JP2009177295A - Wireless communication system and signal correction method, and transmitting apparatus and receiving apparatus used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system capable of correcting a received signal with higher accuracy and a signal correction method used therefor.
A wireless communication system of the present invention includes a BS that transmits a transmission signal in which a pilot signal and a data signal are arranged in a communication frame, and an MS that receives the transmission signal. The BS 10 generates the transmission signal in which a pilot area PA consisting of an area where only the pilot signals are arranged and a data area DA consisting of an area where the data signals are arranged alternately along the time axis A transmission signal generation unit 13 for performing the transmission. The MS 20 includes a transmission path estimation unit 23 for obtaining the transmission path estimation value for each pilot area PA based on a pilot signal in the pilot area PA included in the received transmission signal, and a data area DA included in the received transmission signal. It has a signal correction unit 24 for correcting the signal of the data signal based on the transmission path estimation value.
[Selection] Figure 1

Description

  The present invention relates to a radio communication system and a signal correction method used in a broadband mobile radio communication system and the like, and a transmission apparatus and a reception apparatus used therefor.

In recent years, as a communication system that can cover a wide area wirelessly and provide high-speed broadband services, for example, a so-called “WiMAX” broadband mobile radio communication system (Broadband Wireless Access System) defined in IEEE 802.16. However, it is attracting attention.
In general, in the above wireless communication system, the amplitude and phase of a received signal on the receiving side changes in accordance with the transmission path environment with respect to the signal transmitted on the transmitting side. For this reason, in the conventional wireless communication apparatus, a method of correcting the received signal based on the estimated value of the transmission path characteristic (transmission path estimated value) obtained from the pilot signal included in the received signal has been adopted. (For example, refer to Patent Document 1).

FIG. 8 is a diagram showing the structure of a transmission signal used in the conventional wireless communication system. In the figure, the horizontal axis represents time and the vertical axis represents frequency. As shown in the figure, the transmission signal includes a plurality of data signals arranged in subcarriers (open circles) and a pilot signal arranged in a predetermined position in the arrangement of the plurality of data signals (black circles). And have. When a receiving-side apparatus that has received a transmission signal having such a configuration obtains a transmission path estimation value in the frequency axis direction, transmission path estimation of a pair of pilot signals that are located via a plurality of data signals in the frequency axis direction A value is obtained, and further, estimation by linear interpolation is performed based on the transmission path estimation value, and transmission path estimation values of the plurality of data signals located between the pair of pilot signals are obtained. Similarly to the frequency axis direction in the time axis direction, the channel estimation value between these signals is obtained by performing linear interpolation using the channel estimation values of a pair of pilot signals arranged in the time axis direction.
In the above conventional example, each data signal in which a phase change or the like has occurred is corrected based on the transmission path estimation value corresponding to each data signal obtained as described above.

JP 2007-124553 A (FIGS. 32 to 34)

  In the above conventional signal correction method, the channel characteristics of each pilot signal are estimated, and further, estimation by linear interpolation using the estimated value is performed to obtain the channel estimation value of each data signal. The error that occurs when estimating the transmission path characteristics of this data and the error that occurs due to estimation by linear interpolation synergistically affect the transmission path estimation value of each data signal. For this reason, there is a possibility that an error included in the transmission path estimation value of the data signal is increased, which is a factor of reducing the accuracy of signal correction.

  The present invention has been made in view of such circumstances, and provides a radio communication system and a signal correction method capable of correcting a received signal with higher accuracy, and a transmission device and a reception device used therefor. Objective.

  To achieve the above object, the present invention provides a transmission apparatus for transmitting a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis, and the transmission signal The transmission device includes a data area configured by an area in which the data signals are arranged, and an area in which only the pilot signals are substantially arranged. The configured pilot region has a transmission signal generation unit that generates the transmission signals alternately arranged along the time axis in the same frequency band, and the reception device is included in the received transmission signal A transmission path estimation unit for obtaining a transmission path estimation value for each pilot area based on the pilot signal in the pilot area; and included in the received transmission signal A signal correction unit that performs signal correction on the data signal in the data region based on the transmission path estimation value of the pilot region arranged adjacent to the data region in the time axis direction. It is said.

  According to the wireless communication system configured as described above, when the data signal is corrected, the transmission path estimation value for each pilot region is used as the transmission path estimation value of the data signal. There is no need to perform estimation by linear interpolation. For this reason, it is possible to reduce the error included in the transmission path estimation value for correcting the data signal, and as a result, it is possible to correct the received signal with higher accuracy.

  The transmission path estimation unit obtains a transmission path estimation value for each frequency based on pilot signals arranged in the time axis direction at the same frequency among the pilot signals included in the pilot region, and the signal correction unit, It is preferable to perform signal correction for each corresponding frequency on the data signal included in the data area based on the transmission path estimation value for each frequency calculated by the transmission path estimation unit.

  In this case, since the transmission path estimation value obtained for each frequency is corrected as the transmission path estimation value of the data signal of the corresponding frequency, it is possible to perform signal correction according to the change in the transmission path environment caused by the frequency. This can increase the accuracy of signal correction.

  In the wireless communication system, the communication frame has a user data area including a burst area for transmitting the transmission signal, and the pilot area and the data area respectively minimize the burst area. It may be configured as a unit, and in this case, it is easy to multiplex the pilot signal and the data signal.

  Further, the present invention is a transmission apparatus that transmits a transmission signal, in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis, to a reception apparatus, A data region composed of regions in which the data signals are arranged and a pilot region substantially composed of regions in which only the pilot signals are arranged are alternately arranged along the time axis in the same frequency band. A transmission signal generation unit that generates the transmitted signal, receives the transmission signal, obtains a transmission path estimation value for each pilot region based on the pilot signal included in the transmission signal, The transmission signal is transmitted to the receiving apparatus that performs signal correction based on a transmission path estimation value.

  According to the transmission apparatus having the above configuration, when the reception apparatus performs signal correction, an error included in the transmission path estimation value for correcting the data signal can be reduced. As a result, the received signal can be corrected with higher accuracy.

  Further, the present invention is a receiving device that receives a transmission signal from a transmitting device that transmits a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis. A data region configured by a region in which the data signals are arranged and a pilot region substantially constituted by a region in which only the pilot signals are arranged in the same frequency band along the time axis. Alternatingly arranged, receiving the transmission signal transmitted from the transmission apparatus, and based on the pilot signal in the pilot region included in the received transmission signal, a transmission path estimation value for each pilot region A transmission path estimation unit for obtaining a data signal in the data area included in the received transmission signal with respect to the data area In is characterized in that based on the channel estimation value of adjacently disposed the pilot regions has a signal correction unit that performs signal correction.

  According to the receiving apparatus having the above configuration, as described above, the error included in the transmission path estimation value for correcting the data signal can be reduced, and as a result, the received signal can be corrected more accurately. it can.

  Further, the present invention is a signal correction method for a wireless communication system that performs communication using a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis, The transmission signal in which pilot groups in which only the pilot signals are arranged in the first time width and data groups in which only the data signals are arranged in the second time width are alternately arranged along the time axis A transmission signal generation step for generating the transmission signal, a transmission step for transmitting the transmission signal generated by the transmission signal generation step, a transmission signal transmitted by the transmission step, and the pilot included in the received transmission signal While obtaining a transmission path estimation value of the pilot signal in the group, based on this transmission path estimation value, A transmission path estimation step for obtaining an average value of the transmission path estimation values of the pilot signal for each pilot group, and a data signal in the data group included in the received transmission signal on the time axis with respect to the data group And a signal correction step of performing signal correction based on the average value of the pilot groups arranged adjacent to each other.

  According to the signal correction method configured as described above, since it is not necessary to perform estimation by linear interpolation as described above, an error included in an average value used as a transmission path estimation value for correction of a data signal The received signal can be corrected with higher accuracy.

  As described above, according to the wireless communication system and the signal correction method of the present invention, the received signal can be corrected with higher accuracy.

[Configuration of wireless communication system]
Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of a wireless communication system according to an embodiment of the present invention. As this wireless communication system, for example, a communication system conforming to “WiMAX” defined in IEEE802.16 that supports an orthogonal frequency division multiple access (OFDMA) system in order to realize broadband wireless communication is adopted. Base station apparatus 10 (hereinafter also referred to as BS10) and a large number of mobile terminals 20 (hereinafter also referred to as MS20) capable of moving. In FIG. 1, one BS 10 and one MS 20 are shown.
The BS 10 establishes communication with the MS 20 and puts information in a predetermined communication frame so that user data can be transmitted and received. The MS 20 can enter the external network by transmitting and receiving user data. Become. Thereby, the BS 10 can provide a high-speed broadband service by wireless communication to the MS 20.

  The BS 10 has a functional unit for transmitting a downlink transmission signal toward the MS 20, and the functional unit generates a data signal by performing parallel conversion, encoding, modulation, and the like of user data transmitted to the MS 20. A data conversion unit 11 for generating a pilot signal, a pilot signal generating unit 12 for generating a pilot signal, a transmission signal generating unit 13 for arranging the data signal and the pilot signal to generate a downlink transmission signal, and the downlink transmission signal A transmission unit 14 that performs inverse fast Fourier transform, D / A conversion, amplification, and the like and transmits a downlink transmission signal as a signal wave via the antenna 15 is configured.

The data conversion unit 11 converts user data in parallel and generates a data signal by arranging a sequence for each frequency (for each subcarrier) in a communication frame, which will be described later, on the time axis.
The pilot signal generation unit 12 generates a pilot signal that is a signal set to a predetermined signal characteristic value, and outputs the pilot signal to the transmission signal generation unit 13. This pilot signal is arranged in a communication frame and transmitted to MS 20. The MS 20 that has received the pilot signal stores a predetermined signal characteristic value at the time of transmission of the pilot signal, and uses the signal characteristic value at the time of transmission and the signal characteristic value of the pilot signal after reception. Thus, it is possible to estimate the transmission path characteristics of the received signal.

The transmission signal generation unit 13 generates a downlink transmission signal by arranging the pilot signals generated by the pilot signal generation unit 12 in the arrangement of the data signals generated by the data conversion unit 11.
As described above, the data conversion unit 11 and the transmission signal generation unit 13 generate a downlink transmission signal in which the data signal and the pilot signal are arranged on a two-dimensional area composed of a frequency axis and a time axis.
The transmission unit 14 performs an inverse fast Fourier transform on the downlink transmission signal generated by the transmission signal generation unit 13 to generate a signal modulated by OFDMA, and then performs D / A conversion, and transmits this signal as a signal wave. To do.

  The MS 20 has a functional unit for receiving a downlink transmission signal transmitted from the BS 10, and the functional unit includes an antenna 21 for receiving the transmission wave from the BS 10, and the received signal wave. A receiving unit 22 that obtains a downlink transmission signal by performing amplification, A / D conversion, fast Fourier transform, and the like, and a transmission channel estimation unit that obtains a transmission channel estimation value of the downlink transmission signal based on the obtained downlink transmission signal And a correction unit 24 that corrects the data signal based on the transmission path estimation value. Thereafter, the data signal corrected by the correction unit 24 is subjected to decoding, serial conversion, and the like, and is acquired by the MS 20 as user data.

The BS 10 has a function unit (not shown) similar to the function unit for receiving the downlink transmission signal of the MS 20 as a function unit for receiving the uplink transmission signal from the MS 20. .
Similarly, the MS 20 has a function unit (not shown) similar to the function unit for transmitting the downlink transmission signal included in the BS 10 as a function unit for transmitting the uplink transmission signal toward the BS 10. ing.

[Configuration of communication frame]
FIG. 2 is a diagram illustrating a configuration of a communication frame of the wireless communication system according to the present embodiment. This communication frame is an arrangement configuration of each data represented as two dimensions when the vertical axis is frequency and the horizontal axis is time. Downlink transmission signals generated by the data conversion unit 11 and the transmission signal generation unit 13 are The arrangement of the data signal and the pilot signal can be expressed.
The communication frame of this system is composed of a downlink subframe D to which a downlink transmission signal transmitted from the BS 10 is allocated and an uplink subframe U to which an uplink transmission signal transmitted from the MS 20 is allocated. Both subframes are on the time axis. , Are arranged alternately with a predetermined time gap.
In the communication frame, the time width from the start of transmission of one downlink subframe D to the start of the next downlink subframe D is set to 5 milliseconds.

The downlink subframe includes an area M in which a control message necessary for communication control such as a preamble (Preamble), a frame control header (FCH), and downlink subframe allocation information (DL-MAP) is stored, and a user signal And a downlink user data area du in which pilot signals are stored.
The downlink user data area du is divided into a plurality of downlink burst areas db corresponding to each MS 20 establishing communication with the BS 10, and the plurality of downlink burst areas db has established communication. It is assigned as an area for transmitting user signals and pilot signals corresponding to each MS 20.
An uplink subframe U, which is a transmission area for transmitting an uplink transmission signal of the MS 20, is assigned an uplink user data area uu in which uplink user signals and pilot signals are stored. The uplink user data area uu is divided into a plurality of uplink burst areas ub corresponding to the respective MSs 20 establishing communication with the BS 10, and the plurality of uplink burst areas ub are established with the MS 20 establishing communication. Corresponding to each, it is assigned as an area for transmitting user signals and pilot signals.
In the following, in order to facilitate understanding, description will be given focusing on the downlink transmission signal transmitted from the BS 10 to the MS 20.

  In the present embodiment, the transmission signal generation unit 13 generates two types of downlink subframes D having different signals stored in the downlink user data area du as shown in FIGS. 2 (a) and 2 (b). A data signal and a pilot signal are arranged in That is, as shown in FIG. 2 (a), the transmission signal generator 13 includes a first downlink subframe D1 in which only a pilot signal is substantially arranged in the downlink user data area du, and FIG. 2 (b). As shown, the data signal and the pilot signal are arranged so that the second downlink subframe D2 in which only the data signal is arranged in the downlink user data area du is generated.

In the first downlink subframe D1 shown in FIG. 2A, only the pilot signal is substantially stored in the entire downlink user data area du, and all downlink burst areas db constituting the downlink user data area du are included. Also, only the pilot signal is substantially stored. Therefore, only the pilot signal is transmitted for signal transmission in the downlink burst region db of the first downlink subframe D1 to each MS 20 that has established communication with the BS 10.
Here, in the downlink user data area du and the downlink burst area db included therein, the state in which only the pilot signal is substantially stored means that no data signal is arranged in the area, and a large number of A state in which pilot signals and null signals constituting guard subcarriers, center frequency subcarriers, and the like are stored.

In the second downlink subframe D2 shown in FIG. 2 (b), the data signal is stored in the entire downlink user data area du, and substantially in all the downlink burst areas db constituting the downlink user data area du. Only the user signal is stored. Therefore, only the data signal is transmitted to each MS 20 that has established communication with the BS 10 for signal transmission in the downlink burst area db of the second downlink subframe D2.
The transmission signal generation unit 13 alternately generates both downlink subframes D1 and D2 within a predetermined time width range, thereby reducing the time width range in which both downlink subframes D1 and D2 are arranged to the time. Place them alternately on the axis.

FIG. 3 is a diagram illustrating a manner of arrangement of both downlink subframes D1 and D2 in a communication frame. FIG. 3 shows a part of the communication frame F when the horizontal axis is the time axis. In the figure, the hatched portion indicates a region where the first downlink subframe D1 is transmitted in the communication frame, and the other portion indicates a region where the second downlink subframe D2 is transmitted. Show. These two regions are alternately arranged on the time axis.
The first time width t1 that is the time width of the region in which the first downlink subframe D1 is transmitted and the second time width t2 that is the time width of the region in which the second downlink subframe D2 is transmitted are Both are set to a predetermined value, and the interval between the start times of the adjacent downstream subframes D is 5 milliseconds as described above. Therefore, both of these time widths t1 and t2 are 5 milliseconds. Is set to a multiple of.
The first time width t1 is set to be smaller than the second time width t2. In the first time width t1, since it is transmitted in the first downlink subframe D1, the signal transmitted to the MS 20 by the downlink burst region db is only a pilot signal. For this reason, if the first time width t1 is set large, the substantial transmission speed when transmitting the data signal may be reduced. For this reason, it can suppress that the transmission speed of a data signal falls by setting 1st time width t1 smaller than 2nd time width t2.

  As described above, both downlink subframes D1 and D2 are arranged in ranges of both time widths t1 and t2 that are alternately arranged on the time axis.

[Transmission signal structure]
FIG. 4 is a schematic diagram showing the structure of the downlink transmission signal when the MS 20 receives the downlink transmission signal transmitted by the communication frame. In the figure, the horizontal axis represents time and the vertical axis represents frequency. FIG. 4 shows only signals transmitted in the downlink burst region db, white circles indicate data signals, and black circles indicate pilot signals.
In the figure, in the first time width t1, the downlink transmission signal is transmitted by the first downlink subframe D1 including the downlink burst area db (downlink user data area du) in which only the pilot signals are substantially arranged. Therefore, substantially only pilot signals are arranged in the first time width t1.
As described above, the transmission signal of the present embodiment has a pilot area PA that is substantially composed of an area in which only pilot signals are arranged in the first time width t1. In the example shown in the figure, the first time width t1 is set to 10 milliseconds, for example, and the pilot area PA includes pilot signals transmitted by two downlink burst areas db (downlink user data areas du), respectively. Consists of including. That is, the pilot area PA is configured with the downlink burst area db in which only the pilot signals are substantially arranged as a minimum unit.

In the second time width t2, the downlink transmission signal is transmitted in the second downlink subframe D2 including the downlink burst area db (downlink user data area du) in which only the data signals are arranged. In the time width t2, only data signals are arranged.
As described above, the downlink transmission signal of the present embodiment has the data area DA that is an area where only the data signals are arranged in the range of the second time width t2. In the illustrated example, the second time width t2 is set to 15 milliseconds, for example, and the data area DA is only a data signal transmitted by each of the three downlink burst areas db (downlink user data area du). It is comprised including. That is, although a signal such as a control message is included in the transmission signal, the data area DA is configured with the downlink burst area db in which only the data signal is arranged as a minimum unit. The data area DA and the pilot area PA are arranged in the same frequency band.

Since both downlink subframes D1 and D2 are arranged in the range of both time widths t1 and t2 arranged alternately on the time axis (see FIG. 3), the pilot area PA and the data area DA are the same. They are alternately arranged along the time axis in the frequency band.
The transmission signal generation unit 13 of the BS 10 generates a transmission signal so as to adopt the above-described structure.

[Signal correction]
Next, signal correction of the downlink transmission signal by the MS 20 that has received the downlink transmission signal transmitted by the BS 10 will be described.
The MS 20 that has received the transmission wave transmitted from the BS 10 first obtains a downlink transmission signal having the structure shown in FIG. 4 by performing A / D conversion, fast Fourier transform, and the like by the receiving unit 22.
Referring to FIG. 4, next, MS 20 sends transmission path estimation value H for each of a plurality of pilot signals arranged in pilot area PA among the obtained downlink transmission signals to transmission path estimation section 23. Let me ask. Here, the MS 20 stores a predetermined signal characteristic value at the time of transmission of the pilot signal, and the transmission path estimation unit 23 transmits the signal characteristic value at the time of transmission and the pilot signal included in the received transmission signal. Thus, the propagation characteristic of the pilot signal can be estimated, and the transmission path estimation value H of each of the plurality of pilot signals can be obtained.

Furthermore, the transmission path estimation unit 23 obtains an average value H _ave of transmission path estimation values H of pilot signals arranged in the time axis direction for each frequency. That is, an average value H _ave of transmission line estimation values H of pilot signals arranged in the time axis direction at the same frequency is obtained for each frequency.
That is, the transmission path estimation unit 23 obtains an average value H _ave as a transmission path estimation value for each pilot area PA for each frequency based on the pilot signal in the pilot area PA.

Then, the MS 20 causes the correction unit 24 to correct the data signal included in the data area DA based on the average value _Have for each frequency obtained by the transmission path estimation unit 23.
At this time, the correction unit 24 arranges the data area DA adjacent in the time axis direction to the pilot area PA to which the pilot signal for which the average value _Have is found (in the example shown, on the right side of the page following the pilot area PA). The data signal contained in the arranged data area DA) is corrected.

The correction unit 24 performs signal correction for each corresponding frequency on the data signal included in the data area DA based on the average value _Have for each frequency. That is, using the average value H _ave of the transmission path estimation values H of a plurality of pilot signals arranged in the time axis direction at the same frequency, the time at the same frequency as the pilot signal for which the average value H _ave is obtained in the data area DA. Signal correction is performed for each of a plurality of data signals arranged in the axial direction.
As described above, the correction unit 24 performs signal correction by using the average value _Have for each frequency of the transmission path estimation value H of the pilot signal as the transmission path estimation value of the data signal included in the data area DA.

  As described above, the data signal corrected by the correction unit 24 is then subjected to decoding processing, serial conversion, and the like, restored to user data, and acquired by the MS 20.

According to the radio communication system configured as described above, when correcting a data signal, an average value _Have obtained for each frequency as a transmission path estimation value for each pilot area PA is obtained as a transmission path estimation value of the data signal. Therefore, it is not necessary to perform estimation by linear interpolation as in the conventional example. For this reason, the error contained in the average value _Have used as the transmission path estimation value for correcting the data signal can be reduced, and as a result, the received data signal can be corrected more accurately.

Further, in the wireless communication system of the present embodiment, the average value H _ave obtained for each frequency is corrected as the transmission channel estimation value of the data signal of the corresponding frequency, so that the transmission path environment caused by the frequency is changed. Accordingly, it is possible to perform signal correction in accordance with the signal correction, and it is possible to further improve the accuracy of signal correction.

  In the wireless communication system, the pilot area PA and the data area DA are configured with the downlink burst area db in which only the pilot signal and the data signal are disposed as a minimum unit. Multiple processing becomes easy.

In the above embodiment, the first downlink subframe D1 in which only the pilot signal is stored for the entire range of the downlink user data area du, or the second downlink subframe in which only the data signal is stored for the entire range of the downlink user data area du. The transmission signal is transmitted by one of the frames D2 (see FIG. 2). For example, as shown in FIG. 5, for each downlink burst area db allocated for transmission to each MS 20 in the downlink user data area du In addition, a region in which only the pilot signal or the data signal is stored is generated, and the downlink transmission signal received by the specific MS 20 has a signal structure in which the pilot region PA and the data region DA are alternately arranged in the time axis direction. You can also
Even in this case, the pilot area PA and the data area DA are configured with the area in the downlink burst area db allocated to the MS 20 as a minimum unit with the specific MS 20.
According to the said structure, BS10 can control about the structure of a downlink transmission signal for every MS20 which has established communication.

The present invention is not limited to the above embodiments. For example, in each of the above embodiments, with the downlink burst area db as the minimum unit, the pilot area PA in which only the pilot signals are arranged and the data area DA in which the data signals are arranged are arranged in the communication frame. However, as shown in FIG. 6, the pilot signal and the data signal may be multiplexed so that the pilot area PA and the data area DA are alternately arranged in the time axis direction within one downlink burst area db. .
In this case, since the pilot signal and the data signal are arranged in the same downlink burst area db and the data signal is corrected using the average value H _ave by the pilot area PA arranged in the same area, the time is Errors caused by the passage of time can be suppressed, and signal correction can be performed with higher accuracy.

Further, in the case where the downlink transmission signal is configured by multiplexing the pilot signal and the data signal so that the pilot area PA and the data area DA are alternately arranged in the time axis direction within one downlink burst area db, As shown in FIG. 7, the pilot area PA and the data area DA can also be arranged so as to be alternately arranged also in the frequency axis direction.
In this case, the transmission path estimation unit 23 obtains an average value H _ave ′ of the transmission path estimation values H of the pilot signals arranged in the frequency axis direction at the same time for each time, and the correction unit 24 calculates the average value H Based on _ave ′, signal correction can be performed for each of a plurality of data signals arranged in the frequency axis direction at a corresponding time.

Further, in the above embodiment, the transmission path estimation unit 23 calculates the average value H _ave of the transmission path estimation values H of pilot signals arranged in the time axis direction at the same frequency in the pilot area PA, for each pilot area PA. The value is calculated for each frequency, but in addition to calculating the average value, for example, among pilot signals arranged in the time axis direction, the pilot weight is changed according to the position in the time axis direction (time difference from the data signal). You may obtain | require the transmission-line estimated value for every area | region PA. In this case, the correction can be performed with higher accuracy by increasing the weighting of the pilot signal closer to the data signal on the time axis.

  Moreover, although the said embodiment demonstrated the downlink transmission signal transmitted toward BS20 from BS10, it is applicable also to the uplink transmission signal transmitted toward BS10 from MS20.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the radio | wireless communications system which is one Embodiment of this invention. It is a figure which shows the structure of the communication frame of the radio | wireless communications system of this embodiment. It is a figure which shows the aspect of arrangement | positioning of both downstream sub-frames D1 and D2 in a communication frame. It is the schematic diagram which showed the structure of the said downlink transmission signal when a mobile terminal receives the downlink transmission signal transmitted with a communication frame. It is the schematic diagram which showed the other structure of the downlink transmission signal. It is the schematic diagram which showed the structure where the pilot area | region and the data area | region were alternately arrange | positioned in the time-axis direction within one downlink burst area | region. It is the schematic diagram which showed another structure which is further different among the structures where the pilot area | region and the data area | region were alternately arrange | positioned in the time-axis direction within one downlink burst area | region. It is a figure which shows the structure of the transmission signal used with the conventional radio | wireless communications system.

Explanation of symbols

10 base station apparatus 11 data converter 12 pilot signal generator
13 Transmission signal generator 14 Transmitter 15 Antenna
DESCRIPTION OF SYMBOLS 20 Mobile terminal 21 Antenna 22 Receiving part 23 Transmission path estimation part 24 Correction part

Claims (6)

Wireless communication comprising: a transmission device that transmits a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame that includes a frequency axis and a time axis; and a reception device that receives the transmission signal A system,
The transmitter is
A data region composed of regions in which the data signals are arranged and a pilot region substantially composed of regions in which only the pilot signals are arranged are alternately arranged along the time axis in the same frequency band. A transmission signal generator for generating the transmitted signal,
The receiving device is:
A transmission path estimator for obtaining a transmission path estimation value for each pilot area based on the pilot signal in the pilot area included in the received transmission signal;
A signal correction unit that performs signal correction on a data signal in the data area included in the received transmission signal based on the transmission path estimation value of the pilot area arranged adjacent to the data area in the time axis direction A wireless communication system characterized by comprising: The transmission path estimation unit obtains a transmission path estimation value for each frequency based on pilot signals arranged in the time axis direction at the same frequency among the pilot signals included in the pilot region,
The signal correction unit performs signal correction for each corresponding frequency on the data signal included in the data region based on the transmission channel estimation value for each frequency calculated by the transmission channel estimation unit. The wireless communication system according to 1. The communication frame has a user data area including a burst area for transmitting the transmission signal,
The radio communication system according to claim 1 or 2, wherein each of the pilot area and the data area is configured with the burst area as a minimum unit. A transmission device that transmits a transmission signal, in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis, to a reception device,
A data region composed of regions in which the data signals are arranged and a pilot region substantially composed of regions in which only the pilot signals are arranged are alternately arranged along the time axis in the same frequency band. A transmission signal generator for generating the transmitted signal,
Receiving the transmission signal, obtaining a transmission channel estimation value for each pilot region based on the pilot signal included in the transmission signal, for the receiving device that performs signal correction based on the transmission channel estimation value, A transmission apparatus that transmits the transmission signal. A receiving device that receives a transmission signal from a transmitting device that transmits a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis,
A data region composed of regions in which the data signals are arranged and a pilot region substantially composed of regions in which only the pilot signals are arranged are alternately arranged along the time axis in the same frequency band. And receiving the transmission signal transmitted from the transmission apparatus, and obtaining a transmission path estimation value for each pilot region based on the pilot signal in the pilot region included in the received transmission signal. A path estimation unit;
A signal correction unit that performs signal correction on a data signal in the data area included in the received transmission signal based on the transmission path estimation value of the pilot area arranged adjacent to the data area in the time axis direction A receiving apparatus comprising: A signal correction method for a wireless communication system in which communication is performed using a transmission signal in which a pilot signal and a data signal are arranged in a two-dimensional communication frame composed of a frequency axis and a time axis,
A data region composed of regions in which the data signals are arranged and a pilot region substantially composed of regions in which only the pilot signals are arranged are alternately arranged along the time axis in the same frequency band. A transmission signal generating step for generating the transmitted signal,
A transmission step of transmitting the transmission signal generated by the transmission signal generation step;
A transmission path estimation step of receiving a transmission signal transmitted by the transmission step and obtaining a transmission path estimation value for each pilot area based on the pilot signal in the pilot area included in the received transmission signal;
A signal correction step of performing signal correction on a data signal in the data area included in the received transmission signal based on the transmission path estimation value of the pilot area arranged adjacent to the data area in the time axis direction And a signal correction method for a wireless communication system.

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