Channel estimation optimization in wireless communication systems

Abstract

A method performed by a receiver of a wireless communication system to reduce channel estimation latency. The method includes receiving a data signal and a reference signal sequence communicated over a wireless communication channel. In response to determining that the data signal is time-critical or does not require a threshold reliability of channel estimation, the receiver estimates channel conditions of the wireless communication channel based on a portion of the reference signal sequence. The receiver performs demodulation and decoding of the data signal prior to processing the entirety of the reference signal sequence. The demodulation and decoding are adapted based on the estimated channel conditions of the wireless communication channel.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 057,732, filed July 28, 2020, entitled “Channel Estimation Optimizations in Wireless Communication Systems,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The disclosed teachings relate to wireless communication, and in particular to improvements in the channel estimation process for communication channels. Background Technology

[0004] In wireless communication, channel estimation is a process performed at the receiver side of the communication channel. Channel estimation is performed before demodulation and / or decoding of the received data signal. Channel estimation is based on channel state information (CSI), which refers to the known state of the channel properties of the communication channel. CSI describes how the signal propagates from the transmitter to the receiver and represents the combined effects of factors such as scattering, fading, and power attenuation with distance. CSI enables transmission to adapt to the current channel conditions, which is crucial for achieving reliable communication at high data rates in communication systems.

[0005] The Channel Indicator (CSI) is estimated at the receiver and is typically quantized, with feedback sent to the transmitter. Therefore, the transmitter and receiver can have different CSIs. Due to changes in channel conditions, the instantaneous CSI is periodically estimated on a short-term basis as a channel estimation chain. A common technique involves using a so-called training sequence (or pilot sequence) in which a known reference signal is transmitted, and using combined knowledge of the transmitted and received signals to estimate the channel matrix.

[0006] Delays anywhere in the channel estimation process will cause delays in demodulating and decoding the data signal. This resulting delay increases the computational requirements for subsequent channel estimation within the reference signal sequence. Furthermore, this delay increases the burden of subsequent data processing (e.g., demodulation and decoding), limits the achievable data rate, and increases the computational requirements and power consumption of the receiver. Attached Figure Description

[0007] Embodiments of this technology will be described and explained using the accompanying drawings.

[0008] Figure 1 This is a flowchart illustrating the process of demodulating and decoding data signals performed by a wireless communication system.

[0009] Figure 2 This is a block diagram illustrating an example of the transmission of a data signal interleaved with a reference signal sequence processed at the receiver.

[0010] Figure 3 This is a graph showing the interpolation curves used for channel estimation of the reference signal sequence.

[0011] Figure 4 This is a flowchart illustrating the process used to reduce latency in channel estimation.

[0012] Figure 5 This is a flowchart illustrating the process of dynamically adjusting the quantization size to improve performance or reduce storage space to further optimize channel estimation.

[0013] Figure 6 This is a block diagram illustrating an example of a processing system in which at least some of the operations described herein can be implemented.

[0014] The various features of the technology described herein will become more apparent to those skilled in the art by studying the detailed description in conjunction with the accompanying drawings. Embodiments are shown in the drawings by way of example rather than limitation, and similar reference numerals may indicate similar elements. While the drawings depict various embodiments for illustrative purposes, those skilled in the art will recognize that alternative embodiments may be employed without departing from the principles of the technology. Therefore, although specific embodiments are shown in the drawings, various modifications can be made to the technology. Detailed Implementation

[0015] The disclosed solution improves the channel estimation process by reducing or minimizing latency in channel estimation (among other things). For example, existing techniques process (e.g., demodulate and decode) the data signal only after estimating the overall channel condition based on the reference signal sequence (e.g., until the last reference signal of the transmission unit has been processed). Examples of transmission units include data packets, time slots in 5G New Radio (NR), or subframes in 4G Long Term Evolution (LTE). A transmission unit typically includes 1, 2, 3, 4, or more reference signals at different time points. The reference signals in this sequence are interleaved at the time points of the data transmission unit that includes the data signal.

[0016] In existing technologies, demodulating and decoding data signals in a data transmission unit requires estimating the channel conditions of each reference signal and interpolating the obtained channel estimates to adapt to the current conditions of the communication channel. Therefore, existing channel estimation techniques delay the demodulation and decoding of data signals, which is particularly problematic for time-critical data, especially in 5G systems where high-performance speeds and ultra-low latency are required to manage large volumes of network traffic on massively distributed communication devices.

[0017] The disclosed solution overcomes the shortcomings of existing channel estimation techniques by allowing a receiver (e.g., a user equipment (UE) or base station (BS)) to process data signals based on a portion of a reference signal sequence included in the data packets. In other words, under suitable conditions, the receiver can demodulate and decode data signals based on, for example, a channel estimate based on only one reference signal that arrives before or after the data signal. Examples of suitable conditions include time-critical data signals or situations where highly reliable channel estimation is not required for processing the data signal. "High" reliability can refer to the maximum reliability derived from processing the entire reference signal sequence, which can correspond to an adjustable threshold (e.g., set below a maximum value). Thus, the disclosed solution balances the trade-off between performance and reliability, where only a portion of the reference signal sequence is used for channel estimation when timely processing of the data signal is required and / or when high reliability of channel estimation is not needed.

[0018] The receiver in a wireless communication system can determine when to perform a channel estimation calculation chain (for a reference signal sequence) based on factors such as the temporal location of the reference signal, decoding requirements, and / or channel statistics. This solution allows for high data rates to be supported given computational power, reducing the receiver's computational requirements and thus lowering chipset costs. Furthermore, power consumption is reduced by dynamically relaxing the system-wide timing requirements for channel estimation.

[0019] In addition to reducing latency, this solution can also adjust the quantization bit width of the data signal, or make it possible to reduce the memory utilization / size of the modem performing demodulation and decoding. Conversely, existing technologies perform channel estimation by processing the received signal using a fixed quantization bit width. Therefore, for example, when it is desirable to reduce or minimize memory utilization, the receiver can reduce the quantization bit width of the data signal, thereby reducing the storage space required by the modem. In another example, when improved performance is desired and storage size is not a concern, the receiver can increase the quantization bit width to improve demodulation and decoding accuracy. The quantization size can be adapted to the receiver's capabilities, the requirements of the receive chain, fast fading channel characteristics, etc. Given a fixed storage size, channel estimation latency may require buffering more data signal before processing. Therefore, each signal is quantized with a lower bit width to reduce or avoid buffering, as a trade-off for lower demodulation and decoding performance.

[0020] Figure 1 This is a flowchart illustrating the process of demodulating and decoding data signals performed by a wireless communication system. Process 100 can be implemented at the physical layer of the receiver in the wireless communication system. Process 100 includes signal reception 102, channel estimation 104, demodulation 106, and decoding 108 of the data signal.

[0021] At position 102, the receiver's antenna picks up the signal waveform communicated via the wireless communication channel. The analog signal is digitally quantized and stored in the receiver's memory. Decoding performance is improved by using a high quantization bit width for the analog signal. However, this improved decoding performance comes at the cost of increased storage space requirements for storing the quantized data.

[0022] At position 104, the receiver performs channel estimation based on one or more reference signals transmitted by the transmitter. The receiver knows the expected reference signal. Thus, the receiver can perform channel estimation by comparing the received reference signal with the expected reference signal. The channel estimation is then used to mitigate the impact of channel conditions on the data signal.

[0023] At position 106, the receiver performs a demodulation operation, where each received data signal is represented by one or more information bits. As used herein, demodulation refers to the process of recovering the transmitted coded bits from the received signal.

[0024] At position 108, the receiver performs a decoding operation to check data integrity and correct errors. The reliability of the communication channel is improved by adding redundant bits to the signal at the transmitter side. This helps to detect or correct errors introduced during transmission.

[0025] As mentioned earlier, the entire sequence of reference signals is typically processed by the receiver to perform channel estimation, which is then used to perform demodulation and decoding of the data. Specifically, the channel estimate used for demodulation and decoding is derived based on the interpolation of the channel estimate calculated for the reference signal sequence, with each reference signal received at a different time point. The reference signals themselves are overhead because they do not transmit information related to the data. Therefore, it is desirable to reduce the overhead of the reference signals. To this end, the transmission of reference signals and data is typically interleaved in time, such as... Figure 2 As shown in the figure, a wireless packet comprises two reference signals (R) interleaved in time between three data signals. Interleaving modes include different designs used in wireless communication systems, such as the Common Reference Signal (CRS) design in 4G LTE and the Demodulation Reference Signal (DMRS) design in 5G systems.

[0026] like Figure 2 As shown, channel estimation is performed for each received reference signal after reception by the receiver. However, in the prior art, demodulation and decoding typically occur after channel estimation is performed on two reference signals. That is, channel estimation is more accurate when calculations are performed based on a large number of reference signals. However, the tradeoff is that there is a delay in the demodulation and decoding of the data signal, which is problematic in implementations or applications where the timeliness of the data is critical. Furthermore, in environments where the effects of scattering, fading, and power attenuation with distance are minimal, delaying demodulation and decoding is unnecessary. In these cases, delaying the demodulation and decoding of the data signal until full-channel estimation is performed based on multiple reference signals results in inefficient and delayed data processing.

[0027] like Figure 2 As shown, the disclosed "low latency" technique allows demodulation and decoding to be performed before the entire reference signal sequence is received. Specifically, after channel estimation is performed based on the first reference signal, the data signal is immediately demodulated and decoded, and this process continues after channel estimation is performed based on the second reference signal. Thus, the example technique provides low latency for the demodulation and decoding of the data signal.

[0028] Figure 3 This is a graph illustrating how interpolation for channel estimation of the reference signal sequence is performed over the entire packet. The horizontal axis of the graph represents time, while the vertical axis represents channel estimation. The packet is shown as having data signals 0 through 5 and interleaved reference signals A, B, and C. Each data signal has a specific duration. For example, data signals 1 and 3 have the same duration Ts.

[0029] The dashed lines represent the actual channel over the duration of the packet. As shown, the actual channel varies over the duration of the packet. The star symbols represent the estimated channel values ​​based on reference signals A, B, or C, respectively. In some cases, the estimated channel for reference signal B is based on reference signals A and B (e.g., based on partial interpolation), and the estimated channel for reference signal C is based on reference signals A, B, and C (e.g., based on partial or complete interpolation). The solid lines represent the interpolated channels based on reference signals A, B, and C. Interpolated channels are typically used to adjust the demodulation and decoding of the data signal after the entire set of reference signals has been processed. The accuracy of the interpolation depends on the interpolation algorithm used, which has many known variations; therefore, for brevity, these are omitted in this paper.

[0030] Figure 4 This is a flowchart illustrating the process of reducing latency in channel estimation. Process 400 is performed by a receiver, for example, in a wireless communication system. The receiver or associated device may execute one or more algorithms to perform one or more operations of process 400. The one or more algorithms may include specific implementations understood by those skilled in the art, and therefore are omitted herein for the sake of brevity.

[0031] At 402, the receiver's antenna receives one or more data signals and a reference signal sequence communicated via a wireless communication channel. The data signals and reference signal sequence are communicated from a transmitter at the other end of the communication channel. In one example, the reference signal sequence is interleaved with multiple data signals (see, for example, [link to relevant documentation]). Figure 3 ).

[0032] At position 404, the receiver determines whether the data signal is "time-critical." This can be determined based on factors such as the timing standards implemented by the network, the condition of the communication channel, the type or capabilities of the receiver, and the nature of the data (e.g., time-sensitive data). Therefore, a data signal is time-critical when the delay in demodulating or decoding the data signal based on a channel estimate obtained from the entire processing reference signal sequence is undesirable or unnecessary. In other examples, the receiver may determine whether a data signal is time-critical based on 3GPP timing requirements, processing speed requirements, the amount of data to be processed by the receiver, the receiver's location, or historical information about the data or the receiver. In yet another example, the receiver determines whether a data signal is time-critical based on a measurement of whether the propagation (e.g., Doppler) of the data signal exceeds a threshold used for optimal channel estimation. Therefore, a relatively small Doppler can trigger the implementation of a low-latency channel estimation process. In yet another example, the UE defaults to treating each communication as time-critical and dynamically changes to a more reliable and accurate channel estimation process when channel conditions are unfavorable for a low-latency channel estimation process.

[0033] Consider Section 5.3 of 3GPP TS 38.214, which describes the timing of the UE Physical Downlink Shared Channel (PDSCH) processing procedure. The requirement for a 30kHz subcarrier spacing (SCS) includes that the UE has 13 time symbols from the end of PDSCH reception to complete all necessary processing and send ACK / NACK feedback to the base station. Assume there are DMRS at symbols 2, 5, 8, and 11, and that channel estimation for one DMRS symbol has a duration of one symbol. For higher reliability techniques, demodulation begins after the last DMRS symbol. Therefore, for two consecutive time slots (each with 13 symbols), this leaves 14 symbols for UE data link processing. In contrast, using the disclosed solution, demodulation begins after the first DMRS is processed, leaving 23 symbols for UE data link processing. Therefore, the low-latency channel estimation procedure relaxes the timing requirements by 64%, allowing for low-cost, low-complexity UE designs.

[0034] At point 406, when the data signal is not time-critical, the receiver determines whether a threshold reliability for channel estimation is not required to process the data signal. Channel estimation generated based on the overall reference signal sequence provides the highest reliability for channel estimation. In one example, the threshold reliability has the same level of reliability as channel estimation generated based on the overall reference signal sequence. However, for channel estimation based on, for example, a single reference signal, the threshold reliability can be set below the maximum value but above the minimum value. In some examples, the receiver determines that threshold reliability is not required for channel estimation based on a signal-to-noise ratio (SNR) level that is high enough to indicate that the reception quality exceeds a minimum threshold, the use of a sufficiently low modulation and coding scheme (MCS) (e.g., high SNR is not required), performance loss exceeding a tolerable level, or fast fading channel characteristics.

[0035] At point 408, in response to the determination that high reliability is required (e.g., a reliability threshold must be met), the receiver employs existing techniques to perform optimal channel estimation. For example, the receiver may estimate the channel conditions of the communication channel based on the overall reference signal sequence. The receiver then interpolates the temporally different channel condition sequences based on their respective reference signals within the sequence. The receiver then adapts the interpolated channel conditions for demodulation and decoding of the data signal. This adapted demodulation and decoding occurs after the channel estimation of the final reference signal from the reference signal sequence.

[0036] At 410, in response to determining whether the data signal is time-critical or does not require a threshold reliability for channel estimation, the receiver estimates the channel condition of the wireless communication channel based on a portion of a reference signal sequence. For example, the receiver may select a reference signal from the reference signal sequence based on the timing position of the data signal relative to the reference signal. In one example, this portion of the reference signal sequence includes only one reference signal corresponding to the selected reference signal. Although many wireless communication systems use pre-loaded reference signals when high reliability is required, the pattern of the reference signal in the data packet can vary; therefore, the disclosed technique can handle different patterns to optimize for low latency.

[0037] At 412, in response to determining the timing position of the data signal in the reference signal, the receiver immediately performs demodulation and decoding of the data signal after performing channel estimation based on the selected reference signal. The demodulation and decoding of the data signal is adapted to the estimated channel conditions generated based on the selected reference signal.

[0038] At position 414, in response to the selected reference signal having a common timing position in determining the data signal and reference signal sequences, the receiver performs demodulation and decoding of the data signal based on the selected reference signal after channel estimation. That is, the reference signal arrives simultaneously with the data signal. In these cases, demodulation and decoding of the data signal can occur immediately after generating the channel estimate based on the selected reference signal.

[0039] At 416, in response to determining that the timing position of the last reference signal in the reference signal sequence precedes the data signal, the receiver performs demodulation and decoding of the data signal after the channel estimation of the last reference signal. In one example, the receiver interpolates the channel condition estimates based on the respective reference signals of the sequence. The interpolated channel estimates can be used to process the data signal.

[0040] At 418, the receiver determines that the timing position of the data signal is between a first reference signal and a second reference signal in the reference signal sequence, where the first reference signal precedes the second reference signal. The receiver then determines whether the time difference between the data signal and the first reference signal is less than or equal to a time threshold Ts to determine whether to demodulate and decode the data signal after generating a channel estimate based on the first or second reference signal. The communication channel will remain relatively constant for a short period of time, such as, for example, coherence time. Furthermore, considering the adverse effects of fast fading channel characteristics, the time threshold Ts is a time window in which the channel estimate used for the reference signal can be applied to subsequent data signals. That is, when within the coherence time of a fast fading channel, the channel estimate can be considered reliable. In one example, the time threshold Ts is dynamic. For example, the time threshold Ts can be narrowed when a Doppler frequency exceeding the threshold is detected. In another example, the time threshold Ts is reduced if high performance (e.g., high throughput) is required.

[0041] At 420, in response to determining that the time difference between the data signal and the first reference signal is less than or equal to a time threshold Ts, the receiver may assume that the channel estimation based on the first reference signal is valid for the data signal, or extrapolate the current channel condition for processing the data signal based on the first reference signal preceding the data signal.

[0042] At position 422, in response to determining that the time difference between the data signal and the first reference signal exceeds a time threshold Ts, the receiver waits for the second reference signal and performs interpolation of the channel estimation for the reference signal sequence before demodulating and decoding the data signal. Therefore, the current channel condition for processing the data signal is based on the second reference signal. In other words, when the time gap between the positions of the data signal and the reference signal exceeds the time threshold Ts, the receiver waits for the next reference signal and performs interpolation of the channel estimation before demodulating and decoding.

[0043] In one example, process 400 can be used to process Figure 3The data signals are shown. For example, in a timing-critical situation, the following scheduling occurs. For data signals located in regions #0 and #1 adjacent to reference signal A, demodulation and decoding of the data signals in #0 and #1 occur after channel estimation is performed based on reference signal A. For data signals located in regions #2 and #3 adjacent to reference signal B, demodulation and decoding of data signals #2 and #3 occur after channel estimation is performed based on reference signal B. For data signals located in regions #4 and #5 adjacent to reference signal C, demodulation and decoding of data signals #4 and #5 occur after channel estimation is performed based on reference signal C. Therefore, for example, for data signals in regions #0 to #3, because demodulation and decoding occur before channel estimation for all reference signals is completed, the delay is reduced.

[0044] Figure 5 This is a flowchart illustrating process 500 for dynamically adjusting the quantization size of channel estimation data to improve performance or reduce storage space to further optimize low-latency channel estimation. This adjustment can occur after process 400 or independently of it (at 502).

[0045] At step 504, the receiver determines whether the channel estimation should be further optimized for performance or storage capacity. In one example, optimization is based on criteria associated with the data or reference signal, or on technical limitations of the receiver or another device involved in the channel estimation process.

[0046] At point 506, the receiver determines that performance criteria are met to improve the performance of the receiver's channel estimation process. In one example, performance criteria may include highly secure or confidential data or a requirement for highly reliable channel estimation. In response to meeting the performance criteria, the receiver increases the quantization size of the channel estimation data stored at the receiver (e.g., channel estimation sample results or interpolated channel estimates used for their respective reference signals). Given a larger quantization bit width, the accuracy of the channel estimation results increases; however, the required storage space also increases.

[0047] At point 508, the receiver determines that a storage space criterion is met to reduce the utilization of storage space used to store channel estimation data. In one example, the storage space criterion may include limited availability of memory at the receiver. In response to meeting the storage space criterion, the receiver may maintain or reduce the quantization size used for channel estimation data. Given a reduced quantization bit width, the required storage space is reduced, along with a decrease in the accuracy of the result.

[0048] Figure 6This is a block diagram illustrating an example of a processing system 600, in which at least some of the operations described herein can be implemented. Processing system 600 represents a system capable of running any of the methods / algorithms described herein. For example, any device or component (e.g., module) of the disclosed system may include processing system 600 or a portion thereof. Processing system 600 may include one or more processing devices that may be interconnected via a network or multiple networks. A network may refer to a communication network or a telecommunications network.

[0049] In the illustrated embodiment, the processing system 600 includes one or more processors 602, a memory 604, a communication device 606, and one or more input / output (I / O) devices 608, all interconnected via interconnects 610. The interconnects 610 may be or include one or more conductive traces, buses, point-to-point connections, controllers, adapters, and / or other conventional connectivity devices. Each of the processors 602 may be or include, for example, one or more general-purpose programmable microprocessors or microprocessor cores, microcontrollers, application-specific integrated circuits (ASICs), programmable gate arrays, etc., or combinations of these devices.

[0050] Multiple processors 602 control the overall operation of the processing system 600. Memory 604 may be or include one or more physical storage facilities, which may be in the form of random access memory (RAM), read-only memory (ROM) (which may be erasable and programmable), flash memory, micro hard disk drive, or other suitable types of storage devices, or combinations thereof. Memory 604 may store data and instructions that configure the multiple processors 602 to perform operations according to the above-described techniques. Communication device 606 may be or include, for example, an Ethernet adapter, a cable modem, a Wi-Fi adapter, a cellular transceiver, a Bluetooth transceiver, or combinations thereof. Depending on the specific nature and purpose of the processing system 600, I / O device 608 may include devices such as a display (which may be a touchscreen display), audio speakers, a keyboard, a mouse or other pointing devices, a microphone, a camera, etc.

[0051] Although processes or blocks are presented in a given order, alternative embodiments may execute routines with steps or employ systems with blocks in a different order. Some processes or blocks may be deleted, moved, added, subdivided, combined, and / or modified to provide alternatives or subcombinations, or some processes or blocks may be copied (e.g., executed multiple times). Each of these processes or blocks may be implemented in a variety of different ways. Furthermore, while processes or blocks are sometimes shown as being executed serially, they may alternatively be executed in parallel or may be executed at different times. When a process or step is “based on” a value or calculation, the process or step should be interpreted as being based at least on that value or calculation.

[0052] Software or firmware used to implement the techniques described herein can be stored on a machine-readable storage medium and can be executed by one or more general-purpose or special-purpose programmable microprocessors. As used herein, the term "machine-readable medium" includes any mechanism capable of storing information in a machine-accessible form, such as a computer, network device, cellular phone, personal digital assistant (PDA), manufacturing tool, any device having one or more processors, etc. For example, machine-accessible media include recordable / non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices), etc.

[0053] Note that, unless otherwise stated above or if any such embodiments may be functionally and / or structurally mutually exclusive, any and all of the above embodiments may be combined with each other. Although the invention has been described with reference to specific exemplary embodiments, it should be understood that the invention is not limited to the described embodiments but can be practiced through modifications and variations within the spirit and scope of the disclosed embodiments. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

[0054] Physical and functional components (e.g., devices, engines, modules, and data storage) associated with processing system 600 can be implemented as circuits, firmware, software, other executable instructions, or any combination thereof. For example, functional components can be implemented as dedicated circuits, one or more appropriately programmed processors, single-board chips, field-programmable gate arrays, general-purpose computing devices configured by executable instructions, virtual machines configured by executable instructions, cloud computing environments configured by executable instructions, or any combination thereof. For example, the described functional components can be implemented as instructions on tangible memory, executable by a processor or other integrated circuit chip. Tangible memory can be computer-readable data storage. Tangible memory can be volatile or non-volatile memory. In some embodiments, volatile memory can be considered "non-transient" in the sense that it is not a transient signal. The storage spaces and memories depicted in the figures can also be implemented using tangible memory (including volatile or non-volatile memory).

[0055] Each functional component can operate independently of other functional components. Some or all functional components can execute on the same host device or on separate devices. Separate devices can be connected via one or more communication channels (e.g., wireless or wired channels) to coordinate their operation. Some or all functional components can be combined into a single component. A single functional component can be divided into multiple sub-components, each sub-component executing a separate method step or method step of the single component.

[0056] In some embodiments, at least some functional components share access to memory space. For example, one functional component can access data accessed or transformed by another functional component. If functional components directly or indirectly share physical or virtual connections, allowing data accessed or modified by one functional component to be accessed in another functional component, these functional components can be considered "connected" to each other. In some embodiments, at least some functional components can be remotely upgraded or modified (e.g., by reconfiguring executable instructions for some functional components). The other arrays, systems, and devices described above may include more, fewer, or different functional components for various applications.

[0057] Aspects of the disclosed embodiments can be described based on the algorithms and symbolic representations of operations on data bits stored in memory. These algorithmic descriptions and symbolic representations typically include a series of operations that produce the desired result. These operations require physical manipulation of physical quantities. Typically, though not strictly necessary, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated. For convenience, these signals are often referred to as bits, values, elements, symbols, characters, terms, numbers, etc. These and similar terms are associated with physical quantities and are merely convenient labels applied to them.

[0058] Summarize

[0059] Unless the context explicitly requires otherwise, throughout the specification and claims, the words “comprising,” “including,” etc., shall be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of “including but not limited to.” As used herein, the terms “connection,” “link,” or any variation thereof mean any direct or indirect connection or link between two or more elements; the connection between elements may be physical, logical, or a combination thereof. Furthermore, when used in this application, the words “this article,” “above,” “below,” and similar terms shall refer to the application as a whole and not to any particular part of the application. Where the context permits, the singular or plural terms used in the above specific embodiments may also include the plural or singular, respectively. With respect to a group of two or more items, the word “or” covers all of the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list.

[0060] The above detailed description of embodiments of the system is not intended to be exhaustive or to limit the system to the precise forms disclosed above. While specific embodiments and examples of the system have been described above for illustrative purposes, various equivalent modifications can be made within the scope of the system. For example, some network elements are described herein as performing certain functions. These functions can be performed by other network elements in the same or different networks, which can reduce the number of network elements. Alternatively or additionally, the network elements performing those functions can be replaced by two or more elements to perform a portion of those functions. Furthermore, although processes, messages / data flows, or blocks are presented in a given order, alternative embodiments may execute routines with steps or employ a system with blocks in a different order; some processes or blocks can be deleted, moved, added, subdivided, combined, and / or modified to provide alternatives or sub-combinations. Each of these processes, messages / data flows, or blocks can be implemented in various different ways. Furthermore, although processes or blocks are sometimes shown as being executed serially, these processes or blocks can alternatively be executed in parallel or may be executed at different times. Additionally, any specific numbers mentioned herein are merely examples: alternative implementations can employ different values ​​or ranges. It will also be understood that the actual implementation of a database can take many forms, and the term "database" is used in the general sense in this document to refer to any data structure that allows the storage and access of data, such as tables, linked lists, arrays, etc.

[0061] The methods and systems taught herein can be applied to other systems, not necessarily those described above. Elements and actions of the various embodiments described above can be combined to provide other embodiments. If desired, aspects of this disclosure can be modified to incorporate the systems, functions, and concepts referenced above to provide other embodiments of this disclosure.

[0062] Based on the specific embodiments described above, these and other modifications can be made to the present invention. Although the foregoing description depicts certain embodiments of this disclosure and describes the contemplated best mode, the invention can be implemented in a variety of ways, however detailed it may be in the text. The details of the system may vary considerably in their implementation details, but are still covered by the techniques disclosed herein. As noted above, specific terms used in describing certain features or aspects of the disclosed technology should not be construed as implying that such terms are redefined herein as limited to any particular feature, characteristic, or aspect of the disclosed technology associated with that term. Generally, the terms used in the following claims should not be construed as limiting the invention to the specific embodiments disclosed in the specification, unless these terms are expressly defined in the foregoing detailed description section. Therefore, the actual scope of the invention includes not only the disclosed embodiments but also all equivalent ways in which the invention is practiced or implemented in the claims.

[0063] Although certain aspects of the disclosed technology are presented below in the form of certain claims, the inventors consider all aspects of the technology to be in any number of claims. For example, while only one aspect of the invention is described as embodied in a computer-readable medium, other aspects may also be embodied in a computer-readable medium. Therefore, the inventors reserve the right to add appended claims after filing the application to seek such appended claims for other aspects of the disclosed technology.

Claims

1. A method performed by a receiver of a wireless communication system, the method comprising: Receives data signals and reference signal sequences communicated via a wireless communication channel; The data signal is determined to be time-critical or does not require a threshold reliability for channel estimation before processing. Where the delay in demodulating or decoding the data signal based on the full-channel estimation is undesirable, the data signal is time-critical, and the full-channel estimation is generated based on the entire reference signal sequence. The threshold reliability has the degree of reliability of the full-channel estimation generated based on the entire reference signal sequence; In response to determining that the data signal is time-critical or does not require a threshold reliability for channel estimation, the channel condition of the wireless communication channel is estimated based on a portion of the reference signal sequence; and Demodulation and decoding of the data signal are performed before processing the entire reference signal sequence. The demodulation and decoding are adapted based on the estimated channel conditions of the wireless communication channel. The estimation of the channel condition of the wireless communication channel includes: The timing position of the data signal is determined to occur between the first reference signal and the second reference signal in the reference signal sequence. Wherein, the first reference signal precedes the second reference signal; Determine whether the time difference between the data signal and the first reference signal is less than or equal to the time threshold Ts; In response to the time difference being less than or equal to the time threshold Ts, the current channel condition of the data signal is extrapolated based on the first reference signal preceding the data signal; In response to the time difference exceeding the time threshold Ts, the current channel condition of the data signal is determined based on the second reference signal; The time threshold Ts is dynamic; when the detected Doppler frequency exceeds the threshold, the time threshold Ts narrows.

2. The method according to claim 1, wherein, Receiving the data signal and the reference signal sequence includes: Receive the reference signal sequence interleaved with a plurality of data signals including the data signal.

3. The method according to claim 1, wherein, Estimating the channel conditions of the wireless communication channel includes: The reference signal in the reference signal sequence is selected based on the time position of the data signal relative to the reference signal. The portion of the reference signal sequence includes only one reference signal corresponding to the selected reference signal.

4. The method according to claim 1, wherein, Estimating the channel conditions of the wireless communication channel includes: The timing position of the data signal is determined to be before the reference signal in the reference signal sequence. The reference signal sequence includes the reference signal.

5. The method according to claim 1, wherein, Estimating the channel conditions of the wireless communication channel includes: It is determined that the reference signal of the data signal and the reference signal sequence have a common timing position. The reference signal sequence includes the reference signal.

6. The method according to claim 1, wherein, Estimating the channel conditions of the wireless communication channel includes: The timing position of the final reference signal in the reference signal sequence is determined before the data signal; and Based on the respective reference signals of the reference signal sequence, multiple channel conditions with different interpolation times, The demodulation and decoding of the data signal are adapted based on the channel conditions of the interpolation.

7. The method according to claim 1, wherein, The data signal is a first data signal, and the method further includes: Determine that the second data signal is not time-critical or requires the threshold reliability to process the second data signal; The channel condition of the wireless communication channel is estimated based on the entire reference signal sequence; and Based on the estimated channel conditions, demodulation and decoding of the second data signal are performed.

8. The method according to claim 1, wherein, Based on 3GPP timing requirements, the processing speed requirements of the receiver, or the amount of data to be processed by the receiver, a threshold reliability is determined to determine whether the data signal is time-critical or does not require channel estimation.

9. The method according to claim 1, wherein, Based on the fact that the measurement of the propagation of the data signal is below the threshold used for optimal channel estimation, the data signal is determined to be time-critical.

10. The method according to claim 1, wherein, Based on the signal-to-noise ratio (SNR) level, modulation and coding scheme (MCS), or fast fading channel characteristics, determine the threshold reliability that does not require the channel estimation.

11. The method according to claim 1, further comprising: The estimated channel condition data is quantized into a reduced bit width, thereby reducing memory utilization at the receiver.

12. The method according to claim 1, further comprising: The estimated channel condition data is quantized into an increased bit width, thereby improving the demodulation and decoding performance at the receiver.

Images