CN111786916B

CN111786916B - Channel estimation method and device, terminal and storage medium

Info

Publication number: CN111786916B
Application number: CN202010501699.5A
Authority: CN
Inventors: 刘君
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2022-12-20
Anticipated expiration: 2040-06-04
Also published as: CN111786916A

Abstract

The embodiment of the application discloses a channel estimation method, which comprises the following steps: determining a resource block for bearing the PDCCH in the OFDM symbol according to the resource allocation mode of the control channel; determining at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the association block is a resource block within a certain frequency domain from the resource block; and processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block. The embodiment of the application also provides a channel estimation device, equipment and a storage medium.

Description

Channel estimation method and device, terminal and storage medium

Technical Field

The present application relates to radio technology, and relates to, but is not limited to, a channel estimation method and apparatus, a terminal, and a storage medium.

Background

Channel estimation is performed by using a full-bandwidth DMRS (Demodulation Reference Signal) in a CORESET (Control Resource Set), which can effectively improve MSE (Mean Square Error) performance, thereby improving system Error rate and throughput performance.

However, REGs (Resource Element groups) corresponding to PDCCHs may not be allocated to some physical Resource blocks of the CORESET, and demodulation and decoding are not required on these physical Resource blocks, and channel estimation is not required. Therefore, how to effectively utilize the resource allocation method of the control channel specified by the current protocol is a compromise between the channel estimation performance and the calculation complexity, which is a problem to be solved urgently.

Disclosure of Invention

The embodiment of the application provides a channel estimation method and device, a terminal and a storage medium, which can effectively utilize a resource allocation mode of a control channel specified by a current protocol and improve the MSE performance of channel estimation on the premise of limited increase of system complexity.

The technical scheme of the embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a channel estimation method, including:

determining a resource block for bearing the PDCCH in the OFDM symbol according to the resource allocation mode of the control channel;

determining at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the associated block is a block within a certain frequency domain from the resource block;

and processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block.

In a second aspect, an embodiment of the present application provides a channel estimation apparatus, including:

a first determining module, configured to determine, according to a resource allocation manner of a control channel, a resource block that carries a PDCCH in each OFDM symbol;

a second determining module, configured to determine at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the associated block is a block within a certain frequency domain from the resource block;

and the processing module is used for processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block.

In a third aspect, an embodiment of the present application provides a terminal, including a memory and a processor, where the memory stores a computer program operable on the processor, and the processor implements the steps in the channel estimation method when executing the program.

In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, where the computer program is executed by a processor to implement the steps in the channel estimation method.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

in the embodiment of the application, firstly, a resource block corresponding to a PDCCH in an OFDM symbol is determined; then determining at least two associated blocks according to the frequency domain position of the resource block; finally, processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block; therefore, the pilot signals participating in the channel estimation processing are expanded to the pilot signals carried by the resource block to be detected and the corresponding associated block together, so that the channel estimation results of the resource block to be detected in the subsequent processing are all interpolated, and the MSE performance of the channel estimation is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

FIG. 2 is a resource distribution pattern of wideband PDCCH DMRS in the related art;

fig. 3 is an alternative flow chart of a channel estimation method according to an embodiment of the present application;

fig. 4 is a schematic flowchart of another alternative channel estimation method according to an embodiment of the present application;

fig. 5 is a schematic flowchart of yet another alternative channel estimation method according to an embodiment of the present disclosure;

fig. 6 is a schematic diagram of a PDCCH DMRS channel estimation process provided in the present application;

fig. 7 is a diagram illustrating MSE performance results for channel estimation according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a channel estimation apparatus according to an embodiment of the present application;

fig. 9 is a schematic hardware entity diagram of a terminal according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The following examples are intended to illustrate the present application but are not intended to limit the scope of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Before describing the channel estimation method provided by the embodiment of the present application in detail, a communication system and terms related to the embodiment of the present application will be briefly described.

Referring to fig. 1, fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application, which schematically illustrates a network device 110 and a terminal 120. In some embodiments, the communication system may include a plurality of network devices and each network device may include other numbers of terminals within the coverage area, which is not limited in this application.

A network device 110 in the communication system may provide communication coverage for a particular geographic area and may communicate with terminals 120 located within the coverage area. In some embodiments, the Network device 110 may be an eNB or an eNodeB (evolved Node B) in an LTE system, or a wireless controller in a CRAN (Cloud Radio Access Network), or the Network device 110 may be a mobile switching center, a relay station, an Access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a Network device in a 5G Network, or a Network device in a future communication system, etc.

The communication system further comprises at least one terminal 120 located within the coverage area of the network device 110. As used herein, "terminal" includes, but is not limited to, a connection via a wire Line, such as a connection via PSTN (Public Switched Telephone network), DSL (Digital Subscriber Line), digital cable, direct cable; and/or another data connection/network; and/or via a Wireless interface, such as a Digital television Network, a satellite Network, an AM-FM (Amplitude Modulation-Frequency Modulation) broadcast transmitter for a cellular Network, a WLAN (Wireless Local Area Network), such as a DVB-H (Digital Video Broadcasting-Handheld) Network; and/or means of another terminal arranged to receive/transmit communication signals; and/or IoT (Internet of Things) devices. A terminal that is arranged to communicate over a wireless interface may be referred to as a "wireless communication terminal", "wireless terminal", or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; a PCS (Personal Communications System) terminal that may combine a cellular radiotelephone with data processing, facsimile, and data Communications capabilities; a PDA (Personal Digital Assistant) that may include a radiotelephone, pager, internet/intranet access, web browser, notepad, calendar, and/or GPS (Global Positioning System) receiver; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver. A terminal can refer to an access terminal, UE (User Equipment), subscriber unit, subscriber station, mobile station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or User Equipment. An access terminal may be a cellular phone, a cordless phone, a SIP (Session Initiation Protocol) phone, a WLL (Wireless Local Loop) station, a PDA, a handheld device with Wireless communication capability, a computing device or other processing device connected to a Wireless modem, a vehicle mounted device, a wearable device, a terminal in a 5G Network or a terminal in a future evolved PLMN (Public Land Mobile Network), etc. For convenience of description, the above-mentioned devices are collectively referred to as a terminal.

The PDCCH (Physical Downlink Control Channel) is mainly used for transmitting DCI (Downlink Control Information) and UL Grant (Uplink Grant) so that the terminal correctly receives the PDSCH (Physical Downlink Shared Channel) and allocates Uplink resources for the PUSCH (Physical Uplink Shared Channel).

The PDCCH is a set of physical resource elements, and one PDCCH may include one or more CCEs (Control Channel elements), where a CCE is a minimum resource Element of PDCCH transmission and occupies 6 REGs in a frequency domain. An actual physical Resource to which one CCE is mapped includes 72 REs (Resource elements), that is, 6 RBs (Resource blocks). Where 18 REs are used for demodulation reference signals and 54 REs are used for DCI information transmission.

The REG is a physical resource unit where the time domain occupies one OFDM (Orthogonal Frequency Division Multiplexing) symbol and the Frequency domain occupies one resource block (including 12 subcarriers in which the Frequency domain is continuous). In one REG, 3 REs are used to map PDCCH demodulation reference signals and 9 REs are used to map the REs of DCI. Wherein, the REs for mapping the PDCCH demodulation reference signals are uniformly distributed within the REG and located in subcarriers numbered 1, 5, 9 within the REG.

The number of RE resources used as DMRSs in each REG of each OFDM symbol in an NR (New Radio, new air interface) PDCCH is the same, and each REG of each OFDM symbol has 3 REs as DMRS resources.

REG Bundle (REG bundling) is multiple REGs that are continuous in time domain and/or frequency domain, the number of REGs constituting the REG Bundle may be 1, 2, 3, and 6, and the PDCCHs mapped within one REG Bundle employ the same precoding, i.e., the terminal may perform time domain and/or frequency domain joint channel estimation using demodulation reference signals of all REGs within the REG Bundle, which improves the channel estimation accuracy. The number of REGs included in the REG Bundle in the time and frequency domains is related to the CORESET time domain symbol number and the configuration of REG Bundle size.

CORESET indicates the number of symbols occupied by PDCCH in the time domain and the number of RBs contained in the frequency domain. A CORESET is a time and frequency resource over which a terminal attempts to decode a possible PDCCH using one or more search spaces. The size and time-frequency location of the CORESET are configured semi-statically by the network. The physical resource blocks are comprised in the frequency domain, and the OFDM symbols are comprised in the time domain and can be located anywhere in the slot. The CORESET frequency domain resource needs to be matched with the frequency domain size of the REG Bundle as much as possible, so that the resource fragments of the PDCCH mapped in the CORESET are reduced. The granularity of the CORESET frequency domain resource allocation is set as 6 REGs, and the method can be applied to the allocation of all REG bundles. The time frequency resource occupied by the CORESET is configured by high-level parameters in a semi-static way, does not support the dynamic signaling indication, and the data channel can be mapped in the CORESET resource

Each CORESET has an associated mapping manner from CCE to REG, which is described by the concept of REG Bundle. REG Bundle means that the terminal can consider the precoding of a group of REGs to be the same, which helps to improve the performance of channel estimation. The mapping mode from CCE to REG can be divided into an interleaving mode and a non-interleaving mode, where the non-interleaving mapping is relatively simple to implement, and the REG bundling size is fixed to 6, so that the terminal may consider that precoding is constant over the entire CCE. Consecutive 6 REGs are multiplied to one CCE.

As part of the PDCCH reception process, the terminal needs to perform channel estimation using a reference signal associated with the PDCCH candidate. The PDCCH has a demodulation reference signal of the PDCCH, and a pseudo-random sequence corresponding to the demodulation reference signal is transmitted on a resource block for sending the PDCCH. The demodulation reference signal of one PDCCH candidate will be mapped to one of every 4 subcarriers in REG, and the density of this reference signal is higher than that of LTE (the density of LTE is 1/6).

When a terminal attempts to decode a specific PDCCH candidate occupying several CCEs, the terminal first designs the size of the REG Bundle and then performs channel estimation. Considering that the network may use different precoding between different REG bundles, the channel estimation is done separately for each REG Bundle. In general, this bundling has been able to provide better PDCCH channel estimation performance. It is possible for the network to configure the terminal to assume that all consecutive resource blocks within one CORESET use the same precoding. In this case, the terminal may perform frequency domain interpolation to obtain better channel estimation performance. The terminal may estimate the channel using a reference signal other than the PDCCH.

The PDCCH signals are not placed in the CORESET completely, and are only placed in the CCE, the RB with the DMRS signals does not necessarily have the PDCCH signals, and the DMRS signals are filled in the CORESET completely only for the accuracy of channel estimation. When data is decoded, the whole CORESET is taken out, then all DMRS signals are taken out for channel estimation and signal detection, and then all possible positions of CCE initial positions are calculated for blind detection.

When each terminal of the PDCCH performs blind detection in the search space to receive the DCI information of the terminal, channel estimation may be performed in each REG Bundle to obtain more accurate channel parameters, or channel estimation may be performed in the entire PDCCH bandwidth, that is, channel estimation is not limited to the bandwidth in the core set of the terminal.

The method for estimating the physical downlink control channel provided by the embodiment of the application can be applied to a wireless communication system. This wireless communication system may employ a system of the fifth generation (5th generation, 5g) mobile communication technology (hereinafter, both may be referred to as the 5G system).

Next, to facilitate understanding of the scheme of the embodiment of the present application, a PDCCH channel estimation processing method in the related art is analyzed and explained:

in the 5G NR protocol design of 3GPP, for DMRS of PDCCH, when a precoding granularity parameter of CORSET in RRC (Radio Resource Control) configuration is configured as an all continuous Resource block, PDCCH DMRS demodulation reference signals are mapped to the whole CORSET, as shown in fig. 2 below. Therefore, when the pilot frequency point of the channel estimation is subjected to frequency domain filtering, the full-bandwidth DMRS can be used for processing, and the de-noising performance of the channel estimation is improved. When the precoding granularity of the set in the RRC configuration is configured to be a sameaasereg-Bundle (bundled with REG-Bundle, resource Element Group), under this scenario, the narrowband mapping is equivalent to the above-mentioned narrowband mapping, that is, PDCCH DRMS is mapped only on a REG with a PDCCH, and at this time, frequency domain channel estimation is usually performed inside the REG Bundle (Resource Element Group Bundle, resource Element Group bundling), that is, DMRSs carried on all Resource blocks in the REG Bundle are used for frequency domain filtering.

When the parameter precoding granularity is configured to be an alloconteguous sRB scene in RRC configuration, the full-bandwidth DMRS is used for channel estimation, so that the MSE performance of the channel estimation can be effectively improved, and the error rate and throughput performance of the system are improved.

However, REGs mapped with PDCCH may not be allocated on some PRBs (Physical RBs) of sets, and demodulation and decoding are not required on these PRBs, and thus, channel estimation is not required. When the bandwidth of the CORSET itself is large and the actually detected REGs in the CORSET are few, if channel estimation is performed on all PRBs of the COREST, the channel estimation process on the REGs that do not need to be detected will cause waste of system complexity and power consumption.

For example, when the CORESET bandwidth is 270 PRBs and the CORESET duration is 3 OFDM symbols, according to the protocol, REGs corresponding to PDCCHs that may exist within a single symbol can occupy a maximum of 112 PRBs. When frequency-domain filtering is performed using all 270 PRBs, the increase in system complexity and power consumption is 1.4 times that of frequency-domain filtering for 112 PRBs. When the number of REGs allocated to the PDCCH is less than 112 PRBs, the increase in system complexity and power consumption caused by filtering and denoising using all 270 PRBs may increase continuously with the decrease in the number of REGs.

Therefore, how to effectively utilize the resource allocation mode of the control channel specified by the current protocol is a compromise between the channel estimation performance and the computational complexity, which is very important.

The embodiment of the application provides a channel estimation method, which is applied to a terminal and can improve the channel estimation performance on the premise of limited increase of the system complexity. The functions implemented by the method can be implemented by calling program codes through a processor in the terminal, and the program codes can be stored in a computer storage medium. Fig. 3 is an optional flowchart of the channel estimation method according to the embodiment of the present application, and as shown in fig. 3, the method at least includes the following steps:

step S310, according to the resource allocation mode of the control channel, determining the resource block carrying PDCCH in the OFDM symbol.

Here, the resource allocation method of the control channel includes a resource allocation method of an uplink control channel and a resource allocation method of a downlink control channel.

In some possible embodiments, the resource allocation manner of the control channel may be embodied as a pilot pattern, which characterizes a transmission rule of a pilot signal on time and/or space, frequency, and code channels, and may be expressed by a graph, a table, a sequence, or the like. The pilot pattern may be described by a series of parameters, such as Tcycle (pilot pattern period), tburst (length of time the pilot is transmitted in each period), and Toffset (time offset of the pilot with respect to the starting time of some reference time frame). Wherein the Tcycle, tburst and Toffset parameters may be used to define the transmission rule of a pilot signal in time.

In some possible embodiments, the resource allocation manner of the control channel may be understood as time-frequency distribution of the reference signal on the physical resource, such as time-frequency distribution of PDCCH DMRS on the physical resource. Note that the resource locations of PDCCH DMRS are located on subcarriers numbered 1, 5, 9 within one REG. The sequence PDCCH DMRS can be generated according to a slot index, an OFDM symbol index and a cell ID; in addition, NR also supports generation of PDCCH DMRS sequences without cell ID, where the DMRS sequence generation parameters may be configured by higher layer parameters. The PDCCH DMRS sequence is specific to the channel estimate for a particular terminal and is transmitted only on the resource blocks allocated to that terminal.

Here, the resource block carrying the PDCCH is an REG mapped with the PDCCH in the CORESET, and it should be noted that here, the PDCCH corresponds to several consecutive resource blocks on a physical resource. In the implementation process, the terminal determines a plurality of continuous resource blocks occupied by the PDCCH in each OFDM symbol by using a resource allocation mode and resource mapping distribution of a control channel configured by a network. The following embodiments of the present application will be described only in terms of how to perform channel estimation on a single resource block. For the case of multiple consecutive resource blocks occupied by the PDCCH, each of the multiple consecutive resource blocks may be processed separately.

Notably, the resource mapping of PDCCH DMRS supports both narrowband mapping and wideband mapping. Under narrowband mapping, PDCCH DMRS maps only on REGs with PDCCH; under wideband mapping, PDCCH DRMS maps on consecutive resource blocks containing PDCCH.

It should be noted that, the data of PDCCH in 5G NR is all put in CORESET, but not the CORESET is completely filled with PDCCH data, because PDCCH is formed by aggregating several CCEs, and there is PDCCH data only in the CCEs. And the terminal determines a resource block corresponding to the PDCCH according to the corresponding relation between one CCE index and the REG Bundle index sent by the network equipment.

Step S320, determining at least two associated blocks according to the frequency domain position of the resource block.

Here, the associated block is a block within a certain frequency domain from the resource block in the frequency domain. The association block may include one resource block or may include a plurality of resource blocks. For example, several resource blocks other than the REG Bundle where the resource block is located may be used as the association block, or several resource blocks adjacent to the resource block in the frequency domain may be used as the association block.

Here, the resource block is any one resource block corresponding to the PDCCH on the physical resource, and when the REG Bundle includes a plurality of consecutive resource blocks, at least two associated blocks corresponding to each resource block are determined according to the frequency domain position of each resource block.

Step S330, processing the pilot signal carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block.

Here, the pilot signal is a reference signal defined in advance, and is a special signal placed in transmission data. The reference signal occupies a specific time-frequency resource unit and is used for channel estimation, channel measurement, channel detection or channel demodulation and the like. The NR standard specifies several different reference signals, and different transmission modes, for reception in different scenarios, to obtain accurate channel state information. The pilot signal in the embodiment of the present application may be PDCCH DMRS.

Here, the pilot position is a frequency position where the RE for mapping the pilot signal is located in each resource block, and for example, the REs for mapping PDCCH DMRS are uniformly distributed in REG and located in subcarriers numbered 1, 5, and 9 in REG.

It should be noted that, in the embodiment of the present application, a sliding filtering scheme is proposed based on a conventional fixed filtering scheme, that is, a resource block carrying a PDCCH and a DMRS carried on an associated block are used for processing, so that channel estimation performance is improved while a small amount of computational complexity is increased.

In the embodiment of the application, firstly, a resource block carrying a PDCCH in an OFDM symbol is determined; then determining at least two associated blocks according to the frequency domain position of the resource block; finally, processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block; therefore, the pilot signals participating in the channel estimation processing are expanded to the pilot signals carried by the resource block to be detected and the corresponding associated block together, so that the channel estimation results of the resource block to be detected in the subsequent processing are all interpolated, and the MSE performance of the channel estimation is improved.

Fig. 4 is an optional flowchart of a channel estimation method according to an embodiment of the present application, and as shown in fig. 4, the method includes:

step S410, according to the resource allocation mode of the control channel, determining the resource block carrying the PDCCH in the OFDM symbol.

Here, the resource allocation manner of the control channel is understood as a transmission rule of the pilot signal on time and/or space, frequency, and code channel, and may be expressed by a graph, a table, a sequence, or the like. The resource allocation of the control channel may be described by a series of parameters, such as a period of the resource allocation of the control channel, a time length of transmitting the pilot in each period, and a time offset of the pilot with respect to a starting time of a reference time frame.

Here, the resource block carrying the PDCCH is an REG mapped with the PDCCH in the CORESET, and it should be noted that here, the PDCCH corresponds to several consecutive resource blocks on a physical resource. And the terminal determines a plurality of continuous resource blocks occupied by the PDCCH in each OFDM symbol by using the resource allocation mode and the resource mapping distribution of the control channel configured by the network.

Step S420, determining resource blocks adjacent to both sides of the frequency domain position of the resource block as the association block.

Here, the associated block is a resource block adjacent to the resource block on both sides in the frequency domain, that is, the resource block and the associated block are continuous in the frequency domain, and for example, the resource block is an RB ₀ The corresponding association block may then comprise the resource block RB ₀ The two sides of the adjacent symmetrical resource blocks can also be RB ₀ And a plurality of asymmetric resource blocks adjacent to each other at two sides.

Exemplary, RB ₀ Includes an association block with an RB ₀ RB of adjacent high frequency domain position _-1 And RB ₀ RB of adjacent low frequency domain positions ₁ (ii) a Or, RB ₀ Includes an association block with an RB ₀ RB of adjacent high frequency domain position _-2 And RB _-1 And also include and RB ₀ RB of adjacent low frequency domain positions ₁ And the like.

In some embodiments, the above-mentioned manner of determining the associated block may be implemented by:

step S4201, determining M high frequency domain positions and N low frequency domain positions adjacent to the frequency domain position of the resource block.

Here, several frequency domain positions adjacent to the frequency domain position where the resource block is located are respectively determined, including M high frequency domain positions and N low frequency domain positions. Wherein both M and N are greater than or equal to 1. For example, M is 1, N is 1, or M is 2, N is 1, etc.

Step S4202, using the resource blocks in the M high-frequency domain positions and the resource blocks in the N low-frequency domain positions as the association blocks.

Here, a corresponding resource block is distributed at each frequency domain position, and the associated block corresponding to the resource block is finally determined by determining the frequency domain position satisfying a specific range.

In some embodiments, M is the same as N, i.e. M is 2 and N is 2, which ensures that the result of channel estimation of the pilot signal carried by the resource block is the result of interpolation.

Step S430, processing the pilot signal carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of the pilot position in the resource block.

In some embodiments, the pilot signals are distributed on resource blocks mapped with the PDCCH and resource blocks not mapped with the PDCCH in the CORESET; the resource blocks mapped with the PDCCH and the resource blocks not mapped with the PDCCH are continuous on a frequency domain.

Here, the resource block on which the pilot signal PDCCH DRMS is mapped includes both the resource block on which the PDCCH is mapped and the resource block on which the PDCCH is not mapped, and the resource block on which the PDCCH is mapped and the resource block on which the PDCCH is not mapped are consecutive in the frequency domain.

In some embodiments, all resource blocks within the CORESET described above use the same precoding.

Here, the precoding granularity of CORESET is all continuous resource blocks, and channel estimation may be performed using a full-bandwidth DMRS on all resource blocks of CORESET. The channel estimation accuracy is improved by increasing the number of demodulated PDCCH DMRS. Because the terminal can utilize the PDCCH and PDCCH DMRS in the adjacent RB thereof to carry out time domain and frequency domain joint channel estimation under the broadband mapping, the channel estimation quality is improved.

Fig. 5 is an optional flowchart of the channel estimation method according to the embodiment of the present application, and as shown in fig. 5, the method includes at least the following steps:

step S510, determining a resource block carrying the PDCCH in the OFDM symbol according to a resource allocation manner of the control channel.

Step S520, the resource blocks adjacent to the two sides of the frequency domain position of the resource block are determined as the related blocks.

Here, in the frequency domain, the associated block is a block that satisfies a specific frequency domain range with the frequency domain position where the resource block is located. For example, several resource blocks outside the REG Bundle where the resource block is located may be used as the association block, or several resource blocks adjacent to the resource block in the frequency domain may be used as the association block.

Here, the resource blocks include all resource blocks in the REG Bundle corresponding to the PDCCH, and in an implementation process, a correlation block corresponding to each resource block is determined.

Step S530, processing the pilot signal carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of the pilot position in the resource block.

Here, the pilot position is a specific subcarrier on the resource block. The channel estimation value of the pilot frequency position is the channel estimation value of the sub-carrier where the PDCCH DMRS signal is located.

It should be noted that the basic process of the pilot-based channel estimation method is to insert a pilot at a proper position at a transmitting end, and a receiving end recovers channel information H at the pilot position by using the pilot, and then obtains the channel information H at all time intervals by using a specific processing means (such as interpolation, filtering, transformation, etc.). That is to say, for the channel estimation process of the PDCCH, a certain number of DMRSs are inserted into a specific time-frequency domain resource by the network device, and the terminal obtains the frequency domain channel response on the whole subframe through the frequency domain channel estimation and interpolation algorithm for the DMRS positions.

Here, in the process of processing the pilot signal, one possible implementation manner is to multiply the locally generated DMRS signal with the received DMRS signal conjugate to obtain a PDCCH channel estimate at the subcarrier where the DMRS signal is located; another possible implementation manner is to perform frequency domain filtering and denoising on the DMRS signals, for example, to extract a channel estimation value at an effective subcarrier through a wiener filtering algorithm.

Here, after obtaining the channel estimation value of the subcarrier where the DMRS signal is located, to obtain the channel estimation value of the subcarrier where the non-DMRS signal is located, further linear interpolation needs to be performed on the channel estimation value of the subcarrier where the DMRS signal is located in the frequency domain and the time domain of the time-frequency resource, respectively, so as to achieve the purpose of accurately estimating the PDCCH channel estimation value.

Step S540, interpolating the channel estimation value of the pilot position in at least one resource block to obtain the channel estimation result of the PDCCH.

Here, when the PDCCH corresponds to a plurality of resource blocks on a physical resource, channel estimation values of pilot positions in each resource block are obtained, and then these channel estimation values are interpolated to obtain a final channel estimation result of the PDCCH.

The channel estimation method is described below with reference to a specific embodiment, however, it should be noted that the specific embodiment is only for better describing the present application and is not to be construed as a limitation of the present application.

In the existing 5G NR protocol, when a precoding granularity parameter of a CORSET in RRC configuration is configured as allo contigousrb, PDCCH DMRS is mapped to the whole CORSET, that is, REs with

indexes

1, 5, and 9 in all RBs in the CORESET all carry DMRS signals. The PDCCH is mapped in the REG bundle part in the CERESET, and detection including demodulation and decoding is required for the REG bundle part.

According to the technical scheme, the REG bundle is taken as a center, the DMRS participating in filtering is expanded to a plurality of RBs except the REG bundle needing to be detected for frequency domain filtering, and the channel estimation results of PRBs in the REG bundle are all interpolation results in the filtering process, so that the MSE performance of channel estimation is effectively improved, and the effects of improving the error rate and the throughput performance of a system are further achieved.

Fig. 6 is a schematic diagram of a PDCCH DMRS channel estimation process provided in the embodiment of the present application. Wherein, the left side in fig. 6 shows the DMRS signal distribution of all PDCCHs in one CORESET, wherein the gray part shows the REG Bundle corresponding to a certain PDCCH # n. Right hand side of FIG. 6Frequency domain filtering scheme of PDCCH # n over one OFDM symbol. PRB contained in REG Bundle corresponding to PDCCH # n ₀ 、PRB ₁ 、PRB ₂ The channel estimation procedure of (a) is described as follows:

for PRB ₀ As shown in the right side of fig. 6, frequency-domain filtering is performed by using the 1 st group of pilot sequences to obtain PRBs ₀ The channel estimation result of (2); wherein the 1 st group pilot sequence is composed of continuous PRB _-2 /PRB _-1 /PRB ₀ /PRB ₁ /PRB ₂ Corresponding PDCCH DMRS, it can be seen that PRB is in the frequency domain ₀ In the middle of the pilot sequence in group 1.

For PRB ₁ As shown in the right side of fig. 6, frequency-domain filtering is performed by using the 2 nd group of pilot sequences to obtain PRBs ₁ The channel estimation result of (2); wherein the 2 nd group pilot sequence is composed of continuous PRB _-1 /PRB ₀ /PRB ₁ /PRB ₂ /PRB ₃ Corresponding PDCCH DMRS, it can be seen that PRB is in the frequency domain ₁ In the middle of the group 2 pilot sequences.

For PRB ₂ As shown in the right side of fig. 6, frequency-domain filtering is performed by using the 3 rd group of pilot sequences to obtain PRBs ₂ The channel estimation result of (2); wherein the 3 rd group pilot sequence is composed of continuous PRB ₀ /PRB ₁ /PRB ₂ /PRB ₃ /PRB ₄ The corresponding PDCCH DMRS composition, it can be seen that PRB in the frequency domain ₂ In the middle of the group 3 pilot sequences.

After PDCCH DMRS filtering is performed by using the filtering scheme provided by the embodiment of the present application, all channel estimation positions output by frequency domain filtering are interpolation results. Compared with the scheme of channel estimation inside the REG bundle, the MSE performance of the channel estimation is greatly improved. Fig. 7 is a schematic diagram of the performance result of channel estimation MSE provided in the embodiment of the present application, and it can be seen from fig. 7 that, when the frequency domain filtering is extended from the fixed filtering of 3RB to the sliding filtering of 5RB, the gain of the performance of channel estimation MSE is about 5dB around the SNR of-5 dB. And the channel estimation MSE gain will increase continuously as the number of RBs participating in filtering increases.

When the CORESET bandwidth is 270 PRBs and the CORESET duration is 3 OFDM symbols, the maximum possible REG in a single symbol can occupy 112 PRBs. Assuming that the filtering process of each PRB is extended from 3RB fixed filtering to 5RB sliding filtering, the number of PRBs involved in calculation is 112/3 × 5=187, and a calculation amount is saved by 30% relative to full bandwidth calculation. When the number of allocated REGs is less than 112 PRBs, the computational load of the system complexity saved may be more than 30%.

In the embodiment of the application, the DMRSs available in the system is effectively utilized, a sliding filtering scheme is used, that is, the DMRSs participating in filtering are extended to a plurality of PRBs outside the required detection area, so that in the filtering process, the channel estimation results of the PRBs requiring detection (demodulation and decoding) are all obtained by interpolation, and thus the channel estimation performance is improved on the premise that the complexity of the system is increased to a limited extent.

Based on the foregoing embodiments, an embodiment of the present application further provides a channel estimation apparatus, where the apparatus includes modules and units included in the modules, and may be implemented by a processor in a terminal; of course, it may also be implemented by logic circuitry; in the implementation, the Processor may be a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like.

Fig. 8 is a schematic structural diagram of a channel estimation apparatus provided in an embodiment of the present application, and as shown in fig. 8, the apparatus 800 includes a first determining module 801, a second determining module 802, and a processing module 803, where:

the first determining module 801 is configured to determine, according to a resource allocation manner of a control channel, a resource block that carries a PDCCH within an OFDM symbol;

the second determining module 802 is configured to determine at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the associated block is a block within a certain frequency domain from the resource block;

the processing module 803 is configured to process the pilot signal carried by the resource block and the pilot signals carried by the at least two associated blocks, so as to obtain a channel estimation value of a pilot position in the resource block.

In some embodiments, the second determining module is further configured to determine resource blocks adjacent to two sides of a frequency domain position of the resource block as the association block.

In some embodiments, the second determining module further comprises a first determining submodule and a second determining submodule, wherein: the first determining submodule is used for determining M high-frequency domain positions and N low-frequency domain positions which are adjacent to the frequency domain position where the resource block is located; wherein both M and N are greater than or equal to 1; the second determining submodule is configured to use the resource blocks in the M high-frequency-domain positions and the resource blocks in the N low-frequency-domain positions as the association blocks.

In some embodiments, the M is the same as the N.

In some embodiments, the apparatus 800 further includes an interpolation module, configured to interpolate a channel estimation value of a pilot position in at least one of the resource blocks to obtain a channel estimation result of the PDCCH.

In some embodiments, the resource block carrying the PDCCH is a resource element group mapped with the PDCCH in the CORESET.

In some embodiments, all resource blocks within the CORESET use the same precoding.

In some embodiments, the pilot signals are distributed on resource blocks mapped with a PDCCH and resource blocks not mapped with the PDCCH in the CORESET; wherein the resource blocks mapped with the PDCCH and the resource blocks not mapped with the PDCCH are continuous on a frequency domain.

It is to be noted here that: the above description of the apparatus embodiments, similar to the above description of the method embodiments, has similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

Correspondingly, based on the same technical concept, the embodiments of the present application provide a terminal for implementing the channel estimation method described in the above method embodiments. Fig. 9 is a schematic diagram of a hardware entity of a terminal according to an embodiment of the present application, and as shown in fig. 9, the hardware entity of the terminal 900 includes: a processor 901, a receiver 902, a transmitter 903, a memory 904, and a bus 905. It should be noted that fig. 9 is only an exemplary architecture diagram, and the network architecture may include other functional units besides the functional units shown in fig. 9, which is not limited in this embodiment of the present application.

The processor 901 includes one or more processing cores, and the processor 901 executes various functional applications and information processing by executing software programs and modules.

The receiver 902 and the transmitter 903 may be implemented as one communication component, which may be a communication chip.

The memory 904 is coupled to the processor 901 by a bus 905.

The memory 904 may be used to store a computer program which the processor 901 is configured to execute in order to implement the various steps of the channel estimation method performed by the terminal in the above-described method embodiments.

Further, the memory 904 may be implemented by any type or combination of volatile or non-volatile storage devices, including, but not limited to: magnetic or optical disk, EEPROM (electrically erasable programmable read-only memory), EPROM (erasable programmable read-only memory), SRAM (static random access memory), ROM (read-only memory), magnetic memory, flash memory, PROM (programmable read-only memory).

In an exemplary embodiment, the terminal includes a processor 901 and a memory 904, and the processor is configured to invoke a computer program stored in the memory 904 to execute a channel estimation method in the method embodiment, including: determining a resource block for bearing the PDCCH in the OFDM symbol according to the resource allocation mode of the control channel; determining at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the association block is a resource block within a certain frequency domain from the resource block; and processing the pilot signals carried by the resource block and the pilot signals carried by the at least two associated blocks to obtain a channel estimation value of a pilot position in the resource block.

In some embodiments, the processor 901 is further configured to determine resource blocks adjacent to two sides of the frequency domain position of the resource block as the association block.

In some embodiments, the processor 901 is further configured to determine M high frequency domain positions and N low frequency domain positions adjacent to the frequency domain position where the resource block is located; wherein both M and N are greater than or equal to 1; and taking the resource blocks at the M high-frequency domain positions and the resource blocks at the N low-frequency domain positions as the association blocks.

In some embodiments, the M is the same as the N.

In some embodiments, the processor 901 is further configured to interpolate a channel estimation value of a pilot position in at least one of the resource blocks to obtain a channel estimation result of the PDCCH.

In some embodiments, the pilot signals are distributed on resource blocks mapped with a PDCCH and resource blocks not mapped with the PDCCH in the CORESET; the resource blocks mapped with the PDCCH and the resource blocks not mapped with the PDCCH are continuous on a frequency domain.

Correspondingly, the embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the channel estimation method provided in the above embodiment.

It is to be noted here that: the above description of the storage medium and device embodiments is similar to the description of the method embodiments above, with similar advantageous effects as the method embodiments. For technical details not disclosed in the embodiments of the storage medium and apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

Correspondingly, in an embodiment of the present application, a chip is further provided, where the chip includes a programmable logic circuit and/or program instructions, and when the chip runs, the chip is configured to implement the channel estimation method according to any of the above embodiments.

Correspondingly, in an embodiment of the present application, there is also provided a computer program product, which is configured to implement the channel estimation method according to any of the foregoing embodiments when the computer program product is executed by a processor of a terminal.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description, and do not represent the advantages and disadvantages of the embodiments.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Alternatively, the integrated units described above in the present application may be stored in a computer-readable storage medium if they are implemented in the form of software functional modules and sold or used as independent products. Based on such understanding, the technical solutions of the embodiments of the present application, in essence or parts contributing to the related art, may be embodied in the form of a software product, where the computer software product is stored in a storage medium and includes several instructions for causing an automatic test line of a device to perform all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

The methods disclosed in the several method embodiments provided in the present application may be combined arbitrarily without conflict to obtain new method embodiments.

The features disclosed in the several method or apparatus embodiments provided in the present application may be combined arbitrarily, without conflict, to arrive at new method embodiments or apparatus embodiments.

The above description is only for the embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of channel estimation, the method comprising:

determining a resource block for bearing a Physical Downlink Control Channel (PDCCH) in an Orthogonal Frequency Division Multiplexing (OFDM) symbol according to a resource allocation mode of a control channel;

2. The method of claim 1, wherein the determining at least two associated blocks according to the frequency domain location of the resource block comprises:

and determining the resource blocks adjacent to the two sides of the frequency domain position of the resource blocks as the associated blocks.

3. The method of claim 2, wherein the determining resource blocks adjacent to both sides of a frequency domain position of the resource block as the association block comprises:

determining M high-frequency domain positions and N low-frequency domain positions which are adjacent to the frequency domain position of the resource block; wherein both M and N are greater than or equal to 1;

and taking the resource blocks at the M high-frequency domain positions and the resource blocks at the N low-frequency domain positions as the association blocks.

4. The method of claim 3, wherein M is the same as N.

5. The method of any of claims 1 to 4, further comprising:

and interpolating the channel estimation value of the pilot frequency position in at least one resource block to obtain the channel estimation result of the PDCCH.

6. The method of claim 1, wherein the resource block carrying the PDCCH is a resource element group mapped with the PDCCH in a control resource set (CORESET).

7. The method of claim 6, wherein all resource blocks within the CORESET use the same precoding.

8. A channel estimation apparatus, comprising a first determination module, a second determination module, and a processing module, wherein:

the first determining module is configured to determine, according to a resource allocation manner of a control channel, a resource block that carries the PDCCH in each OFDM symbol;

the second determining module is configured to determine at least two associated blocks according to the frequency domain position of the resource block; wherein, in a frequency domain, the association block is a resource block within a certain frequency domain from the resource block;

the processing module is configured to process the pilot signal carried by the resource block and the pilot signals carried by the at least two association blocks to obtain a channel estimation value of a pilot position in the resource block.

9. A terminal comprising a memory and a processor, the memory storing a computer program operable on the processor, wherein the processor when executing the program performs the steps of the method of any one of claims 1 to 7.

10. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.