pool of source symbols for groupcast transmission via a network coding scheme, encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols, transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission, receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols, and adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • UEs user equipments
  • the network communications manager 1115 may manage communications with the core network (e.g., via one or more wired backhaul links) .
  • the network communications manager 1115 may manage the transfer of data communications for client devices, such as one or more UEs 115.
  • the transceiver 1120 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above.
  • the transceiver 1120 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver.
  • the transceiver 1120 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.
  • the wireless device may include a single antenna 1125. However, in some cases the device may have more than one antenna 1125, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.
  • the memory 1130 may include RAM, ROM, or a combination thereof.
  • the memory 1130 may store computer-readable code 1135 including instructions that, when executed by a processor (e.g., the processor 1140) cause the device to perform various functions described herein.
  • the memory 1130 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.
  • BIOS basic input/output system
  • the processor 1140 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) .
  • the processor 1140 may be configured to operate a memory array using a memory controller.
  • a memory controller may be integrated into processor 1140.
  • the processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting sliding window coding techniques for wireless communications systems) .
  • the inter-station communications manager 1145 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1145 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1145 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.
  • the code 1135 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications.
  • the code 1135 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1135 may not be directly executable by the processor 1140 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.
  • FIG. 12 shows a flowchart illustrating a method 1200 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the operations of method 1200 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 1200 may be performed by a communications manager as described with reference to FIGs. 8 through 11.
  • a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.
  • the base station may identify a pool of source symbols for groupcast transmission via a network coding scheme.
  • the operations of 1205 may be performed according to the methods described herein. In some examples, aspects of the operations of 1205 may be performed by a symbol pool component as described with reference to FIGs. 8 through 11.
  • the base station may encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols.
  • the operations of 1210 may be performed according to the methods described herein. In some examples, aspects of the operations of 1210 may be performed by a coding component as described with reference to FIGs. 8 through 11.
  • the base station may transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission.
  • UEs user equipments
  • the operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be performed by a groupcast component as described with reference to FIGs. 8 through 11.
  • the base station may receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols.
  • the operations of 1220 may be performed according to the methods described herein. In some examples, aspects of the operations of 1220 may be performed by a feedback component as described with reference to FIGs. 8 through 11.
  • the base station may adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the operations of 1225 may be performed according to the methods described herein. In some examples, aspects of the operations of 1225 may be performed by a window adjustment component as described with reference to FIGs. 8 through 11.
  • FIG. 13 shows a flowchart illustrating a method 1300 that supports sliding window coding techniques for wireless communications systems in accordance with aspects of the present disclosure.
  • the operations of method 1300 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 1300 may be performed by a communications manager as described with reference to FIGs. 8 through 11.
  • a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.
  • the base station may identify a pool of source symbols for groupcast transmission via a network coding scheme.
  • the operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed by a symbol pool component as described with reference to FIGs. 8 through 11.
  • the base station may encode, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols.
  • the operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed by a coding component as described with reference to FIGs. 8 through 11.
  • the base station may transmit the first set of encoded symbols to one or more user equipments (UEs) via groupcast transmission.
  • UEs user equipments
  • the operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed by a groupcast component as described with reference to FIGs. 8 through 11.
  • the base station may receive, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols.
  • the operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed by a feedback component as described with reference to FIGs. 8 through 11.
  • the base station may determine the portion of the first set of source symbols based on the received feedback, where the portion of the first set of source symbols includes one or more source symbols of the first set of source symbols for which at least one negative acknowledgement was received from the one or more UEs.
  • the operations of 1325 may be performed according to the methods described herein. In some examples, aspects of the operations of 1325 may be performed by a portion component as described with reference to FIGs. 8 through 11.
  • the base station may adjust the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based on the received feedback, and additional source symbols from the pool of source symbols.
  • the operations of 1330 may be performed according to the methods described herein. In some examples, aspects of the operations of 1330 may be performed by a window adjustment component as described with reference to FIGs. 8 through 11.
  • Example 1 A method for wireless communications at a base station, comprising: identifying a pool of source symbols for groupcast transmission via a network coding scheme; encoding, in accordance with the network coding scheme, a first set of source symbols from the pool of source symbols, the first set of source symbols being within a sliding window and being encoded into a first set of encoded symbols; transmitting the first set of encoded symbols to one or more UEs via groupcast transmission; receiving, from the one or more UEs, feedback for one or more source symbols of the first set of source symbols; and adjusting the sliding window for additional groupcast transmission of a second set of source symbols from the pool of source symbols, the second set of source symbols including a portion of the first set of source symbols, based at least in part on the received feedback, and additional source symbols from the pool of source symbols.
  • Example 2 The method of example 1, wherein adjusting the sliding window comprises: receiving, from the one or more UEs, a set of acknowledgment sequence numbers as part of the feedback, each acknowledgment sequence number associated with a respective UE of the one or more UEs; and adjusting the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols such that an initial symbol of the second set of source symbols is a symbol of the first set of source symbols corresponding to a smallest acknowledgment sequence number of the set of acknowledgment sequence numbers.
  • Example 3 The method of any of examples 1 or 2, wherein adjusting the sliding window further comprises: including a contiguous subset of the pool of source symbols as the second set of source symbols, beginning at the initial symbol.
  • Example 4 The method of any of examples 1 to 3, further comprising: determining the portion of the first set of source symbols based at least in part on the received feedback, wherein the portion of the first set of source symbols includes one or more source symbols of the first set of source symbols for which at least one negative acknowledgement was received from the one or more UEs.
  • Example 5 The method of any of examples 1 to 4, wherein symbols of the second set of source symbols are not contiguous within the pool of source symbols.
  • Example 6 The method of any of examples 1 to 5, wherein receiving the feedback comprises: receiving a bitmap corresponding to the first set of source symbols, the bitmap indicating a set of negative acknowledgement bits, each negative acknowledgement bit of the set of negative acknowledgement bits corresponding to the portion of the first set of source symbols.
  • Example 7 The method of any of examples 1 to 6, wherein adjusting the sliding window comprises: automatically adjusting the sliding window for the additional groupcast transmission by shifting the sliding window within the pool of source symbols a predefined number of source symbols from an initial symbol of the first set of source symbols, the predefined number of source symbols being less than a number of source symbols in the sliding window.
  • Example 8 The method of any of examples 1 to 7, wherein the portion of the first set of source symbols included within the second set of source symbols includes an overlapping portion of the first set of source symbols arising from the sliding window being adjusted the predefined number of source symbols less than the number of source symbols in the sliding window, the portion of the first set of source symbols also including any source symbols within the predefined number of source symbols for which a negative acknowledgement was received.
  • Example 9 The method of any of examples 1 to 8, wherein adjusting the sliding window comprises: receiving, from an upper layer of the base station, the additional source symbols sequentially to the first set of source symbols, wherein automatically adjusting the sliding window is based at least in part on receiving the additional source symbols.
  • Example 10 The method of any of examples 1 to 9, further comprising: encoding, in accordance with the network coding scheme, the second set of source symbols from the pool of source symbols, the second set of source symbols being within the sliding window and being encoded into a second set of encoded symbols; and transmitting the second set of encoded symbols to the one or more UEs via groupcast transmission.
  • Example 11 The method of any of examples 1 to 10, wherein the network coding scheme comprises a fountain coding scheme, a raptor coding scheme, a gaussian elimination process scheme, a belief propagation scheme, or a combination thereof.
  • the network coding scheme comprises a fountain coding scheme, a raptor coding scheme, a gaussian elimination process scheme, a belief propagation scheme, or a combination thereof.
  • Example 12 The method of any of examples 1 to 11, wherein the base station communicates with the one or more UEs via a multicast radio bearer or dual radio bearer.
  • Example 13 An apparatus comprising at least one means for performing a method of any of examples 1 to 12.
  • Example 14 An apparatus for wireless communications comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 1 to 12.
  • Example 15 A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of examples 1 to 12.
  • LTE, LTE-A, LTE-A Pro, or NR may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks.
  • the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.
  • UMB Ultra Mobile Broadband
  • IEEE Institute of Electrical and Electronics Engineers
  • Wi-Fi Institute of Electrical and Electronics Engineers
  • WiMAX IEEE 802.16
  • IEEE 802.20 Flash-OFDM
  • Information and signals described herein may be represented using any of a variety of different technologies and techniques.
  • data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
  • a general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine.
  • a processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .
  • the functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
  • Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
  • a non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer.
  • non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium.
  • RAM random-access memory
  • ROM read-only memory
  • EEPROM electrically erasable programmable ROM
  • flash memory compact disk (CD) ROM or other optical disk storage
  • CD compact disk
  • magnetic disk storage or other magnetic storage devices or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer,
  • Disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne des procédés, des systèmes et des dispositifs destinés aux communications sans fil. Certaines techniques peuvent comprendre un dispositif, tel qu'une station de base, identifiant un groupe de symboles source pour la transmission. Le dispositif peut coder, conformément à un schéma de codage de réseau, un premier ensemble de symboles de source provenant du groupe de ressources dans un premier ensemble de symboles codés, le premier ensemble de symboles source se trouvant à l'intérieur d'une fenêtre glissante. Le dispositif peut transmettre le premier ensemble de symboles codés à un ou plusieurs autres dispositifs au moyen d'une transmission de diffusion de groupe. Le dispositif peut ajuster la fenêtre glissante pour une transmission de diffusion de groupe supplémentaire d'un second ensemble de symboles source du groupe de symboles source. Le second ensemble de symboles source peut comprendre une partie du premier ensemble de symboles source, d'après au moins en partie la rétroaction reçue, et des symboles source supplémentaires du groupe de symboles source.
PCT/CN2020/110474 2020-08-21 2020-08-21 Techniques de codage de fenêtre glissante pour des systèmes de communication sans fil WO2022036679A1 (fr)

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