WO2024049050A1

WO2024049050A1 - Reception device and method for receiving mimo-ofdm signal

Info

Publication number: WO2024049050A1
Application number: PCT/KR2023/011945
Authority: WO
Inventors: 전요셉; 하성영; 양경철
Original assignee: 삼성전자주식회사; 포항공과대학교 산학협력단
Priority date: 2022-08-29
Filing date: 2023-08-11
Publication date: 2024-03-07

Abstract

A reception device is disclosed. One embodiment may comprise: determining a channel estimation sequence of OFDM symbols in which data symbols are transmitted; determining a channel prediction value for a first OFDM symbol in a first channel estimation sequence among the OFDM symbols using at least one of reference signal-based channel estimation information and channel estimation information determined before the first channel estimation sequence; detecting first data symbols from a received signal at the first OFDM symbol using the determined channel prediction value; determining a first channel estimate value for the first OFDM symbol on the basis of the detected first data symbols; determining a second channel estimate value for the first OFDM symbol on the basis of the determined first channel estimate value and the determined channel prediction value; determining whether the first channel estimation sequence is the last channel estimation sequence; and if the first channel estimation sequence is not the last channel estimation sequence, performing channel estimation for a second OFDM symbol in the next channel estimation sequence.

Description

Receiving device and method for receiving MIMO-OFDM signals

One embodiment relates to a receiving device for receiving a MIMO-OFDM signal and a method of operating the same.

Multiple-Input Multiple-Output (MIMO) communication system is a technology that can increase the transmission speed and communication stability of wireless communication and can be used as a core technology in various wireless communication systems. To ensure high communication stability in a MIMO communication system, the receiver must accurately know MIMO channel information.

A method for a receiver to acquire MIMO channel information includes an RS-based channel estimation method using a reference signal (RS). In the RS-based channel estimation method, the transmitter can use some of the radio resources to transmit an RS that the receiver already knows to the receiver, and the receiver can estimate the MIMO channel using the RS received from the transmitter. In general, the accuracy of MIMO channel information that can be obtained through an RS-based channel estimation method can be improved as the amount of RS increases.

In the case of a MIMO-OFDM communication system utilizing Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA), it includes multiple subcarriers and OFDM symbols. Accurate MIMO channel estimation must be made for a resource block (RB).

In the existing MIMO-OFDM communication system, RS may be limitedly allocated to some subcarriers and OFDM symbols within the RB. Because of this, when the RS-based channel estimation method is applied to the existing MIMO-OFDM communication system, there may be a limit to the accuracy of channel information that the receiver can obtain. In addition, when the channel changes over time due to changes in the wireless environment, different channels may be formed for each OFDM symbol in the RB, which may reduce the channel estimation accuracy of the existing RS-based channel estimation method.

One embodiment may provide a receiving device that can achieve high accuracy of channel estimation when the channel changes over time by utilizing limited RS.

A reception method of a reception device according to an embodiment includes determining a channel estimation order of OFDM symbols through which data symbols are transmitted; determining a channel estimate for a first OFDM symbol in a first channel estimation order among the OFDM symbols using at least one of RS-based channel estimation information and channel estimation information determined before the first channel estimation order; detecting first data symbols from a received signal in the first OFDM symbol using the determined channel prediction value; determining a first channel estimate for the first OFDM symbol based on the detected first data symbols; determining a second channel estimate for the first OFDM symbol based on the determined first channel estimate and the determined channel estimate; determining whether the first channel estimation order is the last channel estimation order; and when the first channel estimation order is not the last channel estimation order, performing channel estimation on a second OFDM symbol in the next channel estimation order.

A receiving device according to an embodiment includes a plurality of antennas; an RF communication circuit that receives an RF signal from a transmitting device through the antennas and converts the received RF signal into a baseband signal; And it may include a processor connected to the RF communication circuit. The processor may determine a channel estimation order of OFDM symbols through which data symbols are transmitted. The processor may determine a channel estimate value for a first OFDM symbol in a first channel estimation order among the OFDM symbols using at least one of RS-based channel estimation information or channel estimation information determined before the first channel estimation order. there is. The processor may obtain a received signal in the first OFDM symbol based on the converted baseband signal. The processor may detect first data symbols from the obtained received signal using the determined channel prediction value. The processor may determine a first channel estimate for the first OFDM symbol based on the detected first data symbols. The processor may determine a second channel estimate for the first OFDM symbol based on the determined first channel estimate and the determined channel estimate. The processor may determine whether the first channel estimation order is the last channel estimation order. If the first channel estimation order is not the last channel estimation order, the processor may perform channel estimation on the second OFDM symbol in the next channel estimation order.

In one embodiment, detected data symbols can be used for channel estimation and symbol detection can be performed sequentially according to the position of the reference signal, thereby improving reception performance and achieving a low frame error rate.

1 is a configuration diagram of a multiple input/output antenna communication system according to an embodiment.

Figure 2 is a block diagram illustrating an example of the configuration of a base station in a wireless communication system according to an embodiment.

FIG. 3 is a block diagram illustrating an example of the configuration of a UE in a wireless communication system according to an embodiment.

Figure 4 is a diagram explaining a demodulation block according to an embodiment.

FIG. 5 is a diagram illustrating an example of a receiving device according to an embodiment.

FIG. 6 is a diagram illustrating an example of a channel estimation order according to an embodiment.

Figure 7 is a flowchart explaining a receiving method of a receiving device according to an embodiment.

Figures 8 to 10 are diagrams illustrating the frame error rate versus signal-to-noise ratio that various reception methods can achieve.

Figure 11 is a block diagram illustrating an example of the configuration of a receiving device according to an embodiment.

Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be changed and implemented in various forms. Accordingly, the actual implementation form is not limited to the specific disclosed embodiments, and the scope of the present specification includes changes, equivalents, or substitutes included in the technical idea described in the embodiments.

Terms such as first or second may be used to describe various components, but these terms should be interpreted only for the purpose of distinguishing one component from another component. For example, a first component may be named a second component, and similarly, the second component may also be named a first component.

When a component is referred to as being “connected” to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may exist in between.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of the described features, numbers, steps, operations, components, parts, or combinations thereof, and are intended to indicate the presence of one or more other features or numbers, It should be understood that this does not exclude in advance the possibility of the presence or addition of steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art. Terms as defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings they have in the context of the related technology, and unless clearly defined in this specification, should not be interpreted in an idealized or overly formal sense. No.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the description with reference to the accompanying drawings, identical components will be assigned the same reference numerals regardless of the reference numerals, and overlapping descriptions thereof will be omitted.

Figure 1 illustrates a receiving device 110 and a transmitting device 120 as some of the nodes that use a wireless channel in a wireless communication system. Although Figure 1 shows only one receiving device 110 and one transmitting device 120, a wireless communication system may include multiple receiving devices and multiple transmitting devices.

The receiving device 110 may correspond to a base station and the transmitting device 120 may correspond to a user equipment (UE). Alternatively, the receiving device 110 may correspond to a UE and the transmitting device 120 may correspond to a base station.

A base station may be a network infrastructure that provides wireless access to UEs. A base station may have coverage defined as a certain geographic area based on the distance over which it can transmit signals. The base station is “access point (AP)”, “eNB (eNodeB)”, “5G node (5th generation node)”, “gNB (next generation nodeB)”, “wireless point ( It may be referred to as “wireless point”, “transmission/reception point (TRP)” or other terms with equivalent technical meaning.

Each of the UEs is a device used by a user and can communicate with a base station through a wireless channel.

At least one of the UEs may operate without user involvement. At least one of the UEs is a device that performs machine type communication (MTC) and may not be carried by the user. Each of the UEs is a “terminal”, “mobile station”, “subscriber station”, “remote terminal”, “wireless terminal”, or “user device”. It may be referred to as “user device” or another term with equivalent technical meaning.

A base station can receive uplink (UL) signals from UEs through a plurality of antennas. The base station may transmit downlink (DL) signals to UEs through a plurality of antennas.

In order to efficiently use resources within the wireless communication system and reduce interference between transmitted signals, the wireless communication system uses orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA). ) can be used.

The receiving device 110 is

It may include two receiving antenna ports, and the transmitting device 120 is

It may include two transmit antenna ports.

The transmitting device 120

of the OFDM symbol

The data symbol transmitted through the th subcarrier can be expressed as Equation 1 below.

[Equation 1]

In equation 1 above,

Is It may indicate a symbol constellation that the transmitting device 120 and the receiving device 110 share in advance.

The transmitting device 120 may transmit a radio frequency (RF) signal to the receiving device 110 through a plurality of antennas. The receiving device 110 may receive an RF signal from the transmitting device 120 through a plurality of antennas. The receiving device 110 may convert the received RF signal into a baseband signal and obtain a received signal by processing the baseband signal. Processing of the baseband signal may include, for example, at least one of cyclic prefix (CP) removal, serial/parallel conversion, or fast Fourier transform (FFT) (or discrete Fourier transform (DFT)), or parallel/serial conversion. It may include a combination of .

of the OFDM symbol

Received signal on the th subcarrier (

) can be expressed as Equation 2 below. In other words, the receiving device 110

of the OFDM symbol

Received signal observed through the second subcarrier (

) can be expressed as Equation 2 below.

[Equation 2]

In Equation 2 above,

Is

of the OFDM symbol

It can represent the frequency domain channel matrix formed for the th subcarrier,

Is

of the OFDM symbol

It can represent a noise signal observed on the th subcarrier.

Figure 2 is a block diagram illustrating the configuration of a base station in a wireless communication system according to an embodiment.

Terms such as “unit” and “unit” used hereinafter refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

The base station 200 may include a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a control unit 240. The base station 200 can communicate with UEs.

The wireless communication unit 210 may perform operations for transmitting and receiving signals through a wireless channel. The wireless communication unit 210 may perform a conversion operation between a baseband signal and a bit string according to the physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 may generate complex symbols by encoding and modulating the transmission bit string. When receiving data, the wireless communication unit 210 can restore the received bit stream by demodulating and decoding the baseband signal.

The wireless communication unit 210 may up convert a baseband signal into an RF signal and transmit it through antennas. The wireless communication unit 210 may down convert RF band signals received through antennas into baseband signals. To this end, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. The wireless communication unit 210 may include multiple transmission and reception paths.

The wireless communication unit 210 may include a communication module (or packaged module) including at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit (e.g., a radio frequency integrated circuit (RFIC)), and the analog unit may be used for operating power, operating frequency, etc. Accordingly, it may be composed of multiple sub-units. A digital unit may be implemented with at least one processor (eg, digital signal processor (DSP)).

The wireless communication unit 210 can transmit and receive signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a “transmitter,” “receiver,” or “transceiver.” Additionally, in the following description, transmission and reception performed through a wireless channel may be used to mean that the processing as described above is performed by the wireless communication unit 210.

The backhaul communication unit 220 may provide an interface for communicating with other nodes in the network. For example, the backhaul communication unit 220 can convert a bit string transmitted from the base station 200 to another node (e.g., another access node, another base station, upper node, core network, etc.) into a physical signal, and the other node The physical signal received from can be converted into a bit string.

The storage unit 230 may store data such as basic programs, application programs, and setting information for operation of the base station 200. The storage unit 230 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. The storage unit 230 may provide stored data upon request from the control unit 240.

The control unit 240 can control the overall operations of the base station 200. For example, the control unit 240 may transmit and receive signals through the wireless communication unit 210 or the backhaul communication unit 220. The control unit 240 can write data to and read data from the storage unit 230. The control unit 240 can perform protocol stack functions required by communication standards. In another example, the protocol stack may be included in the wireless communication unit 210. The control unit 240 may include at least one processor as a hardware component for performing the above functions.

Figure 3 is a block diagram explaining the configuration of a UE in a wireless communication system according to an embodiment.

Referring to FIG. 3, the UE 300 may include a communication unit 310, a storage unit 320, and a control unit 330.

The communication unit 310 may perform operations for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 may perform a conversion function between a baseband signal and a bit string according to the physical layer standard of the system. For example, when transmitting data, the communication unit 310 may generate complex symbols by encoding and modulating the transmission bit string. When receiving data, the communication unit 310 can restore the received bit stream by demodulating and decoding the baseband signal.

The communication unit 310 may up-convert the baseband signal into an RF band signal and transmit it to the base station 200 through one or more antennas. The communication unit 310 may down-convert an RF band signal received through one or more antennas into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

The communication unit 310 may include multiple transmission and reception paths. The communication unit 310 may include at least one antenna array composed of multiple antenna elements. For example, an antenna element may be referred to as an antenna, and an antenna array composed of multiple antenna elements may be understood as including multiple antennas.

In terms of hardware, the communication unit 310 may be composed of a digital circuit and an analog circuit (eg, RFIC). For example, digital circuits and analog circuits can be implemented in one package. The communication unit 310 may include multiple RF chains. The communication unit 310 may perform beamforming.

The communication unit 310 can transmit and receive signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a “transmitter,” “receiver,” or “transceiver.” Additionally, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the communication unit 310.

The storage unit 320 may store data such as basic programs, application programs, and setting information for operation of the UE 300. The storage unit 320 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. The storage unit 320 provides stored data upon request from the control unit 330.

The controller 330 may control the overall operations of the UE 300. For example, the control unit 330 may transmit and receive signals through the communication unit 310. The control unit 330 can write data to and read data from the storage unit 320. The control unit 330 can perform protocol stack functions required by communication standards. The control unit 330 may include at least one processor or microprocessor to perform the above functions, or may be implemented as part of a processor. For example, a portion of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP).

Referring to FIG. 4, a demodulation block 410 according to an embodiment may be the minimum unit to which the reception method of the reception device 110 is applied.

The demodulation block 410 is

with adjacent subcarriers

It may include adjacent OFDM symbols 420-1 to 420-14. The demodulation block 410 may be, for example, a resource block (RB) of the 5G NR communication standard. In this case, demodulation block 410 may include 12 subcarriers and 14 OFDM symbols. The demodulation block 410 is not limited to RB and may be a unit smaller than RB or may be a unit combining several RBs. Depending on the embodiment, the demodulation block 410 may be a unit that is adaptively set according to the time-domain correlation and frequency-domain correlation of the channel.

of demodulation block 410

Among the OFDM symbols (420-1 to 420-14)

A reference signal (RS) or a demodulation reference signal (DMRS) known to both the transmitting device 120 and the receiving device 110 is provided through the OFDM symbols 420-3 and 420-12. can be transmitted. In the case of the demodulation block 410 shown in FIG. 4, for example, RS may be transmitted through the 3rd OFDM symbol 420-3 and the 12th OFDM symbol 420-13.

Data symbols containing transmission data may be transmitted through OFDM symbols 420-1, 420-2, 420-4 to 420-11, 420-13, and 420-14.

RS is transmitted within the demodulation block 410.

The OFDM symbol indices are

It can be. data symbols are transmitted

The OFDM symbol indices are

It can be. Additionally, in the demodulation block 410

The adjacent subcarrier indices are

It can be.

The receiving device 110 may perform channel estimation on the demodulation block 410.

Referring to FIG. 5, the receiving device 500 (e.g., the receiving device 110 of FIG. 1) includes an RS-based channel estimator 505, an order determiner 510, and a channel predictor 520. , a symbol detector 530, a detected symbol (DS)-based channel estimator 540, a linear combiner 550, and a memory 560.

The base station 200 of FIG. 2 or the UE 300 of FIG. 3 may operate as the reception device 500.

RS-based channel estimator 505, orderer 510, channel predictor 520, symbol detector 530, DS-based channel estimator 540, and linear combiner 550 are processors of receiving device 500. It can be implemented by .

The RS-based channel estimator 505 is a demodulation block (e.g., demodulation block 410 in FIG. 4).

Channel estimate for the OFDM symbol (

)(below, "

(referred to as the “RS-based channel estimate” of the OFDM symbol) may be determined. For example, the RS-based channel estimator 505 may determine

of the OFDM symbol

The average of the frequency domain channel estimates for the subcarriers is

It can be determined by the RS-based channel estimate of the th OFDM symbol.

RS-based channel estimator 505 provides RS-based channel estimation information (e.g., RS-based channel estimate and symbol index information (

)) can be transmitted to the channel predictor 520.

The order determiner 510 determines the channel estimation order of OFDM symbols (e.g., N OFDM symbols in FIG. 4) through which data symbols are transmitted among the OFDM symbols of the demodulation block (e.g., demodulation block 410 in FIG. 4). You can decide. In one embodiment, the order determiner 510 may determine the channel estimation order of OFDM symbols through which data symbols are transmitted using the positions of OFDM symbols through which RS is transmitted and the positions of OFDM symbols through which data symbols are transmitted.

For example, in the demodulation block 410 shown in FIG. 4, RS may be transmitted through the 3rd OFDM symbol 420-3 and the 12th OFDM symbol 420-12. In the demodulation block 410, the order determiner 510 estimates the channel as the first one of the 2nd OFDM symbol 420-2 and the 4th OFDM symbol 420-4, which are closest to the 3rd OFDM symbol 420-3. can be determined as the OFDM symbol on which to perform channel estimation, and the other can be determined as the second OFDM symbol on which to perform channel estimation. The order determiner 510 selects one of the 11th OFDM symbol (420-11) and the 13th OFDM symbol (420-13), which are closest to the 12th OFDM symbol (420-12), as the third OFDM symbol to perform channel estimation. can be determined, and another one can be determined as the fourth OFDM symbol to perform channel estimation. The order determiner 510 selects the 1st OFDM symbol 420-1 and the 5th OFDM symbol 420-5 that are different from the position (or index) (i.e., 3) of the 3rd OFDM symbol 420-3 by 2. One of them can be determined as the fifth OFDM symbol on which to perform channel estimation, and the other one can be determined as the sixth OFDM symbol on which channel estimation will be performed. The order determiner 510 selects the 10th OFDM symbol (420-10) and the 14th OFDM symbol (420-14) that differ by 2 from the position (or index) (i.e., 12) of the 12th OFDM symbol (420-12). One of them can be determined as the seventh OFDM symbol to perform channel estimation, and the other can be determined as the eighth OFDM symbol to perform channel estimation. In this way, the order determiner 510 can determine the channel estimate order of OFDM symbols 420-1, 420-2, 420-4 to 420-11, 420-13, and 420-14 through which data symbols are transmitted. there is.

Second, the index of the OFDM symbol on which channel estimation is performed is

It is defined as here,

It can be.

Table 1 below shows an example of the channel estimation order of OFDM symbols 420-1, 420-2, 420-4 to 420-11, 420-13, and 420-14 through which data symbols are transmitted.

번째로 채널 추정이 수행되는 OFDM 심볼의 인덱스( ) Index of the OFDM symbol on which channel estimation is performed ( )	설명explanation
	OFDM 심볼(420-2)의 채널 추정 순서가 1번째The channel estimation order of the OFDM symbol (420-2) is 1st.
	OFDM 심볼(420-4)의 채널 추정 순서가 2번째The channel estimation order of the OFDM symbol (420-4) is 2nd.
	OFDM 심볼(420-11)의 채널 추정 순서가 3번째The channel estimation order of the OFDM symbol (420-11) is 3rd.
	OFDM 심볼(420-13)의 채널 추정 순서가 4번째The channel estimation order of the OFDM symbol (420-13) is 4th.
	OFDM 심볼(420-1)의 채널 추정 순서가 5번째The channel estimation order of the OFDM symbol (420-1) is 5th.
	OFDM 심볼(420-5)의 채널 추정 순서가 6번째The channel estimation order of the OFDM symbol (420-5) is 6th.
	OFDM 심볼(420-10)의 채널 추정 순서가 7번째The channel estimation order of the OFDM symbol (420-10) is 7th.
	OFDM 심볼(420-14)의 채널 추정 순서가 8번째The channel estimation order of OFDM symbol (420-14) is 8th.
	OFDM 심볼(420-6)의 채널 추정 순서가 9번째The channel estimation order of the OFDM symbol (420-6) is 9th.
	OFDM 심볼(420-9)의 채널 추정 순서가 10번째The channel estimation order of the OFDM symbol (420-9) is 10th.
	OFDM 심볼(420-7)의 채널 추정 순서가 11번째The channel estimation order of the OFDM symbol (420-7) is 11th.
	OFDM 심볼(420-8)의 채널 추정 순서가 12번째The channel estimation order of the OFDM symbol (420-8) is 12th.

The order determiner 510 provides channel estimate order information of OFDM symbols through which data symbols are transmitted (

) (e.g. 2, 4, 11, 13, …, 8) can be transmitted to the channel predictor 520.

for example,

It may be the th channel estimation order. Memory 560 contains channel estimation information from the previous order, e.g.

) may be stored. The previous order's channel estimate information is, for example, the previous order's linear combination-based channel estimates (

) and symbol index information (

) may include.

Channel predictor 520 may provide RS-based channel estimation information, e.g.

) and channel estimation information stored in memory 560 (e.g.

) using

OFDM symbol of the th channel estimation order (i.e. OFDM symbol

) Channel forecast for (

) can be determined.

In one embodiment, channel predictor 520 generates RS-based channel estimates (

) and channel estimates based on a linear combination of the previous sequence (

) by applying a time domain interpolation technique to

can be decided.

In one embodiment, the channel predictor 520 determines the OFDM symbol indices through which the RS was transmitted (

) and OFDM symbol indices on which channel estimation (or symbol detection) was performed (

) OFDM symbol

You can find the closest index to

can be decided. For example, it may currently be the 4th channel estimation order. OFDM symbols according to Table 1 above

Since is the 13th OFDM symbol 420-13, the channel predictor 520 uses the OFDM symbol indexes on which the RS was transmitted (e.g., 3 and 12) and the OFDM symbol indexes on which channel estimation (or symbol detection) was performed (e.g., : OFDM symbols among 2, 4, 11)

You can find the closest index 12 to index 13. In other words, the channel predictor 520 uses the OFDM symbols 420-3 and 420-12 on which RS has been transmitted and the OFDM symbols 420-2, on which channel estimation (e.g., linear combination-based channel estimation) has already been performed. 420-4, 420-11) OFDM symbol

You can find the OFDM symbol (420-12) at the closest position. The channel predictor 520 is a channel estimate based on a linear combination of OFDM symbols 420-12 (

) OFDM symbol

Channel prediction value (

) can be determined.

Channel predictor 520 is an OFDM symbol

Channel forecast for (

) can be transmitted to the symbol detector 530 and the linear combiner 550.

The symbol detector 530 is an OFDM symbol

Channel forecast for (

) using OFDM symbol

The received signals (

) can detect data symbols from. receiving signal

The data symbols detected from

It can be expressed as

In one embodiment, the symbol detector 530 may detect data symbols through a maximum likelihood detection method. Data symbols detected through the maximum likelihood detection method can be expressed in Equation 3 below.

[Equation 3]

In one embodiment, the symbol detector 530 may detect data symbols through a linear detection method (eg, zero-forcing). Zero forcing is

It can be used when Data symbols detected through zero forcing can be expressed in Equation 4 below.

[Equation 4]

Depending on the embodiment, the elements of the detected data symbol may not be represented as one of the elements of the symbol constellation. In this case, the symbol detector 530 may correspond to the detected data symbol with the closest element among the elements of the symbol constellation.

DS-based channel estimator 540 receives received signals (

) and detected data symbols (

) using OFDM symbol

A DS-based channel estimate (or first channel estimate) for can be determined. OFDM symbol

The DS-based channel estimate for is

It can be expressed as

In one embodiment, the DS-based channel estimator 540 calculates the OFDM symbol through the least square method.

A DS-based channel estimate for can be determined. The DS-based channel estimate determined through the least squares method can be expressed as Equation 5 below.

[Equation 5]

In Equation 5 above,

can represent the received signal matrix,

may represent the detected data symbol matrix,

can represent the Hermitian operation,

can represent an inverse matrix operation.

In one embodiment, the DS-based channel estimator 540 calculates OFDM symbols through a linear least mean square error method.

A DS-based channel estimate for can be determined. The DS-based channel estimate determined through the linear least mean square error method can be expressed as Equation 6 below.

[Equation 6]

In Equation 6 above,

Is

It can represent the covariance matrix of the channel formed from each transmit antenna port to each receive antenna port,

can represent the variance of the noise signal,

Is

It can represent a dimensional identity matrix.

The method by which the DS-based channel estimator 540 determines the DS-based channel estimate is not limited to the least squares method and the linear least mean square error method described above.

Linear combiner 550 is an OFDM symbol

Channel forecast for (

) and OFDM symbols

DS-based channel estimates for (

) is linearly combined to create an OFDM symbol

A linear combination-based channel estimate (or second channel estimate) may be determined. OFDM symbol

The linear combination-based channel estimate for can be expressed as Equation 7 below.

[Equation 7]

In Equation 7 above,

is the OFDM symbol

used for channel estimation of

and

It can represent the combination ratio between and can be determined as a value between 0 and 1.

Linear combiner 550 provides optimal

can be decided.

In one embodiment, the linear combiner 550 determines the optimal value through mean square error (MSE).

can be decided. in this case,

Can be expressed as Equation 8 below.

[Equation 8]

In Equation 8 above,

is the OFDM symbol

DS-based channel estimates for (

) can represent the mean square error of

is the OFDM symbol

Channel forecast for (

) can represent the mean square error.

The linear combiner 550 determines the optimal

When using, the channel estimate determined through linear combination (

) can be determined through Equation 9 below.

[Equation 9]

In one embodiment,

may vary depending on whether the DS-based channel estimator 540 uses the least squares method or the linear least mean square error method.

When the DS-based channel estimator 540 uses the least squares method, the linear combiner 550 uses Equation 10 below:

can be decided.

[Equation 10]

When the DS-based channel estimator 540 uses the linear least mean square error method, the linear combiner 550 uses Equation 11 below:

can be decided.

[Equation 11]

In one embodiment, linear combiner 550 is

can be calculated.

Linear combiner 550 provides RS-based channel estimates (

)) By applying a time-domain interpolation technique to the calculated mean square errors,

can be decided.

The linear combiner 550 uses the OFDM symbol indices through which RS is transmitted (

) and the OFDM symbol index of the previous order (

) OFDM symbol

The OFDM symbol index closest to can be determined. The linear combiner 550 calculates the mean square error for the determined OFDM symbol index.

can be decided. For example, it may currently be the 4th channel estimation order. OFDM symbol according to Table 1 above

may be the 13th OFDM symbol (420-13). The linear combiner 550 selects an OFDM symbol from among OFDM symbol indices (e.g., 3 and 12) on which RS is transmitted and OFDM symbol indices (e.g., 2, 4, and 11) for which linear combination-based channel estimation has already been performed.

You can find the closest index 12 to index 13. In other words, the linear combiner 550 selects the OFDM symbols (420-3, 420-12) on which RS has been transmitted and the OFDM symbols (420-2, 420-4, 420-11) on which channel estimation has already been performed. symbol

You can find the OFDM symbol (420-12) at the closest position. Linear combiner 550 calculates the mean square error of the channel estimates for OFDM symbols 420-12.

can be decided.

Linear combiner 550 is an OFDM symbol

A linear combination-based channel estimate for (

) and index (

) can be stored in the memory 560. In other words, the linear combiner 550 provides a channel estimate (

) and index (

) to the channel estimation information from the previous sequence, e.g.

) by including channel estimation information (e.g.

) can be updated. Channel estimation information updated in memory 560 (

) can be stored.

Although not shown in FIG. 5, the receiving device 500 may further include a channel decoder. The receiving device 500 may complete channel estimation for each OFDM symbol through which data symbols are transmitted. When channel estimation for OFDM symbols through which data symbols are transmitted is completed, for example, the symbol detector 530 detects data symbols from the received signals of each of the OFDM symbols through which data symbols are transmitted (

) can be transmitted to the channel decoder for decoding. As another example, the symbol detection unit 530 detects data symbols (

) can be transmitted to the channel decoder.

Referring to FIG. 6, the receiving device 500 receives the OFDM symbol through which RS is transmitted.

Channel estimate for (e.g., OFDM symbol 420-3 in FIG. 4) and OFDM symbol on which RS is transmitted

A channel estimate may be determined for (e.g., OFDM symbol 420-12 in FIG. 4).

As described above, the receiving device 500 can determine the channel estimation order of OFDM symbols through which data symbols are transmitted. According to the determined channel estimation order, the receiving device 500 may determine a linear combination-based channel estimate for each OFDM symbol through which data symbols are transmitted.

In the example shown in FIG. 6, the receiving device 500 receives an OFDM symbol

A linear combination-based channel estimate for (e.g., OFDM symbol 420-2 in FIG. 4) can be determined first.

The receiving device 500 uses an OFDM symbol

A linear combination-based channel estimate for (e.g., OFDM symbol 420-4 in FIG. 4) may be determined second.

The receiving device 500 uses an OFDM symbol

A linear combination-based channel estimate for (e.g., OFDM symbol 420-11 in FIG. 4) may be determined thirdly.

The receiving device 500 uses an OFDM symbol

OFDM symbol

A linear combination-based channel estimate for each can be sequentially determined.

The receiving device 500 uses an OFDM symbol

A linear combination-based channel estimate for (e.g., OFDM symbol 420-8 in FIG. 4) may be determined last.

Referring to FIG. 7, in operation 710, the receiving device 500 may determine the channel estimation order of OFDM symbols through which data symbols are transmitted and may initialize the index. The receiving device 500 is

You can initialize the index by doing .

In operation 720, the receiving device 500 receives an OFDM symbol.

The channel prediction value for can be determined.

Therefore, in operation 720, the receiving device 500 receives the OFDM symbol.

Channel forecast for (

) can be determined. for example,

In this case, the linear combination-based channel estimation information of the previous order may not be stored in the memory 560. The receiving device 500 selects an OFDM symbol among OFDM symbols through which RS is transmitted in the RS-based channel estimation information.

(e.g., the index of the OFDM symbol closest to the second OFDM symbol (420-2)) can be found. OFDM symbol

The index of may be 2, and the index of the OFDM symbol 420-3 in FIG. 4 among the OFDM symbols through which RS is transmitted is 3. OFDM symbol (420-3) is the OFDM symbol

It may be closest to . The receiving device 500 converts the channel estimate for the OFDM symbol 420-3 into an OFDM symbol.

Channel forecast for (

) can be determined.

In operation 730, the receiving device 500 receives an OFDM symbol.

Channel forecast for (

) OFDM symbol based on

Data symbols for can be detected. For example, the receiving device 500 receives the OFDM symbol through Equation 3 above or Equation 4 above.

Data symbols for can be detected.

In operation 740, the receiving device 500 receives the detected data symbol (

) OFDM symbol based on

A DS-based channel estimate of can be determined. For example, the receiving device 500 receives the OFDM symbol through Equation 5 or Equation 6 above.

A DS-based channel estimate of can be determined.

In operation 750, receiving device 500 receives an OFDM symbol.

The channel estimate for can be linearly combined with the DS-based channel estimate. For example, the receiving device 500 receives the OFDM symbol through Equation 7 above.

By linearly combining the channel estimate and the DS-based channel estimate for

Linear combined channel estimates for (

) can be determined.

The receiving device 500 uses an OFDM symbol

Linear combined channel estimates for (

) and symbol index (

) can be stored in the memory 560.

In operation 760, receiving device 500

go

You can determine whether it is smaller than . As explained above,

may represent the number of OFDM symbols through which data symbols are transmitted.

The receiving device 500 is

go

is less than, so in operation 770

can be updated.

According to the update of

= can be 2.

The receiving device 500 uses an OFDM symbol

Operations 720 to 760 may be performed.

In operation 720, the receiving device 500 receives an OFDM symbol.

The channel prediction value for can be determined. As an example, the receiving device 500 may receive RS-based channel estimates (

) and a channel estimate based on a linear combination of the previous sequence (

) by applying a time domain interpolation technique to

can be decided. As another example, the receiving device 500 receives the OFDM symbol indexes through which the RS was transmitted (

) and the OFDM symbol index on which channel estimation (or symbol detection) was performed (

) OFDM symbol

You can find the closest index to

can be decided.

In operation 730, the receiving device 500 receives an OFDM symbol.

Channel forecast for (

) OFDM symbol based on

Data symbols for can be detected.

In operation 740, the receiving device 500 receives the detected data symbols (

) OFDM symbol based on

A DS-based channel estimate of can be determined.

In operation 750, receiving device 500 receives an OFDM symbol.

Linear combined channel estimates for (

) can be determined.

The receiving device 500 uses an OFDM symbol

Linear combined channel estimates for (

) and symbol index (

) can be stored in the memory 560.

In operation 760, receiving device 500

go

You can determine whether it is smaller than .

The receiving device 500 is

go

is less than, so in operation 770

can be updated.

The receiving device 500 uses an OFDM symbol

Operations 720 to 770 may be repeatedly performed. By repeatedly performing operations 720 to 770, an OFDM symbol

The channel estimation order for may arrive.

In operation 720, the receiving device 500 receives an OFDM symbol.

) by applying a time domain interpolation technique to

) OFDM symbol

You can find the closest index to

can be decided.

In operation 730, the receiving device 500 receives an OFDM symbol.

Channel forecast for (

) OFDM symbol based on

Data symbols for can be detected.

In operation 740, the receiving device 500 receives the detected data symbols (

) OFDM symbol based on

A DS-based channel estimate of can be determined.

In operation 750, receiving device 500 receives an OFDM symbol.

Linear combined channel estimates for (

) can be determined.

In operation 760, receiving device 500

go

You can determine whether it is smaller than .

Is

Therefore, the receiving device 500 may end the channel estimation operation for each OFDM symbol through which data symbols are transmitted.

The receiving device 500 uses an OFDM symbol

OFDM symbol

Data symbols for each (

), the decoding operation can be performed based on.

The embodiments described with reference to FIGS. 1 to 6 may be applied to the reception method of FIG. 7 .

In the examples shown in FIGS. 8 to 10, the existing method may represent a reception method using existing RS-based channel estimation, and the embodiment may represent a reception method of the receiving device 500.

In the examples shown in Figures 8 and 9,

It may be, and the modulation method may be 4-quadrature amplitude modulation (QAM).

Each of the reception methods of FIGS. 8 and 9 (existing method, embodiment, reception method with perfect channel information) can use the least squares method for channel estimation, and the linear least mean square error method for data symbol detection. Available.

In the examples shown in FIGS. 8 and 9, the channel may change over time as shown in Equation 12 below.

[Equation 12]

In equation 12 above,

may represent the time domain correlation coefficient between the current channel and the previous channel,

may represent a complex Gaussian random matrix with the same variance as the channel.

In the example shown in Figure 8

= 0.9530, in the example shown in Figure 9

= could be 0.9924. When the carrier frequency is 3.5 GHz and the OFDM symbol period is 71.35 ㎲, the correlation coefficient (

= 0.9530) may correspond to the case where the moving speed of the receiving device 500 is 300 km/h, and the correlation coefficient (

=0.9924) may correspond to a case where the moving speed of the receiving device 500 is 120 km/h.

In the examples shown in FIGS. 8 and 9, the reception method of the reception device 500 can achieve a lower frame error rate than the existing method in an environment where channels change over time. The reception method of the moving reception device 500 can achieve a lower frame error rate than the existing method.

Figure 10 shows the frame error rate versus signal-to-noise ratio that can be achieved by reception methods for various numbers of antennas.

In the example shown in FIG. 10, channel estimation and symbol detection for each of the reception methods (existing method, embodiment, reception method with perfect channel information) may use the least squares method.

In the example shown in Figure 10,

It may be, and the modulation method may be 4-QAM. In the example shown in Figure 10, the channel may not change over time.

In the example shown in FIG. 10, the embodiment can achieve lower frame error rates than existing methods for various antenna numbers.

and

In , the reception method of the reception device 500 can achieve a lower frame error rate than the existing method.

Referring to FIG. 11, the receiving device 1100 (e.g., the receiving device 110 of FIG. 1 and the receiving device 500 of FIG. 5) according to an embodiment includes antennas 1110 and an RF communication circuit 1120. , a processor 1130, and a memory 1140 (eg, memory 560 in FIG. 5).

The base station 200 of FIG. 2 or the UE 300 of FIG. 3 may operate as the reception device 1100.

The RF communication circuit 1120 may receive an RF signal from a transmitting device (eg, the transmitting device 120 of FIG. 1) through the antennas 1110.

The RF communication circuit 1120 may convert the received RF signal into a baseband signal.

The RF communication circuit 1120 may transmit a baseband signal to the processor 1130.

The processor 1130 may be connected to the RF communication circuit 1120.

Processor 1130 includes RS-based channel estimator 505, orderer 510, channel predictor 520, symbol detector 530, DS-based channel estimator 540, and linear combiner 550 of FIG. 5. can be implemented.

The processor 1130 may determine the channel estimation order of OFDM symbols through which data symbols are transmitted. For example, the processor 1130 may use the positions of one or more OFDM symbols through which RS is transmitted and the positions of each OFDM symbol through which data symbols are transmitted, to determine the channel estimation order of OFDM symbols through which data symbols are transmitted. . The processor 1130 determines the index (or position) of the first OFDM symbol among the OFDM symbols through which data symbols are transmitted (e.g.,

) is closest to the index (or position) of the OFDM symbol through which the RS is transmitted, the channel estimation order of the first OFDM symbol can be determined as the first channel estimation order.

The channel estimation order of the first OFDM symbol is referred to as the first channel estimation order.

The processor 1130 selects the first OFDM symbol in the first channel estimation order among OFDM symbols through which data symbols are transmitted (e.g., OFDM symbol

) channel estimates, e.g.

) to RS-based channel estimation information, e.g.

) or channel estimation information determined prior to the first channel estimation sequence (e.g.

) can be determined using at least one of: Channel estimation information, e.g.

) may be stored in the memory 1140.

For example, the processor 1130 may determine a channel estimate for the first OFDM symbol by performing interpolation (e.g., time domain interpolation) on the RS-based channel estimation information and the channel estimation information determined before the first channel estimation sequence. .

In another example, the processor 1130 includes the index of the OFDM symbol through which the RS was transmitted and channel estimation information (e.g.

), the index closest to the index of the first OFDM symbol can be found among the OFDM symbol indexes included in ). The processor 1130 may determine the channel estimate for the OFDM symbol of the found index as the channel estimate for the first OFDM symbol.

The processor 1130 may receive a received signal in the first OFDM symbol based on the baseband signal (e.g.,

) can be obtained. For example, the processor 1130 processes the baseband signal (e.g., serial/parallel conversion, FFT, etc.) to obtain a received signal in the first OFDM symbol (e.g.,

) can be obtained.

Processor 1130 may store the determined channel estimate, e.g.

) to receive signals (e.g.

) from the first data symbols (e.g.

) can be detected. For example, the processor 1130 generates first data symbols (e.g., Equation 3 above or Equation 4 above).

) can be detected.

The processor 1130 generates a first channel estimate for the first OFDM symbol based on the detected first data symbols (e.g.,

) can be determined. For example, processor 1130 may generate a received signal matrix for the received signal, e.g.

), a data symbol matrix (e.g.,

), and the Hermitian matrix of the data symbol matrix, e.g.

) can be used to determine the first channel estimate. The processor 1130 generates a first channel estimate (e.g., for the first OFDM symbol) through Equation 5 or Equation 6 above.

) can be determined.

Processor 1130 generates a second channel estimate for the first OFDM symbol based on the first channel estimate and the channel estimate (e.g.,

) can be determined. For example, the processor 1130 may determine the second channel estimate by linearly combining the first channel estimate and the channel estimate. The processor 1130 may determine the second channel estimate through Equation 7 above.

The processor 1130 may determine whether the first channel estimation order is the last channel estimation order.

If the first channel estimation order is not the last channel estimation order, the processor 1130 uses the second channel estimate as channel estimation information (e.g.,

), the channel estimation information can be updated. Memory 1140 may store updated channel estimate information, e.g.

) can be saved.

If the first channel estimation order is not the last channel estimation order, the processor 1130 may perform channel estimation on the second OFDM symbol having a channel estimation order next to the first channel estimation order. For example, processor 1130 may provide RS-based channel estimate information or updated channel estimate information, e.g.

) can be used to determine the channel prediction value for the second OFDM symbol. The processor 1130 may detect second data symbols from the received signal in the second OFDM symbol using the channel prediction value for the second OFDM symbol. The processor 1130 may determine a first channel estimate for the second OFDM symbol based on the detected second data symbols. The processor 1130 may determine a second channel estimate for the second OFDM symbol based on the first channel estimate for the second OFDM symbol and the channel estimate for the second OFDM symbol.

When the first channel estimation order is the last channel estimation order, the processor 1130 detects data symbols (e.g., received signals from each of the OFDM symbols through which data symbols are transmitted).

), decoding can be performed based on .

The embodiments described with reference to FIGS. 1 to 10 may be applied to the receiving device 1100 of FIG. 11 .

A reception method of a receiving device according to an embodiment includes determining a channel estimation order of OFDM symbols through which data symbols are transmitted, determining a channel estimate for a first OFDM symbol in a first channel estimation order among the OFDM symbols based on a reference signal. An operation of determining using at least one of channel estimation information or channel estimation information determined before the first channel estimation sequence, detecting first data symbols from a received signal in the first OFDM symbol using the determined channel prediction value. An operation of determining a first channel estimate for the first OFDM symbol based on the detected first data symbols, a first channel estimate for the first OFDM symbol based on the determined first channel estimate and the determined channel prediction value. Determining a two-channel estimate, determining whether the first channel estimation order is the last channel estimation order, and if the first channel estimation order is not the last channel estimation order, a second of the next channel estimation order An operation of performing channel estimation on OFDM symbols may be included.

The operation of determining the channel estimation order may include determining the channel estimation order of the OFDM symbols using the positions of one or more OFDM symbols through which the reference signal is transmitted and the positions of each of the OFDM symbols.

The operation of determining the channel estimation order includes determining the first channel estimation order as the first channel estimation order when the index of the first OFDM symbol among the OFDM symbols is closest to the index of the OFDM symbol through which the reference signal is transmitted. It may include actions such as:

The operation of determining the channel prediction value may include determining the channel prediction value by performing interpolation on the reference signal-based channel estimation information and the channel estimation information.

The operation of determining the channel prediction value includes: finding an index closest to the index of the first OFDM symbol among the index of the OFDM symbol through which the reference signal is transmitted and the OFDM symbol index included in the channel estimation information; and determining a channel estimate for the OFDM symbol of the found index as the channel prediction value.

The operation of determining the first channel estimate is performed by using a received signal matrix for the received signal, a data symbol matrix for the detected first data symbols, and a Hermitian matrix of the data symbol matrix. The operation may include determining a channel estimate.

Determining the second channel estimate may include determining the second channel estimate by linearly combining the determined first channel estimate and the determined channel estimate.

The receiving method of the receiving device may further include performing decoding based on data symbols detected from received signals of each of the OFDM symbols when the first channel estimation order is the last channel estimation order.

The receiving method of the receiving device may further include updating the channel estimation information by including the determined second channel estimate in the channel estimation information.

The operation of performing the channel estimation for the second OFDM symbol includes determining a channel prediction value for the second OFDM symbol using at least one of the reference signal-based channel estimation information or the updated channel estimation information, Detecting second data symbols from a received signal in the second OFDM symbol using a channel prediction value for the second OFDM symbol, determining a first channel for the second OFDM symbol based on the detected second data symbols. It may include determining an estimate, and determining a second channel estimate for the second OFDM symbol based on a first channel estimate for the second OFDM symbol and a channel estimate for the second OFDM symbol. there is.

The embodiments described above may be implemented with hardware components, software components, and/or a combination of hardware components and software components. For example, the devices, methods, and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, and a field programmable gate (FPGA). It may be implemented using a general-purpose computer or a special-purpose computer, such as an array, programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and software applications running on the operating system. Additionally, a processing device may access, store, manipulate, process, and generate data in response to the execution of software. For ease of understanding, a single processing device may be described as being used; however, those skilled in the art will understand that a processing device includes multiple processing elements and/or multiple types of processing elements. It can be seen that it may include. For example, a processing device may include multiple processors or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are possible.

Software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing unit to operate as desired, or may be processed independently or collectively. You can command the device. Software and/or data may be used on any type of machine, component, physical device, virtual equipment, computer storage medium or device to be interpreted by or to provide instructions or data to a processing device. , or may be permanently or temporarily embodied in a transmitted signal wave. Software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on a computer-readable recording medium.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. A computer-readable medium may store program instructions, data files, data structures, etc., singly or in combination, and the program instructions recorded on the medium may be specially designed and constructed for the embodiment or may be known and available to those skilled in the art of computer software. there is. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

The hardware devices described above may be configured to operate as one or multiple software modules to perform the operations of the embodiments, and vice versa.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can apply various technical modifications and variations based on this. For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent.

Therefore, other implementations, other embodiments and equivalents of the claims also fall within the scope of the following claims.

Claims

In the receiving method of the receiving device (110, 500, 1100),

An operation of determining a channel estimation order of orthogonal frequency division multiplexing (OFDM) symbols through which data symbols are transmitted;

Determining a channel prediction value for the first OFDM symbol of the first channel estimation order among the OFDM symbols using at least one of reference signal-based channel estimation information or channel estimation information determined before the first channel estimation order. movement;

detecting first data symbols from a received signal in the first OFDM symbol using the determined channel prediction value;

determining a first channel estimate for the first OFDM symbol based on the detected first data symbols;

determining a second channel estimate for the first OFDM symbol based on the determined first channel estimate and the determined channel estimate;

determining whether the first channel estimation order is the last channel estimation order; and

If the first channel estimation order is not the last channel estimation order, performing channel estimation on the second OFDM symbol in the next channel estimation order

Including,

Receiving method of the receiving device.
According to paragraph 1,

The operation of determining the channel estimation order is,

An operation of determining a channel estimation order of the OFDM symbols using the positions of one or more OFDM symbols through which the reference signal is transmitted and the positions of each of the OFDM symbols.

Including,

Receiving method of the receiving device.
According to any one of claims 1 and 2,

The operation of determining the channel estimation order is,

When the index of the first OFDM symbol among the OFDM symbols is closest to the index of the OFDM symbol through which the reference signal is transmitted, determining the first channel estimation order as the first channel estimation order

Including,

Receiving method of the receiving device.
According to any one of claims 1 to 3,

The operation of determining the channel prediction value is:

An operation of determining the channel prediction value by performing interpolation on the reference signal-based channel estimation information and the channel estimation information.

Including,

Receiving method of the receiving device.
According to any one of claims 1 to 4,

The operation of determining the channel prediction value is:

An operation of finding an index closest to the index of the first OFDM symbol among the index of the OFDM symbol through which the reference signal is transmitted and the OFDM symbol index included in the channel estimation information; and

An operation of determining a channel estimate for an OFDM symbol of the found index as the channel estimate.

Including,

Receiving method of the receiving device.
According to any one of claims 1 to 5,

The operation of determining the first channel estimate is performed by using a received signal matrix for the received signal, a data symbol matrix for the detected first data symbols, and a Hermitian matrix of the data symbol matrix. Includes the operation of determining a channel estimate; or

Determining the second channel estimate includes determining the second channel estimate by linearly combining the determined first channel estimate and the determined channel estimate.

Receiving method of the receiving device.
According to any one of claims 1 to 6,

When the first channel estimation order is the last channel estimation order, performing decoding based on data symbols detected from received signals of each of the OFDM symbols; or

An operation of updating the channel estimate information by including the determined second channel estimate in the channel estimate information.

Containing more,

Receiving method of the receiving device.
In clause 7,

The operation of performing the channel estimation for the second OFDM symbol is:

determining a channel prediction value for the second OFDM symbol using at least one of the reference signal-based channel estimation information or the updated channel estimation information;

detecting second data symbols from a received signal in the second OFDM symbol using a channel prediction value for the second OFDM symbol;

determining a first channel estimate for the second OFDM symbol based on the detected second data symbols; and

An operation of determining a second channel estimate for the second OFDM symbol based on the first channel estimate for the second OFDM symbol and the channel estimate for the second OFDM symbol.

Including,

Receiving method of the receiving device.
In the receiving device (110, 500, 1100),

A plurality of antennas 1110;

an RF communication circuit 1120 that receives an RF signal from a transmitting device through the antennas and converts the received RF signal into a baseband signal; and

Processor 1130 connected to the RF communication circuit

Including,

The processor,

Determine the channel estimation order of OFDM symbols through which data symbols are transmitted, and determine the channel estimate for the first OFDM symbol in the first channel estimation order among the OFDM symbols using reference signal-based channel estimation information or before the first channel estimation order. A decision is made using at least one of the determined channel estimation information, a received signal in the first OFDM symbol is obtained based on the converted baseband signal, and a first received signal is obtained from the obtained received signal using the determined channel estimate value. Detect data symbols, determine a first channel estimate for the first OFDM symbol based on the detected first data symbols, and determine the first OFDM symbol based on the determined first channel estimate and the determined channel estimate. Determine a second channel estimate for, determine whether the first channel estimation order is the last channel estimation order, and if the first channel estimation order is not the last channel estimation order, the second channel estimate order for Performing channel estimation on OFDM symbols,

Receiving device.
According to clause 9,

The processor,

Determining a channel estimation order of the OFDM symbols using the location of one or more OFDM symbols through which the reference signal is transmitted and the location of each of the OFDM symbols,

Receiving device.
According to any one of claims 9 to 10,

The processor,

When the index of the first OFDM symbol among the OFDM symbols is closest to the index of the OFDM symbol through which the reference signal is transmitted, determining the first channel estimation order as the first channel estimation order,

Receiving device.
According to any one of claims 9 to 11,

The processor is configured to determine the channel prediction value by performing interpolation on the reference signal-based channel estimation information and the channel estimation information; or,

The processor finds the index closest to the index of the first OFDM symbol among the index of the OFDM symbol through which the reference signal was transmitted and the OFDM symbol index included in the channel estimation information, and provides a channel estimate for the OFDM symbol of the found index. configured to determine with the channel prediction value,

Receiving device.
According to any one of claims 9 to 12,

the processor is configured to determine the first channel estimate using a received signal matrix for the received signal, a data symbol matrix for the detected first data symbols, and a Hermitian matrix of the data symbol matrix; or

The processor is configured to determine the second channel estimate by linearly combining the determined first channel estimate and the determined channel estimate.

Receiving device.
According to any one of claims 9 to 13,

The processor is configured to perform decoding based on data symbols detected from received signals of each of the OFDM symbols when the first channel estimation order is the last channel estimation order; or,

The processor is configured to update the channel estimate information by including the determined second channel estimate in the channel estimate information,

Receiving device.
According to clause 14,

The processor,

Determine a channel prediction value for the second OFDM symbol using at least one of the reference signal-based channel estimation information or the updated channel estimation information, and determine the second OFDM symbol using the channel prediction value for the second OFDM symbol. Detect second data symbols from a received signal in, determine a first channel estimate for the second OFDM symbol based on the detected second data symbols, and determine a first channel estimate for the second OFDM symbol and Determining a second channel estimate for the second OFDM symbol based on the channel estimate for the second OFDM symbol,

Receiving device.