JP5138761B2 - Transmitter and transmission method - Google Patents

Description

  The present invention relates to a transmitter and a transmission method, and more particularly, to a transmitter and a transmission method for wirelessly transmitting signals from a plurality of transmission antennas to a receiver.

In recent years, DTD (Delay Transmit Diversity) or CDTD (Cyclic Delay Transmit Diversity) for transmitting simultaneously from a transmitter having a plurality of transmission antennas with different delays for each transmission antenna. Multicarrier transmission to be used has been proposed (Non-Patent Document 1).
According to the technique described in Non-Patent Document 1, for example, a signal is transmitted from a transmitter having two different transmission antennas to a receiver. The receiver receives a composite wave of signals transmitted from the two transmission antennas of the transmitter by the reception antenna.

  FIG. 28A is a diagram illustrating a delay profile that is a time domain representation of a propagation path between a transmission antenna and a reception antenna when a signal is transmitted from one of the two transmission antennas. The horizontal axis represents time, and the vertical axis represents received power. As shown in the figure, two signals w01 and w02 are received by the receiver at different times. FIG. 28B is a diagram illustrating a delay profile that is a time domain representation of a propagation path between a transmission antenna and a reception antenna when a signal is transmitted from the other transmission antenna of the two transmission antennas. The horizontal axis represents time, and the vertical axis represents received power. As shown in the figure, three signals w03 to w05 are received by the receiver at different times.

A signal transmitted from the transmitting antenna having the propagation path shown in FIG. 28B to the receiving antenna is transmitted from the transmitting antenna having the propagation path shown in FIG. 28A to the receiving antenna. , That is, when the above DTD or CDTD is adopted between one transmitting antenna and the other transmitting antenna, as shown in FIG. 28A and 28B can be regarded as having arrived at the receiving antenna through the propagation path obtained by synthesizing the delay profiles shown in FIGS. FIG. 29 (b) is a frequency domain representation of FIG. 29 (a). dmax indicates the maximum delay time.
Since the frequency selectivity of the channel can always be strengthened by using the above transmission diversity method, frequency diversity effect is obtained and excellent in multicarrier transmission such as OFDM (Orthogonal Frequency Division Multiplexing) method. An average BER (Bit Error Rate) characteristic can be obtained.
The difference between DTD (Delay Transmit Diversity) and CDTD, and the cyclic delay are described in Non-Patent Document 1.

FIGS. 30A and 30B are diagrams illustrating an example of a signal when DTD is applied. FIG. 30A shows a signal transmitted from the first transmission antenna, and FIG. 30B shows a signal transmitted from the second transmission antenna. Here, a delay is added to the signal transmitted from the second transmission antenna with respect to the signal transmitted from the first transmission antenna.
FIGS. 30A and 30B show a case where the effective symbol section is 4 samples and the guard interval section is 1 sample. Here, focusing on the effective symbol period, the second transmission antenna has a delay of one sample compared to the first transmission antenna.

FIGS. 31A and 31B are diagrams illustrating an example of signals when CDTD is applied to FIG. FIG. 31A shows a signal transmitted from the first transmission antenna, and FIG. 31B shows a signal transmitted from the second transmission antenna. Here, a cyclic delay is added to the signal transmitted from the second transmission antenna with respect to the signal transmitted from the first transmission antenna. FIGS. 31A and 31B show a case where the effective symbol interval is 4 samples and the guard interval interval is 1 sample. Here, focusing on the effective symbol period, the second transmission antenna has a delay of one sample compared to the first transmission antenna.
In multicarrier transmission, a pilot channel signal, which is a known signal at a known interval, is used as a reference signal for SINR (Signal to Interference plus Noise Ratio) estimation and propagation path estimation. Insert (Non-Patent Document 2).

32 and 33 are diagrams showing pilot channels arranged in subchannels, where the horizontal axis is frequency f and the vertical axis is time t. FIG. 32 shows a case where pilot channels are inserted at equal intervals of the number of subcarriers ΔNf in subcarriers within the same OFDM symbol. Pilot channels are arranged in regions r01 to r04 in FIG. FIG. 33 shows a case where pilot channels are inserted into regions r06 to r09 at equal intervals of the number of subcarriers ΔNf in subcarriers of different OFDM symbols.
32 and 33, when calculating propagation path estimated values in subcarriers in the regions r05 and r10, for example, propagation calculated from four pilot channels connected by arrows D01 in FIG. 32 and arrows D02 to D04 in FIG. By setting the average value of the path estimation values, it is possible to accurately estimate the propagation path.

IEICE Technical Report RCS2004-392, “Effects of Cyclic Delay Transmit Diversity on DS-CDMA with Frequency Domain Equalization” 3GPP contribution, R1-050853, “Common Pilot Channel Structure for OFDM Based Radio Access in Evolved UTRA Downlink”

As described above, in multicarrier transmission such as OFDM, frequency diversity can be enhanced by applying transmission diversity such as CDTD, and a good average BER characteristic can be obtained due to the frequency diversity effect. On the other hand, when the frequency selectivity of the received signal is strong and the frequency fluctuation becomes severe, the difference in the propagation path of each pilot channel inserted in the subcarrier increases as shown in FIG. FIG. 34 (a) shows the received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis, and the received power of the received signal in the pilot channel varies greatly. FIG. 34 (b) shows the arrangement of the pilot channels in FIG.
As described above, when the propagation paths of the subcarriers around the pilot channel are estimated using the average of propagation path estimation values calculated from the four pilot channels in FIG. 34 (b), the received power of each pilot channel is greatly different. Therefore, there arises a problem that the propagation path estimation accuracy deteriorates.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transmitter capable of accurately estimating a propagation path with a receiver even when frequency selectivity is strong. And providing a transmission method.

(1) In the transmitter according to one aspect of the present invention, in the case where phase rotation with small frequency fluctuation is given to each subcarrier, a common pilot channel is arranged and phase rotation with high frequency fluctuation is given to each subcarrier. In this case, a subcarrier allocation unit that arranges the common pilot channel and the dedicated pilot channel is provided.

(2) In the transmitter according to another aspect of the present invention, in the case where phase rotation with a frequency fluctuation pitch with a small frequency fluctuation is given to each subcarrier, a common pilot channel is arranged and the frequency fluctuation pitch with a large frequency fluctuation pitch is provided. Is provided for each subcarrier, a subcarrier allocating unit for arranging the common pilot channel and the dedicated pilot channel is provided.

(3) In the transmission method according to one aspect of the present invention, in the case where phase rotation with small frequency fluctuation is given to each subcarrier, a common pilot channel is arranged and phase rotation with high frequency fluctuation is given to each subcarrier. In this case, a common pilot channel and a dedicated pilot channel are arranged.

(4) In the transmission method according to another aspect of the present invention, in the case where phase rotation with a frequency fluctuation pitch with a small frequency fluctuation is given to each subcarrier, a common pilot channel is arranged and the frequency fluctuation pitch with a large frequency fluctuation pitch is provided. When providing the phase rotation for each subcarrier, a common pilot channel and a dedicated pilot channel are arranged.

In the present invention, the number of pilot channels per transmission signal band is changed by subcarrier allocation means depending on whether or not to perform delay transmission diversity in which a signal is transmitted with a delay between a plurality of transmission antennas.
Thus, the channel estimation accuracy can be changed by changing the number of pilot channels per transmission signal band depending on whether or not to perform delayed transmission diversity.

It is a figure which shows the transmission method of the signal from the transmitter 2 provided with the several transmission antennas 1a and 1b to the receiver 4 provided with the receiving antenna 3a. FIG. 10 is a diagram showing a delay profile in which a propagation path between a transmission antenna 1a included in a transmitter 2 and a reception antenna 3a included in a receiver 4 is expressed in the time domain. It is a figure which shows an example of arrangement | positioning of a common pilot channel when not using CDTD. It is a figure which shows arrangement | positioning of a common pilot channel in the case of performing CDTD. It is a figure which shows an example in the case of arrange | positioning a common pilot channel to a different OFDM symbol. It is a figure which shows an example in the case of arrange | positioning a common pilot channel to a different OFDM symbol. It is a block diagram which shows the structure of the transmitting apparatus by the 1st Embodiment of this invention. It is a figure which shows an example of a structure of the signal which a transmitter transmits. It is a figure which shows pilot channel arrangement | positioning in the case of performing CDTD in the transmitter which transmits the signal which has arrange | positioned the common pilot channel previously. When CDTD is performed, it is a figure which shows the case where it arrange | positions in a different OFDM symbol in the arrangement | positioning which inserts an individual pilot channel between the common pilot channels arrange | positioned previously. It is a figure which shows the example of arrangement | positioning which inserts a separate pilot channel in the case of performing CDTD, when a common pilot channel is previously arrange | positioned in a different OFDM symbol. It is a block diagram which shows the structure of the transmitting apparatus by the 2nd Embodiment of this invention. It is a figure which shows an example of a structure of the signal which a transmitter transmits. It is a top view which shows an example of arrangement | positioning relationship between a base station apparatus and a receiver. It is a figure which shows the structure of the transmission signal to the receiver 11a-the receiver 11c of the 1st OFDM symbol by which the common pilot channel and a dedicated pilot channel are arrange | positioned. It is a figure which shows the case where a signal is transmitted by applying CDTD with a transmitter with n transmitting antennas. It is a figure which shows an example of the method of assigning the user in a shared data channel to a subcarrier. It is a figure for demonstrating the case where a user is allocated to a subcarrier in a shared data channel. It is a figure which shows the case where the pilot channel arrange | positioned previously is a common pilot channel. It is a figure etc. which show the delay profile which expressed the propagation path in the time domain. It is a figure which shows the structure of the subcarrier transmitted to a receiver from a transmitter. It is a block diagram which shows the structure of the transmitting apparatus by the 3rd Embodiment of this invention. It is a figure which shows the case where the pilot channel arrange | positioned previously is a common pilot channel. It is a figure which shows the arrangement pattern of the pilot channel in this embodiment. It is a figure which shows the arrangement pattern of the pilot channel in this embodiment. It is a figure which shows the delay profile which expressed the propagation path to the time domain. It is a block diagram which shows the structure of the transmitting apparatus by the 4th Embodiment of this invention. It is a figure which shows the delay profile which is a time-domain expression of the propagation path between a transmitting antenna and a receiving antenna at the time of transmitting a signal with two transmitting antennas. It is a figure etc. which show the delay profile of the signal transmitted from two transmission antennas. It is a figure which shows an example of the signal at the time of applying DTD. It is a figure which shows an example of the signal at the time of applying CDTD. It is a figure which shows the pilot channel arrange | positioned at a subchannel. It is a figure which shows the pilot channel arrange | positioned at a subchannel. It is a figure for demonstrating the problem of a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a case where CDTD is used will be described as a representative example of delayed transmission diversity in which a signal is transmitted with a delay between a plurality of transmission antennas.
There are various types of pilot channels to be inserted into subcarriers for propagation path estimation depending on their roles. In Evolved UTRA & UTRAN studied in 3GPP (3rd Generation Partnership Project), a common pilot channel (Downlink Common Pilot Channel) and a dedicated pilot channel (Downlink Dedicated Pilot Channel) are proposed as pilot channels of physical channels. The common pilot channel is a pilot channel that is commonly used for propagation path estimation in a plurality of receivers and is regularly arranged. The dedicated pilot channel is a pilot channel that is used for propagation path estimation in one receiver and is temporarily arranged.
In the following embodiment, a case where a common pilot channel and a dedicated pilot channel are used as pilot channels will be described.

The common pilot channel corresponds to a pilot channel CPICH of W-CDMA (Wideband Code Division Multiple Access), and is used for estimation of downlink propagation path conditions, cell search, and uplink transmission power control in AMCS (Adaptive Modulation and Coding Scheme). Used for channel loss measurement.
The dedicated pilot channel is transmitted to a dedicated mobile station from a transmission antenna having a different propagation path (directivity) from a cell shared antenna such as an adaptive array antenna, or a downlink common pilot channel is transmitted to a mobile station with low reception quality. It can also be used for the purpose of reinforcement. Note that the physical channels of W-CDMA and HSDPA (High Speed Downlink Packet Access) of the common pilot channel and the dedicated pilot channel are described in “Keiji Tachikawa,“ W-CDMA mobile communication system ”, ISBN4-621-04894-5. "It is described in.

(First embodiment)
In the present embodiment, a technique for changing the common pilot channel arrangement depending on whether or not CDTD is used will be described.
FIG. 1 is a diagram illustrating a method of transmitting a signal from a transmitter 10 including a plurality of transmission antennas 1 and 2 to a receiver 11 including a reception antenna 3. As shown in the figure, the transmitter 10 transmits the signals s1 and s2 from the two transmission antennas 1 and 2 included therein, respectively, and the receiver 11 receives the signals s1 and s1 through the single reception antenna 3 included therein. Receive s2.

FIG. 2A shows a time domain representation of a propagation path between the transmission antenna 1 provided in the transmitter 10 (FIG. 1) and the reception antenna 3 provided in the receiver 11 (FIG. 1). It is a figure which shows a profile. As shown in the figure, the receiving antenna 3 receives the signal w1 from the transmitting antenna 1 at time t1.
FIG. 2B is a diagram illustrating a delay profile in which a propagation path between the transmission antenna 2 included in the transmitter 10 and the reception antenna 3 included in the receiver 11 is expressed in the time domain. . As shown in the figure, the receiving antenna 3 receives the signal w2 from the transmitting antenna 2 at time t2. 2C and 2D will be described later.

  FIG. 3A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG. 3B is a diagram showing an example of the arrangement of common pilot channels when CDTD is not used. In the figure, the horizontal axis is the frequency axis f, and the vertical axis is the time axis t. FIG. 3B illustrates a case where the frequency f is divided into 31 subcarriers and the time t is divided into 7 OFDM symbols. In the embodiment of the present invention, an area determined by a predetermined frequency band and a predetermined time length is called a chunk. An area determined by a basic frequency band (frequency band of one subcarrier) and a basic time length (time length in which one OFDM symbol is arranged) is called a unit area. A chunk is composed of one or a plurality of unit areas. In the embodiment of the present invention, when the unit region s (1, 1) having the lowest frequency and the earliest time is used as a reference, the basic time length of the m-th row is n columns. A region determined by the frequency band that is the basis of the eye is represented as a unit region s (m, n).

  Unit regions s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21), s (1,25) , S (1, 29) indicate areas where common pilot channels are arranged. That is, they are arranged in OFDM symbols of the same time at intervals of ΔNf = 4 in the frequency axis f direction. The common pilot channel is multiplied by an orthogonal variable spreading factor (OVSF) code, which is an orthogonal code, in the frequency axis f direction. A series of orthogonal codes # 1 to # 4 includes an OVSF code sequence CSF. The components when SF = 4 of m (m = 1, 2,..., SF and SF are code lengths) are shown. For example, when SF = 4, C4.1 = (1,1,1,1), C4.2 = (1,1, −1, −1), C4.3 = (1, −1,1) -1) and C4.4 = (1, -1, -1, 1). The pilot channel is multiplied by a different OVSF code sequence for each cell, each sector, or each transmission antenna, and is used for distinguishing between cells, sectors, and transmission antennas. The same applies to other embodiments described later.

  CSF. m = (# 1, # 2,..., #SF) (1)

The arrangement interval ΔNf = 4 of the common pilot channel in FIG. 3B is an example, and is appropriately determined depending on the wireless communication system to be applied. The transmitter 10 (FIG. 1) transmits simultaneously the signal in which the common pilot channel shown in FIG. 3B is arranged from the transmission antenna 1 (FIG. 1) and the transmission antenna 2 (FIG. 1). This means that the delay time τ = 0 between the transmission antenna 1 and the transmission antenna 2.
The receiver 11 receives a signal arranged as shown in FIG. 3B from the transmitter 10 through the propagation path of the delay profile shown in FIG.
That is, the receiver 11 receives signals w1 and w2 from the transmitter 10 at times t1 and t2, respectively. Note that the propagation path of FIG. 3A is a representation of the propagation path of FIG. 2C in the frequency domain, the horizontal axis is the frequency axis f, and the vertical axis is the power axis p of the received power. .

On the receiving side, a despreading process is performed on the common pilot channel inserted in the subcarrier of the received signal using the OVSF code to be multiplied to estimate the propagation path. For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 3B is the result of performing the despreading process in the common pilot channels # 1 to # 4 connected by the arrow D31 in FIG. By Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.
FIG. 3 (b) shows the arrangement of common pilot channels when signals are transmitted simultaneously from two transmission antennas when CDTD is not performed, but the same applies when signals are transmitted from only one transmission antenna. It is.

FIG. 4A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG.4 (b) is a figure which shows arrangement | positioning of a common pilot channel in the case of performing CDTD. In the figure, the unit areas s (1,1), s (1,3), s (1,5), s (1,7), s (1,9), s (1,11), s (1 13), s (1,15), s (1,17), s (1,19), s (1,21), s (1,23), s (1,25), s (1, 27), s (1,29), and s (1,31) indicate areas where common pilot channels are arranged. As shown in FIG. 4B, in the case where CDTD is performed, the subcarrier interval ΔNf of the common pilot channel is arranged smaller than in the case where CDTD is not performed.
In FIG. 4B, they are arranged in the same OFDM symbol with a subcarrier interval of ΔNf = 2 in the frequency axis f direction. The common pilot channel is multiplied by an OVSF code having a code length SF = 4 in the frequency axis f direction. In FIG. 4B, # 1 to # 4 indicate components of the OVSF code sequence.

The transmitter transmits a signal in which the common pilot channel shown in FIG. 4B is arranged, and the transmission antenna 1 (FIG. 1) gives a delay τ to the transmission antenna 2 (FIG. 1). FIG. 2D shows a delay profile expressed in the time domain of the propagation path received by the receiving antenna 3 (FIG. 1). As shown in FIG. 2D, the receiver 11 receives signals w1 and w2 from the transmitter 10 at times t1 and t3 (= t2 + τ). Note that the propagation path in FIG. 4A represents the propagation path in FIG. 2D in the frequency domain.
On the receiving side, a despreading process is performed on the common pilot channel inserted in the subcarrier of the received signal using the OVSF code to be multiplied to estimate the propagation path. For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 4B is obtained from the result of performing the despreading process on the common pilot channels # 1 to # 4 connected by the arrow D41.
Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

In FIG. 4B, the common pilot channels are arranged at equal intervals of ΔNf. However, the present invention is not limited to this. For example, when CDTD is performed, the interval between the common pilot channels is smaller than when CDTD is not performed. Any arrangement may be used.
As described above, when CDTD is performed, the common pilot used for channel estimation is reduced by reducing the arrangement interval ΔNf in the frequency axis f direction between the common pilot channels of the same OFDM symbol when CDTD is not performed. It is possible to reduce the difference in frequency fluctuation between channels.

5 (a) and 6 (a) are diagrams showing received signals with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIGS. 5B and 6B are diagrams illustrating an example in which the common pilot channel is arranged in different OFDM symbols. FIG. 5B shows the arrangement of common pilot channels when CDTD is not performed, and FIG. 6B shows the arrangement of common pilot channels when CDTD is performed. In the case of performing CDTD in FIG. 6B, the subcarrier interval ΔNf with the adjacent common pilot channel is narrowed from ΔNf = 4 when not performing CDTD to ΔNf = 2 over different OFDM symbols.
As shown in FIG. 5 (b), the receiver despreads the propagation path estimation value of the unit region s (2, 6) with four common pilot channels # 1 to # 4 connected by arrows D51 to D53. It is possible to calculate by performing the processing. Further, as shown in FIG. 6 (b), the receiver uses the four common pilot channels # 1 to # 4 connected to the subcarrier propagation path estimated values of the unit region s (2, 6) by arrows D61 to D63. It is possible to calculate by performing despreading processing in # 4.

5B and 6B, the common pilot channel arranged in the OFDM symbol in the first row (unit regions s (1,1) to s (1,31)) has a frequency axis f. The fifth row of OFDM symbols (unit regions s (5,1) to s (5,31)) transmitted after the OFDM symbol of the first row by multiplying the OVSF code sequences # 1 to # 4 in order over the direction. The common pilot channel arranged within is multiplied by an OVSF code sequence that is cyclically shifted by 2 bits from the OVSF code sequence multiplied by the OFDM symbol in the first row in the frequency direction. The order of multiplication of the OVSF code sequences is not limited to this, and any order in which orthogonality with other OVSF code sequences can be maintained by performing despreading processing is acceptable.
As described above, in the case where CDTD is performed, the common pilot used for propagation path estimation is reduced by reducing the arrangement interval ΔNf in the frequency axis f direction between the common pilot channels of different OFDM symbols when CDTD is not performed. It is possible to reduce the difference in frequency fluctuation between channels.

FIG. 7 is a block diagram showing the configuration of the transmitter according to the first embodiment of the present invention. This transmitter includes per-user signal processing units 100a and 100b that perform signal processing for each user. In addition, the control unit 101 outputs CDTD presence / absence information and delay time information between transmission antennas. In addition, the subcarrier insertion arrangement of the common pilot channel is determined from the CDTD presence / absence information notified from the control unit 101, and the allocation of the dedicated pilot channel and the output of the signal processing units 100a and 100b for each user to each subcarrier is further determined. A subcarrier allocation determining unit 102 for determining is included.
In addition, it has a pilot signal generation unit 104 that generates a common pilot channel and a dedicated pilot channel multiplied by the OVSF code sequence and inputs them to the subcarrier allocation unit 103.

Further, a phase rotation amount calculation unit 105 that calculates the phase rotation amount of each subcarrier based on the delay time information between the transmission antennas from the control unit 101 is provided. Further, based on subcarrier allocation information in subcarrier allocation determination section 102, subcarrier allocation section 103 that allocates the outputs of per-user signal processing sections 100a and 100b and the output of pilot signal generation section 104 to each subcarrier. In addition, signal processing units 200a and 200b for each antenna that perform signal processing for each transmission antenna are included.
The pilot signal generation unit 104 generates a common pilot channel signal having a pattern determined by the CDTD presence / absence information output from the control unit, and an individual pilot signal generation that generates a signal that assists the common pilot signal. Part 104b. In addition, the dedicated pilot signal generation unit 104 is used for assisting the common pilot channel in an application corresponding to a signal time variation depending on a moving speed of a transmitter or a receiver or a signal frequency variation due to fading. insert.

The per-user signal processing unit 100a includes an error correction encoding unit 151 that performs error correction encoding of an information data sequence that is transmission data. In addition, a modulation unit 152 that performs modulation processing such as QPSK (Quadrature Phase Shift Keying) and 16QAM (Quadrature Amplitude Modulation) on the output of the error correction coding unit 151 is provided. Since the per-user signal processing unit 100b has the same configuration as the per-user signal processing unit 100a, the description thereof is omitted.
The outputs of the per-user signal processing units 100a and 100b are allocated to appropriate subcarriers in the subcarrier allocation unit 103 that allocates to appropriate subcarriers based on the “subcarrier allocation information” notified from the subcarrier allocation determination unit 102. And then output to the signal processing units 200a and 200b for each antenna. At this time, the subcarrier allocation unit 103 also has a role of allocating the output of the pilot signal generation unit 104 to the positions (chunks) of the common pilot channel and the dedicated pilot channel determined by the subcarrier allocation determination unit 102. .

  The signal processing unit for each antenna 200 a inputs the output of the subcarrier allocation unit 103 to the phase rotation unit 161, performs phase rotation for each subcarrier, and outputs the result to an IFFT (Inverse Fast Fourier Transform) unit 162. . The signal processing unit for each antenna 200a includes a parallel / serial conversion unit 163 that performs parallel / serial conversion on the output of the IFFT unit 162. In addition, a GI (Guard Interval) adding unit 164 that adds a guard interval to the output of the parallel-serial conversion unit 163 is provided. In addition, a filter unit 165 that extracts only a signal in a desired band from the output of the GI adding unit 164 is provided. Further, a D / A (Digital / Analog) conversion unit 166 that performs digital-analog conversion on the output of the filter unit 165 is provided. The per-antenna signal processing unit 200b has the same configuration as the per-antenna signal processing unit 200a. The outputs of the signal processing units 200a and 200b for each antenna pass through the radio frequency conversion unit 167 that performs frequency conversion to a radio frequency, are output to the transmission antenna 1 and the transmission antenna 2, and are transmitted to the receiver as radio signals.

Note that the phase rotation θm when phase rotation is added by the phase rotation unit 161 is θm = 2πfm · (n−1) T. Here, fm is the frequency interval between the 0th subcarrier and the mth subcarrier, and is expressed as fm = m / Ts. Ts indicates the symbol length (time) of the OFDM symbol. (N−1) T indicates the magnitude of the cyclic delay time in the transmission antenna n with respect to the transmission antenna 1.
Although FIG. 7 describes the case of the number of users 2 and the number of transmission antennas 2, the number of users and the number of transmission antennas are not limited to this. The present embodiment can also be applied to a case where a signal multiplied by a specific scramble code determined for each transmission antenna, each sector, and each base station is transmitted for each transmission antenna.

  FIG. 8 is a diagram illustrating an example of a configuration of a signal transmitted by the transmitter. In Evolved UTRA & UTRAN under consideration in 3GPP, the downlink synchronization channel (Downlink Synchronization Channel) is the main physical channel other than the common pilot channel (Downlink Common Pilot Channel) and the dedicated pilot channel (Downlink Dedicated Pilot Channel). A common control channel (Downlink Common Control Channel), a common control channel (Downlink Shared Control Channel), and the like have been proposed.

The downlink synchronization channel DSCH corresponds to the W-CDMA synchronization channel SCH and is used for mobile station cell search, OFDM signal radio frame, time slot, transmission timing interval TTI (Transmission Timing Interval), and OFDM symbol timing synchronization. The
The common control channel DCCCH is broadcast information corresponding to the first common control physical channel P-CCPCH, the second common control physical channel S-CCPCH, and the paging indicator channel PICH in the W-CDMA system, a packet Common control of packet paging indicator PI information (corresponding to paging indicator channel PICH) indicating presence / absence of call, packet paging information corresponding to packet call (corresponding to paging channel PCH), downlink access information (corresponding to downlink access channel FACH), etc. Contains information.

  The downlink shared control signaling channel DSCSCH corresponds to the HS-DSCH related shared control channel HS-SCCH, the downlink dedicated control channel DPCCH, and the acquisition indicator AICH included in the high-speed physical downlink shared channel HS-PDSCH of the HSDPA scheme, Shared by the stations and required for demodulation of the high-speed downlink shared channel HS-DSCH (modulation method, spreading code, etc.), error correction decoding processing and HARQ (Hybrid Automatic Repeat Request) processing for each mobile station This information is used for transmission of various information and radio resource (frequency, time) scheduling information.

The downlink shared data channel DSDCH corresponds to the high-speed downlink shared channel HS-DSCH and the downlink dedicated data channel DPDCH included in the high-speed physical downlink shared channel HS-PDSCH of the HSDPA scheme, and transmits packet data addressed to the mobile station from the upper layer. Is used.
As shown in FIG. 8, after transmitting the common control channel symbol, the shared data channel symbol in which the information data signal of each user is stored is transmitted. The shared data channel symbol has a configuration in which a common pilot channel is arranged as shown in FIGS. 3B, 4B, 5B, and 6B. In the common control channel symbol, arrangement information of the shared data channel symbol is stored.

When receiving the signal having the configuration shown in FIG. 8, the receiver first obtains the arrangement information of the shared data channel symbol using the common control channel symbol. Next, propagation path estimation of each subcarrier of the shared data channel symbol is performed using the common pilot channel of the shared data channel symbol according to the arrangement information. However, a known common pilot channel is inserted into the common control channel symbol in a predetermined arrangement, and propagation path estimation is performed using the common pilot channel.
As described above, when CDTD is performed, as an example, by increasing the number of common pilot channels per transmission signal band as compared with the case where CDTD is not performed, the frequency fluctuation of each pilot channel used for propagation path estimation is increased. The difference can be reduced, and the propagation path can be estimated with high accuracy. Also, CDTD can be performed satisfactorily.

(Second Embodiment)
In the present embodiment, a method for interpolating an individual pilot channel to a pilot channel arranged in advance depending on the presence or absence of CDTD, that is, whether or not CDTD is performed will be described.
As in the first embodiment, as shown in FIG. 1, the transmitter transmits signals from its two transmission antennas, and the receiver receives signals by its single reception antenna. The case will be described. Similarly to the first embodiment, FIG. 2A shows a delay profile that represents a propagation path between the transmission antenna 1 provided in the transmitter and the reception antenna 3 provided in the receiver in the time domain. FIG. 2B shows a delay profile in which the propagation path between the transmission antenna 2 provided in the transmitter and the reception antenna provided in the receiver is expressed in the time domain.

First, in a transmitter to which CDTD is applied, it is assumed that the arrangement of pilot channels is determined in advance by the system scheme or the like. As an example, a case will be described in which pilot channels arranged in advance are arranged with a common pilot channel as shown in FIG.
The transmitter transmits simultaneously a signal in which the common pilot channel shown in FIG. 3B is arranged from the transmission antenna 1 and the transmission antenna 2. This means that the delay time τ = 0 between the transmission antenna 1 and the transmission antenna 2.
The receiver receives from the transmitter the signal arranged as shown in FIG. 3B through the propagation path of the delay profile shown in FIG. The propagation path in FIG. 3A is a representation of the propagation path in FIG. 2C in the frequency domain.

On the receiving side, a despreading process is performed on the common pilot channel inserted in the subcarrier of the received signal using the OVSF code to be multiplied to estimate the propagation path.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 3B is the common pilot channel # 1 connected by the arrow D31 in FIG. 3B as described in the first embodiment. It is obtained from the result of the despreading process in ~ # 4. Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver is assumed to know the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

FIG. 3 (b) shows the arrangement of common pilot channels when signals are transmitted simultaneously from two transmission antennas when CDTD is not performed, but the same applies when signals are transmitted from only one transmission antenna. It is.
FIG. 9A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG. 9B is a diagram showing pilot channel arrangement when CDTD is performed in a transmitter that transmits a signal in which common pilot channels are arranged in advance as shown in FIG. 3B.
As shown in FIG. 9B, when performing CDTD, unit regions s (1,1), s (1,5), s (1,9), s (1, 13), s (1,17), s (1,21), s (1,25), s (1,29), between the common pilot channels, that is, the unit region s (1,3 ), S (1,7), s (1,11), s (1,15), s (1,19), s (1,23), s (1,27), s (1,31) An individual pilot channel is arranged in The dedicated pilot channel is multiplied by a sequence obtained by cyclically shifting the same OVSF code sequence as the common pilot channel by 2 bits. In FIG. 9B, # 1 to # 4 indicate OVSF code sequences.

The transmitter transmits a signal in which the above-described common pilot channel and the dedicated pilot channel shown in FIG. 9B are arranged, and the transmission antenna 2 transmits the signal to the transmission antenna 1 with a delay τ. FIG. 2D shows a delay profile expressed in the time domain of the propagation path received by the receiving antenna. The propagation path in FIG. 9A is assumed to represent the propagation path in FIG. 2D in the frequency domain.
On the receiving side, a despreading process is performed on the common pilot channel and the dedicated pilot channel inserted in the subcarriers of the received signal using the OVSF code to be multiplied, and the propagation path is estimated.

For example, the channel estimation results of the subcarriers of the channel s (2, 6) in FIG. 9B are the common pilot channel and the dedicated pilot channels # 1 to # 1 connected by the arrow D91 in FIG. 9B. 4 is obtained by the result of the despreading process.
Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver is assumed to know the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.
In FIG. 9B, the common pilot channel and the dedicated pilot channel are arranged at equal intervals of ΔNf. However, the arrangement is not limited to this. For example, when CDTD is performed, the pilot channel is compared with the case where CDTD is not performed. Any arrangement may be used as long as the interval is small.

As described above, in the case where CDTD is performed, in contrast to the case where CDTD is not performed, a common pilot used for propagation path estimation is obtained by interpolating a pilot channel previously arranged with individual pilot channels arranged in the same OFDM symbol. The arrangement interval ΔNf in the frequency direction between channels can be reduced, and the difference in frequency fluctuation between the common pilot channels used for propagation path estimation can be reduced.
In addition, the dedicated pilot channel is multiplied by a code sequence obtained by cyclically shifting the OVSF code sequence multiplied by the common pilot channel, so that the propagation path can be estimated using the common pilot channel and the dedicated pilot channel. It is possible to maintain orthogonality with the OVSF code sequence.

FIG. 10A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG. 10B shows a case in which unit regions s (1,1), s (1,5), s (1,9), s (1,13), s (1,17) are preliminarily performed when CDTD is performed. , S (1,21), s (1,25), s (1,29), and OFDM symbols that are different in time between the common pilot channels, that is, s (4,3), s ( 4,7), s (4,11), s (4,15), s (4,19), s (4,23), s (4,27), s (4,31) dedicated pilot channels It is a figure which shows the case where is inserted.
As shown in FIG. 10 (b), when performing CDTD, dedicated pilot channels are arranged in OFDM symbols that are subcarriers between common pilot channels arranged in advance in the frequency axis f direction. .
Similarly to FIG. 9B, the dedicated pilot channel is multiplied by a sequence obtained by cyclically shifting the same OVSF code sequence as the common pilot channel by 2 bits. In FIG. 10B, # 1 to # 4 indicate components of the OVSF code sequence.
The receiver that has received the signal in which the pilot channel shown in FIG. 10B is arranged has, for example, four common pilots connected by arrows D101 to D103 as the propagation path estimation values of the unit region s (2, 6). It is possible to calculate by performing despreading processing on channels 1 and # 4 of dedicated pilot channels.

  FIG. 11A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG. 11B is a diagram illustrating an arrangement example in which a dedicated pilot channel is inserted when CDTD is performed when a common pilot channel is arranged in advance in different OFDM symbols (FIG. 5B). In FIG. 11B, the unit areas s (1,1), s (1,9), s (1,17), s (1,25), s (5,5), s (5,13) , S (5, 21) and s (5, 29) have a common pilot channel. The unit areas s (3,3), s (3,11), s (3,19), s (3,27), s (7,7), s (7,15), s (7,7 23) and s (7, 31) have dedicated pilot channels. # 1 to # 4 indicate components of the OVSF code sequence multiplied by each pilot channel.

In FIG. 11B, the OFDM symbol in the first row (s (1,1) to s (1,31)) and the OFDM symbol in the fifth row (s (5,1) to s (5,31)) , A common pilot channel is arranged, and the common pilot channel arranged in the fifth row OFDM symbol is common to the common symbol arranged in the first row OFDM symbol as in FIG. The OVSF code sequence obtained by cyclically shifting the OVSF code sequence multiplied by the pilot channel by 2 bits is multiplied.
In the frequency axis f direction, the dedicated pilot channel is inserted between the adjacent common pilot channels over different OFDM symbols, and the subcarrier interval ΔNf between the adjacent pilot channels is ΔNf when CDTD is not performed. = 4 to ΔNf = 2. In addition, in the time axis t direction, the dedicated pilot channel is a third row OFDM symbol (s) between the common pilot channel arranged in the first row OFDM symbol and the common pilot channel arranged in the fifth row OFDM symbol. (3,1) to s (3,31)) and the OFDM symbol in the seventh row (s (7,1) to s (7,31)) transmitted after the OFDM symbol in the fifth row Yes. Further, the dedicated pilot channel arranged in the OFDM symbol in the third row is multiplied by the OVSF code sequence obtained by cyclically shifting the OVSF code sequence multiplied by the common pilot channel arranged in the OFDM symbol in the first row by 1 bit, The dedicated pilot channel arranged in the first OFDM symbol is multiplied by the OVSF code series obtained by cyclically shifting the OVSF code series multiplied by the common pilot channel arranged in the fifth row OFDM symbol by 1 bit.
The receiver that has received the signal in which the pilot channel shown in FIG. 11B is arranged has, for example, four common pilots in which the propagation path estimation values of the unit region s (2, 6) are connected by arrows D111 to D113. It is possible to calculate by performing despreading processing on channels 1 and # 4 of dedicated pilot channels.

9B, 10B, and 11B, the dedicated pilot channel is multiplied by a sequence obtained by bit-cycle shifting the same OVSF code sequence as that of the common pilot channel. The arrangement is not limited to this, and any arrangement that can maintain orthogonality with other OVSF code sequences by performing despreading processing may be used.
As described above, in the case where CDTD is performed, in contrast to the case where CDTD is not performed, by interpolating a pilot channel arranged in advance with a dedicated pilot channel arranged in a different OFDM symbol, the pilot channels used for channel estimation are interpolated. It is possible to reduce the arrangement interval ΔNf in the frequency direction and reduce the difference in frequency fluctuation between pilot channels used for propagation path estimation.
In addition, the dedicated pilot channel is multiplied by a code sequence obtained by cyclically shifting the OVSF code sequence multiplied by the common pilot channel, so that the propagation path can be estimated using the common pilot channel and the dedicated pilot channel. It is possible to maintain orthogonality with the OVSF code sequence.

FIG. 12 is a block diagram showing a configuration of a transmitter according to the second embodiment of the present invention.
The transmitter according to the present embodiment includes a control unit 101 that outputs CDTD presence / absence information and delay time information between transmission antennas. Further, the subcarrier insertion arrangement of the dedicated pilot channel is determined from the CDTD presence / absence information notified from the control unit 101, and the common pilot channel and the output of the signal processing units 100a and 100b for each user are allocated to each subcarrier. A subcarrier allocation determining unit 102 for determining is included. In addition, it has a pilot signal generation unit 104 that generates a common pilot channel and a dedicated pilot channel multiplied by the OVSF code sequence and inputs them to the subcarrier allocation unit 103. A phase rotation amount calculation unit 105 that calculates the phase rotation amount of each subcarrier based on the delay time information between the transmission antennas from the control unit 101 is included. Further, based on subcarrier allocation information in subcarrier allocation determination section 102, subcarrier allocation section 103 that allocates the outputs of per-user signal processing sections 100a and 100b and the output of pilot signal generation section 104 to each subcarrier. In addition, signal processing units 200a and 200b for each antenna that perform signal processing for each transmission antenna are included. The pilot signal generation unit 104 is shared with an individual pilot signal generation unit 104b that generates an individual pilot channel signal having a pattern determined by the CDTD presence / absence information output from the control unit 101, and a pattern determined in advance by a system method or the like. A common pilot signal generation unit 104a that generates a pilot channel signal is provided.
Since other configurations are the same as the configuration of the transmitter according to the first embodiment (FIG. 7), the same reference numerals are given and description thereof is omitted.

FIG. 13 is a diagram illustrating an example of a configuration of a signal transmitted by the transmitter. In FIG. 13, the role of each channel is as described in the first embodiment. As shown in the figure, after transmitting the common control channel symbol, the shared data channel symbol storing the information data signal of each user is transmitted. As shown in FIG. 9B, FIG. 10B, and FIG. 11B, the common pilot channel and the dedicated pilot channel are arranged in the shared data channel symbol. The common control channel stores arrangement information of shared data channel symbols. The shared control signaling channel stores arrangement information of dedicated pilot channels.
When receiving the signal having the signal configuration shown in FIG. 13, the receiver first obtains the arrangement information of the shared data channel symbols using the common control channel symbols. At this time, arrangement information of the common pilot channel is obtained.
Next, propagation path estimation is performed on the common pilot channel of the shared data channel symbol according to the common pilot arrangement information.

Next, propagation path estimation of the shared control signaling channel is performed based on the propagation path estimated value, demodulation processing is performed, and dedicated pilot channel information stored in the shared control signaling channel is obtained.
Finally, according to the arrangement information of the common pilot channel and the dedicated pilot channel acquired by the above procedure, the propagation path of the subcarrier to which the user information data is allocated is estimated using the common pilot channel and the dedicated pilot channel.
However, a known common pilot channel is inserted into the common control channel symbol in a predetermined arrangement, and propagation path estimation is performed using the common pilot channel.
In addition, when CDTD is applied to a base station apparatus, and a method of interpolating a common pilot channel arranged in advance with a dedicated pilot channel when performing CDTD as described above, it belongs to the base station apparatus. In the sector, dedicated pilot channels are arranged on the same subcarrier and the same OFDM symbol.

FIG. 14 is a diagram illustrating an example of an arrangement relationship between the base station apparatus and the receiver. As shown in the figure, the base station apparatus 12 has three sectors, sector 13a to sector 13c. The sector 13a transmits a signal to the receiver 11a, the sector 13b transmits a signal to the receiver 11b, and the sector 13c transmits a signal to the receiver 11c. Here, a case where CDTD is performed for transmission from the base station apparatus 12 to the receiver 11a will be described. However, it is assumed that the sectors are synchronized. Further, the common pilot channel and the dedicated pilot channel are multiplied by a different series of OVSF codes for each sector.
First, the base station apparatus 12 transmits a signal to each of the receivers 11a to 11c with the common pilot channel arrangement shown in FIG.
Next, when the base station apparatus 12 performs CDTD on the receiver 11a, transmission is performed in the arrangement shown in FIG. 9B in which the common pilot channel is interpolated with the dedicated pilot channel.
At that time, signals are also transmitted in the dedicated pilot channel arrangement shown in FIG. 9B in the transmission signals to the receiver 11b of the sector 13b and the receiver 11c of the sector 13c.

15 (a) to 15 (c) are OFDM symbols in the first row in which the common pilot channel and the dedicated pilot channel are arranged in FIG. 9 (b), and the receiver 11a to the receiver 11c (FIG. 14). It is a figure which shows the structure of the transmission signal to. OVSF code C4. Multiplying common pilot channel and dedicated pilot channel. In m = (# 1, # 2, # 3, # 4), the sector 13a is multiplied by the OVSF code of C4.1 = (1,1,1,1) as shown in FIG. 15 (a). ing. Further, as shown in FIG. 15B, the sector 13b is multiplied by an OVSF code of C4.2 = (1, 1, −1, −1). The sector 13c is multiplied by an OVSF code of C4.3 = (1, -1, 1, -1).
In the receiver 11a performing CDTD, for example, when calculating the channel estimation value of the unit region s (2, 6) in FIG. 9B, the common pilot channel and the dedicated pilot connected by the arrow D151 in FIG. By performing despreading processing using the channel, the orthogonality with the receiver 11b and the receiver 11c is maintained, so that it can be performed with high accuracy.
Alternatively, in the transmission signal to the receiver 11b in the sector 13b and the receiver 11c in the sector 13c, a null signal is assigned to the subcarrier in which the dedicated pilot channel of the transmission signal to the receiver 11a is allocated, so that the receiver It is also possible to maintain orthogonality with 11b and the receiver 11c.
In the second and subsequent embodiments, in the case of interpolating a common pilot channel arranged in advance with a dedicated pilot channel, the pilot arrangement method described in FIGS. 14 and 15 is similarly applied.

As described above, when performing CDTD, by inserting a dedicated pilot channel between pre-arranged common pilot channels in the frequency axis f direction, and increasing the number of pilot channels per frequency band of the transmission signal, It is possible to reduce the difference in frequency fluctuation of each pilot channel used for propagation path estimation, and it is possible to perform propagation path estimation with high accuracy.
In the above description, when performing CDTD, the number of pilot channels per transmission signal band is increased by interpolating between common pilot channels with dedicated pilot channels. However, the common pilot described in the first embodiment is used. It is also possible to increase the number of pilot channels per transmission signal band by combining techniques for reducing the channel spacing.

  In the first and second embodiments described above, transmission is performed by the CDTD presence / absence information that notifies the subcarrier allocation unit 103 whether to perform delay transmission diversity in which a signal is transmitted with a delay between a plurality of transmission antennas. The number of pilot channels per signal band was changed. Thereby, the propagation path estimation accuracy can be changed by changing the number of pilot channels per transmission signal band by subcarrier allocating section 103 according to whether or not to perform delayed transmission diversity.

In the first and second embodiments described above, the number of pilot channels per transmission signal band is greater when the subcarrier allocating unit 103 performs the delayed transmission diversity than when the delayed transmission diversity is not performed. You may make it do. As a result, when performing delayed transmission diversity, the subcarrier allocating unit 103 allocates a larger number of pilot channels to the transmission signal, so that it is possible to improve the propagation path estimation accuracy during communication using the delayed transmission diversity. it can.
Further, in the second embodiment described above, the number of pilot channels per transmission signal band is changed by interpolating the dedicated pilot channels to the pilot channels arranged in advance by the subcarrier allocation unit 103. Thereby, the propagation path estimation accuracy can be improved as compared with the case where the propagation path estimation is performed using only the pilot channels arranged in advance, and the communication quality between the transmitter and the receiver can be enhanced. Also, CDTD can be performed satisfactorily.

(Third embodiment)
The present embodiment is arranged in advance as an example in the case of changing the interval of the pilot channel in the CDTD according to the comparison result between the delay time given between the transmission antennas and the threshold value determined in the system to which the CDTD is applied. A method for interpolating the dedicated pilot channel into the pilot channel will be described.
Here, a case will be described in which a threshold α for switching the arrangement of pilot channels determined by the method of the wireless communication system is set in a transmitter to which CDTD is applied. When the inter-antenna delay time τ is smaller than the threshold α with respect to this threshold value α, a pilot channel is inserted in a predetermined arrangement by the system method or the like, and when the inter-antenna delay time τ is larger than the threshold α, The pilot channel is interpolated with the dedicated pilot channel in a predetermined arrangement according to the system method or the like.
The inter-antenna delay time τ is a delay time with a transmission antenna that gives a maximum delay with respect to a reference transmission antenna in a plurality of transmission antennas.

In the case of transmitting a signal by applying CDTD with a transmitter having n transmission antennas ANT1, ANT2,..., ANTn shown in FIG. Shown in b). w1, w2,..., wn are incoming waves of signals transmitted from the transmission antennas of ANT1, ANT2,.
Next, an example of setting the threshold value α will be shown. FIG. 17 shows an example of a method for assigning users on a shared data channel to subcarriers in a transmitter to which CDTD is applied. As shown in FIG. 17, users 1, 2, and 3 of the shared data channel are allocated in units of section Fc in which a plurality of subcarriers are grouped in the frequency axis f direction, and a plurality of OFDM symbols are allocated in the time axis t direction. Allotted in units (chunks) called TTIs. BW in FIG. 17 is a transmission frequency bandwidth used for transmission of a transmission frame. The head of the chunk is assigned to the common pilot channel and the shared control signaling channel.
Further, in a transmitter to which CDTD is applied, there are a case where a user wants to obtain a frequency diversity effect and a case where a user wants to obtain a user diversity effect. In the user allocation shown in FIG. 17, the frequency region where the frequency diversity effect is desired and the frequency region where the user diversity effect is desired are switched in units of chunks. In this case, it is desirable that the frequency fluctuation is small in the frequency domain in the chunk where it is desired to obtain the user diversity effect, and the CDTD delay time τ is set small. In a chunk where it is desired to obtain the frequency diversity effect, it is desirable that the frequency fluctuation is large in the frequency region, and the CDTD delay time τ is set large.

From the above, the threshold α for switching the pilot arrangement is set to α = 1 / Fc, assuming that the frequency bandwidth of the chunk is Fc. If the inter-antenna delay time τ is smaller than the threshold α, it is determined in advance by the system method or the like. When the pilot channel is inserted in the determined arrangement and the inter-antenna delay time τ is larger than the threshold value α, the pilot channel is interpolated with the dedicated pilot channel in an arrangement determined in advance by the system method or the like.
As another setting method example of the threshold value α, a case where users are assigned to subcarriers in a shared data channel as shown in FIG. 18 will be described.
As shown in FIG. 18, the user of the shared data channel is allocated over a plurality of chunks in the frequency axis f direction. In FIG. 18, users 1, 2, and 3 are allocated across three chunks. In the direction of the time axis t, allocation is performed in units of TTI in which a plurality of OFDM symbols are collected.

  Further, in a transmitter to which CDTD is applied, there are a case where a user wants to obtain a frequency diversity effect and a case where a user wants to obtain a user diversity effect. In the user allocation shown in FIG. 18, the frequency region where the frequency diversity effect is desired and the frequency region where the user diversity effect is desired are switched in units of users. In this case, the user who wants to obtain the user diversity effect preferably has a small frequency fluctuation in the frequency domain of the user allocated over a plurality of chunks, and the CDTD delay time τ is set small. A user who wants to obtain a frequency diversity effect desirably has a large frequency fluctuation in the frequency domain of the user allocated over a plurality of chunks, and sets the CDTD delay time τ to be large.

  From the above, the threshold α for switching the pilot arrangement is set to α = 1 / Fu when the frequency bandwidth of the user allocated over a plurality of chunks is Fu, and the inter-antenna delay time τ is smaller than the threshold α. If the pilot channel is inserted in a predetermined arrangement according to the system method or the like, and the inter-antenna delay time τ is larger than the threshold value α, the pilot channel is assigned to the dedicated pilot channel in the predetermined arrangement according to the system method or the like. Interpolate with.

As in the first and second embodiments, a specific example of the third embodiment, as shown in FIG. 1, the transmitter transmits signals from the two transmission antennas included therein, and the receiver A case will be described where a signal is received by a single receiving antenna. The assignment of users on the shared data channel to subcarriers will be described with reference to FIG.
First, in a transmitter to which CDTD is applied, the arrangement of pilot channels is determined in advance by the method of the wireless communication system. As an example, a case will be described in which the pilot channels arranged in advance are common pilot channels as shown in FIG. FIG. 19A shows the received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis.

  In FIG. 19B, the unit areas s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21) , S (1, 25), s (1, 29) are common pilot channels. Further, these common pilot channels are arranged in the same OFDM symbol (here, the OFDM symbol in the first row) at intervals of ΔNf = 4 in the frequency axis f direction. The common pilot channel is multiplied by an OVSF code having a code length SF = 4 in the frequency axis f direction. In FIG. 19B, # 1 to # 4 indicate the components of the OVSF code sequence as in the description in the first embodiment. Further, when the number of subcarriers in one chunk is 15, and the frequency bandwidth of one chunk is Fc, the threshold value α is α = 1 / Fc.

The transmitter transmits the transmission antenna 1 and the transmission antenna 2 with a delay time τ = T1.
FIG. 20A shows a delay profile in which the propagation path at this time is expressed in the time domain. In FIG. 20A, w1 is a signal output from the transmission antenna 1, and w2 is a signal output from the transmission antenna 2. The propagation path in FIG. 19A is a frequency domain representation of the propagation path in FIG. As shown in FIG. 19B, when α = 1 / Fc> T1 and transmission is performed with the delay time τ = T1 given to the transmission antenna 1 and the transmission antenna 2, the transmitter is assigned with a pre-assigned common A signal in which a pilot channel is arranged is transmitted.
The receiver receives the signal arranged as shown in FIG. 19B from the transmitter through the propagation path of the delay profile shown in FIG. Note that the propagation path in FIG. 19A represents the propagation path in FIG. 20A in the frequency domain.

On the receiving side, a despreading process is performed on the common pilot channel inserted in the subcarrier of the received signal using the OVSF code to be multiplied to estimate the propagation path.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 19B is the result of performing the despreading process on the common pilot channels # 1 to # 4 connected by the arrow D191 in FIG. By Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.
The transmitter transmits the transmission antenna 1 and the transmission antenna 2 with a delay time τ = T2.
FIG. 20B shows a delay profile representing the propagation path at this time in the time domain.
In FIG. 20B, w1 is a signal output from the transmission antenna 1, and w2 is a signal output from the transmission antenna 2.

FIG. 21 (a) is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis. FIG. 21B is a diagram illustrating a configuration of subcarriers transmitted from the transmitter to the receiver. The propagation path in FIG. 21A is a frequency domain representation of the propagation path in FIG. As shown in FIG. 21 (b), since α = 1 / Fc <T2, when transmitting with a delay time τ = T2 to the transmitting antenna 1 and the transmitting antenna 2, the transmitter transmits in the frequency axis f direction. , The unit areas s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21), s (1 25), s (1,29), and OFDM symbols at different times between the common pilot channels, that is, unit regions s (4,3), s (4,7), s (4, 11), s (4,15), s (4,19), s (4,23), s (4,27), and s (4,31), a signal in which dedicated pilot channels are arranged is transmitted. In the frequency axis f direction, the dedicated pilot channel is inserted between the adjacent common pilot channels over different OFDM symbols, and the subcarrier interval ΔNf between the adjacent pilot channels is changed from ΔNf = 4 to ΔNf = 2. It is narrowing. Further, in the time axis t direction, the fourth row OFDM symbol (s (4) transmitted after the common pilot channel arranged in the first row OFDM symbol (s (1,1) to s (1,31))). , 1) to s (4, 31)).
Also, the dedicated pilot channel is multiplied by a sequence obtained by cyclically shifting the same OVSF code sequence as that of the common pilot channel by 2 bits. In FIG. 21B, # 1 to # 4 indicate OVSF code sequences.

The receiver receives from the transmitter the signal arranged as shown in FIG. 21B through the propagation path of the delay profile shown in FIG. The propagation path in FIG. 21A is a representation of the propagation path in FIG. 20B in the frequency domain.
On the receiving side, a despreading process is performed on the common pilot channel inserted in the subcarrier of the received signal using the OVSF code to be multiplied to estimate the propagation path.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 21B is subjected to despreading processing in the common pilot channels # 1 to # 4 connected by arrows D211 to D213 in FIG. According to the result. Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

  As described above, in the transmitter to which CDTD is applied, when the inter-antenna delay time τ is smaller than the threshold value α with respect to the threshold value α for switching the pilot arrangement determined by the method of the wireless communication system, When a pilot channel having a predetermined arrangement is inserted and the inter-antenna delay time τ is larger than the threshold value α, the propagation channel can be obtained by interpolating the pilot channel having a predetermined arrangement according to the system method or the like with an individual pilot channel. It is possible to reduce the difference in frequency fluctuation of each pilot channel used for estimation, and it is possible to estimate the propagation path with high accuracy.

FIG. 22 is a block diagram showing a configuration of a transmitter according to the third embodiment of the present invention. The transmitter according to the present embodiment includes a control unit 101 that outputs magnitude information for a delay time threshold between transmission antennas and delay time information between transmission antennas. Further, the subcarrier insertion arrangement of the dedicated pilot channel is determined based on the magnitude information with respect to the delay time threshold between the transmitting antennas notified from the control unit 101, and further, the output of the common pilot channel and the signal processing units 100a and 100b for each user. The subcarrier allocation determining unit 102 determines the allocation to each subcarrier. In addition, it has a pilot signal generation unit 104 that generates a common pilot channel and a dedicated pilot channel multiplied by the OVSF code sequence and inputs them to the subcarrier allocation unit 102. Further, a phase rotation amount calculation unit 105 that calculates the phase rotation amount of each subcarrier based on the delay time information between the transmission antennas from the control unit 101 is provided. Further, based on subcarrier allocation information in subcarrier allocation determination section 102, subcarrier allocation section 103 that allocates the outputs of per-user signal processing sections 100a and 100b and the output of pilot signal generation section 104 to each subcarrier. In addition, signal processing units 200a and 200b for each antenna that perform signal processing for each transmission antenna are included. The pilot signal generation unit 104 includes a dedicated pilot signal generation unit 104b that generates a dedicated pilot channel signal having a pattern determined by magnitude information with respect to a threshold value of a delay time between transmission antennas output from the control unit, It comprises a common pilot signal generation unit 104a that generates a signal of a common pilot channel having a pattern determined by a method or the like.
Since other configurations are the same as the configuration of the transmitter according to the first embodiment (FIG. 7), the same reference numerals are given and description thereof is omitted.

As described above, when the delay time τ between the transmitting antennas is larger than the threshold α determined in advance by the transmitter, the dedicated pilot channel is inserted between the common pilot channels arranged in the frequency axis f direction, By increasing the number of pilot channels per band, it is possible to reduce the difference in frequency fluctuation of each pilot channel used for propagation path estimation, and it is possible to perform propagation path estimation with high accuracy.
In the above description, when the delay time τ between the transmitting antennas is larger than the threshold α predetermined by the transmitter, the number of pilot channels per band is increased by interpolating between the common pilot channels with the dedicated pilot channel. However, the method of reducing the interval of the common pilot channel described in the first embodiment, or the method of reducing the interval of the common pilot channel described in the first embodiment and the common pilot channel in the dedicated pilot channel. It is also possible to increase the number of pilot channels per transmission signal band by combining techniques for interpolating between them.

In the third embodiment described above, the subcarrier allocating unit 103 arranges the number of pilot channels per transmission signal band to be increased when the delay amount of delayed transmission diversity is larger than the predetermined threshold value α. As a result, the propagation path estimation accuracy can be improved when using frequency diversity which is effective when the delay amount of delay transmission diversity is large.
For example, the reciprocal 1 / Fc of the chunk frequency band or the reciprocal 1 / Fu of the user's occupied frequency band can be used as the predetermined threshold α. Also, CDTD can be performed satisfactorily.

(Fourth embodiment)
In the present embodiment, a method for interpolating a dedicated pilot channel to a pilot channel arranged in advance will be described as an example in the case where the interval of the pilot channel is adaptively changed according to the delay time given between transmitting antennas in CDTD. To do.
As shown in FIG. 1, a case will be described in which a transmitter transmits a signal from two transmission antennas included therein, and a receiver receives a signal from the one reception antenna included in the transmitter.
The transmitter transmits a signal by providing a delay time difference τ between the transmission antenna 1 and the transmission antenna 2 in CDTD. In this case, the frequency fluctuation pitch of the combined wave of the transmission antenna 1 and the transmission antenna 2 received by the receiver is 1 / τ. In the present embodiment, as an example, an individual pilot channel is interpolated into a pilot channel that is arranged in advance so that the frequency bandwidth Fc used for calculating the propagation path estimation information is Fc <1 / τ. The specific contents of the fourth embodiment will be described below.
First, in a transmitter to which CDTD is applied, the arrangement of common pilot channels is determined in advance according to the system scheme or the like. As an example, a case will be described in which the pilot channels arranged in advance are common pilot channels as shown in FIG. FIG. 23A shows the received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis.

In FIG. 23B, the unit areas s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21) , S (1, 25), s (1, 29), common pilot channels are arranged. They are arranged in the same OFDM symbol with a subcarrier interval ΔNf = 4 in the frequency axis f direction. The common pilot channel is multiplied by an OVSF code having a code length SF = 4 in the frequency axis f direction. As in the description of the first embodiment, # 1 to # 4 in FIG. 23B indicate the components of the OVSF code sequence.
In the arrangement of the pilot channels shown in FIG. 23B, for example, when estimating the propagation path of the unit region s (2, 6), calculation is performed using four common pilot channels connected by the arrow D231 in FIG. . The Fc1 section in FIG. 23B is a frequency bandwidth used for calculation of propagation path estimation information, and Fc = Fc1.

On the receiving side that has received the signal having the arrangement shown in FIG. 23B, the common pilot channel inserted in the subcarrier of the received signal is subjected to despreading processing by the OVSF code to be multiplied, and the propagation path is set. presume.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 23B is the result of performing the despreading process in the common pilot channels # 1 to # 4 connected by the arrow D231 in FIG. By Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

In addition, as a pilot channel arrangement pattern, the transmitter interpolates the pilot arrangement of FIG. 23 (b) with the dedicated pilot channel, and sets the subcarrier interval ΔNf = 2 in the frequency direction as shown in FIG. 24 (b). The arrangement pattern is held. FIG. 24A shows the received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis.
In FIG. 24B, the unit areas s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21) , S (1, 25), s (1, 29), common pilot channels are arranged. The unit regions s (4,3), s (4,7), s (4,11), s (4,15), s (4,19), s (4,23), s (4, 27) and s (4, 31), dedicated pilot channels are arranged. Fc2 in FIG. 24B is a frequency bandwidth used for calculating propagation path estimation information in each pilot arrangement.
In FIG. 24 (b), # 1 to # 4 indicate constituent elements of the OVSF code sequence that is multiplied by the common pilot channel and the dedicated pilot channel, and the dedicated pilot channel includes the OVSF code sequence that is multiplied by the common pilot channel. Multiply cyclically shifted sequences. In FIG. 24B, a sequence obtained by cyclically shifting the OVSF code sequence to be multiplied by the common pilot channel by 2 bits is multiplied.

On the receiving side that has received the signal having the arrangement shown in FIG. 24 (b), despread processing is performed on the common pilot channel and the dedicated pilot channel inserted in the subcarriers of the received signal using the OVSF code to be multiplied. Estimate the propagation path.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 24B is obtained as a result of performing the despreading process on the common pilot channels # 1 to # 4 connected by the arrows D241 to D243. Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

In addition, as a pilot channel arrangement pattern, the transmitter interpolates the pilot arrangement shown in FIG. 23 (b) with the dedicated pilot channel and sets the subcarrier interval ΔNf = 1 in the frequency direction to the pilot channel shown in FIG. 25 (b). An arrangement pattern can also be held. FIG. 25A is a diagram showing a received signal with the frequency axis f on the horizontal axis and the power axis p on the vertical axis.
In FIG. 25B, the unit areas s (1,1), s (1,5), s (1,9), s (1,13), s (1,17), s (1,21) , S (1, 25), s (1, 29), common pilot channels are arranged.
The unit regions s (3,2), s (3,6), s (3,10), s (3,14), s (3,18), s (3,22), s (3, 26), s (3, 30), s (5, 3), s (5, 7), s (5, 11), s (5, 15), s (5, 19), s (5, 23 ), S (5,27), s (5,31), s (7,4), s (7,8), s (7,12), s (7,16), s (7,20) , S (7, 24), s (7, 28), dedicated pilot channels are arranged. Fc2 and Fc3 in FIGS. 24B and 25B are frequency bandwidths used for calculation of propagation path estimation information in each pilot arrangement. However, Fc1>Fc2> Fc3.

  In FIG. 25 (b), # 1 to # 4 indicate components of the OVSF code sequence that is multiplied by the common pilot channel and the dedicated pilot channel, and the dedicated pilot channel is the OVSF code sequence that is multiplied by the common pilot channel. Multiply cyclically shifted sequences. In FIG. 25 (b), the dedicated pilot channel arranged in the OFDM symbol (s (3,1) to s (3,31)) in the third row is 1-bit cyclic from the OVSF code sequence multiplied by the common pilot channel. Multiplying the shifted series. The dedicated pilot channel arranged in the OFDM symbol (s (5,1) to s (5,31)) in the fifth row is multiplied by a sequence obtained by cyclically shifting 2-bits from the OVSF code sequence multiplied by the common pilot channel. doing. Further, the individual pilot channels arranged in the OFDM symbols (s (7, 1) to s (7, 31)) in the seventh row are multiplied by a sequence that is cyclically shifted by 3 bits from the OVSF code sequence that is multiplied by the common pilot channel. ing. The m-th row (m is an integer of 1 or more) OFDM symbol means an OFDM symbol including unit regions s (m, 1), s (m, 2), s (m, 3),. Show.

On the receiving side that has received the signal having the arrangement shown in FIG. 25 (b), despread processing is performed on the common pilot channel and the dedicated pilot channel inserted in the subcarriers of the received signal using the OVSF code to be multiplied. Estimate the propagation path.
For example, the propagation path estimation result of the unit region s (2, 6) in FIG. 25B is obtained as a result of performing the despreading process on the common pilot channels # 1 to # 4 connected by the arrows D251 to D253. Alternatively, the amplitude (or received power) and phase of the subcarrier in which the pilot channel of the received signal is arranged can be adopted as the channel value. However, the receiver knows the pilot channel arrangement, the pilot channel, the OVSF code to be multiplied, and the number of pilots used to calculate the propagation path value.

  The transmitter performs transmission with a delay of τ = T1 between the transmitting antennas. FIG. 26A shows a delay profile in which the propagation path when a delay of τ = T1 is given is expressed in the time domain. The propagation path in FIG. 23A is a frequency expression of the delay profile in FIG. It is a thing. w1 represents the arrival wave of the signal transmitted from the transmission antenna 1 (FIG. 1), and w2 represents the arrival wave of the signal transmitted from the transmission antenna 2 (FIG. 1). Since the frequency fluctuation pitch of the propagation path in FIG. 23A is 1 / T1, and 1 / T1> Fc1> Fc2> Fc3, the transmitter transmits a signal in the pilot arrangement shown in FIG.

  Next, the above transmitter performs transmission with a delay of τ = T2 between the transmission antennas. FIG. 26B shows a delay profile in which the propagation path when a delay of τ = T2 is given is expressed in the time domain, and the propagation path in FIG. 24A is a frequency expression of the delay profile in FIG. It is what. w1 represents the arrival wave of the signal transmitted from the transmission antenna 1, and w2 represents the arrival wave of the signal transmitted from the transmission antenna 2. The frequency variation pitch of the propagation path in FIG. 24A is 1 / T2, and Fc1> 1 / T2> Fc2> Fc3. Therefore, the transmitter transmits a signal in the pilot arrangement shown in FIG.

  Next, the above transmitter performs transmission with a delay of τ = T3 between the transmission antennas. FIG. 26C shows a delay profile expressing the propagation path when a delay of τ = T3 is given in the time domain, and the propagation path of FIG. 25A is a frequency expression of the delay profile of FIG. It is what. w1 represents the arrival wave of the signal transmitted from the transmission antenna 1, and w2 represents the arrival wave of the signal transmitted from the transmission antenna 2. Since the frequency variation pitch of the propagation path in FIG. 25A is 1 / T3 and Fc1> Fc2> 1 / T2> Fc3, the transmitter transmits a signal in the pilot arrangement shown in FIG.

FIG. 27 is a block diagram showing a configuration of a transmitter according to the fourth embodiment of the present invention.
The transmitter according to the present embodiment includes a control unit 101 that outputs delay time information between transmission antennas. Further, the subcarrier insertion arrangement of the dedicated pilot channel is determined from the delay time information between the transmitting antennas notified from the control unit 101, and further to the common pilot channel and each subcarrier output from the signal processing units 100a and 100b for each user. A subcarrier allocation determination unit 102 that determines the allocation of. In addition, it has a pilot signal generation unit 104 that generates a common pilot channel and a dedicated pilot channel multiplied by the OVSF code sequence and inputs them to the subcarrier allocation unit 103. Further, a phase rotation amount calculation unit 105 that calculates the phase rotation amount of each subcarrier based on the delay time information between the transmission antennas from the control unit 101 is provided. Further, based on subcarrier allocation information in subcarrier allocation determination section 102, subcarrier allocation section 103 that allocates the outputs of per-user signal processing sections 100a and 100b and the output of pilot signal generation section 104 to each subcarrier. The pilot signal generation unit 104 includes an individual pilot signal generation unit 104b that generates an individual pilot channel signal having a pattern determined by delay time information between transmission antennas output from the control unit 101, and a system scheme or the like in advance. A common pilot signal generation unit 104a that generates a common pilot channel signal of a predetermined pattern is included.

Since other configurations are the same as the configuration of the transmitter according to the first embodiment (FIG. 7), the same reference numerals are given and description thereof is omitted.
As described above, in a transmitter to which CDTD is applied, transmission is performed by switching to a pilot arrangement pattern in which the frequency bandwidth Fc used for calculation of propagation path estimation information becomes small with respect to the delay time τ given between transmission antennas. Thus, it is possible to reduce the difference in frequency fluctuation of each pilot channel used for propagation path estimation, and it is possible to perform propagation path estimation with high accuracy.
In the present embodiment, the frequency bandwidth Fc used for calculating the propagation path estimation information is reduced by the pattern obtained by interpolating the common pilot channel with the dedicated pilot channel, but the interval between the common pilot channels described in the first embodiment is reduced. Used to calculate propagation path estimation information by combining the method of reducing the common pilot channel interval described in the first embodiment and the method of interpolating between the common pilot channels using dedicated pilot channels. It is also possible to reduce the frequency bandwidth Fc.

In the fourth embodiment described above, the number of pilot channels per transmission signal band is monotonously increased by the subcarrier allocation unit 103 as the delay amount of delayed transmission diversity increases. Thereby, even if the delay amount increases, it is possible to prevent the number of pilot channels per transmission signal band from decreasing, and it is possible to improve the propagation path estimation accuracy.
In the fourth embodiment described above, the subcarrier allocation unit 103 has a frequency bandwidth over which a pilot channel multiplied by a series of orthogonal codes # 1 to # 4 for estimating a propagation path is arranged. The reciprocal of the delay time of the transmitting antenna can be set to be large.

In the fourth embodiment described above, the subcarrier allocation unit 103 can also be set to change the number of pilot channels per transmission signal band by changing the arrangement interval of the common pilot channels.
In the above-described fourth embodiment, the pilot signal generator 104 interpolates the pilot channels that are arranged in advance, and the dedicated pilot channels for maintaining orthogonality over the common pilot channel and the dedicated pilot channel. The code sequence (for example, a sequence obtained by cyclically shifting the OVSF code multiplied by the common pilot channel) is multiplied. As a result, since the dedicated pilot channel and the common pilot channel are transmitted with orthogonality maintained, interference between these pilot channels can be prevented, and propagation path estimation accuracy between the transmitter and the receiver can be prevented. Can be improved. Also, CDTD can be performed satisfactorily.

  According to the transmitters according to the first to fourth embodiments described above, by performing delay transmission diversity such as DTD and CDTD in multicarrier transmission such as OFDM, the frequency diversity effect which is an advantage in multicarrier transmission is achieved. While being obtained effectively, it is possible to perform highly accurate propagation path estimation without being affected by frequency selectivity.

  In the above-described embodiment, the control unit 101, the subcarrier allocation determination unit 102, the subcarrier allocation unit 103, the pilot signal generation unit 104, the phase rotation amount calculation unit 105, the error correction coding unit 151, the modulation unit 152, Functions of phase rotation unit 161, IFFT unit 162, parallel-serial conversion unit 163, GI addition unit 164, filter unit 165, D / A conversion unit 166, radio frequency conversion unit 167, or a part of these functions The transmitter may be controlled by recording the program on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, it is also assumed that a server that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1, 2 ... Transmission antenna, 3 ... Reception antenna, 10 ... Transmitter, 11 ... Receiver, 100a, 100b ... Signal processing part for every user, 101 ... Control part, 102 ... subcarrier allocation determination unit, 103 ... subcarrier allocation unit, 104 ... pilot signal generation unit, 104a ... common pilot signal generation unit, 104b ... individual pilot signal generation unit, 105 -Phase rotation amount calculation unit, 151 ... error correction coding unit, 152 ... modulation unit, 161 ... phase rotation unit, 162 ... IFFT unit, 163 ... parallel-serial conversion unit, 164 ..GI addition unit, 165... Filter unit, 166... D / A conversion unit, 167... Radio frequency conversion unit, 200a, 200b.

Claims (4)

A multicarrier transmission transmitter comprising a plurality of transmission antennas and transmitting a signal for each subcarrier with phase rotation,
When giving phase rotation for each subcarrier to reduce frequency fluctuation, arrange a common pilot channel,
In the case where phase rotation that increases frequency fluctuation is given to each subcarrier, a subcarrier allocation unit that arranges a common pilot channel and a dedicated pilot channel is provided ,
The transmitter including the dedicated pilot channel arranged on a subcarrier different from the arrangement of the common pilot channel . A multicarrier transmission transmitter comprising a plurality of transmission antennas and transmitting a signal for each subcarrier with phase rotation,
When providing phase rotation for each subcarrier with a frequency fluctuation pitch with small frequency fluctuation, arrange a common pilot channel,
In granting the phase rotation frequency fluctuation becomes larger frequency variation pitch for each subcarrier comprises a subcarrier allocation unit for arranging the common pilot channel and the dedicated pilot channels,
The transmitter including the dedicated pilot channel arranged on a subcarrier different from the arrangement of the common pilot channel . A transmission method for multicarrier transmission comprising a plurality of transmission antennas and transmitting a signal for each subcarrier with phase rotation,
When giving phase rotation for each subcarrier to reduce frequency fluctuation, arrange a common pilot channel,
When giving phase rotation that increases frequency fluctuation for each subcarrier, arrange a common pilot channel and a dedicated pilot channel ,
The transmission method in which the dedicated pilot channel includes one arranged in a subcarrier different from the arrangement of the common pilot channel . A transmission method for multicarrier transmission comprising a plurality of transmission antennas and transmitting a signal for each subcarrier with phase rotation,
When providing phase rotation for each subcarrier with a frequency fluctuation pitch with small frequency fluctuation, arrange a common pilot channel,
In granting the phase rotation frequency fluctuation becomes larger frequency variation pitch for each subcarrier is to place the common pilot channel and the dedicated pilot channels,
The dedicated pilot channel includes a dedicated pilot channel arranged on a subcarrier different from the arrangement of the common pilot channel. The dedicated pilot channel is arranged on a subcarrier different from the arrangement of the common pilot channel. The transmission method that contains what is .

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