CN115811452A

CN115811452A - Channel estimation method, device, equipment and storage medium of downlink control channel

Info

Publication number: CN115811452A
Application number: CN202211477550.3A
Authority: CN
Inventors: 徐国琴; 李晓飞; 郭青云
Original assignee: Zeku Technology Beijing Corp Ltd
Current assignee: Zeku Technology Beijing Corp Ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-03-17

Abstract

The application discloses a channel estimation method, a device, equipment and a storage medium of a downlink control channel, relating to the field of mobile communication. The method comprises the following steps: performing channel estimation on the PDCCH in a second TTI by using a first reference signal in the first TTI and a second reference signal in the second TTI; wherein the first TTI is a TTI preceding the second TTI. The method enables the terminal to judge whether the second TTI is the TTI only with the PDCCH or not more quickly, thereby closing the radio frequency component earlier and reducing the radio frequency power consumption.

Description

Channel estimation method, device, equipment and storage medium of downlink control channel

Technical Field

The present application relates to the field of mobile communications, and in particular, to a method, an apparatus, a device, and a storage medium for channel estimation of a downlink control channel.

Background

In a Long Term Evolution (LTE) system, a monitoring result of a Physical Downlink Control Channel (PDCCH) indicates that a case where a current Transmission Time Interval (TTI) is a PDCCH-only TTI occupies a large proportion of an internet traffic, that is, there is no valid Downlink Control Information (DCI) to schedule a Physical Uplink Shared Channel (PUSCH) and a Physical Downlink Shared Channel (PDSCH).

When the channel condition is lower than the threshold, more Cell-specific Reference signals (CRS) are required in the same subframe for PDCCH channel estimation, which increases the radio frequency power consumption to some extent.

Disclosure of Invention

The embodiment of the application provides a channel estimation method, a device, equipment and a storage medium of a downlink control channel, so that a terminal can more quickly judge whether the current TTI is a TTI only with a PDCCH (physical downlink control channel), thereby closing a radio frequency component earlier and reducing radio frequency power consumption. The technical scheme is as follows:

according to an aspect of the present application, a method for channel estimation of a downlink control channel is provided, where the method includes:

performing channel estimation on a downlink control channel (PDCCH) in a second TTI by using a first reference signal in a first TTI and a second reference signal in the second TTI;

wherein the first TTI is a TTI preceding the second TTI.

According to another aspect of the present application, there is provided a channel estimation apparatus for a downlink control channel, the apparatus including:

a signal estimation module, configured to perform channel estimation on a physical downlink control channel PDCCH in a second TTI by using a first reference signal in the first TTI and a second reference signal in the second TTI;

wherein the first TTI is a subframe preceding the second TTI.

According to another aspect of the present application, there is provided a chip, which includes programmable logic circuits and/or program instructions, and when a communication device installed with the chip is operated, the chip is used for implementing the channel estimation method for the downlink control channel as described above.

According to another aspect of the present application, there is provided a computer device comprising: a processor and a memory, the memory having stored therein at least one instruction, at least one program, a set of codes, or a set of instructions, the at least one instruction, the at least one program, the set of codes, or the set of instructions being loaded and executed by the processor to implement the method for channel estimation of downlink control channels as described above.

According to another aspect of the present application, there is provided a computer-readable storage medium having at least one instruction, at least one program, a set of codes, or a set of instructions stored therein, which is loaded and executed by a processor to implement the method for channel estimation of downlink control channels as described above.

According to another aspect of the present application, there is provided a computer program product comprising at least one program, the at least one program being stored in a computer readable storage medium; the processor of the communication device reads the at least one program from the computer readable storage medium, and executes the at least one program, so that the communication device executes the channel estimation method of the downlink control channel as described above.

According to another aspect of the present application, there is provided a computer program comprising at least one program segment, the at least one program segment being stored in a computer readable storage medium; the processor of the communication device reads the at least one program from the computer-readable storage medium, and executes the at least one program, so that the communication device performs the channel estimation method for the downlink control channel as described above.

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

by using the first reference signal in the first TTI and the second reference signal in the second TTI, channel estimation is performed on the PDCCH in the second TTI, so that the terminal can be helped to judge whether the second TTI is the TTI only with the PDCCH or not under the condition that the channel condition is not good, the radio frequency component can be closed earlier, and the radio frequency power consumption is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a diagram of a frame structure provided by an exemplary embodiment of the present application;

FIG. 2 is a schematic illustration of a reference signal provided by another exemplary embodiment of the present application;

fig. 3 is a schematic diagram of a communication system provided by another exemplary embodiment of the present application;

fig. 4 is a diagram illustrating a channel estimation method provided in an exemplary embodiment of the related art;

fig. 5 is a diagram illustrating a channel estimation method according to another exemplary embodiment of the related art;

fig. 6 is a diagram illustrating a channel estimation method of a PDCCH according to another exemplary embodiment of the present application;

fig. 7 is a flowchart of a channel estimation method for PDCCH provided in another exemplary embodiment of the present application;

fig. 8 is a diagram illustrating a channel estimation method of a PDCCH according to another exemplary embodiment of the present application;

fig. 9 is a diagram illustrating a channel estimation method for PDCCH according to another exemplary embodiment of the present application;

fig. 10 is a diagram illustrating a channel estimation method of a PDCCH according to another exemplary embodiment of the present application;

fig. 11 is a diagram illustrating a channel estimation method for PDCCH according to another exemplary embodiment of the present application;

fig. 12 is a diagram illustrating a channel estimation method for PDCCH according to another exemplary embodiment of the present application;

fig. 13 is a diagram illustrating a channel estimation method of a PDCCH according to another exemplary embodiment of the present application;

fig. 14 is a block diagram of a channel estimation apparatus of a PDCCH provided in another exemplary embodiment of the present application;

fig. 15 is a block diagram of a terminal provided in another exemplary embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

First, terms related to the present application will be explained.

TTI: in the time domain, a TTI is a basic unit for scheduling data transmission. In one TTI, the base station may schedule the terminal for uplink transmission and/or downlink transmission through one DCI. Uplink transmission refers to transmission from the terminal to the base station, and downlink transmission refers to transmission from the base station to the terminal. One TTI may be one subframe, one slot, a micro-slot, a symbol group, etc. Hereinafter, one TTI is exemplified as one subframe.

And (3) frame structure: refers to a structure for dividing time-frequency resources.

For example, as shown in fig. 1, a radio frame may be divided into two half-frames and may be divided into 10 subframes, which correspond to subframes 0 to 9, respectively. Each subframe may be divided into a plurality of slots, for example, subframe 0 may be divided into slot 0 and slot 1, and each slot includes a plurality of symbols in the time domain direction, for example, a slot includes 14 symbols, which respectively correspond to symbol 0 to symbol 13. When the interval of the sub-carrier is increased, the duration of each symbol is decreased, and the length of the corresponding time slot is also decreased, that is, when one sub-frame 0 includes 2 time slots, the corresponding symbol length is smaller than the corresponding symbol length when the sub-frame 0 only includes 1 time slot, and the corresponding sub-carrier interval is larger than the corresponding sub-carrier interval when the sub-frame 0 only includes 1 time slot.

DCI: refers to control information for transmitting uplink data and/or receiving downlink data in one subframe or slot.

PDCCH: the PDCCH is responsible for receiving DCI, and the DCI is used for uplink data transmission and/or downlink data reception in the subframe or the time slot. The terminal sends uplink data to the base station, and the base station receives downlink data to the terminal. The PDCCH typically occupies at least one of the first 4 symbols in one subframe. The PDCCH is mainly illustrated as occupying symbol 0 and symbol 1 in this application.

CRS: a reference signal in LTE, which is also commonly referred to as a common reference signal, may be generally used by a terminal for Channel estimation of a downlink physical Channel or for acquiring Channel State Information (CSI). The present application mainly relates to reference signals related to channel estimation, and reference signals referred to hereinafter may be understood as short for reference signals used for PDCCH channel estimation.

Illustratively, as shown in fig. 2, taking a frame structure of one subframe as an example, the frame structure includes 14 symbols, and a typical configuration manner of the reference signals is to occupy a symbol 0, a symbol 4, a symbol 7, and a symbol 11 in a time domain, where the reference signals located at the symbol 0 and the symbol 7 occupy a subcarrier 0 and a subcarrier 6 in a frequency domain, and the reference signals located at the symbol 4 and the symbol 11 occupy a subcarrier 3 and a subcarrier 9 in the frequency domain.

In some embodiments, taking the reference signal as the CRS as an example, the configuration manner of the reference signal further includes other cases:

illustratively, reference signals on 1 antenna port, 2 antenna ports, or 4 antenna ports may be used.

For example, only using the reference signals on 1 antenna port, the reference signals occupy symbol 0, symbol 4, symbol 7 and symbol 11 in the time domain corresponding to the above typical configuration, where the reference signals located at symbol 0 and symbol 7 occupy subcarrier 0 and subcarrier 6 in the frequency domain, and the reference signals located at symbol 4 and symbol 11 occupy subcarrier 3 and subcarrier 9 in the frequency domain.

For example, using reference signals on 2 antenna ports, the reference signal on the 1 st antenna port and the reference signal on the 2 nd antenna port are multiplexed in the frequency domain, the reference signal on the 1 st antenna port occupies symbol 0, symbol 4, symbol 7 and symbol 11 in the time domain, wherein the reference signals located on symbol 0 and symbol 7 occupy subcarrier 0 and subcarrier 6 in the frequency domain, and the reference signals located on symbol 4 and symbol 11 occupy subcarrier 3 and subcarrier 9 in the frequency domain; the reference signals on the 2 nd antenna port occupy symbol 0, symbol 4, symbol 7 and symbol 11 in the time domain, wherein the reference signals located on symbol 0 and symbol 7 occupy subcarrier 3 and subcarrier 9 in the frequency domain, and the reference signals located on symbol 4 and symbol 11 occupy subcarrier 0 and subcarrier 6 in the frequency domain.

Exemplarily, the reference signals on the 1 st antenna port occupy symbol 0, symbol 4, symbol 7 and symbol 11 in the time domain using the reference signals on 4 antenna ports, wherein the reference signals on symbol 0 and symbol 7 occupy subcarrier 0 and subcarrier 6 in the frequency domain, and the reference signals on symbol 4 and symbol 11 occupy subcarrier 3 and subcarrier 9 in the frequency domain; reference signals on the 2 nd antenna port occupy a symbol 0, a symbol 4, a symbol 7 and a symbol 11 in a time domain, wherein the reference signals located on the symbol 0 and the symbol 7 occupy a subcarrier 3 and a subcarrier 9 in a frequency domain, and the reference signals located on the symbol 4 and the symbol 11 occupy a subcarrier 0 and a subcarrier 6 in the frequency domain; the reference signal on the 3 rd antenna port occupies symbol 2 and symbol 8 in the time domain, wherein the reference signal located on symbol 2 occupies subcarrier 0 and subcarrier 6 in the frequency domain, and the reference signal located on symbol 8 occupies subcarrier 3 and subcarrier 9 in the frequency domain; the reference signal at the 4 th antenna port occupies symbol 2 and symbol 8 in the time domain, wherein the reference signal at symbol 2

occupies subcarriers

3 and 9 in the frequency domain, and the reference signal at symbol 8

occupies subcarriers

0 and 6 in the frequency domain.

It should be noted that, in different communication systems, the configuration of the reference signal for channel estimation may be different. CRS is used herein by way of example, and not limitation.

Fig. 3 is a schematic diagram of a communication system provided in an exemplary embodiment of the present application. The communication system 100 may include: a terminal 101, an access network device 102 and a core network device 103.

The number of the terminals 101 is usually plural, and one or more terminals 101 may be distributed in a cell managed by each access network device 102. The terminal 101 may include various handheld devices, vehicle mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem with wireless communication capabilities, as well as various forms of User Equipment (UE), mobile Station (MS), and the like. For convenience of description, in the embodiments of the present application, the above-mentioned devices are collectively referred to as a terminal.

The access network apparatus 102 is a device deployed in an access network to provide a wireless communication function for the terminal 101. The access network device 102 may include various forms of macro base stations, micro base stations, relay stations, access points. In systems employing different radio access technologies, the names of devices that function as access network devices may vary. As communication technology evolves, the name "access network equipment" may change. For convenience of description, in the embodiment of the present application, the above-mentioned apparatuses providing a wireless communication function for the terminal 101 are collectively referred to as access network equipment. The access network device 102 and the terminal 101 may establish a connection over the air interface, so that communication is performed through the connection, including signaling and data interaction. The number of the access network devices 102 may be multiple, and two adjacent access network devices 102 may communicate with each other in a wired or wireless manner. The terminal 101 may switch between different access network devices 102, i.e. establish a connection with different access network devices 102. In the following, the access network device 102 is exemplified as a base station.

The core network device 103 mainly functions to provide user connection, manage users, and complete service bearers, and serves as a bearer network to provide an interface to an external network. The access network device 102 and the core network device 103 may be collectively referred to as a network device, and the network device in the embodiment of the present application may be referred to as an access network device. The core network device 103 and the access network device 102 communicate with each other through some over-the-air technology, and a communication relationship can be established between the terminal 101 and the core network device 103 through the access network device 102.

And monitoring the PDCCH based on the channel estimation in a TTI, and indicating whether the TTI is a TTI only with the PDCCH or a TTI with data scheduling according to the monitoring result of the PDCCH. A PDCCH-only TTI means that no valid DCI is received in the TTI; or DCI is received in the TTI but the DCI indication is not used to schedule PDSCH. The TTI scheduled with data means that there is an effective DCI in the TTI indicating that uplink transmission or downlink reception is required. For example, if it is detected that the TTI is a PDCCH-only TTI, the radio frequency component may be turned off in the remaining symbols, or radio frequency transceiving may be suspended, or a sleep state may be entered to reduce power consumption; if the TTI is detected to be a TTI scheduled with data, the radio frequency component may be turned on all the time, so as to perform uplink transmission or downlink reception.

For example, when determining whether the TTI is a PDCCH-only TTI, channel estimation of a PDCCH is required, and the following is a schematic diagram of performing PDCCH channel estimation when a channel condition is higher than a threshold and when the channel condition is lower than the threshold in the related art. The threshold may be preset in advance, or may be adjusted according to a channel state, where specifically, a case that the channel condition is higher than the threshold means that the terminal performs PDCCH channel estimation only using the reference signal in symbol 0 in each subframe, and a case that the channel condition is lower than the threshold means that the terminal needs the reference signals in multiple symbols to perform PDCCH channel estimation in each subframe.

For example, as shown in fig. 4, in case that the channel condition is higher than the threshold, the terminal performs PDCCH channel estimation using the reference signal in symbol 0 in each subframe, and performs PDCCH channel estimation before symbol 4 after Fast Fourier Transform (FFT), channel estimation, demodulation and decoding. In the case where the channel condition is above the threshold, there is no need to utilize reference signals within other symbols in the subframe. Meanwhile, after the PDCCH channel estimation is finished, under the condition that no effective DCI is found, the terminal can quickly close the radio frequency component after the symbol 4, or suspend the radio frequency transceiving, or enter a dormant state, so that the power consumption and the waste are reduced.

Exemplarily, as shown in fig. 5, in case that the channel condition is lower than the threshold, PDCCH channel estimation needs to be performed by using the reference signals in symbol 0 and symbol 4 at the same time. PDCCH channel estimation is started after the reference signal in symbol 4 is received. Under the condition that the channel condition is lower than the threshold, the PDCCH channel estimation can be completed before the symbol 8 most quickly, and under the condition that no effective DCI is found after the PDCCH channel estimation is completed, the terminal can only close the radio frequency component after the symbol 8 most quickly, or suspend radio frequency transceiving, or enter a sleep state.

For example, comparing the PDCCH channel estimation performed when the channel condition is higher than the threshold and when the channel condition is lower than the threshold, the power loss when the channel condition is higher than the threshold is significantly lower than that when the channel condition is lower than the threshold in the case of no valid DCI.

In order to further optimize the problem of large power loss. The present application presents a solution: PDCCH channel estimation is performed by using at least one reference signal in a previous subframe and a reference signal of a current subframe jointly, so that the PDCCH channel estimation can be started from a symbol 0 as soon as possible in the current subframe.

Fig. 6 is a diagram illustrating a channel estimation method for PDCCH according to an exemplary embodiment of the present application.

The PDCCH occupies at least one symbol and at most four symbols in one subframe, such as symbol 0, symbol 1, symbol 2, and symbol 3 in one subframe. In fig. 6, PDCCH occupies symbol 0 and symbol 1 as an example.

Subframe n +1 performs channel estimation on the PDCCH in subframe n +1 using at least one reference signal in the previous subframe n and the reference signal in subframe n + 1.

Based on fig. 6, when the channel condition is lower than the threshold, the subframe n +1 can start channel estimation at symbol 0, and the radio frequency component can be turned off, or the radio frequency transceiving is suspended, or the sleep state is entered at the fastest speed at symbol 4, where turning off the radio frequency component, or suspending the radio frequency transceiving, or entering the sleep state is the same meaning or the same implementation, and is intended to reduce the power consumption of the radio frequency component in the PDCCH-only scenario.

Fig. 7 is a flowchart of a channel estimation method for PDCCH according to an exemplary embodiment of the present application. The method is executed by a terminal, and comprises the following steps:

step 410: receiving at least one reference signal in a first TTI as a first reference signal;

one TTI may be at least one of a radio frame, a subframe, a slot, a micro-slot, and a symbol group, and hereinafter, one TTI is a subframe and one subframe includes 14 symbols.

At least one reference signal in the first subframe is received as a first reference signal before channel estimation is started in the second subframe.

In some embodiments, the first subframe is a previous subframe of the second subframe, and the first subframe and the second subframe are consecutive.

In some embodiments, the first subframe may also be a subframe preceding the second subframe that is discontinuous from the second subframe.

The first reference signal is a reference signal in the first subframe, and may be a reference signal used for PDCCH channel estimation in the first subframe. The first reference signal may be a reference signal on at least one time domain unit in the first subframe. The time domain granularity of the time domain unit is smaller than the time domain granularity of the TTI, for example, the time domain unit is a symbol.

Step 420: performing channel estimation on the PDCCH in the second TTI by using a first reference signal in the first TTI and a second reference signal in the second TTI;

in some embodiments, each subframe is configured with a reference signal for channel estimation.

Under the condition that the channel condition is higher than the threshold value, the reference signal on the symbol 0 can be used for carrying out channel estimation on the PDCCH in the same TTI; in case the channel condition is below a threshold, more reference signals on symbols are needed in the same TTI for channel estimation on the PDCCH.

There are several possibilities for the way in which the time domain unit is used as a symbol and the first reference signal occupies the symbol in the first subframe, and selecting reference signals on different symbols as the first reference signal may have different effects.

The first method is as follows: and selecting a reference signal on a symbol with the minimum time domain distance from the PDCCH in at least two symbols occupied by the reference signal for channel estimation as a first reference signal in the first TTI.

The second method comprises the following steps: and selecting a reference signal on a symbol closest to a terminal processing end time of the PDCCH among at least two symbols occupied by the reference signal for channel estimation as a first reference signal in the first TTI.

The third method comprises the following steps: and selecting the reference signal on the symbol with the minimum time domain distance from the second TTI in the at least two symbols occupied by the reference signal for channel estimation in the first TTI as the first reference signal.

The method is as follows: and selecting a reference signal on any symbol of at least two symbols occupied by the reference signal for channel estimation in the first TTI as the first reference signal.

Step 430: monitoring the PDCCH based on the channel estimation;

channel estimation is performed on the PDCCH in the second TTI based on using the first reference signal and the second reference signal. And monitoring the PDCCH according to the result of channel estimation.

Step 440: turning off the radio frequency component in at least one symbol located after the second reference signal in the second TTI, in case that the monitoring result of the PDCCH indicates that the second TTI is the PDCCH-only TTI;

illustratively, after the PDCCH channel estimation, demodulation and decoding in the second subframe are completed, the monitoring result of the PDCCH indicates whether the second subframe is a PDCCH-only case. A PDCCH-only TTI means that no valid DCI is received in the TTI; or DCI is received in the TTI but the DCI indication is not used to schedule PDSCH.

If the monitoring result of the PDCCH indicates that the second subframe is not the PDCCH only condition, and the effective DCI exists, the radio frequency component continues to work.

If the monitoring result of the PDCCH indicates that the second subframe is a PDCCH-only condition, and no effective DCI exists, the radio frequency component is turned off in the remaining symbols of the second subframe, or radio frequency transceiving is suspended, or the second subframe enters a dormant state.

For example, in the case that the channel condition is higher than the threshold, the subframe may start channel estimation at symbol 0, start demodulation and decoding after receiving symbol 1, find that there is no valid DCI, configure the front end fastest to turn off the radio frequency component at symbol 4, or suspend radio frequency transceiving, or enter a sleep state.

For example, in the case that the channel condition is lower than the threshold, the subframe needs to start channel estimation after receiving symbol 0 and symbol 4, and no valid DCI is found, and the fastest configuration can turn off the radio frequency component at symbol 7.

In some embodiments, in the case that the channel condition is below a threshold, channel estimation is performed on the PDCCH in the current subframe using at least one reference signal of the previous subframe and symbol 0 of the current subframe. Under the condition that the PDCCH demodulation time sequence is not influenced, the channel estimation performance of the PDCCH is improved, and whether the PDCCH is only exists or not is judged more quickly. If the symbol 0 of the previous subframe and the symbol 0 of the current subframe are used to perform channel estimation on the PDCCH in the current subframe, the symbol 0 of the current subframe may start channel estimation under the condition that the channel condition is lower than the threshold, demodulation and decoding are started after the symbol 1 is received, it is found that there is no valid DCI, and the radio frequency component can be turned off at the symbol 4 by configuring the front end most quickly.

Exemplarily, as shown in fig. 8, the PDCCH in subframe n +1 is channel estimated using the first reference signal in subframe n and the second reference signal in subframe n + 1.

For example, in subframe n, symbol 0 may start channel estimation, demodulation and decoding may start after symbol 1 is received, detection of all candidates in PDCCH may be completed according to timing analysis, and channel estimation may be completed before symbol 4 if no valid DCI is found.

For example, the channel estimation method may be implemented to turn off the rf at symbol 3 or turn off the rf at symbol 2 according to better channel conditions, faster demodulation and decoding.

Illustratively, in case of completing channel estimation of subframe n, the monitoring result of PDCCH indicates whether subframe n is a PDCCH-only subframe.

If the monitoring result of the PDCCH indicates that the subframe n is a subframe of only the PDCCH, the radio frequency component is turned off in at least one symbol after the symbol 0, or radio frequency transceiving is suspended, or a sleep state is entered.

Step 450: receiving at least one reference signal for channel estimation located after the second reference signal in the second TTI.

Receiving at least one reference signal located after the second reference signal in the second TTI and used for channel estimation; wherein the at least one reference signal is used for channel estimation for a PDCCH in a third TTI, which is a TTI subsequent to the second TTI. The second TTI is the current TTI for channel estimation, and the third TTI is the next TTI.

In case that the monitoring result of the PDCCH indicates that the second TTI is the PDCCH-only TTI, a next reference signal for channel estimation, which is located after the second reference signal, is received. And receiving a reference signal which has the smallest time domain distance with a third TTI in the second TTI and is used for channel estimation under the condition that the monitoring result of the PDCCH indicates that the second TTI is a TTI with the PDCCH and the PDSCH at the same time.

For example, in the channel estimation method in the foregoing embodiment, channel estimation is performed on a PDCCH in a current subframe, and a reference signal in the current subframe and a reference signal in a previous subframe need to be used, and after the PDCCH channel estimation in the current subframe is completed, at least one reference signal used for channel estimation needs to be received for PDCCH channel estimation in a next subframe.

Exemplarily, as shown in fig. 8, in case that the subframe n completes channel estimation, at least one reference signal for channel estimation needs to be continuously received, and is used for subframe n +1 for PDCCH channel estimation.

For example, if the first reference signal occupies symbol 4 or symbol 7 or symbol 11 in subframe n, the reference signal on symbol 4 or symbol 7 or symbol 11 in subframe n and the reference signal on symbol 0 in subframe n +1 are used to perform channel estimation on the PDCCH in subframe n + 1. Meanwhile, it is also necessary to receive a reference signal on symbol 4 or symbol 7 or symbol 11 in subframe n +1 for PDCCH channel estimation in subframe n + 2.

If the first reference signal occupies the symbol 0 in the subframe n, the reference signal on the symbol 0 in the subframe n and the reference signal on the symbol 0 in the subframe n +1 are used to perform channel estimation on the PDCCH in the subframe n + 1.

In some embodiments, if only PDCCH is found after subframe n channel estimation is completed, then the radio frequency component may be selected to be turned off, or radio frequency transceiving may be suspended, or a sleep state may be entered, and only the reference signal occupying symbol 0 in subframe n is used for PDCCH channel estimation in subframe n + 1; or continue to receive symbol 4, using the reference signal occupying symbol 4 in subframe n for PDCCH channel estimation in subframe n + 1.

In some embodiments, if it is found that the subframe has both PDCCH and PDSCH after the channel estimation is completed, it is preferable to receive a reference signal which has the smallest time-domain distance from the subframe n +1 and is used for channel estimation, such as the reference signal in symbol 11; alternatively, the reference signal occupying other symbols in the received subframe n, such as the reference signal occupying symbol 4 in the received subframe n, or the reference signal occupying symbol 7 in the received subframe n, may be received.

In summary, in this embodiment, by receiving at least one reference signal in the first TTI as the first reference signal, and performing channel estimation on the PDCCH in the second TTI by using the first reference signal in the first TTI and the second reference signal in the second TTI, it can help the terminal to determine whether the current TTI is the TTI with only the PDCCH faster under the condition of poor channel conditions. Under the condition that whether the current subframe is the subframe only provided with the PDCCH or not is judged, the radio frequency power consumption in the channel is reduced by turning off the radio frequency component, or suspending the radio frequency transceiving, or entering a dormant state.

Aiming at the first mode:

in some embodiments, a reference signal on a symbol having a smallest time-domain distance from a PDCCH among at least two symbols occupied by reference signals for channel estimation is selected as the first reference signal in the first TTI. The PDCCH refers to the PDCCH in the first TTI, and the reference signal refers to the PDCCH in the first TTI.

In some embodiments, assuming that the first reference signal occupies symbol i in the first subframe, the time domain distance between symbol i and the first symbol is less than the terminal processing time of the PDCCH. The first symbol is a symbol occupied by the PDCCH in the first subframe.

For example, the first symbol may be symbol 0 in the first subframe or symbol 1 in the first subframe. This depends on the way in which the reference signal is configured in the first subframe, when the reference signal is configured on symbol 0 in the first subframe, the first symbol is symbol 0; when a reference signal is configured on symbol 1 in the first subframe, the first symbol is symbol 1.

In some embodiments, the terminal processing time of the PDCCH includes: the time that the PDCCH is FFT, channel estimation, demodulation and decoding.

In some embodiments, the PDCCH in the second subframe is channel estimated using a reference signal in a first reference signal in the first subframe (i.e., symbol i in the first subframe) and a reference signal in a second reference signal in the second subframe (i.e., symbol 0 in the second subframe).

In some embodiments, if the symbol i is symbol 0 in the first subframe, the PDCCH in the second subframe is channel estimated using the reference signal in the first subframe (i.e., symbol 0 in the first subframe) and the reference signal in the second subframe (i.e., symbol 0 in the second subframe).

Exemplarily, as shown in fig. 8, the PDCCH occupies two symbols in the channel, and the reference signal occupies symbol 0, symbol 4, symbol 7, and symbol 11 in one subframe. PDCCH channel estimation requires a duration of at least 4 symbols.

In some embodiments, the PDCCH in subframe n +1 is channel estimated using the reference signal in occupied symbol 0 in subframe n and the reference signal in occupied symbol 0 in subframe n + 1.

In some embodiments, if the symbol i is symbol 1 in the first subframe, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe, i.e., the reference signal in symbol 1 in the first subframe, and a second reference signal in the second subframe, i.e., the reference signal in symbol 0 in the second subframe.

Illustratively, as shown in fig. 9, the PDCCH occupies two symbols in the channel, and the reference signal occupies symbol 1 and symbol 8 in one subframe. The PDCCH channel estimation needs at least 4 symbols for the example.

In some embodiments, the PDCCH in subframe n +1 is channel estimated using the reference signal in occupied symbol 1 in subframe n and the reference signal in occupied symbol 0 in subframe n + 1.

If the first TTI is a PDCCH-only TTI, the radio frequency component is turned off from the second symbol in the first TTI, or radio frequency transceiving is suspended, or the first TTI enters a sleep state, and the second symbol is the next symbol after the end of the terminal processing of the PDCCH in the first TTI.

In some embodiments, the radio frequency component is turned off, or radio frequency transceiving is suspended, or a sleep state is entered from a next symbol after a terminal processing time elapses after the first reference signal in the first subframe (i.e., symbol i in the first subframe). If the symbol i is symbol 0 in the first subframe, the radio frequency component is turned off from the next symbol after the terminal processing time elapses after the first reference signal (i.e., symbol 0 in the first subframe) in the first subframe, or the radio frequency transceiving is suspended, or the sleep state is entered. If the symbol i is symbol 1 in the first subframe, the radio frequency component is turned off from the next symbol after the terminal processing time elapses after the first reference signal (i.e., symbol 1 in the first subframe) in the first subframe, or the radio frequency transceiving is suspended, or the sleep state is entered.

For example, as shown in fig. 8 and 9, when the first reference signal (i.e., symbol i in the first subframe) in the first subframe is symbol 0 or symbol 1, and the next symbol after the terminal processing time after the first reference signal is symbol 4, the radio frequency component is turned off from symbol 4, or the radio frequency transceiving is suspended, or the sleep state is entered.

In summary, in this embodiment, the reference signal on the symbol with the smallest time-domain distance from the PDCCH is selected as the first reference signal, and the PDCCH in the second subframe is subjected to channel estimation, so that the terminal does not need to receive reference signals on other symbols except the first reference signal, and the radio frequency component can be turned off after the terminal completes processing on the PDCCH, thereby reducing the radio frequency power loss of the channel to the greatest extent.

In the second embodiment:

in some embodiments, a reference signal on a symbol closest to a terminal processing end time of a PDCCH among at least two symbols occupied by the reference signal for channel estimation is selected as the first reference signal in the first TTI.

In some embodiments, it is assumed that the first reference signal occupies a symbol j in the first subframe, the symbol j being a symbol closest to a terminal processing end time of the PDCCH in the first subframe.

In some embodiments, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., the reference signal in symbol j in the first subframe) and a second reference signal in the second subframe (i.e., the reference signal in symbol 0 in the second subframe).

In some embodiments, if the symbol j is symbol 4 in the first subframe, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., a reference signal on symbol 4 in the first subframe) and a second reference signal in the second subframe (i.e., a reference signal on symbol 0 in the second subframe).

For example, as shown in fig. 10, a time duration that PDCCH channel estimation requires at least 4 symbols is taken as an example for explanation. And under the condition that the PDCCH channel estimation is finished in the subframe n, continuously receiving the reference signal on the symbol 4 in the subframe n, and performing channel estimation on the PDCCH in the subframe n +1 by using the reference signal on the symbol 4 in the subframe n and the reference signal on the symbol 0 in the subframe n + 1.

If the first TTI is a TTI only with a PDCCH, the radio frequency component is closed from a third symbol in the first subframe, or radio frequency transceiving is suspended, or the first subframe enters a dormant state; the third symbol is symbol 5, or the third symbol is the next symbol after the terminal processing end time of the PDCCH. If the symbol 5 is after the next symbol after the terminal processing end time of the PDCCH, the third symbol is symbol 5; if the symbol 5 is a symbol next to the terminal processing end time of the PDCCH, the third symbol is a symbol next to the terminal processing end time of the PDCCH.

For example, as shown in fig. 10, when the terminal processing end time of the PDCCH is symbol 4, the radio frequency component is turned off from symbol 5, or radio frequency transceiving is suspended, or a sleep state is entered.

In summary, in this embodiment, by selecting the reference signal on the symbol closest to the end time of the terminal processing of the PDCCH as the first reference signal and performing channel estimation on the PDCCH in the second subframe, the reference signal on the symbol 4 can be continuously received without turning off the radio frequency component, and the radio frequency component is turned off from the symbol 5, so that the loss when the channel radio frequency is repeatedly turned on and off can be effectively reduced.

The third method is as follows:

in some embodiments, a reference signal on a symbol having a smallest time-domain distance from the second subframe among at least two symbols occupied by the reference signal for channel estimation is selected as the first reference signal in the first TTI.

In some embodiments, it is assumed that the first reference signal occupies a symbol k in the first subframe, the symbol k being a symbol in the first subframe having a smallest time domain distance from the second subframe.

In some embodiments, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., the reference signal in symbol k in the first subframe) and a second reference signal in the second subframe (i.e., the reference signal in symbol 0 in the second subframe).

In some embodiments, if the symbol k is the symbol 11 in the first subframe, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., the reference signal on the symbol 11 in the first subframe) and a second reference signal in the second subframe (i.e., the reference signal on the symbol 0 in the second subframe).

For example, as shown in fig. 11, a time duration that PDCCH channel estimation requires at least 4 symbols is taken as an example for explanation. And under the condition that the PDCCH channel estimation is finished in the subframe n, continuously receiving the reference signal on the symbol 11 in the subframe n, and performing channel estimation on the PDCCH in the subframe n +1 by using the reference signal on the symbol 11 in the subframe n and the reference signal on the symbol 0 in the subframe n + 1.

For example, if the symbol k is the symbol 8 in the first subframe, the PDCCH in the second subframe is channel-estimated using the first reference signal in the first subframe (i.e., the reference signal on the symbol 8 in the first subframe) and the second reference signal in the second subframe (i.e., the reference signal on the symbol 0 in the second subframe).

For example, as shown in fig. 12, a time duration that PDCCH channel estimation requires at least 4 symbols is taken as an example for explanation. And under the condition that the PDCCH channel estimation is finished in the subframe n, continuously receiving the reference signal on the symbol 8 in the subframe n, and performing channel estimation on the PDCCH in the subframe n +1 by using the reference signal on the symbol 8 in the subframe n and the reference signal on the symbol 0 in the subframe n + 1.

If the first TTI is a PDCCH-only TTI, the radio frequency component is turned off from the second symbol in the first TTI, or radio frequency transceiving is suspended, or the first TTI enters a sleep state, and the second symbol is the next symbol after the terminal processing end time of the PDCCH in the first TTI.

And turning on the radio frequency component at the symbol occupied by the first reference signal to receive the first reference signal, and continuing to turn off the radio frequency component at the next symbol.

For example, as shown in fig. 11, the terminal turns off the rf component at symbol 4, or suspends rf transceiving, or enters a sleep state when the time required for PDCCH processing is up to symbol 3. The first reference signal occupies the reference signal on the symbol 11, and then the rf component is turned on at the symbol 11 to receive the first reference signal, and turned off after the symbol 12. As shown in fig. 12, the terminal turns off the rf component at symbol 4, or suspends rf transceiving, or enters a sleep state when the time required for PDCCH processing is up to symbol 3. The first reference signal occupies the reference signal on the symbol 8, and then the rf component is turned on at the symbol 8 to receive the first reference signal, and turned off after the symbol 9.

In summary, in this embodiment, a reference signal on a symbol with the smallest time domain distance from the second subframe in the first subframe is selected as the first reference signal, channel estimation is performed on the PDCCH in the second subframe, and by using the reference signal on the symbol with the smallest time domain distance from the second subframe in the first subframe, the received signal is more stable, and the result of PDCCH channel estimation is also more stable.

Aiming at the fourth mode:

in some embodiments, a reference signal on any of at least two symbols occupied by a reference signal for channel estimation in the first TTI is selected as the first reference signal.

In some embodiments, it is assumed that the first reference signal occupies a symbol t in the first subframe, which is an arbitrary symbol in the first subframe.

In some embodiments, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., the reference signal in symbol t in the first subframe) and a second reference signal in the second subframe (i.e., the reference signal in symbol 0 in the second subframe).

In some embodiments, if the symbol t is symbol 7 in the first subframe, the PDCCH in the second subframe is channel estimated using a first reference signal in the first subframe (i.e., a reference signal on symbol 7 in the first subframe) and a second reference signal in the second subframe (i.e., a reference signal on symbol 0 in the second subframe).

Illustratively, as shown in fig. 13, in the case that the PDCCH channel estimation is completed in the subframe n, the reference signal on the symbol 7 in the subframe n continues to be received, and the PDCCH in the subframe n +1 is subjected to channel estimation by using the reference signal on the symbol 7 in the subframe n and the reference signal on the symbol 0 in the subframe n + 1.

For example, as shown in fig. 13, the terminal turns off the rf component at symbol 4, or suspends rf transceiving, or enters a sleep state when the time required for PDCCH processing is up to symbol 3. The first reference signal occupies the reference signal on symbol 7, and then the rf component is turned on at symbol 7 to receive the first reference signal, and turned off after symbol 8.

In summary, in this embodiment, a reference signal on any symbol in a first subframe is selected as a first reference signal, and channel estimation is performed on a PDCCH in a second subframe, which can help a terminal to determine whether a current TTI is a TTI only with the PDCCH faster under a poor channel condition, so that channel estimation performance of the PDCCH is effectively improved.

It should be noted that, the above embodiments may be combined or separated by a person skilled in the art, and the present application is not limited thereto. For example, when the power of the terminal is greater than the threshold, a third method with better channel estimation performance is selected; when the power of the terminal is less than the threshold, a first mode with better power saving performance is selected, and so on is not described again.

Fig. 14 is a block diagram of a channel estimation apparatus of a PDCCH according to another exemplary embodiment of the present application. The device comprises:

a channel estimation module 1410, configured to perform channel estimation on a PDCCH in a second TTI by using a first reference signal in the first TTI and a second reference signal in the second TTI; wherein the first TTI is a TTI preceding the second TTI.

The device also includes:

a monitoring module 1420 configured to monitor the PDCCH based on the channel estimation.

And a radio frequency management module 1430 configured to, in a case where the monitoring result of the PDCCH indicates that the second TTI is a PDCCH-only TTI, turn off the radio frequency component in at least one symbol located after the second reference signal in the second TTI.

The second reference signal is a reference signal for channel estimation that occurs earliest in the second TTI.

The device also includes:

a receiving module 1440 for receiving at least one reference signal for channel estimation located after the second reference signal in the second TTI; wherein the at least one reference signal is used for channel estimation for the PDCCH in a third TTI, which is a TTI subsequent to the second TTI.

The receiving module 1440 is further configured to receive a next reference signal for channel estimation, which is located after the second reference signal, if the monitoring result of the PDCCH indicates that the second TTI is the PDCCH-only TTI.

The receiving module 1440 is further configured to receive, in a case that the monitoring result of the PDCCH indicates that the second TTI is a TTI in which the PDCCH and the PDSCH are simultaneously present, a reference signal which is used for channel estimation and has a smallest time domain distance from a third TTI in the second TTI.

In some embodiments, a time-domain distance between a symbol occupied by a first reference signal in a first TTI and the first symbol is less than a terminal processing time of the PDCCH; wherein the first symbol is a symbol occupied by the PDCCH in the first TTI. The symbol occupied by the first reference signal in the first TTI is symbol 0 or symbol 1.

A radio frequency management module 1430, further configured to turn off the radio frequency component starting from the second symbol in the first TTI; the second symbol is a next symbol after the terminal processing end time of the PDCCH.

In some embodiments, the symbol occupied by the first reference signal in the first TTI is the symbol closest to the terminal processing end time of the PDCCH. The symbol occupied by the first reference signal in the first TTI is symbol 4.

A radio frequency management module 1430, further configured to turn off the radio frequency component starting from the third symbol in the first TTI; the third symbol is symbol 5, or the third symbol is the next symbol after the terminal processing end time of the PDCCH. The first TTI is a PDCCH-only subframe.

In some embodiments, the symbol occupied by the first reference signal in the first TTI is the symbol in the first TTI that is the smallest in time-domain distance from the second TTI. The first TTI is a TTI with both PDCCH and PDSCH.

The symbol occupied by the first reference signal in the first TTI is symbol 8 or symbol 11.

The rf management module 1430 is further configured to turn off the rf components starting from the second symbol in the first TTI. The rf management module 1430 is further configured to turn on the rf components to receive the first reference signal at symbol 8 and turn off the rf components after symbol 9; or, turning on the radio frequency component at symbol 11 to receive the first reference signal, and turning off the radio frequency component after symbol 12; the second symbol is a symbol next to a terminal processing end time of the PDCCH.

The channel estimation module 1410 may be implemented by a processor in the terminal device, where the processor loads and executes at least one instruction, at least one program, a set of codes, or a set of instructions stored in a memory to make the determination.

The monitoring module 1420 may be implemented by a processor in the terminal device, where the processor loads and executes at least one instruction, at least one program, a set of codes, or a set of instructions stored in the memory to determine.

The rf management module 1430 may be implemented by a processor in the terminal device, where the processor loads and executes at least one instruction, at least one program, a set of codes, or a set of instructions stored in a memory to determine.

The receiving module 1440 may be implemented by a transceiver in the terminal device, which is connected to the processor and controls one or more antennas to transmit and/or receive radio signals.

Fig. 15 is a block diagram of a terminal 1500 provided in another exemplary embodiment of the present application. Illustratively, the terminal 1500 includes a processor 1510, a power management module 1511, a battery 1512, a display 1513, a keypad 1514, a Subscriber Identity Module (SIM) card 1515, memory 1520, a transceiver 1530, and one or more antennas 1531.

The processor 1510 may be implemented to implement the functions, procedures, and/or methods set forth herein. The processor 1510 may be configured to control one or more other components of the terminal 1500 to implement the functions, processes, and/or methods set forth herein. Layers of the radio interface protocol may be implemented in the processor 1510. The processor 1510 may include an Application Specific Integrated Circuit (ASIC), other chipsets, logic circuitry, and/or data processing devices. Processor 1510 may be an Application Processor (AP). Processor 1510 may include at least one of a Digital Signal Processor (DSP), a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a modem (modulator and demodulator).

The memory 1520 is operatively coupled with the processor 1510 and stores various information to operate the processor 1510. The Memory 1520 may include Read-Only Memory (ROM), random Access Memory (RAM), flash Memory, memory cards, storage media, and/or other storage devices. The memory 1520 may be implemented within the processor 1510 or external to the processor 1510, in which case it can be communicatively coupled to the processor 1510 via various means as is known in the art.

The transceiver 1530 is operatively coupled to the processor 1510 and transmits and/or receives radio signals. The transceiver 1530 includes a transmitter and a receiver. The transceiver 1530 may include a baseband circuit to process radio frequency signals. The transceiver 1530 controls one or more antennas 1531 to transmit and/or receive radio signals.

The processor 1510 is configured to implement the functions of the channel estimation module, the monitoring module, and the rf management module, the memory 1520 is configured to provide at least one instruction, at least one program, code set, or instruction set for the processor to implement the functions of the modules, and the transceiver 1530 is configured to implement the functions of the receiving module.

The present application further provides a chip, where the chip includes a programmable logic circuit and/or a program instruction, and when a communication device equipped with the chip runs, the chip is configured to implement the channel estimation method for a downlink control channel provided in the foregoing method embodiments.

The present application also provides a computer device, comprising: the apparatus includes a processor and a memory, where the storage medium stores at least one instruction, at least one program, a set of codes, or a set of instructions, and the at least one instruction, the at least one program, the set of codes, or the set of instructions is loaded and executed by the processor to implement the method for channel estimation of a downlink control channel provided in the above method embodiments.

The present application further provides a computer-readable storage medium, where at least one instruction, at least one program, a code set, or a set of instructions is stored in the storage medium, and the at least one instruction, the at least one program, the code set, or the set of instructions is loaded and executed by a processor to implement the method for channel estimation of a downlink control channel provided in the foregoing method embodiments.

The present application also provides a computer program product comprising at least one program, said at least one program being stored in a computer readable storage medium; a processor of the communication device reads the at least one program from the computer-readable storage medium, and the processor executes the at least one program, so that the communication device executes the channel estimation method for the downlink control channel provided in the foregoing method embodiments.

The present application also provides a computer program comprising at least one program segment, said at least one program segment being stored on a computer readable storage medium; the processor of the communication device reads the at least one program from the computer-readable storage medium, and executes the at least one program, so that the communication device executes the channel estimation method for the downlink control channel provided in the above method embodiments.

It should be understood that reference herein to "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

The present application is intended to cover various modifications, equivalent arrangements, improvements, etc. without departing from the spirit and scope of the present application.

Claims

1. A method for channel estimation of a downlink control channel, the method comprising:

performing channel estimation on a downlink control channel (PDCCH) in a second Transmission Time Interval (TTI) by using a first reference signal in the TTI and a second reference signal in the second TTI;

wherein the first TTI is a TTI preceding the second TTI.

2. The method of claim 1, further comprising:

monitoring the PDCCH based on the channel estimate;

turning off a radio frequency component in at least one symbol following the second reference signal in the second TTI, in case the monitoring result of the PDCCH indicates that the second TTI is a PDCCH-only TTI.

3. The method of claim 1, wherein the second reference signal is a reference signal for channel estimation that occurs earliest in the second TTI.

4. The method of claim 1, further comprising:

receiving at least one reference signal located after the second reference signal in the second TTI and used for channel estimation;

wherein the at least one reference signal is used for channel estimation for PDCCH in a third TTI, which is a TTI following the second TTI.

5. The method of claim 4, wherein the receiving at least one reference signal for channel estimation located after the second reference signal in the second TTI comprises:

receiving a next reference signal for channel estimation located after the second reference signal, in case the monitoring result of the PDCCH indicates that the second TTI is a PDCCH-only TTI.

6. The method of claim 4, wherein the receiving at least one reference signal for channel estimation located after the second reference signal in the second TTI comprises:

and receiving a reference signal which has the minimum time domain distance from the third TTI and is used for channel estimation in the second TTI under the condition that the monitoring result of the PDCCH indicates that the second TTI has the PDCCH and the PDSCH at the same time.

7. The method according to any of claims 1 to 6, wherein the time-domain distance between the symbol occupied by the first reference signal in the first TTI and the first symbol is less than the terminal processing time of the PDCCH;

wherein the first symbol is a symbol occupied by the PDCCH in the first TTI.

8. The method of claim 7, wherein the symbol occupied by the first reference signal in the first TTI is symbol 0 or symbol 1.

9. The method of claim 8, further comprising:

turning off the radio frequency component starting from a second symbol in the first TTI;

wherein the second symbol is a next symbol after a terminal processing end time of the PDCCH.

10. The method of any one of claims 1 to 6, wherein the symbols occupied by the first reference signal in the first TTI are symbols closest to a terminal processing end time of the PDCCH, among at least two symbols occupied by reference signals used for channel estimation.

11. The method of claim 10, wherein the symbol occupied by the first reference signal in the first TTI is symbol 4.

12. The method of claim 11, further comprising:

turning off the radio frequency component starting from a third symbol in the first TTI;

wherein the third symbol is symbol 5, or the third symbol is a next symbol after a terminal processing end time of the PDCCH.

13. The method of any of claims 7 to 12, wherein the first TTI is a PDCCH-only subframe.

14. The method of any of claims 1 to 6, wherein the symbol occupied by the first reference signal in the first TTI is a symbol with a smallest time domain distance from a second TTI in at least two symbols occupied by the reference signal for channel estimation.

15. The method of claim 14, wherein the first TTI is a TTI in which a PDCCH and a PDSCH are both present.

16. The method of claim 14, wherein the symbol occupied by the first reference signal in the first TTI is symbol 8 or symbol 11.

17. The method of claim 16, further comprising:

turning on the radio frequency component at the symbol 8 to receive the first reference signal, and turning off the radio frequency component after the symbol 9; or, turning on the radio frequency component at the symbol 11 to receive the first reference signal, and turning off the radio frequency component after the symbol 12;

18. A channel estimation device for a downlink control channel, the device comprising:

a channel estimation module, configured to perform channel estimation on a downlink control channel PDCCH in a second transmission time interval TTI by using a first reference signal in the first TTI and a second reference signal in the second TTI;

wherein the first TTI is a TTI preceding the second TTI.

19. The apparatus of claim 18, further comprising:

a monitoring module to monitor the PDCCH based on the channel estimate;

a radio frequency management module, configured to turn off a radio frequency component in at least one symbol following the second reference signal in the second TTI, if the monitoring result of the PDCCH indicates that the second TTI is a PDCCH-only TTI.

20. The apparatus of claim 18, wherein the second reference signal is a reference signal for channel estimation that occurs earliest in the second TTI.

21. The apparatus of claim 18, further comprising:

a receiving module for receiving at least one reference signal for channel estimation located after the second reference signal in the second TTI;

wherein the at least one reference signal is used for channel estimation for PDCCH in a third TTI, which is a TTI subsequent to the second TTI.

22. The apparatus of claim 21, wherein the receiving module is further configured to receive a next reference signal for channel estimation after the second reference signal if the monitoring result of the PDCCH indicates that the second TTI is a PDCCH-only TTI.

23. The apparatus of claim 21, wherein the receiving module is further configured to receive a reference signal used for channel estimation and having a smallest time-domain distance from the third TTI in the second TTI if the monitoring result of the PDCCH indicates that the second TTI is a TTI in which a PDCCH and a PDSCH (physical downlink shared channel) are simultaneously present.

24. The apparatus of any of claims 18 to 23, wherein a time-domain distance between a symbol occupied by the first reference signal in the first TTI and the first symbol is less than a terminal processing time of the PDCCH;

wherein the first symbol is a symbol occupied by the PDCCH in the first TTI.

25. The apparatus of claim 24, wherein the symbol occupied by the first reference signal in the first TTI is symbol 0 or symbol 1.

26. The apparatus of claim 25, wherein the radio frequency management module is further configured to turn off the radio frequency component starting from a second symbol in the first TTI;

27. The apparatus of any one of claims 18 to 23, wherein the symbol occupied by the first reference signal in the first TTI is a symbol closest to a terminal processing end time of the PDCCH, among at least two symbols occupied by reference signals for channel estimation.

28. The apparatus of claim 27, wherein the symbol occupied by the first reference signal in the first TTI is symbol 4.

29. The apparatus of claim 28, wherein the radio frequency management module is further configured to turn off the radio frequency component in the first TTI starting from a third symbol;

30. The apparatus of any one of claims 24 to 29, wherein the first TTI is a PDCCH-only subframe.

31. The apparatus of any one of claims 18 to 23, wherein the symbol occupied by the first reference signal in the first TTI is a symbol with a smallest time domain distance from a second TTI among at least two symbols occupied by reference signals for channel estimation.

32. The apparatus of claim 31, wherein the first TTI is a TTI in which a PDCCH and a PDSCH are present simultaneously.

33. The apparatus of claim 31, wherein the symbol occupied by the first reference signal in the first TTI is symbol 8 or symbol 11.

34. The apparatus of claim 33, wherein the rf management module is further configured to turn off the rf component in the first TTI starting from a second symbol;

the radio frequency management module is further configured to turn on the radio frequency component at the symbol 8 to receive the first reference signal, and turn off the radio frequency component after the symbol 9; or, turning on the radio frequency component at the symbol 11 to receive the first reference signal, and turning off the radio frequency component after the symbol 12;

35. A chip comprising programmable logic circuits and/or program instructions, wherein a communication device in which the chip is installed is operative to implement the channel estimation method for a downlink control channel according to any one of claims 1 to 17.

36. A computer device, characterized in that the computer device comprises: a processor and a memory, the memory having stored therein at least one instruction, at least one program, a set of codes, or a set of instructions, the at least one instruction, the at least one program, the set of codes, or the set of instructions being loaded and executed by the processor to implement the method for channel estimation for a downlink control channel according to any one of claims 1 to 17.

37. A computer-readable storage medium, wherein at least one instruction, at least one program, a set of codes, or a set of instructions is stored in the storage medium, and the at least one instruction, the at least one program, the set of codes, or the set of instructions is loaded and executed by a processor to implement the method for channel estimation of downlink control channel according to any one of claims 1 to 17.

38. A computer program product, characterized in that the computer program product comprises at least one program, which is stored in a computer-readable storage medium; a processor of a communication device reads the at least one program from the computer-readable storage medium, and executes the at least one program to cause the communication device to perform the channel estimation method for the downlink control channel according to any one of claims 1 to 17.

39. A computer program, characterized in that the computer program comprises at least one program segment, which is stored in a computer-readable storage medium; a processor of a communication device reads the at least one program from the computer-readable storage medium, and executes the at least one program to cause the communication device to perform the channel estimation method for the downlink control channel according to any one of claims 1 to 17.