CN116055019A

CN116055019A - Method, device and terminal for receiving physical downlink control channel

Info

Publication number: CN116055019A
Application number: CN202211459425.XA
Authority: CN
Inventors: 柳敦; 柏青
Original assignee: Zeku Technology Beijing Corp Ltd
Current assignee: Zeku Technology Beijing Corp Ltd
Priority date: 2022-11-21
Filing date: 2022-11-21
Publication date: 2023-05-02

Abstract

A method, a device and a terminal for receiving a physical downlink control channel are provided. The method for receiving the physical downlink control channel comprises the following steps: under the condition that a first symbol corresponding to a physical downlink control channel is not received, controlling the radio frequency module to be in a closed state at the first symbol; and controlling the radio frequency module to receive the downlink control channel in the rest symbols except the first symbol corresponding to the physical downlink control channel. In the embodiment of the application, under the condition that the data of the first symbol is not received, the radio frequency module is controlled to be in the closed state in the first symbol, so that the symbol with smaller contribution to decoding can not be received, and the radio frequency module receiving power is reduced and the probability of successful decoding of the physical downlink control channel is guaranteed.

Description

Method, device and terminal for receiving physical downlink control channel

Technical Field

The embodiment of the application relates to the technical field of wireless communication, and more particularly relates to a method, a device and a terminal for receiving a physical downlink control channel.

Background

For a communication system such as a new radio, the physical downlink control channel (physical downlink control channel, PDCCH) data actually transmitted to the terminal device is uniformly distributed in the PDCCH symbols defined by the control resource set. In order to reduce the power consumption of the terminal device, when the channel condition is good enough, it can be considered to reduce the reception of one symbol of the PDCCH, and the last symbol is currently less received. However, under different transmission scenarios, the last symbol of the PDCCH is removed, and even under very good channel conditions and signal-to-noise ratio, the terminal device may still cause decoding failure.

Disclosure of Invention

The embodiment of the application provides a method, a device and a terminal for receiving a physical downlink control channel. Various aspects related to embodiments of the present application are described below.

In a first aspect, a method for receiving a physical downlink control channel is provided, including: under the condition that a first symbol corresponding to a physical downlink control channel is not received, controlling the radio frequency module to be in a closed state at the first symbol; and controlling the radio frequency module to receive the physical downlink control channel in the rest symbols except the first symbol corresponding to the physical downlink control channel.

In a second aspect, an apparatus for receiving a physical downlink control channel is provided, including: the control module is used for controlling the radio frequency module to be in a closed state in the first symbol under the condition that the first symbol corresponding to the physical downlink control channel is not received; and controlling the radio frequency module to receive the physical downlink control channel in the rest symbols except the first symbol corresponding to the physical downlink control channel.

In a third aspect, there is provided a terminal comprising a memory for storing code and a processor for executing the code stored in the memory to implement the method according to the first aspect.

In a fourth aspect, a computer readable storage medium is provided, on which a computer program is stored, the computer program being for performing the method according to the first aspect.

According to the method and the device for decoding the physical downlink control channel, the characteristics of the physical downlink control channel coding transmission process are analyzed, the contribution of data of different symbols to decoding is analyzed, and the radio frequency module is controlled to be in a closed state when the first symbol corresponding to the physical downlink control channel is determined not to be received. In the embodiment of the application, under the condition that the data of the first symbol is not received, the radio frequency module is controlled to be in the closed state in the first symbol, so that the symbol with smaller contribution to decoding can not be received, and the radio frequency module receiving power is reduced and the probability of successful decoding of the physical downlink control channel is guaranteed.

Drawings

Fig. 1 is a schematic diagram of an application scenario in an embodiment of the present application.

Fig. 2 is a schematic flow diagram of a PDCCH receiving end.

Fig. 3 is a diagram of several off RF modes during PDCCH symbols.

Fig. 4 is a schematic diagram of turning off RF at the last PDCCH symbol.

Fig. 5 is a flowchart of an NR PDCCH transmitting end.

Fig. 6 is a schematic diagram of sub-block interleaving.

Fig. 7 is a schematic diagram of two rate matching modes.

Fig. 8 is a diagram of a de-sub-block interleaving in which the last PDCCH symbol is not received.

Fig. 9 is a flowchart of a method for receiving a physical downlink control channel according to an embodiment of the present application.

Fig. 10 is a schematic diagram of the method of fig. 9 turning off RF at the first PDCCH symbol.

Fig. 11 is a flowchart of a PDCCH receiving end using the method of fig. 9.

Fig. 12 is a flow chart of a possible implementation of step S1110 in fig. 11.

Fig. 13 is a schematic diagram of a de-sub-block interleaving of the method of fig. 9 that does not receive the first PDCCH symbol.

Fig. 14a is a schematic diagram of another de-sub-block interleaving in which the last PDCCH symbol is not received.

Fig. 14b is a schematic diagram of another de-sub-block interleaving of the method of fig. 9 without receiving the first PDCCH symbol.

Fig. 15 is a schematic structural diagram of an apparatus for receiving a physical downlink control channel according to an embodiment of the present application.

Fig. 16 is a schematic structural diagram of a terminal provided in an embodiment of the present application.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments.

The technical solution of the embodiment of the application can be applied to various communication systems, for example: global system for mobile communications (global system of mobile communication, GSM), code division multiple access (code division multiple access, CDMA) system, wideband code division multiple access (wideband code division multiple access, WCDMA) system, general packet radio service (general packet radio service, GPRS), long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), universal mobile telecommunications system (universal mobile telecommunication system, UMTS), worldwide interoperability for microwave access (worldwide interoperability for microwave access, wiMAX) communication system, fifth generation (5th generation,5G) system, or New Radio (NR), and the like. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system, a satellite communication system and the like.

Fig. 1 is a schematic diagram of a communication scenario of an embodiment of the present application. As shown in fig. 1, the application scenario includes a network device 110 and a terminal device 120, where the network device 110 may be an access network device, such as a base station. Each network device 110 includes one or more cells. In a new wireless (NR) system, for example, the network device 110 transmits downlink control information (downlink control information, DCI) over a physical downlink control channel (physical downlink control channel, PDCCH) to control the transmission of information related to a physical downlink data channel (physical downlink share channel, PDSCH). DCI is a special information set for scheduling PDSCH.

The PDCCH generates a DCI code stream according to the scheduling information of the PDSCH and the DCI format information, and 24-bit cyclic redundancy check (cyclic redundancy check, CRC) coding is usually adopted in 5G NR; next, polar codes (Polar) are encoded, whose code length is defined to be an integer power of 2, according to the original definition of Polar codes. Thus, polar codes require a rate matching process to adjust the code length to fit the actual transmission resources.

Fig. 2 is a schematic flow diagram of a PDCCH receiving end. As shown in fig. 2, on the terminal side, the main flow of PDCCH reception and demodulation includes: radio frequency reception, time-frequency domain conversion, quadrature phase shift keying (quadrature phase shift keying, QPSK) demodulation, calculation and extraction of data of time-frequency positions corresponding to all resource particle groups (resource element group REG) are carried out on the current PDCCH candidate channel, and then descrambling, rate de-matching, sub-block de-interleaving, polar decoding and CRC check are carried out.

In normal reception operation, the terminal device receives all orthogonal frequency division multiplexing (quadrature frequency division multiplexing, OFDM) symbols from the radio frequency module.

OFDM mainly converts a single channel into a plurality of orthogonal sub-channels, namely, divides a frequency band into a plurality of sub-channels for data transmission, thereby converting a high-speed data signal into parallel low-speed sub-data streams, and then modulating the data streams to each sub-channel for signal transmission. The orthogonality in the orthogonal frequency division multiplexing means that the two signals and the electromagnetic wave can be distinguished; frequency division, also referred to as frequency division, refers to the transmission of information by a signal using a plurality of subcarriers; multiplexing refers to the reuse of a certain segment of frequency in order to achieve reuse of frequency resources.

In Polar decoding, serial cancellation list (successive cancellation list, SCL) decoding algorithms are commonly used in the industry. Polar coding is a forward error correction coding scheme used for signal transmission. On the decoding side, the polarized channel can obtain the performance similar to the maximum likelihood decoding with lower complexity by using a simple successive interference cancellation decoding method. SCL decoding carries out serial decoding processing on Polar codes, and adopts a list ordering method. Based on complexity considerations, a maximum of 8 best decoding paths are typically saved, and at the time of final output, path selection output based on path metric values and CRC check results is performed.

In the overall downlink reception of a terminal device (UE), the terminal device needs to receive and process the PDCCH first, and obtain the scheduling information of the PDSCH after decoding is completed, so as to further decode the PDSCH. After the PDCCH symbol is received, the baseband processing has a processing delay of several symbols, and the Radio Frequency (RF) module needs to be turned on all the time to keep the PDSCH symbol reception possible. There are typically two cases, one case is shown in fig. 3 (a), where the RF on time is all 14 symbols of the transmission time interval (transmission time interval, TTI). Or as shown in fig. 3 (b), the PDSCH scheduling without the TTI is turned off until the PDCCH blind detection ends.

A TTI refers to the length of an independently decoded transmission in a radio link. I.e. the transmission duration of one subframe, one slot in NR is the basic unit of time governed by radio resource management. 1 tti=1 ms is generally considered. In a normal Cyclic Prefix (CP) mode, one TTI may be divided into 14 symbols (symbols); in the extended CP mode, it is divided into 12 symbols.

Since the power consumption of RF occupies a considerable weight in a modem (modem) chip, and most of the time the base station does not schedule DCI for the terminal, in order to greatly reduce the terminal power consumption, as shown in fig. 3 (c), many chips employ a scheme in which RF receives only symbols during PDCCH (duration) and then turns off when appropriate. There is mostly no effect in the scenario without DCI scheduling, and when there is no DCI scheduling PDSCH, PDSCH reception will fail because RF has stopped receiving. However, the RF reception time may be adjusted in the following TTI, and the complete PDSCH retransmission may be received and decoded. Thus although the output time (T _put ) The overall power consumption can be greatly reduced, though it is affected.

For NR PDCCH, the PDCCH data actually transmitted to the terminal is uniformly distributed in PDCCH symbols defined by a control resource set (control resource set, CORESET). When the channel condition is good enough, it can be considered to further reduce the symbols received by the PDCCH, and although this will result in the loss of some useful data of the PDCCH, reducing the reception of one symbol still has a high probability of successful decoding when the channel condition has a sufficient margin with respect to the condition of successful decoding corresponding to the PDCCH code rate. Since the RF on time and TTI boundaries are typically aligned, the last symbol is seldom received. For example, when the period (duration) of CORESET is 3 symbols, the RF receives

symbols

0 and 1 and does not receive symbol 2. Fig. 4 is a schematic diagram of turning off RF at the last PDCCH symbol. As shown in fig. 4, the RF receives

symbols

0 and 1 and does not receive the last symbol 2. For another example, when the CORESET period is 2 symbols, the RF receives symbol 0 and does not receive the last symbol 1.

However, for SCL decoding processing algorithms, the contribution of the data of different symbols to the decoding probability is different, and it may not be optimal to remove the last symbol. Therefore, in different transmission scenarios, when SCL decoding, the last symbol of PDCCH is removed, and even under very good channel conditions and signal-to-noise ratio, the terminal device may still cause decoding failure.

Based on this, the embodiment of the application proposes a method for receiving a physical downlink control channel, where when the channel condition is good, the radio frequency module may receive one PDCCH symbol, so as to determine that the first symbol may not be received, but not the last symbol is not received in general. Before describing embodiments of the present application in detail, the following first analyzes the cause of the technical problem.

Fig. 5 is a flowchart of an NR PDCCH transmitting end. As shown in fig. 5, the coding flow of the PDCCH prescribed by the 3gpp 5g NR standard may mainly include steps S510 to S580, which are described in detail below.

In step S510, a cyclic redundancy check code is added. Assume that the original payload (payload) of the input DCI is an a-bit (bit). After the CRC is applied, K bits, e.g., k=a+24, are output.

CRC is a hash function with a short fixed bit check code, which is used mainly to detect or check errors that may occur after data transmission or storage. The CRC-generated number is calculated before transmission or storage and appended to the data, and then the receiver checks to determine if the data has changed.

In step S520, bit interleaving is performed, and K bits are output.

Bit interleaving refers to the process of randomizing errors by rearranging bits in a bit stream prior to transmission. Bit interleaving changes the information structure without changing the information content. The coding mode proposed for the channel with memory diffuses burst errors generated on the channel in time and converts the burst errors into random errors, so that common coding technology can be adopted for error correction.

In step S530, polarization encoding is performed, and N bits are output. Where N is a value calculated from K and the length E after rate matching, and is an integer power of 2. For NR PDCCH, N may take values of 128, 256 and 512.

Polar codes (Polar codes) are a type of forward error correction coding used for signal transmission. On the decoding side, the polarized channel can obtain the performance similar to the maximum likelihood decoding with lower complexity by using a simple successive interference cancellation decoding method.

In step S540, sub-block interleaving is performed, and N bits are output. The bit stream with the length of N can be divided into 32 sub-blocks (sub-blocks) and then sub-block interleaving is performed. Fig. 6 is a schematic diagram of sub-block interleaving, as shown in fig. 6, with each block having a bit length of N/32. For example, when N is 256, the bit length of each block is 8.

In step S550, rate matching and bit selection are performed, and E bits are extracted, where E is the length of the transmission PDCCH selected by the base station side. The base station side may decide an aggregation level of the PDCCH, and possible levels include 1, 2, 4, 8 or 16 control channel elements (control channel element, CCE). The CCE is a basic scheduling unit for controlling channel resource allocation, the number of CCEs is also referred to as the aggregation level and aggregation level of the PDCCH, the more the number of CCEs, the more corresponding resources, and E is a parameter related to the CCE aggregation level.

Rate matching (rate matching) refers to the alignment of the number of bits encoded on a transport channel with the actual amount of available transmission resources to match the bearing capacity of the physical channel, and the channel mapping achieves the bit rate required by the transport format. Depending on parameters K, E and N, rate matching typically has three modes:

and (one) repeating the pattern. If E > =n, the length of 8 or 16 CCEs corresponds to the aggregation level, and if e=864 or 1728, and if n=512, the code bits of n=512 length are cyclically repeated to the length of E and transmitted in a repetition pattern.

And (II) a punching mode. If E < N and K/E < = 7/16, a puncturing pattern is used. The first N-E bits are pruned from the N bits and the last E bit output is selected. N may be 128, 256 or 512, then the corresponding E is 108, 216 or 432. Fig. 7a is a schematic diagram of a puncturing rate matching mode. As shown in fig. 7a, the deletion length corresponds to 5 sub-blocks (sub-blocks), and only the latter 27 sub-blocks are transmitted.

And (III) shortening mode. If E < N, and K/E >7/16, the shortened mode is employed. The last N-E bits are pruned from the N bits and the previous E bits are selected for output. N may be 128 or 256, and the corresponding E108 or 216. Fig. 7b is a schematic diagram of a shortened rate matching mode. As shown in fig. 7b, the deletion length is also 5 sub-blocks, and only the first 27 sub-blocks are transmitted.

The rate matching does not affect the transmission of information bit bits, does not change the payload, and only a certain number of low density parity check bits are affected.

In step S560, a scrambling code is added, and E bits are output.

In step S570, quadrature Phase Shift Keying (QPSK) modulation is performed, and an E/2 symbol (symbol) is output.

QPSK is a modulation method for conveying data by conversion or modulation, and phasing of reference signals (carriers). Also known as quadrature PSK or quadrature phase pre-shared key (4-PSK), QPSK encodes each symbol into two bits over four phases.

Within an OFDM symbol is typically a composite signal comprising a plurality of modulated sub-carriers, each of which may be modulated by Phase Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM). The OFDM transmitter maps the information bit stream into a PSK or QAM symbol sequence and then converts the serial symbol sequence into a parallel symbol stream. Every N serial-to-parallel converted symbols are modulated by different subcarriers. Because serial-to-parallel conversion is adopted, the original high-speed serial data is converted into low-speed parallel data to be transmitted, and the original transmission time of N symbols (symbols after digital mapping, such as each QPSK symbol comprises 2 bits) is equivalent to the transmission time of only one symbol (but because of parallel transmission, N subcarriers are respectively transmitted with one symbol, which is equivalent to the simultaneous transmission of N symbols). The length of an OFDM symbol, or OFDM symbol period, refers to the time each OFDM symbol lasts from a time domain perspective.

In step S580, the mapping is performed to time-frequency resources.

The PDCCH maps to a duration parameter specified by a control resource set (control resource set, core), i.e., the number of OFDM symbols in the time direction. The duration may be 1 to 3 symbols. The mapping of the PDCCH is performed according to the direction of the first frequency domain and the second time domain, namely, the data is mapped to the frequency domain direction of the 1 st OFDM symbol, and then to the frequency domain direction of the 2 nd and the 3 rd OFDM symbols. The modulated data will be evenly distributed over each symbol and the entire frequency domain.

The coding and transmitting process of the PDCCH transmitting end is introduced above, and the contribution of the data of different symbols to terminal decoding is further analyzed below. The NR PDCCH adopts Polar coding, and the main stream terminal chips adopt SCL decoding method. For the SCL decoding processing algorithm, the contribution of the data of different symbols to the decoding probability is different.

Taking the puncturing pattern and 2 symbols (symbol) during CORESET as an example, the RF is presented as not receiving the effect of the last symbol. The terminal decoder needs to fill the unknown data with 0 s first for the received data. The unknown data here includes two locations: one is pruned at the transmitting end and the other is due to RF shutdown of the non-received data. And then performing sub-block de-interleaving operation opposite to the transmission process. Fig. 8 is a diagram of a de-sub-block interleaving in which the last PDCCH symbol is not received. As shown in fig. 8, after deinterlacing, the gray sub-blocks represent data 0 (indicating no valid information), and the dot matrix blocks represent sub-blocks containing useful data after deinterlacing. After receiving 32 sub-blocks of data, the Polar decoder typically uses an SCL algorithm, and in a first step, a simplified log-likelihood ratio (LLR) process is performed using a so-called f-function. The LLR is calculated as follows:

LLR(y _i )≈sign(LLR(x _i ))*sign(LLR(x _i+N/2 ))*min(|LLR(x _i ),LLR(x _i+N/2 )|)

Wherein, the liquid crystal display device comprises a liquid crystal display device,

as can be seen from fig. 8, the N/2 LLR data obtained by the first step f of the function processing is all zero. The SCL processing of the first half of the data has no valid data at this time.

Polar coding is usually based on the ordering of the reliability of the sub-channels, where most of the information bits are mapped to the second half of the N long bits, but the first half will also have a small number of information bits. And determining a specific mapping position according to the DCI information bit length and the coding length. Assuming that the information bits of the first half are n, if 2 ⁿ >L, where L is the maximum path that SCL decoding can preserve, since the first half has no valid data, the correct path cannot be preserved. Even if the signal-to-noise ratio is very high (i.e. the information of the sub-block portions of the lattice is very reliable), it cannot be decoded correctly.

The DCI generally includes scheduling information of a plurality of terminals and also includes redundancy information. The contribution of the data of different symbols to the decoding probability of the terminal is different, so that in different transmission scenarios, when the SCL is decoded, it may not be appropriate to remove the last symbol of the PDCCH, and sometimes decoding failure of the terminal equipment may still be caused even under very good channel conditions and signal-to-noise ratio.

The reason why decoding failure is possible by removing the last symbol of the PDCCH is analyzed above. The following describes a method for receiving a physical downlink control channel according to an embodiment of the present application.

Fig. 9 is a flowchart of a method for receiving a physical downlink control channel according to an embodiment of the present application. As shown in fig. 9, the method of receiving the physical downlink control channel may include steps S910 to S920. It should be noted that the steps of the method are merely for convenience of description, and there is no time or sequence of steps in the process, and the steps are described in detail below.

In step S910, under the condition that it is determined that the first symbol corresponding to the physical downlink control channel is not received, the control radio frequency module is in the off state at the first symbol.

The symbol may be an OFDM symbol (symbol) of a PDCCH of the current communication system, e.g., an OFDM symbol of a PDCCH of NR, e.g., the first symbol may be symbol 0 of the PDCCH. The symbol may also be a time domain symbol of a PDCCH of a future communication system such as 6G.

The radio frequency module can be an independent radio frequency module or a radio frequency module of the terminal equipment.

In step S920, the control radio frequency module receives the physical downlink control channel at the remaining symbols except the first symbol corresponding to the physical downlink control channel.

The remaining symbols except the first symbol corresponding to the physical downlink control channel may be 1 or 2 in the current communication system. For example, when the control resource set of the NR PDCCH is 3 symbols, the remaining symbols except the first symbol may be symbol 1 and symbol 2 of the PDCCH. The remaining symbols except the first symbol corresponding to the physical downlink control channel may be more than 2 in future communication systems.

After the channel estimation result is generally obtained, it is determined whether one symbol of the PDCCH can be deleted according to the current channel condition. The current channel condition is good, and if one symbol of the PDCCH is not received, it is judged whether the first symbol or the last symbol of the PDCCH is not received. If the contribution of the data of the first symbol of the PDCCH to the successful decoding probability is relatively small, determining that the data of the first symbol corresponding to the physical downlink control channel is not received. If the contribution of the data of the last symbol of the PDCCH to the successful decoding probability is relatively small, determining that the data of the last symbol corresponding to the physical downlink control channel is not received.

The number of bits of DCI on the PDCCH that typically needs to be monitored before PDCCH blind detection runs is known. In some implementations, the strategy for a given DCI bit may be predetermined. For example, it may be determined whether all PDCCH symbols are normally received, or the first symbol may not be received, or the last symbol may not be received, based on the result of the offline simulation and based on the real-time channel estimation result.

In some implementations, due to the different combinations of the number of bits (size) of DCI and PDCCH aggregation, the information bits are different in the mapping positions of the Polar codes, resulting in different decoding performance losses caused by not receiving different portions of data. In some embodiments, for a part of the larger DCI bit number and in the case of CCE aggregation level of 1, not receiving (or deleting) one symbol may result in failure to decode normally even under the channel condition of extremely high signal-to-noise ratio (SNR), and then data of all symbols corresponding to the physical downlink control channel needs to be received. In some embodiments, such as where the number of DCI bits is partially small and the CCE aggregation level is large (4, 8), not receiving one symbol does not result in decoding failure under good channel conditions. In some embodiments, the performance penalty of not receiving the first symbol may be less than the performance penalty of not receiving the last symbol. In some embodiments, it may be better not to receive the last symbol than the first symbol.

Before the control radio frequency module is in the off state, it needs to first determine whether to receive the first symbol corresponding to the physical downlink control channel. In some implementations, whether to receive the first symbol corresponding to the physical downlink control channel may be determined according to the number of bits occupied by the downlink control information carried in the physical downlink control channel and/or the aggregation level of the physical downlink control channel.

In different rate matching modes, the mapping positions of the target information bits in the Polar codes are different, and the loss of decoding performance caused by deleting data of different parts is also different. To determine whether to receive the first symbol corresponding to the physical downlink control channel, in some implementations, a rate matching mode of the physical downlink control channel may be determined; and according to the rate matching mode, determining that the first symbol is not received or the last symbol corresponding to the physical downlink control channel is not received.

In some implementations, if the rate matching mode is a puncturing mode, the performance penalty for not receiving the first symbol may be less than the performance penalty for not receiving the last symbol, and it is determined that the first symbol is not received. In some embodiments, if the rate matching mode is a shortened mode, the performance penalty for not receiving the first symbol may be greater than the performance penalty for not receiving the last symbol, and it is determined that the last symbol is not received.

In some implementations, the relative magnitudes of the contributions of the data of the first symbol and the data of the last symbol of the PDCCH to the probability of successful decoding may be determined according to a combination of at least one or more of the DCI bit number, the CCE aggregation level, and the rate matching mode, so as to determine the first symbol or the last symbol that does not receive the PDCCH.

If it is determined that the first symbol of the PDCCH is not received, RF is turned off during the first symbol of the PDCCH, which may serve to save power consumption. If it is determined that the last symbol of the PDCCH is not received, RF is turned off during the last symbol of the PDCCH in order to save power consumption.

Fig. 10 is a schematic diagram of the method of fig. 9 turning off RF at the first PDCCH symbol. If the data of the first symbol of the PDCCH is smaller than the data of the last symbol has a smaller contribution to the successful decoding probability, determining that the first symbol of the PDCCH is not received. As shown in fig. 10, the control resource set duration is 3 symbols (symbols). During PDCCH processing the baseband module is operating normally and the radio frequency module is in an off state for the first symbol (symbol 0) and is only on during symbol 1 and symbol 2. Fig. 10 is similar to the total duration of the RF switch-on of fig. 4, but achieves better decoding.

If the first symbol or the last symbol of the PDCCH is not received, in the decoding process, the data corresponding to the symbol not received in the downlink control information is usually decoded after being complemented. For example, the data at the corresponding position of the symbol which is not received is fully zero-padded and then decoded.

According to the embodiment of the application, the characteristics of the PDCCH coding transmission process are analyzed, the contribution of data of different symbols to decoding is analyzed, and the radio frequency module is controlled to be in a closed state in the first symbol under the condition that the first symbol corresponding to the physical downlink control channel is not received. In the embodiment of the invention, under the condition that the data of the first symbol is not received, the radio frequency module is controlled to be in the closed state in the first symbol, so that the symbol with smaller contribution to decoding can not be received, thereby being beneficial to reducing the receiving power of the radio frequency module and ensuring the probability of successful decoding of the PDCCH.

Fig. 11 is a flowchart of a PDCCH receiving end using the method of fig. 9. As shown in fig. 11, the flow of PDCCH reception and demodulation may mainly include steps S1110 to S1191, which are described in detail below.

In step S1110, a radio frequency reception time is determined. For example, when the control resource set duration is 3 symbols, it is determined that the first symbol (symbol 0) is not received, and then the radio frequency receiving times are symbol1 and symbol 2. In another example, when the control resource set duration is symbol 0 and symbol1, it is determined that the first symbol (symbol 0) is not received, and then the radio frequency receiving time is symbol1. The method for determining the radio frequency reception time is described in detail below.

In step S1120, a radio frequency signal is received. Typically received as OFDM signals.

In step S1130, time-frequency domain conversion is performed. Such as converting frequency domain data of a received OFDM signal into time domain data.

In step S1140, QPSK demodulation is performed.

In step S1150, the data of the time-frequency locations corresponding to all REGs are calculated and extracted for the candidate channels of the current PDCCH. And obtaining the data of the target DCI of the terminal.

REG is a control channel basic constituent unit, and includes 12 subcarriers in frequency and one symbol in time domain in NR.

In step S1160, if it is determined in step S1110 that an OFDM symbol is not received (or referred to as deleted), the data is zero-padded at the corresponding position of the non-received OFDM symbol.

In step S1170, descrambling is performed. For example, E-bit data.

In step S1180, rate matching is solved. Such as N-bit data.

In step S1190, the sub-blocks are deinterleaved. Such as N-bit data.

In step S1191, polar decoding and CRC checking are performed. Such as to obtain the transmitted a-bit valid data.

Fig. 12 is a flow chart of a possible implementation of step S1110 in fig. 11. As shown in fig. 12, the method for determining the radio frequency reception time may include steps S1210 to S1270, which will be described in detail below.

In step S1210, a channel estimation result is acquired.

In step S1220, it is determined whether the current channel condition is sufficient to delete one OFDM symbol of the PDCCH. If yes, go to step S1240; if not, step S1230 is entered.

In step S1230, the symbols of the PDCCH cannot be deleted, and all the symbols of the PDCCH control resource set are normally received.

In step S1240, it is determined whether there is a limitation to deletion of a specific symbol according to the DCI bit number and CCE aggregation level combination for PDCCH blind detection. If there is a limit, returning to step S1230; if there is no limitation, step S1250 is entered.

In some embodiments, for a part of the larger DCI bit number and in the case of CCE aggregation degree of 1, not receiving one symbol may result in failure to decode normally even under the channel condition of extremely high signal-to-noise ratio (SNR), and then data of all symbols corresponding to the physical downlink control channel needs to be received. In some embodiments, such as where the number of DCI bits is partially small and the CCE aggregation is large (e.g., 4, 8), not receiving one symbol does not result in decoding failure under good channel conditions.

In step S1250, it is determined that it is appropriate not to receive the first symbol. For example, the size of the contribution of the non-received first and non-received last symbols to successful decoding. If it is appropriate not to receive the first symbol, step S1260 is entered; if it is not appropriate to not receive the first symbol, the process proceeds to step S1270.

In step S1260, the first symbol of the PDCCH control resource set is not received.

In step S1270, the last symbol of the PDCCH control resource set is not received.

In the embodiment of the application, under the condition that the channel condition is good enough and one OFDM symbol of the PDCCH is not received, the radio frequency module is controlled to be in a closed state at the first symbol under the condition that the data of the first symbol is not received. The radio frequency module may also be controlled to be in an off state at the last symbol if it is determined that the data of the last symbol is not received. The embodiment of the application can not receive the symbol with smaller contribution to decoding, thereby being beneficial to reducing the receiving power of the radio frequency module and ensuring the probability of successful decoding of the PDCCH.

Fig. 13 is a schematic diagram of a de-sub-block interleaving of the method of fig. 9 that does not receive the first PDCCH symbol. In fig. 13, the rate matching is a puncturing pattern, the duration of CORESET is 2 symbols, RF is turned off in the first symbol (symbol 0), and RF is turned on in symbol 1. Fig. 13 is a schematic diagram of decoder input data after de-rate matching, sub-block de-interleaving, and first stage f-function processing. As shown in fig. 13, gray sub-block representing data corresponding to symbol 0 is 0 (indicating no valid information), and white sub-block representing data corresponding to symbol 1 is 1 (indicating valid information is received). After deinterleaving, the number of sub-blocks of the effective data is 2.5. Wherein the lattice blocks represent sub-blocks containing valid data. It can be seen that the number of sub-blocks of valid data is significantly increased compared to the effect of fig. 8, in which the last PDCCH symbol is not received. And part of effective LLR data is reserved, so that subsequent channel decoding is facilitated.

Fig. 14a is a schematic diagram of another de-sub-block interleaving in which the last PDCCH symbol is not received. In fig. 14a, the rate matching is a puncturing pattern, the duration of CORESET is 3 symbols, and RF is turned off at the last symbol (symbol 2). Fig. 14a is a schematic diagram of decoder input data after de-rate matching, sub-block de-interleaving and first stage f-function processing. As shown in fig. 14a, gray sub-blocks corresponding to symbol 2 represent data 0 (indicating no valid information), and white sub-blocks corresponding to symbol 0 and symbol1 represent data 1 (indicating valid information is received). After deinterleaving, the number of sub-blocks of the effective data is 2. Wherein the lattice blocks represent sub-blocks containing valid data.

Fig. 14b is a schematic diagram of another de-sub-block interleaving of the method of fig. 9 without receiving the first PDCCH symbol. In fig. 14b, the rate matching is a puncturing pattern, the duration of CORESET is 3 symbols, and RF is turned off in the first symbol (symbol 0). As shown in fig. 14b, gray sub-blocks corresponding to symbol 0 represent data 0 (indicating no valid information), and white sub-blocks corresponding to symbol1 and symbol 2 represent data 1 (indicating valid information is received). After de-interleaving, the number of sub-blocks of the effective data is 4.5. Wherein the lattice blocks represent sub-blocks containing valid data. It can be seen that the number of sub-blocks of valid data is significantly increased compared to the effect of fig. 14a, in which the last PDCCH symbol is not received. Closing the first symbol can retain more valid data than closing the last symbol, facilitating subsequent channel decoding.

Method embodiments of the present application are described in detail above in connection with fig. 1-14, and apparatus embodiments of the present application are described in detail below in connection with fig. 15 and 16. It is to be understood that the description of the device embodiments corresponds to the description of the method embodiments, and that parts not described in detail can therefore be seen in the preceding method embodiments.

Fig. 15 is a schematic structural diagram of an apparatus for receiving a physical downlink control channel according to an embodiment of the present application. The dashed lines in fig. 15 indicate that the unit or module is optional. The apparatus 1500 includes a control module 1510.

The control module 1510 is configured to, when determining that the first symbol corresponding to the physical downlink control channel is not received, control the radio frequency module to be in a closed state in the first symbol; the control module 1510 controls the rf module to receive the physical downlink control channel at the remaining symbols except the first symbol corresponding to the physical downlink control channel.

Optionally, the apparatus 1500 may further include a first determination module 1520. The first determining module 1520 is configured to determine whether to receive the first symbol according to the number of bits occupied by the downlink control information carried in the physical downlink control channel and/or the aggregation level of the physical downlink control channel.

Optionally, the apparatus 1500 may further comprise a second determination module 1530. The second determining module 1530 is configured to determine a rate matching mode of the physical downlink control channel; and according to the rate matching mode, determining that the first symbol is not received or the last symbol corresponding to the physical downlink control channel is not received.

Optionally, the second determining module 1530 is further configured to determine not to receive the first symbol if the rate matching mode is a puncturing mode; if the rate matching mode is the shortened mode, it is determined that the last symbol is not received.

Fig. 16 is a schematic structural diagram of a terminal provided in an embodiment of the present application. A terminal 1600 according to an embodiment of the present application is described below with reference to fig. 16. The dashed lines in fig. 16 indicate that the unit or module is optional. The terminal 1600 may be used to implement the methods described in the method embodiments above, and may be any of the terminal devices mentioned above. The terminal 600 may include a memory 1610 and a processor 1620.

The memory 1610 has stored thereon a program that can be executed by the processor 1620 to cause the processor 1620 to perform any of the methods described above. The memory 1610 may be separate from the processor 1620 or may be integrated in the processor 1620. Memory 1610 may be one or more memories.

Processor 1620 may support terminals to implement the methods described in the method embodiments above. Processor 1620 may be one or more processors.

Optionally, terminal 1600 can also include a transceiver 1630. Processor 1620 may communicate with other devices via transceiver 1630. For example, processor 1620 may transmit and receive data to and from other devices via transceiver 1630.

In general, the NR PDCCH is received from the start time of a predetermined monitoring timing. A method for detecting the difference between the embodiment of the method and the conventional receiving method can construct a good channel environment in a laboratory, configure a PDCCH monitoring time defined by an NR PDCCH search space (search space) from a first symbol (symbol 0), and judge the difference between the embodiment of the method and the conventional method by detecting current and other means when the embodiment of the method is used for skipping the symbol 0 and closing a last symbol.

The present embodiments also provide a computer readable storage medium having stored thereon a computer program for performing a method as described in any of the foregoing.

The terminal device in the embodiments of the present application may also be referred to as a terminal, a User Equipment (UE), a user terminal, an access terminal, a subscriber unit, a subscriber station, a Mobile Station (MS), a Mobile Terminal (MT), a remote terminal, a remote station, a mobile device, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the application can be a device for providing voice and/or data connectivity for a user, and can be used for connecting people, things and machines, such as a handheld device with a wireless connection function, a vehicle-mounted device and the like. The terminal device in the embodiments of the present application may be a mobile phone (mobile phone), a tablet (Pad), a notebook, a palm, a mobile internet device (mobile internet device, MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), or the like. Alternatively, the UE may be used to act as a base station. For example, the UEs may act as scheduling entities that provide side-uplink signals between UEs in V2X or D2D, etc. For example, a cellular telephone and a car communicate with each other using side-link signals. Communication between the cellular telephone and the smart home device is accomplished without relaying communication signals through the base station.

The network device in the embodiments of the present application may be a device for communicating with a terminal device, which may also be referred to as an access network device or a radio access network device, e.g. the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (radio access network, RAN) node (or device) that accesses the terminal device to the wireless network. The base station may broadly cover or replace various names in the following, such as: a node B (NodeB), an evolved NodeB (eNB), a next generation NodeB (gNB), a relay station, an access point, a transmission point (transmitting and receiving point, TRP), a transmission point (transmitting point, TP), a master MeNB, a secondary SeNB, a multi-mode wireless (MSR) node, a home base station, a network controller, an access node, a wireless node, an Access Point (AP), a transmission node, a transceiver node, a baseband unit (BBU), a remote radio unit (Remote Radio Unit, RRU), an active antenna unit (active antenna unit, AAU), a radio head (remote radio head, RRH), a Central Unit (CU), a Distributed Unit (DU), a positioning node, and the like. The base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station may also refer to a communication module, modem, or chip for placement within the aforementioned device or apparatus. The base station may also be a mobile switching center, a device-to-device (D2D), a vehicle-to-device (V2X), a device that assumes a base station function in machine-to-machine (M2M) communication, a network-side device in a 6G network, a device that assumes a base station function in a future communication system, or the like. The base stations may support networks of the same or different access technologies. The embodiment of the application does not limit the specific technology and the specific device form adopted by the network device.

The base station may be fixed or mobile. For example, a helicopter or drone may be configured to act as a mobile base station, and one or more cells may move according to the location of the mobile base station. In other examples, a helicopter or drone may be configured to function as a device to communicate with another base station.

In some deployments, the network device in embodiments of the present application may refer to a CU or a DU, or the network device includes a CU and a DU. The gNB may also include an AAU.

Network devices and terminal devices may be deployed on land, including indoors or outdoors, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aerial planes, balloons and satellites. In the embodiment of the application, the scene where the network device and the terminal device are located is not limited.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present disclosure, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a machine-readable storage medium or transmitted from one machine-readable storage medium to another machine-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The machine-readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more servers, data centers, etc. integrated with the available medium. The usable medium may be a magnetic medium (e.g., a floppy Disk, a hard Disk, a magnetic tape), an optical medium (e.g., a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present disclosure may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely specific embodiments of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the disclosure, and it is intended to cover the scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method of receiving a physical downlink control channel, comprising:

under the condition that a first symbol corresponding to a physical downlink control channel is not received, controlling the radio frequency module to be in a closed state at the first symbol;

And controlling the radio frequency module to receive the physical downlink control channel in the rest symbols except the first symbol corresponding to the physical downlink control channel.

2. The method of claim 1, wherein before the controlling the radio frequency module is in the off state at the first symbol, the method further comprises:

and determining whether to receive the first symbol according to the bit number occupied by the downlink control information carried in the physical downlink control channel and/or the aggregation level of the physical downlink control channel.

3. The method of claim 1, wherein before the controlling the radio frequency module is in the off state at the first symbol, the method further comprises:

determining a rate matching mode of the physical downlink control channel;

and according to the rate matching mode, determining that the first symbol is not received or the last symbol corresponding to the physical downlink control channel is not received.

4. A method according to claim 3, characterized in that the method further comprises:

if the rate matching mode is a puncturing mode, determining not to receive the first symbol;

if the rate matching mode is a shortened mode, it is determined that the last symbol is not received.

5. An apparatus for receiving a physical downlink control channel, comprising:

the control module is used for controlling the radio frequency module to be in a closed state in the first symbol under the condition that the first symbol corresponding to the physical downlink control channel is not received;

6. The apparatus of claim 5, wherein the apparatus further comprises:

and the first determining module is used for determining whether to receive the first symbol according to the bit number occupied by the downlink control information carried in the physical downlink control channel and/or the aggregation level of the physical downlink control channel.

7. The apparatus of claim 5, wherein the apparatus further comprises:

a second determining module, configured to determine a rate matching mode of the physical downlink control channel;

8. The apparatus of claim 7, wherein the second determination module is further configured to:

9. A terminal comprising a memory for storing code and a processor for executing code stored in the memory to perform the method of any of claims 1-4.

10. A computer readable storage medium, characterized in that it has stored thereon a computer program for implementing the method according to any of claims 1-4 when executed.