JP7114503B2 - Wireless communication device, method and program - Google Patents

Description

TECHNICAL FIELD Embodiments of the present invention relate to a radio communication apparatus, method, and program relating to full-duplex communication, which transmits a signal in the frequency band in which the signal is being received while the signal is being received.

A full-duplex communication technology has been developed in which transmission and reception are performed using the same frequency band. In full-duplex communication using OFDM (Orthogonal Frequency Division Multiplexing), there is a time-series difference in interference between signals for reception and signals for transmission. A radio communication apparatus is desired that can accurately estimate interference propagation path characteristics even when this deviation occurs.

Japanese Patent No. 6373369

The problem to be solved by the embodiments of the present invention is that in full-duplex communication using OFDM, even if there is a time-series deviation in the interference caused by the signal to be received and the signal to be transmitted, the interference propagation path can be accurately A wireless communication device, method, and program capable of estimating characteristics are provided.

In order to solve the above problems, a wireless communication apparatus according to an embodiment includes a receiving unit for receiving a first OFDM signal, a processing unit for generating a second OFDM signal, a transmitting frequency band and a transmitting unit, in a receiving frequency band and a receiving time band. A transmitter is provided for transmitting the second OFDM signal in a time slot. The reception frequency band and the transmission frequency band overlap at least in a first frequency band, and the reception time band and the transmission time band overlap at least partially. This first OFDM signal and this second OFDM signal are signals allocated to a plurality of resource elements separated by frequency bands and time bands. At least one first resource element in the first frequency band of the first OFDM signal is assigned nulls or symbols less than the first power . The resource elements in the first frequency band of the second OFDM signal include second resource elements to which known symbols whose phases are consecutive are assigned to at least two consecutive resource elements in the time band, and the second resource elements of the second resource elements Also includes a third resource element assigned a symbol different from this known symbol. This second resource element overlaps the time zone of this first resource element.

FIG. 2 is a system diagram of wireless communication according to the first embodiment; FIG. 2 is a diagram showing communication between wireless communication devices 100 and 200 in FIG. 1; 4 is a diagram showing the configuration of resource elements of signal B transmitted by radio communication apparatus 200. FIG. 4 is a diagram showing the configuration of resource elements of signal A transmitted by radio communication apparatus 100. FIG. FIG. 4 is a diagram showing a waveform of a signal in which known symbols are assigned to two resource elements in signal A; FIG. 4 is a diagram showing the waveform of a signal in which known symbols with continuous phases are assigned to two resource elements in signal A. FIG. 1 is a diagram showing the configuration of a wireless communication device 100 according to a first embodiment; FIG. 4 is a flowchart of operations when the wireless communication device 100 configures the signal A in the first embodiment. FIG. 4 is a diagram for explaining a time-series deviation of signal B and signal A that interferes with signal B; FIG. 7 is a diagram for explaining an interval in which an FFT window is applied in FIG. 6; FIG. 4 is a diagram for explaining that the configuration of signal A is changed to signal a due to a time-series shift of signal B and signal A that interferes with signal B; FIG. 5 is a configuration diagram of signal A in which known symbols with consecutive _phases are assigned to resource elements in frequency bands on both sides of resource element CT in FIG. FIG. 3 is a diagram showing that signal B transmitted by wireless communication apparatus 200 interferes with signal A in FIG. 2 ; 4 is a diagram showing the configuration of resource elements of a signal 2B transmitted by the wireless communication device 200, applicable to the first embodiment; FIG. 4 is a diagram showing the configuration of resource elements of a signal 2A transmitted by the wireless communication device 100, applicable to the first embodiment; FIG. FIG. 4 is a diagram for explaining the time-series deviation of the signal 2A and the signal 2B that interferes with the signal 2A;

Embodiments for carrying out the invention will be described below.

(First embodiment)
FIG. 1 is a diagram showing a wireless communication system according to the first embodiment. Data A is transmitted from at least one terminal 10 to the base station 20 . Base station 20 transmits data A to wireless communication device 100 connected to base station 20 . This wireless communication device 100 wirelessly transmits signal A including this data A to wireless communication device 200 . This data A is sent from wireless communication device 200 to network 250 . On the other hand, data B sent from network 250 to wireless communication device 200 is included in signal B and sent to wireless communication device 100 . This data B is sent from the wireless communication device 100 to the base station 20 and sent to the terminal 10 . That is, wireless communication devices 100 and 200 are repeaters that connect base stations and networks. In this embodiment, communication between the wireless communication devices 100 and 200 is performed by full-duplex communication.

FIG. 2 is a diagram for explaining communication between wireless communication devices 100 and 200. As shown in FIG. As a premise, communication between wireless communication apparatuses 100 and 200 in this embodiment uses the OFDM scheme. Radio communication apparatus 100 uses at least part of the frequency band for receiving signals from radio communication apparatus 200 to transmit signals while receiving signals. That is, radio communication apparatuses 100 and 200 perform full-duplex communication. In FIG. 2, wireless communication devices 100 and 200 are performing full-duplex communication using frequency band α. A signal transmitted by wireless communication apparatus 100 is signal A, and a signal transmitted by wireless communication apparatus 200 is signal B. FIG.

Signal B received by radio communication apparatus 100 is interfered by signal A. FIG. In order to demodulate data B from signal B, this interference experienced by signal B must be reduced. Radio communication apparatus 100 estimates interference propagation path characteristics (hereinafter referred to as _IA ) of interference given by signal _A to signal B, and generates a signal (hereinafter referred to as RA) that reduces this interference. . Radio communication apparatus 100 can reduce the interference of signal B and demodulate data B using this signal _RA .

Since the interference propagation path characteristics _IA may change over time, the radio communication apparatus 100 estimates the interference propagation path characteristics _IA and reduces interference while updating them. This estimation of the interference propagation path characteristic _IA may be performed at regular time intervals determined by the radio communication apparatus 100, or may be performed when the conditions determined by the radio communication apparatus 100 are satisfied.

FIG. 3 is a diagram showing the configuration of signal B transmitted by radio communication apparatus 200. As shown in FIG. Signal B in this embodiment is described by a plurality of resource elements separated by time and frequency bands. Although the frequency bands are numbered from 1 to 18 in FIG. 3, they are included in the frequency band α in FIG. Each resource element is assigned either a data symbol or no symbol. In FIG. 3, resource elements to which data symbols are assigned are denoted by D _R , and resource elements to which no symbols are assigned are denoted by N. In FIG. That is, signal _B is represented by multiple resource elements shown in FIG.

Note that resource elements to which symbols are not assigned are also expressed as resource elements to which nulls are assigned, in addition to resource elements N. That is, some resource elements of signal B are assigned nulls.

In addition, the resource element N includes not only resource elements to which symbols are not assigned, but also resource elements to which symbols are assigned, but the power of the symbols is below a certain level. For example, if the power of this symbol is so small that it cannot be demodulated. Since wireless communication apparatus 100 determines that no symbols are assigned to this resource element, it is regarded as resource element N.

Resource element _DR is a resource element unknown to radio communication apparatus 100 because data symbols are assigned to it. On the other hand, since no symbol is assigned to resource element N, radio communication apparatus 100 can easily recognize resource element N upon reception.

The estimation of the interference propagation path characteristic _IA is performed by aligning the resource elements of the signal A transmitted by the radio communication apparatus 100 with the reception timing of the resource elements N of the signal B shown in FIG. Since all the resource elements of the signal A to be transmitted are known to the wireless communication apparatus 100, the transmitted signal A and the interference that the signal A gives to the resource elements N can be compared. Based on this comparison, radio communication apparatus 100 can estimate interference propagation path characteristic _IA .

FIG. 4 is a diagram showing a resource element configuration of signal A transmitted by radio communication apparatus 100. As shown in FIG. Like signal B, signal A in this embodiment is represented by a plurality of resource elements separated by frequency bands and time bands. Frequency bands 1 to 18 in resource elements of signal A in FIG. 4 are included in frequency band α in FIG. It is also assumed that frequency bands 1 to 18 of signal A and frequency bands 1 to 18 of signal B are located in the same frequency band.

In FIG. 4, a resource element to which a data symbol including data A is assigned is denoted by _DT , and a resource element to which two known symbols are assigned is denoted by _CT . A known symbol is a symbol whose content is shared between radio communication apparatuses 100 and 200 in advance, such as a pilot symbol. In this embodiment, this resource element C _T is assigned known symbols with continuous phases. Also, this resource element C _T is combined with the resource element N of the signal B to estimate the interference propagation path characteristics I _A. Signal A will be explained in the same way as signal B. Signal A represents the signal for the entire resource element shown in FIG. 4, and symbols mean signals assigned to individual resource elements.

In addition, the resource elements of signal A include resource elements _CT to which known symbols with consecutive phases are assigned. This resource element _CT will be described with reference to FIGS. 5 and 6. FIG. A case where known symbols whose phases are not consecutive are assigned will be described with reference to FIG. Next, a case in which known symbols with continuous phases are assigned will be described with reference to FIG. The difference between these two cases will be explained, and the reason for using the resource element _CT to which the known symbol with continuous phase is assigned to the resource element of the signal A will be explained.

First, FIG. 5 is a diagram showing waveforms of signals in which known symbols are assigned to two resource elements, respectively. In this case, the phases of the known symbols assigned to the two resource elements are discontinuous. For the sake of explanation, one resource element to which a known symbol is assigned is denoted as resource element _PT .

That is, when a known symbol is assigned to each of two consecutive resource elements, two resource elements _PT are arranged in chronological order. FIG. 5 shows the waveform of the signal of this resource element _PT . In FIG. 5, the signal interval of the resource element P _T is represented as P _T (t). Here, CP (Cyclic Prefix) in FIG. 5 is a copy of part of the symbol. CPs are assigned to prevent mixing of symbols assigned to time-sequentially adjacent resource elements in the OFDM scheme. Although this CP is assigned after P _T (t) in FIG. 5, it may be assigned before P _T (t).

In FIG. 5, since the CP is assigned after P _T (t), the discontinuity of the waveform between CP and P _T (t) is indicated by a dashed line. The discontinuity of the waveform of this signal is expressed as the discontinuity of the symbol phase. If the timing of this resource element _PT does not coincide with the timing of the resource element N of the signal B due to the discontinuity of the symbol phase, the accuracy of the estimation of the interfering channel characteristics _IA will be degraded.

On the other hand, FIG. 6 is a diagram showing the waveform of a signal in which known symbols with consecutive phases are assigned to two resource elements. These two resource elements are collectively expressed as resource element _CT . This resource element _CT is used for the signal A in this embodiment. In FIG. 6, the interval of the signal of this resource element C _T is denoted as C _T (t). To make the phase of the known symbol continuous, a phase-rotated signal is assigned to _PT following the first CP in FIG. The phase-rotated signal is represented as e ^-jθ in FIG. By allocating this phase-rotated signal, the continuity of the waveform between the first CP and the second P _T (t) is indicated by a dashed line. This first CP is a copy of part of the first P _T (t). That is, radio communication apparatus 100 can grasp the phase at the end of the first CP. Radio communication apparatus 100 rotates the phase at the beginning of the second _PT to overlap the phase at the end of the first CP. By doing so, the waveforms of the two known symbols can be made continuous. The fact that the waveforms of the two symbols are continuous is also expressed as the phases of the two symbols being continuous. Since the waveforms are continuous, it is possible to accurately estimate the interference propagation path characteristics _IA even if there is a time-series deviation between the signals A and B that cause interference.

Therefore, the timing of the resource element _CT and the _timing of the resource element N of the signal B do not have to match by using the resource element CT to which the known symbols with continuous phases are assigned. If the resource element N of the signal B overlaps with the two resource elements C _T , even if there is a time-series deviation between the interfering signals A and B, the interference channel characteristics I _A can be estimated. can be performed with high accuracy.

The configuration of the signal B shown in FIG. 3 and the configuration of the signal A shown in FIG. 4 are examples, and do not limit the assignment of symbols. Various known symbols, data symbol assignments, and null assignments to resource elements are conceivable, and any combination is possible. If the frequency band to which the resource elements assigned null in signal B belong and the frequency band to which the resource elements assigned the known symbols with continuous phase in signal A belong are the same frequency band, radio communication apparatus 100 It is possible to accurately estimate the interference propagation path characteristic _IA .

Further, in the present embodiment, the phases of the known symbols are continuous in the signal A, but the symbols whose phases are continuous are not limited to this. The phases of data symbols and other symbols may be continuous to form the resource element _CT .

The configuration of the wireless communication device 100 of this embodiment will be described using FIG. Radio communication apparatus 100 includes acquisition section 101 , control section 102 , transmission section 103 , reception section 104 , interference reduction section 105 and output section 106 .

Acquisition unit 101 acquires data A from base station 20 connected to wireless communication device 100 . This data A is data transmitted from the terminal 10 to the base station 20 . These data A are sent to the control section 102 to become the signal A, and delivered to the network 250 through the transmission section 103 and the wireless communication device 200 .

Control section 102 configures signal A by allocating symbols to resource elements. This signal A is sent to the transmission section 103 . Further, the control unit 102 detects the time-series deviation between the interfering signals A and B from the signal B and the signal A that are interfered by the signal A sent from the receiving unit 104 . The control unit 102 assigns symbols with continuous phases so that the resource element N of the signal B and the resource element _CT overlap even if this time-series deviation occurs.

Transmitting section 103 modulates signal A sent from control section 102 and transmits the modulated signal to radio communication apparatus 200 . This transmission is performed wirelessly, for example, by an antenna provided in the transmission section 103 . Also, transmitting section 103 sends this signal A to control section 102 and interference reducing section 105 . This signal A is used to detect the time-series deviation between signal _A and signal B, to estimate the interference channel characteristics _IA , and to generate signal RA that reduces the interference received by signal A from signal B. .

Receiving section 104 receives signal B that has been interfered with by signal A from radio communication apparatus 200 . Signal B, which has been interfered by signal A, is sent to interference reduction section 105 and used for estimating interference propagation path characteristic _IA . This reception is performed wirelessly, for example, by an antenna provided in the receiving section 104 . Further, the receiving section 104 demodulates the signal B whose interference has been reduced by the interference reducing section 105 into data B. FIG. This data B is sent to the output unit 106 .

Interference reduction section 105 estimates interference propagation path characteristics _IA . Interference reduction section 105 also generates signal RA from interference propagation path characteristic _IA and signal _A sent from transmission section 103 . Interference reduction section 105 uses this signal RA to perform processing to reduce interference from signal B, which has been interfered by signal _A sent from reception section 104 . Signal B whose interference has been reduced by interference reduction section 105 is returned to reception section 104 .

The interference propagation path characteristic _IA is estimated by aligning the resource element of signal A transmitted by radio communication apparatus 100 with the reception timing of resource element N of signal B shown in FIG.

Output section 106 outputs data B demodulated by receiving section 104 to base station 20 . This data B is sent from the base station 20 to the terminal 10 .

Note that the signal modulation and demodulation, the processing of the control unit 102, and the processing of the interference reduction unit 105 are each realized by a processing unit such as a processor. A wireless communication device 100 having these components is realized by a circuit such as an LSI. Also, the configuration of this wireless communication apparatus 100 may be realized by connecting independent components, or may be partially integrated.

The configuration of wireless communication device 200 may be an existing configuration as long as it can perform full-duplex communication with wireless communication device 100 . Further, the configuration may be the same as that of the wireless communication device 100 .

Next, operations performed by radio communication apparatus 100 to allocate symbols to resource elements when configuring signal A will be described with reference to FIGS. 8 to 10 . As a premise, it is assumed that wireless communication apparatuses 100 and 200 are performing full-duplex communication in frequency band α. Further, acquisition of data A by acquisition section 101, reception and demodulation of a signal by reception section 104, estimation of interference propagation path characteristic _IA by interference reduction section 105, generation of signal _RA , reduction of interference, data It is assumed that the output of B is performed appropriately. Also, it is assumed that the radio communication apparatus 100 has transmitted the signal A once, and the receiving section 104 has received the signal B that has been interfered by the signal A. FIG. The configurations of these signals A and B are assumed to be those shown in FIGS. 3 and 4. FIG. In the configurations of FIGS. 3 and 4, nulls or known symbols with consecutive phases are assigned to resource elements of frequency bands 5 and 15 by prior exchange when wireless communication devices 100 and 200 perform full-duplex communication. It is configured as follows. It is assumed that radio communication apparatus 200 similarly acquires data B, receives signal A, reduces and demodulates interference, and outputs data A. FIG.

First, the control unit 102 receives the modulated signal A from the transmitting unit 103 and receives the signal B that has been interfered with by the signal A from the receiving unit 104 . From the received two signals, the control unit 102 detects a time-series deviation between the two signals (step S101). Specifically, this chronological shift is detected by determining which resource elements of signal A are interfering with resource elements of signal B to which nulls are assigned.

Next, the control unit 102 generates a signal in which symbols with continuous phases are assigned to a plurality of resource elements whose time zones overlap with the resource element N of the signal B while observing the time-series difference between the two signals. configure (step S102). The control unit 102 sends this configured signal A to the transmission unit 103 .

The operations of steps S101 and S102 will be specifically described with reference to FIG. FIG. 9 is a diagram showing an example of resource elements of signal A that interfere with resource elements N of signal B. FIG. In FIG. 9, portions of the signal B shown in FIG. 3 and the signal A shown in FIG. 4 that have the same frequency band and time band are arranged in chronological order. Since the interfering signal A is received by the receiving unit 104, the time zone of the signal A and the time zone of the signal B do not necessarily match. For example, in FIG. 9, control section 102 determines that signal A and signal B are only t _{lag 1 based} on the timing at which reception is started with the signal of resource element C _T as interference and the time period of the resource element to which null of signal B is assigned. It is detected that there is a deviation.

In order for the interference reduction section 105 to estimate the interference propagation path characteristic _IA , the resource elements of the signal A that interfere with the resource elements N of the signal B are important. For example, in FIG. 9, some of the resource elements C _T of signal A are interfering with resource elements N of signal B. FIG.

When the interference reduction unit 105 estimates the interference propagation path characteristic _IA , it is necessary to specify the section by applying an FFT window at the position of the resource element N of the signal B. FIG. This section will be described with reference to FIG. FIG. 10 shows the waveform of the signal of the resource element _CT of signal A and the section to which the FFT window is applied. From FIG. 10, the FFT window is applied to the phase-continuous symbols. That is, the FFT window is applied to the locations where the waveform of the signal is continuous, so that the interference reduction section 105 can accurately estimate the interference propagation path characteristic _IA . In this embodiment, the symbols with consecutive _phases assigned to the resource elements CT are known symbols. Note that the symbols whose phases are continuous are not limited to known symbols, and may be, for example, data symbols.

In the case of FIG. 9, signal A has a configuration in which known symbols with consecutive phases are assigned to two resource elements whose time zones overlap with resource element N of signal B. In FIG. The control unit 102 thus continues to configure the signal A represented in FIG.

Returning to FIG. 8, transmitting section 103 next modulates the signal sent from control section 102 and transmits it to radio communication apparatus 200 (step S103).

Next, control unit 102 checks whether or not a termination command to terminate the operation of wireless communication device 100 has arrived (step S104). This end command is a command to end the operation of the wireless communication device 100 in this flow, and is transmitted to the control unit 102 by input by the user or by the reception unit 104 receiving a signal including the end command. This end command may be a command to immediately end the operation of wireless communication device 100 .

If the end command has not reached the control unit 102 (step S104: No), the process returns to step S101. On the other hand, if the control unit 102 has received this end command (step S104: Yes), the flow ends and the wireless communication device 100 ends its operation.

The operation of allocating symbols to resource elements performed by radio communication apparatus 100 when forming signal A has been described above. In the example of FIG. 9, the signal B shown in FIG. 3 and part of the signal A shown in FIG. 4 have been explained, but the resource element N in the signal B and the resource element _CT in the signal A are the same. is.

Also, in the example in FIG. 9, signal A is a signal in which symbols with continuous phases are assigned to a plurality of resource elements whose time zones overlap with resource element N of signal B. FIG. A case where signal A is a signal in which symbols with consecutive phases are not assigned to a plurality of resource elements whose time zones overlap with resource element N of signal B will be described using FIG.

In FIG. 11, like FIG. 9, a part of the configuration of the signal A and the signal B is arranged in chronological order. The difference between FIG. 11 and FIG. 9 is the time-series shift between the signal B and the signal A that interferes by going around. Control unit 102 detects that this time-series deviation is t _lag2 from the same operation as described with reference to FIG.

In this case, the resource elements of signal A interfering with resource element N of signal B are part of resource elements _{CT and part of resource elements DT .} Known symbols are assigned to one of these two resource elements, and data symbols are assigned to the other. In other words, symbols with continuous phases are not assigned. Therefore, the waveforms of the signals in these two resource elements are not continuous in the interval where the interference reduction unit 105 applies the FFT window. If the waveform of the signal is not continuous, the accuracy of the interference propagation path characteristic _IA estimated by the interference reduction section 105 is reduced. Therefore, control section 102 configures signal a in which symbols with continuous phases are assigned to a plurality of resource elements whose time zones overlap resource element N of signal B. FIG.

This signal a is transmitted to the wireless communication device 200 through the transmission section 103 . This signal a also interferes with the signal B in the same way as the signal A does. The interference propagation path characteristic of the interference that this signal a gives to signal B is assumed to be I _A without change. FIG. 11 shows parts of the interfering signal a and signal B arranged in chronological order. By using the signal a, two resource elements whose time zones overlap with the resource element N of the signal B are assigned symbols whose phases are continuous. The interval in which the interference reduction unit 105 applies the FFT window spans two resource elements to which the symbols with consecutive phases described in FIG. 10 are assigned. As in the case described with reference to FIG. 9, the FFT window is applied to the place where the waveform of the signal is continuous, so that the interference reduction unit 105 can accurately estimate the interference propagation path characteristics _IA . .

As described above, even if the phases of the symbols assigned to the resource elements of the signal A that interfere with the resource elements N of the signal B are not continuous, by changing the symbol assignment, the resource elements of the signal B can be Symbols with continuous phases can be assigned to two resource elements whose time zones overlap with N.

Although the present embodiment has been described above, various modifications can be implemented and executed. For example, in the present embodiment, in the communication system of radio communication apparatuses 100 and 200 shown in FIG. 2, full duplex communication is performed using all of frequency band α in which signal B is received. Radio communication apparatuses 100 and 200 may perform full-duplex communication in some frequency bands. For example, when frequency band α can be subdivided into frequency bands α ₁ and α ₂ , signal B is transmitted from radio communication apparatus 200 using frequency bands α ₁ and α ₂ , but radio communication apparatus 100 transmits frequency band α ₁ may be used to transmit signal A for full-duplex communication, and frequency band α ₂ may be used to receive signal B. Conversely, signal B is transmitted from radio communication apparatus ₂₀₀ using frequency band α1, while radio communication apparatus ₁₀₀ transmits signal _A using frequency bands α1 and α2 to perform full-duplex communication. can be As for time zones, full-duplex communication may be performed in some time zones.

Also, the configuration of signal B in this embodiment assigns nulls to resource elements in some frequency bands and some time bands. In this signal B, the number of resource elements to which nulls are assigned may be increased or decreased. In addition, in this signal B, null may be assigned not only to some time zones but also to all time zones. In this case, control section 102 does not need to detect a time-series deviation between signals A and B that cause interference.

Signal A may also have a configuration as shown in FIG. FIG. 12 shows the configuration of a signal in which symbols with consecutive phases are assigned to adjacent frequency bands in the same time zone as the resource element _CT to which symbols with consecutive phases are assigned. There is a possibility that symbols from adjacent frequency bands may leak into the resource element N to which nulls of the signal B are assigned. By allocating known symbols with continuous phases to the resource elements of the frequency bands on both sides of the resource element C _T in the signal A, the leakage of symbols from the frequency bands on both sides of the resource element N is reduced, thereby reducing interference. In section 105, the interference propagation path characteristics _IA can be estimated with high accuracy.

In addition, in the signals A and a in this embodiment, symbols with continuous phases are assigned to two resource elements, but even if symbols with continuous phases are assigned to three or more resource elements, good. In addition to the frequency bands to which nulls are assigned in signal B, symbols with continuous phases may be assigned to a plurality of resource elements arranged in time series, as in the present embodiment. Note that when radio communication apparatus 100 allocates symbols with continuous phases to a plurality of resource elements arranged in time series in addition to the frequency band to which nulls are allocated in this signal B, at least some of them have phases. Assign non-consecutive symbols.

Further, in the present embodiment, when the time-series shift between signal A and signal B that has received interference from signal A is greater than the time length of one resource element, radio communication apparatus 100 changes the configuration of signal A. , signal a. By changing the transmission timing of signal A, radio communication apparatus 100 has a plurality of resources allocated with symbols that are continuous with the time period of resource elements allocated with nulls of signal B and the phase of signal A that causes interference. You may make it overlap with the time zone of an element.

In addition, in the present embodiment, radio communication apparatus 100 configures signals so that interference propagation path characteristics _IA can be accurately estimated even when signal B and interfering signal A have a time-series deviation. there is On the other hand, regarding interference, the same applies to wireless communication apparatus 200, which is the other party of full-duplex communication. That is, as shown in FIG. 13 , signal A received by wireless communication device 200 is interfered by signal B transmitted by wireless communication device 200 .

Similarly to radio communication apparatus 100, radio communication apparatus 200 also estimates the interference propagation path characteristics of the interference that signal A receives from signal _B (hereinafter referred to as IB). Radio communication apparatus 200 generates a signal that reduces this interference (hereinafter referred to as RB) from signal _B and interference channel characteristic _IB . Radio communication apparatus 200 can reduce the interference of signal _B and demodulate data A using this signal RB.

Radio communication apparatus 100 may configure and transmit a signal that allows radio communication apparatus 200 to accurately estimate interference propagation path characteristic _IB .

For example, the signal transmitted by the wireless communication device 200 is signal 2B. An example of the configuration of this signal 2B will be described with reference to FIG. Signal 2B, like signal B, has symbols assigned to resource elements separated by frequency bands and time bands. Also, unlike the signal B, this signal 2B is assigned known symbols and data symbols. In FIG. 14, resource elements to which known symbols are assigned are represented as resource elements _PR .

The signal transmitted by the radio communication apparatus 100 in this case is assumed to be a signal 2A. An example of the configuration of this signal 2A will be described with reference to FIG. Signal 2A, like signal A, has symbols assigned to resource elements separated by frequency bands and time bands. Also, unlike the signal A, this signal 2A has nulls assigned to chronologically continuous resource elements in some frequency bands. In addition, known symbols whose phases are continuous are assigned to both neighboring frequency bands in the same time band as the null-assigned time band.

Similar to FIG. 13, signal 2B interferes with signal 2A. The interference propagation path characteristic of the interference that the signal 2A receives from the signal 2B remains the interference propagation path characteristic _IB .

It should be noted that, in the same time zone as the time zone to which this null is assigned, known symbols with continuous phases are assigned to both neighboring frequency bands because This is because there is a possibility that signals may leak from the frequency band of By allocating known symbols with continuous phases to the resource elements of the frequency bands on both sides of the resource element to which the null is allocated, leaking into the resource element to which the null is allocated can also be a known symbol. Since radio communication apparatus 200 can remove the influence of this leaked known symbol, it is possible to accurately estimate interference propagation path characteristic _IB .

The configuration of the signal 2B shown in FIG. 14 and the configuration of the signal 2A shown in FIG. 15 are examples, and do not limit the assignment of symbols. Various known symbols, data symbol assignments, and null assignments to resource elements are conceivable, and any combination is possible. Note that if the frequency band to which the resource elements assigned null in the signal 2A belong and the frequency band to which the resource elements assigned the known symbols with continuous phase in the signal 2B belong are the same, the radio communication apparatus 200 It is possible to accurately estimate the interference propagation path characteristic _IB .

The interference that the signal 2B gives to the signal 2A when the signals 2A and 2B are used will be described with reference to FIG. FIG. 16 shows that known symbols assigned to resource elements _PR of signal 2B interfere with resource elements of signal 2A. As in the case described with reference to FIG. 9, the interfering signal 2B is received by the wireless communication device 200, so the time zone of the signal 2A and the time zone of the signal 2B do not necessarily match. For example, in FIG. 16, signals 2A and 2B are offset by t _lag3 .

In FIG. 16, the known symbols of signal 2B interfere with the null-assigned resource elements of signal 2A. Wireless communication apparatus 200 can acquire the interference caused by the known symbols of signal 2B. It is possible to accurately estimate the interference propagation path characteristic _IB . Therefore, even if the signal 2A and the signal 2B that interferes with the signal 2A have a time _- series deviation, the radio communication apparatus 200 can accurately estimate the interference propagation path characteristic IB.

As described above, radio communication apparatus 100 may configure and transmit signal 2A that enables radio communication apparatus 200 to accurately estimate interference propagation path characteristic _IB .

Note that the known symbols of signal 2B interfere with the null-assigned resource elements of signal 2A, so that radio communication apparatus 200 can acquire the interference given by the known symbols of signal 2B. If the time-series lag in signal 2A and signal 2B that interferes with signal 2A is greater than t _lag3 and the known symbols of signal 2B interfere with the data symbols of signal 2A, nulls are assigned by wireless communication apparatus 200. Known symbols need to be assigned to interfere with the assigned resource elements.

Also, for the sake of explanation, FIG. 16 shows part of signal 2B and signal 2A, respectively, but the same applies to the interference given by other resource elements PR in signal _2B to the resource elements of signal 2A.

Also, the functions of the wireless communication device 100 in this embodiment can be realized by a program. This program may be stored in a computer-readable storage medium such as a CD-ROM, a memory card, a CD-R and a DVD (Digital Versatile Disk) as a file in an installable format or an executable format. good. In addition, this program may be stored on a computer connected to a network such as the Internet and provided via the network, or may be provided by being incorporated in a storage medium such as a ROM, HDD, or SSD. may

As described above, the wireless communication device 100 of the present embodiment transmits a signal to which symbols whose phases are continuous over a plurality of resource elements in time series are assigned in full-duplex communication with the wireless communication device 200. do. Radio communication apparatus 100 allocates symbols with continuous phases, so that resource elements N of a signal transmitted by radio communication apparatus 200 and resource elements C _T to which symbols with continuous phases are allocated are arranged in time series. It becomes easy to overlap. Also, radio communication apparatus 100 allocates symbols with continuous phases such that resource elements N and symbols with continuous phases overlap in time zones. By doing so, even if there is a time-series deviation between the signal transmitted by wireless communication apparatus 200 and the signal transmitted by wireless communication apparatus 100 and causing interference, wireless communication apparatus 100 can detect the interference propagation path characteristic I _A can be estimated with high accuracy.

In addition, radio communication apparatus 100 transmits a signal to which nulls are assigned over a plurality of resource elements in time series. Radio communication apparatus 100 allocates nulls to the plurality of resource elements, so that the resource elements to which symbols in the signal transmitted by radio communication apparatus 200 are allocated and the resource elements N to which nulls are allocated overlap in time series. easier. By doing so, even if there is a time-series deviation between the signal transmitted by wireless communication device 100 and the signal transmitted by wireless communication device 200 and causing interference, wireless communication device 200 can detect the interference propagation path characteristic I _B can be estimated with high accuracy.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These new embodiments can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

REFERENCE SIGNS LIST 10 terminal 20 base station 100 wireless communication device 101 acquisition unit 102 control unit 103 transmission unit 104 reception unit 105 interference reduction unit 106 output unit 200 wireless communication device 250 network

Claims (12)

a receiving unit that receives a first OFDM (Orthogonal Frequency Division Multiplexing) signal in a receiving frequency band and a receiving time band;
a processing unit that generates a second OFDM signal;
a transmitter that transmits the second OFDM signal in a transmission frequency band and a transmission time band;
with
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to a plurality of resource elements separated by frequency bands and time bands,
At least one first resource element in the first frequency band of the first OFDM signal is assigned a null or a symbol less than a first power;
The resource elements in the first frequency band of the second OFDM signal include second resource elements in which known symbols whose phases are consecutive to at least two consecutive resource elements in a time band are assigned, and In addition, including a third resource element to which a symbol different from the known symbol is assigned,
A wireless communication device in which the second resource element overlaps the time zone of the first resource element. the first OFDM signal is interfered by a third OFDM signal transmitted before the second OFDM signal;
The processing unit detects a time lag between the first OFDM signal and the third OFDM signal, and allocates the second resource element to a time slot that overlaps the first resource element based on at least the time lag.
A wireless communication device according to claim 1 . resource elements in the first frequency band of the first OFDM signal include, in addition to the first resource elements, fourth resource elements to which symbols are allocated;
The radio communication device according to claim 1 or 2. Symbols containing data are allocated to resource elements in time zones adjacent before and after the first resource element of the first OFDM signal,
Symbols containing data are allocated to resource elements in time zones adjacent before and after the second resource element of the second OFDM signal,
The radio communication device according to any one of claims 1 to 3. wherein the first resource element is a resource element to which null is assigned;
5. The radio communication device according to any one of claims 1 to 4. The second resource elements are at least two resource elements consisting of the first frequency band and the first time zone,
The resource elements of the second OFDM signal are a second frequency band adjacent to the first frequency band and the first time band, and include a fifth resource element to which the known symbol is assigned.
6. The radio communication device according to any one of claims 1 to 5. resource elements in a frequency band other than the first frequency band of the second OFDM signal include at least one resource element to which a symbol whose phase is not continuous is assigned;
7. The radio communication device according to any one of claims 1-6. a receiving unit that receives a first OFDM (Orthogonal Frequency Division Multiplexing) signal in a receiving frequency band and a receiving time band;
a processing unit that generates a second OFDM signal;
a transmitter that transmits the second OFDM signal in a transmission frequency band and a transmission time band;
with
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to resource elements separated by frequency bands and time bands,
a known symbol is assigned to at least one first resource element in the first frequency band of the first OFDM signal;
resource elements in the first frequency band of the second OFDM signal are assigned nulls, are consecutive in at least two time bands, second resource elements in the same frequency band , and symbols in addition to the second resource elements a third resource element assigned to
A fourth resource element included in the second OFDM signal in the same continuous time band as the second resource element and in a frequency band adjacent to the second resource element has a continuous phase. is assigned a known symbol for
A wireless communication device in which the second resource element overlaps the time zone of the first resource element. receiving a first OFDM (Orthogonal Frequency Division Multiplexing) signal in the reception frequency band and the reception time band;
generating a second OFDM signal;
transmitting the second OFDM signal in a transmission frequency band and a transmission time band;
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to a plurality of resource elements separated by frequency bands and time bands,
At least one first resource element in the first frequency band of the first OFDM signal is assigned a null or a symbol less than a first power;
The resource elements in the first frequency band of the second OFDM signal include second resource elements in which known symbols whose phases are consecutive to at least two consecutive resource elements in a time band are assigned, and In addition, including a third resource element to which a symbol different from the known symbol is assigned,
A method in which the second resource element overlaps the first resource element in a time zone. receiving a first OFDM (Orthogonal Frequency Division Multiplexing) signal in the reception frequency band and the reception time band;
generating a second OFDM signal;
transmitting the second OFDM signal in a transmission frequency band and a transmission time band;
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to resource elements separated by frequency bands and time bands,
a known symbol is assigned to at least one first resource element in the first frequency band of the first OFDM signal;
resource elements in the first frequency band of the second OFDM signal are assigned nulls, are consecutive in at least two time bands, second resource elements in the same frequency band , and symbols in addition to the second resource elements a third resource element assigned to
A fourth resource element included in the second OFDM signal in the same continuous time band as the second resource element and in a frequency band adjacent to the second resource element has a continuous phase. is assigned a known symbol for
A method in which the second resource element overlaps the first resource element in a time zone. to the computer,
receive a first OFDM (Orthogonal Frequency Division Multiplexing) signal in the reception frequency band and the reception time band;
generating a second OFDM signal;
A program for transmitting the second OFDM signal in a transmission frequency band and a transmission time band,
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to a plurality of resource elements separated by frequency bands and time bands,
At least one first resource element in the first frequency band of the first OFDM signal is assigned a null or a symbol less than a first power;
The resource elements in the first frequency band of the second OFDM signal include second resource elements in which known symbols whose phases are consecutive to at least two consecutive resource elements in a time band are assigned, and In addition, including a third resource element to which a symbol different from the known symbol is assigned,
The second resource element is a program whose time zone overlaps with that of the first resource element. to the computer,
receive a first OFDM (Orthogonal Frequency Division Multiplexing) signal in the reception frequency band and the reception time band;
generating a second OFDM signal;
A program for transmitting the second OFDM signal in a transmission frequency band and a transmission time band,
the receive frequency band and the transmit frequency band overlap in at least a first frequency band;
the reception time period and the transmission time period overlap at least partially;
The first OFDM signal and the second OFDM signal are signals allocated to resource elements separated by frequency bands and time bands,
a known symbol is assigned to at least one first resource element in the first frequency band of the first OFDM signal;
resource elements in the first frequency band of the second OFDM signal are assigned nulls, are consecutive in at least two time bands, second resource elements in the same frequency band , and symbols in addition to the second resource elements a third resource element assigned to
A fourth resource element included in the second OFDM signal in the same continuous time band as the second resource element and in a frequency band adjacent to the second resource element has a continuous phase. is assigned a known symbol for
The second resource element is a program whose time zone overlaps with that of the first resource element.

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