JP3628247B2 - Signal demodulation method and receiving apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a signal demodulating method and a receiving apparatus in a cellular CDMA mobile communication system, and more particularly to a signal demodulating method and a receiving apparatus in a cellular CDMA mobile communication system using a common pilot and an individual pilot together and using both transmission diversity and soft handover. .
[0002]
[Prior art]
The spread spectrum communication and the CDMA system using the spread spectrum communication technology are characterized by being strong in multipath fading and capable of speeding up data, further having good communication quality and high frequency utilization efficiency. This is a promising communication method for next-generation mobile communication and multimedia mobile communication.
A transmission signal in such spread spectrum communication and CDMA system is transmitted by being spread over a much wider band than the bandwidth of a signal to be transmitted on the transmission side. On the other hand, on the receiving side, the above-described characteristics are exhibited by restoring the spectrum spread signal to the original signal bandwidth.
[0003]
In addition, as described in the article “Nikkei Electronics no. 747, July 12, 1999 issue” that says “CDMA will not stop, the next growth market will be in China” Common pilots and individual pilots are used as pilot structures. For these pilots, known symbols are transmitted, received by the mobile station, and used for propagation path estimation.
[0004]
FIG. 5 shows a block diagram of a receiving unit in a conventional CDMA system. In the conventional CDMA system, as shown in FIG. 5, after the CDMA signal received by the antenna 51 is amplified by the RF amplification unit 52, the frequency conversion unit 53 converts the radio frequency to an intermediate frequency or baseband frequency, Demodulated data 57 is obtained through an information demodulating unit 55 comprising a despreading / synchronizing unit 54 and synchronous detection and RAKE combining functions.
[0005]
Such a CDMA receiver has a configuration in which a despreading / synchronizing unit 54 is added to the conventional narrowband communication. In addition, since mobile communication operates in a multipath environment, it has a path search unit 56 for grasping the situation, and defines a plurality of paths of received signals to be despread / synchronized and RAKE combined. To do.
Then, the information demodulator 55 obtains a propagation path estimation value using a common pilot in which a known symbol is transmitted with respect to the amplitude and phase of the symbol received through a plurality of paths, and the complex conjugate is obtained from the communication channel. The received symbol is demodulated by complex multiplication of the received symbol. Furthermore, at the time of so-called soft handover for communicating with a plurality of base stations, channel estimation is performed using a common pilot of the plurality of base stations, and communication channels from the plurality of base stations are demodulated.
[0006]
In addition to this, in a system using individual pilots, a method of performing propagation path estimation using individual pilots has been proposed. Further, in the third generation mobile communication system, in order to improve the reception characteristics, as shown in RCS99-12 “Effect of downlink transmission diversity in W-CDMA”, the IEICE technical report, STTD and Feed Back It has been proposed to apply a type of transmit diversity, closed loop fast transmit power control, to a communication channel with dedicated pilots.
[0007]
[Problems to be solved by the invention]
However, in a conventional CDMA receiver that performs channel estimation using a common pilot, when high-speed power control is performed during soft handover, the received signal amplitude of a data channel symbol varies depending on each base station for power control. As a result, the amplitude value portion of the propagation path estimation value obtained from the common pilot and the propagation path estimation value of the data channel portion that should be originally obtained are different, and there is a problem that correct demodulation cannot be performed. In addition, there is a problem in that it is not possible to correctly obtain a power estimation value of a communication channel for performing closed loop transmission power control.
[0008]
Further, in the method of performing channel estimation using dedicated pilots, the dedicated pilots are time-multiplexed with respect to the data channel. However, since the energy allocated to the dedicated pilots is smaller than that of the common pilots, the demodulation characteristics deteriorate. There was a problem.
[0009]
In addition, while a feed back type base station signal needs to perform propagation path estimation using a common pilot, STTD needs to demodulate using an individual pilot. Therefore, when soft handover is attempted between a base station using Feed Back type diversity and a base station using STTD, one performs channel estimation using a common pilot and the other performs dedicated pilot. Therefore, if the communication channel and the common pilot code area transmission power are different, RAKE combining cannot be performed successfully.
[0010]
Further, when soft handover and transmission diversity are used together, there is a problem that the circuit scale increases because the number of diversity combining increases.
The present invention has been proposed in view of the above-described circumstances, and provides a signal demodulation method and receiving apparatus capable of realizing highly reliable RAKE reception in a CDMA mobile communication system in which a common pilot and an individual pilot are used together. With the goal.
[0011]
Another object of the present invention is to provide a signal demodulating method and a receiving apparatus capable of realizing highly reliable RAKE reception even when transmission diversity, closed-loop downlink transmission power control and soft handover are used in combination. To do.
[0012]
[Means for Solving the Problems]
In order to achieve the above-described object, the signal demodulating method and receiving apparatus of the present invention have the following features.
That is, the signal demodulation method of the present invention is a signal demodulation method in a communication system that transmits a known symbol and a data symbol using a plurality of communication channels,
Receiving the known symbol and the data symbol transmitted using the plurality of communication channels, and using the known symbol, the amplitude and phase in a propagation path between transmission and reception corresponding to each communication channel; for plural Propagation path Calculating an estimate; A correction value corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude is calculated. Process, Using the specific propagation path estimated value corrected by the correction value, changing the amplitude and phase of the data symbol and outputting a synthesized symbol; It is characterized by including.
[0013]
By adopting such a configuration, it is possible to correct a channel estimation error to be used for demodulation in the common pilot and the communication channel, to correctly calculate the communication channel reception power, and to perform closed-loop transmission power control. The error at the time can be reduced.
[0014]
Further, the signal demodulation method of the present invention includes: The step of receiving the known symbol and the data symbol transmitted using the plurality of communication channels, and the amplitude and phase in a propagation path between transmission and reception corresponding to each communication channel using the known symbol And a correction corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude. A plurality of base stations, the step of calculating a value and the step of outputting a composite symbol by changing the amplitude and phase of the data symbol using the common channel estimation value corrected by the correction value The received signal amplitude of the data channel symbol of each base station does not change when communicating with each other and performing a soft handover. It is characterized by.
[0015]
With such a configuration, it is possible to correctly demodulate the communication channel even when soft handover and transmission power control are used together.
[0016]
A signal demodulation method according to the present invention is a signal demodulation method in a communication system that transmits a plurality of known symbols and data symbols using a plurality of communication channels,
Receiving the known symbol and the data symbol transmitted on the plurality of communication channels, and using the known symbol, the amplitude and phase in a propagation path between transmission and reception corresponding to each communication channel; for plural Propagation path Calculating an estimate; A correction value corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude is calculated. Process, Using the specific channel estimate, Changing the amplitude and phase of the data symbol and outputting a plurality of correction symbols; Furthermore, using the correction value, And a step of weighting and combining the plurality of correction symbols and outputting a combined symbol.
[0017]
With this configuration, RAKE synthesis can be performed correctly. The signal demodulating method of the present invention is characterized in that in each of the above-described signal demodulating methods, a step of correcting the amplitude and the phase in correspondence with transmission diversity is provided.
In this case, it is possible to further perform weighting correction calculated separately on the amplitude and phase correction symbols and output a combined symbol.
[0018]
With such a configuration, the signal demodulation method of the present invention can be applied even when transmission diversity is used in combination.
[0021]
The receiving apparatus of the present invention is a receiving apparatus used for a communication system that transmits a plurality of known symbols and data symbols using a plurality of communication channels,
A signal receiving unit that receives the known symbol and the data symbol transmitted using the plurality of communication channels, and an amplitude and a phase in a propagation path between transmission and reception corresponding to each communication channel using the known symbol. A channel estimation unit that calculates a plurality of channel estimation values, and a level ratio between a specific channel estimation value and any other channel estimation value among the plurality of channel estimation values for the amplitude A correction calculator that calculates a corresponding correction value, a rake combiner that outputs a combined symbol by changing the amplitude and phase of the data symbol using the common channel estimation value corrected by the correction value; It is provided with the receiving apparatus characterized by the above-mentioned.
[0022]
With such a configuration, the number of transmission diversity combining units can be reduced.
[0023]
Further, in each of the above-described receiving apparatuses, it is possible to correct the propagation path estimated value output signal with the output signal of the correction calculation unit.
Further, in each of the above-described receiving apparatuses, it is possible to correct the data symbol synthesis weight based on the output signal of the correction calculation unit.
[0024]
By adopting such a configuration, the number of digits required for the propagation path estimation value can be reduced.
[0025]
Further, each receiving apparatus described above can include a transmission diversity weight calculation unit.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a signal demodulation method and a receiving apparatus according to the present invention will be described with reference to the drawings.
[0027]
FIG. 1 is a block diagram showing a schematic configuration of a receiving apparatus according to an embodiment of the present invention.
In FIG. 1, 101-1 and 101-n are base stations, 102 is a mobile device, 103 is a receiving unit, 104 is a modulation / transmission unit, 105 is a path search unit, 106 is a despreading / synchronizing / demodulating unit, 107 is A signal control / correction calculation unit, 108 is a system control unit, 109 is a protocol processing unit, 110 is an application unit, and 111-la, 111-1b, and 111-n are base station antennas. Note that the base stations 101-1 to 101-n represent n base stations. These base stations are provided with one or more antennas 111, and perform transmission diversity when two or more antennas are provided.
[0028]
As shown in FIG. 1, the mobile device 102 performs communication by performing a soft handover with one or more base stations 101-j (j = 1,..., N). In the mobile device 102, the received signal is guided to the receiving unit 103, and amplification / frequency conversion is performed. Further, since the mobile device 102 operates in a multipath environment, the mobile device 102 has a path search unit 105 for grasping the situation, and defines a plurality of paths of received signals to be despread / synchronized and Rake combined. .
[0029]
The defined path is selected by the signal control / correction calculation unit 107. The control signal of the signal control / correction calculation unit 107 is input to the despreading / synchronizing / demodulating unit 106, and the received signal is despread at a plurality of path timings to be synchronized, and the amplitude and phase of the symbol are Then, a propagation path estimated value is obtained, and the complex conjugate is complex-multiplied for each path with respect to the received symbol of the communication channel, and then combined at the same timing to obtain an output signal.
[0030]
The output signal is subjected to signal processing according to the communication protocol by the protocol processing unit 109. Then, the output signal of the protocol processing unit 109 is guided to the application unit 110. The signal generated in the application unit 110 is output to the modulation / transmission unit 104 together with the control signal from the signal control / correction calculation unit 107 via the protocol processing unit 109, and is transmitted from the mobile device 102 to the base station 101-j. Sent to.
[0031]
The system control unit 108 controls the operation of the entire system such as the signal control / correction calculation unit 107 and the protocol processing unit 109. When the processing time in the protocol processing unit 109 becomes a problem, the control signal of the signal control / correction calculation unit 107 may be directly input to the modulation transmission unit 104.
[0032]
FIG. 2 shows a transmission signal format from the base station.
As shown in FIG. 2, a common pilot and a communication channel are transmitted from the base station using different codes at the same frequency and at the same time. At this time, a code channel is defined for each code.
[0033]
In the common pilot channel, a known symbol sequence is transmitted in units of slots. In addition, one or more known symbol sequences of one symbol or more are inserted in one slot together with control data in a part of the communication channel and transmitted as an individual pilot. A plurality of slot sequences of both code channels are combined to form one frame, and a plurality of frames are transmitted. Since the transmission power of each slot in one frame in the communication channel is closed loop power control, transmission may be performed with different power. When the base station has two antennas, different symbol sequences orthogonal to each other are used as a common pilot.
[0034]
FIG. 3 is a block diagram showing the main parts of the despreading / synchronization / demodulation unit 106 and the signal control / correction calculation unit 107. The names of the respective parts shown in FIG. 3 represent the actions or functions of the respective parts or are abbreviated and may differ from the names of the respective parts in the following description. And the action and the like are the same.
[0035]
As shown in FIG. 3, the input signal to despread / synchronization / demodulation section 106 is divided into two and input to common pilot despread section 201 and communication channel despread section 203.
The common pilot despreading unit 201 correlates with the code of the common pilot channel. The communication channel despreading section 203 correlates with the communication channel code. Then, the output signal of the common pilot despreading section 201 is input to the antenna separation section (ANT separation section) 202 and correlated with a known symbol sequence, so that the base station transmits the common pilot from each of the two transmission antennas. Isolate.
[0036]
The separated symbol string is one when there is no transmission diversity and two when there is transmission diversity. One or two symbol sequences are input to a common pilot propagation path estimation unit (CH estimation unit) 204. The propagation path estimation unit 204 performs propagation path estimation by taking the average of the complex symbol sequences.
[0037]
On the other hand, the output signal of communication channel despreading section 203 is divided into two parts: a symbol string part including dedicated pilots and a symbol string including data symbols. The symbol sequence including the dedicated pilot is input to the propagation path estimation unit (CH estimation unit) 205. The propagation path estimation unit 205 obtains the propagation path estimation value of the reception slot by taking the average of the individual pilots. At this time, as a channel estimation method, various methods such as a method of averaging individual pilots of a plurality of slots or a method of performing primary interpolation of amplitude and phase of individual pilots of adjacent slots can be used.
[0038]
The output of the propagation path estimation unit 205 is input to the inter-channel level ratio measurement unit (inter-CH level ratio measurement unit) 231 together with the output of the common pilot propagation path estimation unit (CH estimation unit) 204. Then, the inter-channel level ratio measurement unit 231 measures the signal level ratio between the common pilot channel and the communication channel based on the propagation channel estimation values of the two channels. For example, assuming that the propagation path estimation value from the common pilot is A and the propagation path estimation value from the individual pilot is B, the level ratio r = | B | / | A | is calculated and output.
[0039]
Then, based on the output level ratio, the inter-channel level correction unit 206 corrects the common pilot channel estimation value. That is, the propagation path estimated value A ′ corrected by the equation A ′ = r · A is calculated and output. Of course, it is also possible to use a calculation method other than the previous equation that can obtain the same result. At this time, the phase of A ′ is the same as that of A, and the phase information necessary for transmission diversity control is stored, so that Feed Back type transmission diversity control can be performed.
[0040]
The output signal of the inter-channel level correction unit 206 is guided to the propagation channel estimation value selection unit (CH estimation selection unit) 209, 210 via the transmission diversity correction unit 207, and the propagation channel estimation value obtained from the signal and the individual pilot. Is selected, and synchronous detection is performed by multiplying the complex conjugate of the selection signal in the synchronous detectors 211 and 213. An antenna combining unit (ANT combining unit) is provided between the propagation path estimated value selecting unit 209 and the synchronous detection unit 213.
[0041]
Transmission diversity correction section 207 corrects one antenna reception signal phase based on a transmission signal phase determination result from a base station described later. The synchronous detection unit 211 for the control signal performs detection by extrapolating the propagation path estimated value in order to perform closed-loop power control without causing a delay.
[0042]
On the other hand, in the synchronous detection unit 213 for the communication channel, in order to increase the reliability of the signal at the time of detection, symbols for one slot are stored in the buffer 212, and the channel estimation value average unit (CH estimation average unit) 208 Synchronous detection is performed by taking the average of propagation path estimation values for 1 slot.
[0043]
An output signal from the synchronous detection unit 213 is guided to an STTD decoding unit (STTD decoding unit) 215, and performs this processing if STTD decoding is necessary. If the transmission signal is not STTD encoded, the signal is output as it is without being processed.
[0044]
Since the above-described processes are performed for each demodulation path, the demodulated signal for each path is combined at the timing by the RAKE combining unit 222 to obtain one output signal. When there is only one path and only one path is demodulated, the RAKE combining unit 222 is not necessary.
[0045]
The output signal from the synchronous detection unit 211 on the control signal side is input to the pilot separation unit 214 and separated into individual pilots and other control signals. Control signals such as transmission power control bits other than dedicated pilots are guided to an STTD decoding unit (STTD decoding unit) 216, and if STTD encoded, STTD decoding is performed. Then, the RAKE combining unit (RAKE combining unit for each BTS) 223 performs RAKE combining on the signals obtained for each path.
[0046]
The output signal of the RAKE combining unit 223 is input to the TPC determination unit 225, determines a control command for closed-loop transmission power control, and controls transmission power from the modulation / transmission unit 104 (see FIG. 1).
[0047]
The individual pilots are RAKE combined for each path in a RAKE combining unit (RAKE combining unit for each BTS) 217. The signal after RAKE combining is STTD decoded in STTD decoding section (STTD decoding section) 218 if the transmission signal is STTD encoded. In this case, since the STTD decoding is performed on the signal after the RAKE synthesis, the STTD decoding unit 218 is unnecessary for each path, and the circuit configuration is simplified. Such a configuration can also be applied to communication channel demodulation and TPC determination.
[0048]
The output signal of the STTD decoding unit 218 is input to the SIR calculation unit 221 and the synchronization determination processing unit (SW determination processing unit) 219. The SIR calculation unit 221 calculates the reception SIR of the signal from the received symbol strength and variance, and the calculation result is used by the uplink TPC bit determination unit 220 to generate closed-loop uplink power control data.
[0049]
For example, the received SIR is compared with the desired SIR, and the power control bit in the uplink transmission frame is set so that the SIR becomes a desired value. In some cases, the number of received bits of the dedicated pilot is increased to improve the calculation accuracy of the received intensity dispersion value. In addition, a method of performing SIR calculation with a signal that is not STTD decoded is also possible.
[0050]
In addition, the synchronization determination processing unit 219 monitors the synchronization of individual pilots in units of one frame, and performs frame synchronization determination processing. The common pilot signal separated for each base station antenna is input to transmission antenna setting content calculation sections (CH estimation / synchronous detection sections) 226 and 227, and the transmission antenna setting contents in the base station are calculated for each slot. . For example, when the transmission signal phase from the base station takes two types of 0 degrees and 180 degrees, the common pilot demodulation output for each path from the two antennas is combined at 0 degrees and 180 degrees, and 2 One composite output signal is obtained.
[0051]
The combined output signals are respectively input to RAKE combining units (RAKE combining units for each BTS) 228 and 229 and combined for each path. The two output signals from the RAKE combining units 228 and 229 are input to the transmission diversity weight calculation unit 232, and the weight of the transmission signal from the base station, that is, the transmission signal phase, which has a reception strength of 0 degrees or 180 degrees. The transmission diversity control bit to be inserted in the uplink transmission signal is transmitted to the protocol processing unit 109 (see FIG. 1), and the protocol processing unit 109 multiplexes it with the uplink transmission data.
[0052]
The propagation path estimation values obtained from the common pilot and the individual pilot are also input to the transmission antenna phase determination unit 230. The transmission antenna phase determination unit 230 determines the phase of the signal actually transmitted from the base station. The determination result is input to the transmission diversity correction unit 207, the STTD decoding units 215, 216, 218, and the SIR calculation unit 221, and is used to correct the base station transmission signal at the time of decoding.
[0053]
In the above description, the case where the transmission signal phase from the base station is 0 degrees and 180 degrees has been described. However, the present invention is not limited to this, and the case where three or more other phases are set. The present invention can also be applied to cases where the amplitude is weighted.
[0054]
FIG. 4 is a block diagram of a receiving apparatus according to another embodiment of the present invention. In FIG. 4, the same reference numerals are given to the portions having the same functions as those of the above-described receiving apparatus shown in FIG.
[0055]
The receiving apparatus shown in FIG. 4 is an embodiment in the case where the output of the inter-channel level ratio measuring unit 231 is not corrected with respect to the propagation path estimated value but is corrected in the RAKE combining units 217, 222, and 223.
[0056]
As shown in FIG. 4, the RAKE combining units 217, 222, and 223 of this receiving apparatus multiply the output signals of the respective paths by a correction value r and combine them. In this embodiment, correction is required in the plurality of RAKE combining units 217, 222, and 223, but there is an advantage that the number of digits of the propagation path estimation value can be reduced. Also, when there is only one path and only one path is demodulated, the RAKE combining units 217, 222, and 223 are not necessary.
[0057]
Note that the signal demodulation method and the receiving apparatus of the present invention are not limited to the above-described examples, and it is needless to say that various modifications can be made according to the embodiments.
[0058]
【The invention's effect】
Since the signal demodulation method and the receiving apparatus of the present invention have the above-described configuration, it is possible to realize highly reliable RAKE reception in a CDMA mobile communication system in which a common pilot and an individual pilot are used together.
[0059]
Further, even when transmission diversity, closed-loop downlink transmission power control and soft handover are used in combination, it is possible to realize highly reliable RAKE reception.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a receiving apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a transmission signal format from a base station.
FIG. 3 is a block diagram showing the main parts of a despreading / synchronizing / demodulating unit and a signal control / correction calculating unit.
FIG. 4 is a block diagram showing the main parts of a despreading / synchronizing / demodulating unit and a signal control / correction calculating unit in a receiving apparatus according to another embodiment of the present invention.
FIG. 5 is a block diagram showing a schematic configuration of a conventional receiving apparatus.
[Explanation of symbols]
101-l to n: Base station
102: Mobile device
103: Receiver
104: Modulation / transmission unit
105: Path search section
106: Despreading / synchronizing / demodulating unit
107: Signal control / correction calculation unit
108: System control unit
109: Protocol processor
110: Application section
111-la, 111 · lb to 111 · 1n: base station antenna
201: Common pilot despreading unit
202: Antenna separation unit
203: Communication channel despreading section
204: Common pilot propagation path estimation unit
205: Propagation path estimation unit
206: Inter-channel level correction unit
207: Transmission diversity correction unit
208: Propagation path estimated value average part
209: Channel estimation value selection unit
210: Propagation path estimation value selection unit
211: Synchronous detection unit
212: Buffer
213: Synchronous detection unit
214: Pilot separation part
215: STTD decoding unit
216: STTD decoding unit
217: RAKE combining unit
218: STTD decoding unit
219: Synchronization determination processing unit
220: Uplink TPC bit determination unit
221: SIR calculation unit
222: RAKE combining unit
223: RAKE combining unit
224: Antenna combining unit
225: TPC determination unit
226: Transmitter antenna setting content calculation unit
227: Transmitter antenna setting content calculation unit
228: RAKE combining unit
229: RAKE combining unit
230: Transmitting antenna phase determination unit
231: Channel-to-channel level ratio measurement unit
232: Transmission diversity weight calculator
51: Antenna
52: RF amplification section
53: Frequency converter
54: Despreading / synchronizing unit
55: Information demodulator
56: Path search section
57: Demodulated data

Claims (10)

A signal demodulation method in a communication system that transmits a known symbol and a data symbol using a plurality of communication channels,
Receiving the known symbols and the data symbols transmitted using the plurality of communication channels;
A step of calculating the known symbol using a plurality of channel estimation value for the amplitude and phase of the propagation path between transmission and reception corresponding to each communication channel,
Calculating a correction value corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude;
Using the specific propagation path estimated value corrected by the correction value, changing the amplitude and phase of the data symbol and outputting a synthesized symbol;
A signal demodulating method. Receiving the known symbols and the data symbols transmitted using the plurality of communication channels;
Calculating the plurality of channel estimation values for the amplitude and phase in the channel between transmission and reception corresponding to each communication channel using the known symbols;
The step of calculating a correction value corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude;
Using the common channel estimation value corrected by the correction value, changing the amplitude and phase of the data symbol and outputting a combined symbol;
2. The signal according to claim 1, wherein the received signal amplitude of a symbol of a data channel of each base station is not changed when communication is performed for each of a plurality of base stations and soft handover is performed. Demodulation method. A signal demodulation method in a communication system that transmits a plurality of known symbols and data symbols using a plurality of communication channels,
Receiving the known symbols and the data symbols transmitted on the plurality of communication channels;
A step of calculating the known symbol using a plurality of channel estimation value for the amplitude and phase of the propagation path between transmission and reception corresponding to each communication channel,
Calculating a correction value corresponding to a level ratio between a specific propagation path estimation value and another arbitrary propagation path estimation value among the plurality of propagation path estimation values for the amplitude ;
Changing the amplitude and phase of the data symbol using the specific propagation path estimated value, and outputting a plurality of correction symbols;
A step of weighting and combining the plurality of correction symbols using the correction value and outputting a combined symbol;
A signal demodulating method. In correspondence with transmit diversity, the signal demodulating method as claimed in any one of claims 3, characterized in that it comprises the step of correcting the amplitude and phase. 5. The signal demodulation method according to claim 4 , wherein a weighted correction calculated separately is further applied to the amplitude and phase correction symbols, and a combined symbol is output. A receiving apparatus used in a communication system for transmitting a plurality of known symbols and data symbols using a plurality of communication channels,
A signal receiver for receiving the known symbols and the data symbols transmitted using the plurality of communication channels ;
A propagation path estimator that calculates a plurality of propagation path estimation values for amplitude and phase in a propagation path between transmission and reception corresponding to each communication channel, using the known symbols;
Among the plurality of propagation path estimated values for the amplitude, a correction calculation unit that calculates a correction value corresponding to a level ratio between a specific propagation path estimated value and another arbitrary propagation path estimated value;
A rake combiner that outputs a combined symbol by changing the amplitude and phase of the data symbol using the common channel estimation value corrected by the correction value;
Receiving device, characterized in that it comprises a. Receiver according to claim 6, characterized in that it comprises a transmission diversity combining unit that performs transmission diversity combining with respect to the signal after data symbol combining. The receiving apparatus according to claim 6 or 7, wherein a propagation path estimated value output signal is corrected by an output signal of the correction calculation unit. Receiving apparatus according to any one of the correction calculation unit according to claim 8 claims 6, characterized in that to correct the data symbol combining weights by the output signal of the. Receiving apparatus according to any one of claims 9 claims 6, characterized in that it comprises a weight calculator for transmission diversity.

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