JP2002111546A - Demodulator and demodulating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demodulator and demodulating method which reduce the power consumption, while using joint detection demodulation. SOLUTION: A delay profile comparison processor 2 obtains and compares the variations of a previous and preset delay profiles with a specified reference value and outputs a selection result, indicating usage for a previous operation variable or for preparing a new operation variable, if both variations of a previous and present delay profiles are smaller or greater than the reference value, respectively. A joint detection demodulator 3 prepares an operation variable and carries out joint-detection demodulation, if the selection result indicates use for newly preparing operation variable. However, if indicating to use the previously prepared operation variable it will not prepare operation variables this time and will carry out joint-detection demodulation, using the previously prepared operation variable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CDMA (Code D)
The present invention relates to a demodulation device and a demodulation method suitable for use in mobile communication of an ivision multiple access (ivision multiple access) system.

[0002]

2. Description of the Related Art As a conventional demodulation method in CDMA mobile communication, Joint Detection (Joint Detect) is used.
ion) demodulation. Joint detection demodulation is a demodulation method using an interference cancellation equalization method that obtains a signal free from the influence of intersymbol interference and other user interference, and uses a delay profile obtained by channel estimation and a spreading code for all users. A demodulated signal is obtained by performing an operation for removing the effects of intersymbol interference and other user interference from the received signal.

FIG. 13 is a block diagram showing a schematic configuration of a conventional joint detection demodulator. In this figure, the joint detection demodulator is
It is configured to include a channel estimation unit 50, an operation variable creation unit 51, and an interference removal operation unit 52. Channel estimation unit 5
0 performs channel estimation processing using a known signal sequence included in the received baseband signal, and creates a delay profile for all multiplexed codes of all multiplexed users.

[0004] The operation variable creation unit 51 includes a channel estimation unit 5
An operation variable is created based on the delay profile created at 0 and spread code information for all multiplex codes of all multiplex users. The interference removal operation unit 52 performs an operation of removing the influence of intersymbol interference and other user interference using the operation variable created by the operation variable creation unit 51 and the received baseband signal,
Obtain demodulation result. The spreading code information is obtained from a separately provided spreading code estimating unit (not shown) or an upper layer.
The operation variable creation unit 51 and the interference removal operation unit 52 constitute a joint detection demodulation unit 53.

[0005] For the joint detection demodulation, for example, "Interference Cancellation v
s.Channel Equalization and Joint Detection for th
e Downlink of C / TDMA Mobile Radio Concepts '' (Bernd
Steiner, Proceedings of EPMCC Conference Germany 1
997, No. 145, pp. 253-260) or `` EFFICIENT MULTI-R
ATE MULTI-USER DETECTION FOR THE ASYNCHRONOUS WCDM
A UPLINK "(HRKarimi, VTC'99, pp.593-597).

[0006]

However, in the conventional joint detection demodulator, the performance of joint detection demodulation is better than that of ordinary rake demodulation, but the power consumption is high due to the large amount of computation. There is a problem that becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a demodulation apparatus and a demodulation method capable of reducing power consumption while using joint detection demodulation.

[0008]

According to the present invention, there is provided a demodulation apparatus for determining whether a calculation variable used for joint detection demodulation is newly created or used in the past in accordance with a predetermined reference value for each transmission unit. Calculation variable determination means for determining the calculation variable, storage means for storing the calculation variable, and when the calculation variable determination means determines a new creation of the calculation variable, newly creates a calculation variable in the current reception transmission unit. And used in joint detection demodulation and stored in the storage means, and when it is determined to use the one created in the past, the past operation variables stored in the storage means are used for joint detection demodulation. A configuration including a joint detection demodulation means to be used is adopted.

According to this configuration, the operation variable used for the joint detection demodulation is set according to a predetermined reference value.
Calculation variables used for joint detection demodulation, since it was decided whether to use newly created ones or those created in the past, and to use those created in the past when there was no need to create a new one. Can be reduced, and power saving at the time of demodulation can be achieved.

[0010] In the demodulation device according to the present invention, in the demodulation device, the calculation variable determining means measures a change amount of a delay profile between a plurality of transmission units, and compares a delay profile of a past reception transmission unit with a current reception profile. If the amount of change in the delay profile of the transmission unit is equal to or less than a predetermined reference value, the use of the operation variable created in the past reception transmission unit is determined. Use a configuration that determines the use of.

[0011] According to this configuration, since the criterion for determining the operation variable used for joint detection demodulation is the amount of change in the delay profile between a plurality of transmission units, the reception quality can be improved.

Further, in the demodulation device according to the present invention, in the demodulation device, an error detecting means for detecting an error of the decoded signal after the joint detection demodulation, and a reference value based on an error detection result from the error detecting means. And a reference value control means for changing the value.

According to this configuration, when there is an error in the decoded signal, the reference value for selecting the operation variable is changed, so that the reception quality can be improved.

Further, the demodulation device of the present invention comprises a delay profile averaging means for averaging a delay profile among a plurality of transmission units, and a delay profile averaging means for calculating a change in the delay profile averaged by the delay profile averaging means. Measure,
Delay profile comparison processing means for comparing the measured change amount with a predetermined reference value; and if the change amount between the average value of the past delay profile and the average value of the current delay profile is smaller than the reference value, the past reception transmission Perform joint detection demodulation using the operation variables created in units, and if the amount of change is greater than the reference value, newly create operation variables from the current delay profile and perform joint detection demodulation. A configuration having joint detection demodulation is adopted.

According to this configuration, the calculation variables used for joint detection demodulation are newly created or those created in the past according to the amount of change between the average value of the past delay profile and the average value of the current delay profile. When it is not necessary to create a new one, the one created in the past is used, so the number of calculation variables used for joint detection demodulation is reduced, and Power saving.

Further, the demodulation device according to the present invention, in the demodulation device, an error detection means for detecting an error of the decoded signal after the joint detection demodulation, and a delay profile based on an error detection result from the error detection means. And a reference value control means for changing the averaging length or the reference value.

According to this configuration, if there is an error in the decoded signal, the average length or reference value of the delay profile for selecting the operation variable is changed, so that the reception quality can be improved.

Further, the demodulation apparatus of the present invention comprises a delay profile averaging means for averaging a delay profile among a plurality of transmission units, and a joint for performing demodulation by joint detection using an average value of the delay profiles. A configuration including detection demodulation means;

According to this configuration, instead of performing joint detection demodulation using a delay profile for each reception transmission unit, joint detection demodulation is performed using a delay profile averaged over a plurality of transmission units. The number of creations of operation variables used for joint detection demodulation is reduced, and power saving during demodulation can be achieved.

In the demodulation device according to the present invention, in the demodulation device, the received baseband signal is stored during the delay profile averaging process by the delay profile averaging process means, and is stored after the delay profile averaging process is performed. And a storage unit for supplying the received baseband signal to the joint detection demodulation unit.

According to this configuration, the received baseband signal during the delay profile averaging process is stored, and after the delay profile averaging process, the stored received baseband signal is used for the joint detection demodulation. Therefore, joint detection demodulation using an averaged delay profile becomes possible, and power consumption during demodulation can be achieved by reducing the number of creations of operation variables.

Further, the demodulation device of the present invention employs a configuration in which the demodulation device includes a rake demodulation means for rake demodulating a received baseband signal and supplying a rake demodulation symbol obtained thereby to a storage means.

According to this configuration, the storage means does not store the received baseband signal, but stores the rake demodulated symbol that is rake demodulated, so that the storage capacity can be reduced and the cost can be reduced. Since the rake demodulation function can be omitted from the joint detection demodulation means by providing the rake demodulation means, the cost does not increase even if the rake demodulation means is provided outside.

Further, the demodulation device of the present invention, in the demodulation device described above, measures a change amount of a delay profile between a plurality of transmission units and, if the change amount of the delay profile is larger than a predetermined reference value, averages the delay profile. A delay profile comparison processing means for determining whether to continue averaging if the determination is small, and the joint detection demodulation means, if the determination result of the delay profile comparison processing means is averaging discontinuation, the delay profile comparison processing means. A configuration is employed in which joint detection demodulation is performed on a received signal of a transmission unit averaged using the average value.

According to this configuration, the delay profile is averaged among a plurality of transmission units, so that the number of times of creating an operation variable used for joint detection demodulation can be further reduced, and power saving at the time of demodulation can be achieved. Can be achieved. Further, since the averaging period is controlled by the amount of change in the delay profile, the reception quality can be improved.

Further, the demodulation device according to the present invention, in the demodulation device, an error detecting means for detecting an error of the decoded signal after the joint detection demodulation, and a delay profile based on an error detection result from the error detecting means. And a reference value control means for changing a reference value for terminating the averaging.

According to this configuration, if there is an error in the decoded signal, the reference value for terminating the averaging of the delay profile is changed, so that the reception quality can be improved.

A radio base station apparatus according to the present invention employs a configuration including the demodulation device.

A radio communication terminal according to the present invention employs a configuration including the demodulation device.

By having the demodulation device of the present invention, it is possible to provide a wireless base station device or a wireless communication terminal device with reduced power consumption.

In the demodulation method of the present invention, an operation variable used for joint detection demodulation is selected according to a predetermined criterion, and joint detection demodulation is performed using the selected operation variable.

According to this method, the amount of calculation for creating a calculation variable used for joint detection demodulation can be suppressed, and power saving during demodulation can be achieved.

Further, in the demodulation method of the present invention, the delay profile is averaged within a plurality of transmission units, an operation variable used for joint detection demodulation is created using the averaged delay profile, and the created operation variable is created. Is used to perform joint detection demodulation.

According to this method, the number of calculation variables used for joint detection demodulation can be reduced, and power saving during demodulation can be achieved.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention is to use previously created calculation variables instead of newly created calculation variables used in joint detection demodulation when they can be used. is there.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a demodulation device according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing a configuration of the joint detection demodulation unit 3 included in the demodulation device according to the present embodiment.

Referring to FIG. 1, the demodulation apparatus according to the present embodiment includes a channel estimation unit 1, a delay profile comparison processing unit 2, and a joint detection demodulation unit 3. The joint detection demodulation unit 3
As shown in FIG. 2, it is configured to include a calculation variable creation unit 4 and an interference removal calculation unit 5.

The channel estimating unit 1 performs channel estimation using a known signal sequence included in the received signal, creates delay profiles for all users, and performs a delay profile comparison processing unit 2 and a joint detection demodulation unit 3 Output to The delay profile comparison processing unit 2 determines whether or not to create a calculation variable based on the amount of change between the previous delay profile and the current delay profile. That is, the amount of change between the previous delay profile and the current delay profile is obtained, the obtained amount of change in the delay profile is compared with a predetermined reference value, and if the obtained amount of change in the delay profile is smaller than the reference value, the previous calculation is performed. A variable is used, and if it is large, a selection result to create a new operation variable is output. This selection result is input to the joint detection demodulation unit 3. The delay profile comparison unit 6 includes a storage unit that stores the delay profile obtained this time for processing in the next reception transmission unit.

The operation variable creating unit 4 of the joint detection demodulation unit 3 creates an operation variable if the selection result uses the newly created operation variable, and creates an operation variable if the selection result uses the operation variable created last time. This time, no operation variables are created.

In the interference removal operation unit 5 of the joint detection demodulation unit 3, if the selection result uses the newly created operation variable, the joint detection is performed using the newly created operation variable. Demodulation is performed, and if the previously created operation variable is used, joint detection demodulation is performed using the previously created operation variable. The interference removal operation unit 5 includes a storage unit (not shown) for storing the operation variables used this time for the next demodulation. The demodulation result by the joint detection demodulation unit 3 is output to a decoding unit (not shown).

FIG. 3 is a flowchart showing the operation of the demodulation device according to the present embodiment. In this figure, first, channel estimation is performed to create a delay profile. Next, the amount of change is determined by comparing the currently created delay profile with the stored previous delay profile. Then, the obtained change amount is compared with a predetermined reference value, and it is determined whether or not to create a calculation variable. In this determination, if there is no need to create an operation variable, that is, if the amount of change in the delay profile is smaller than the reference value, the previous operation variable is read from the storage means. Then, the interference removal calculation is performed using the read previous calculation variable. On the other hand, if it is necessary to create an operation variable, that is, if the amount of change in the delay profile is larger than the reference value, the operation variable is created.
Then, after the created operation variables are stored, an interference removal operation is performed using them.

As described above, according to the demodulation device of the present embodiment, when an operation variable used for joint detection demodulation can use a past operation variable, no new operation variable is created. Power saving at the time.

(Embodiment 2) FIG. 4 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 2 of the present invention.
In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

The demodulation device of this embodiment includes a delay profile averaging unit 7 and a buffer 8. The delay profile averaging unit 7 averages a delay profile between one or a plurality of transmission units and outputs the averaged delay profile to the joint detection demodulation unit 3. The buffer 8 stores the received baseband signal obtained while the delay profile averaging unit 7 performs the delay profile averaging process. The joint detection demodulation unit 3 creates a calculation variable used for joint detection demodulation from the input average delay profile, and performs joint detection demodulation processing on the received baseband signal in the average period. The demodulation result is sent to a decoding unit (not shown).

As described above, according to the demodulation device of the present embodiment, the number of creations of the operation variables used for the joint detection demodulation can be reduced, and power saving during demodulation can be achieved.

Also, the received baseband signal during the delay profile averaging process is stored in the buffer 8,
Since the delay profile is supplied to the joint detection demodulation unit 3 after the delay profile averaging process, the joint detection demodulation using the averaged delay profile becomes possible, and the demodulation can be saved by reducing the number of creations of operation variables. Electricity can be achieved.

(Embodiment 3) FIG.5 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 3 of the present invention.
In this figure, the same parts as those in FIG. 4 described above are denoted by the same reference numerals.

In the demodulation device of the second embodiment, since the reception baseband signal at the chip rate or the sample rate is stored, the buffer 8 must have a large capacity. In the demodulation device of the present embodiment, a rake (RA) is used so that a buffer having a small memory capacity can be used.
KE) The demodulation unit 9 is added to perform rake demodulation processing for all users performed in the joint detection demodulation process. As a result, the buffer 8 only needs to store the rake demodulated symbols, so that even a small memory capacity can be used.

FIG. 6 is a flowchart showing the operation of the demodulation device according to the present embodiment. In this figure, first, channel estimation is performed to create a delay profile, and rake demodulation is performed. Then, the delay profiles between one or more transmission units are averaged. Then, joint detection demodulation is performed using the average delay profile and the result of rake demodulation.

As described above, according to the demodulation apparatus of the present embodiment, the received baseband signal is rake demodulated during the delay profile averaging process and the rake demodulated symbols are stored, so that the memory capacity can be reduced. Becomes possible,
Inexpensive buffers can be used.

(Embodiment 4) FIG. 7 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 4 of the present invention.
In this figure, the same parts as those in FIGS. 1 and 5 described above are denoted by the same reference numerals.

The demodulation device of the present embodiment has a delay profile comparison processing unit 2 in addition to the same configuration as the demodulation device of the third embodiment. The delay profile comparison processing unit 2 obtains the amount of change between the delay profile at the start of averaging and the current delay profile, and terminates averaging if the amount of change is larger than a predetermined reference value, and continues averaging if it is smaller. Make a decision. The delay profile averaging processing section 7 determines the averaging period of the delay profile according to the determination result of the delay profile comparison processing section 2. The joint detection demodulation unit 3 reads the demodulation result of the rake demodulation unit 9 from the buffer 8 and performs the joint detection demodulation if the result of the determination is the averaging termination. The result after demodulation is output to a decoding unit (not shown).

As described above, according to the demodulation device of the present embodiment, the number of generations of the operation variables used for the joint detection demodulation can be reduced, and power saving during demodulation can be achieved. Further, since the averaging period is controlled by the amount of change in the delay profile, the reception quality can be improved.

(Embodiment 5) FIG. 8 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 5 of the present invention.
In this figure, the same parts as those in FIGS. 1 and 7 described above are denoted by the same reference numerals.

In the demodulation apparatus of the present embodiment, the delay profile comparison processing section 2 of the fourth embodiment is provided after the delay profile average processing section 7. The delay profile comparison processing unit 2 calculates the amount of change between the previous average delay profile and the current average delay profile, and performs a process of selecting an operation variable used for joint detection demodulation. That is, if the change amount is smaller than the reference value, the previous calculation variable is used. If the change amount is larger than the reference value, a selection result of creating a new calculation variable from the current average delay profile is input to the joint detection demodulation unit 3.

The joint detection demodulation unit 3
According to the selection result from the delay profile comparison processing unit 2, a process is performed to determine whether an operation variable is created from the current delay profile or to use the previous operation variable.
Performs detection demodulation. The result after demodulation is output to a decoding unit (not shown).

As described above, according to the demodulation apparatus of the present embodiment, the number of times of generating the operation variables used for the joint detection demodulation can be reduced, and furthermore, according to the amount of change in the averaged delay profile. Thus, the operation variables can be reused, so that power saving during demodulation can be achieved.

(Embodiment 6) FIG. 9 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 6 of the present invention.
In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, in addition to the same configuration as the demodulation device of the above-described first embodiment, an error detector (which detects an error of a decoded bit and outputs the result to delay profile comparison processor 2) Error detecting means, reference value controlling means) 11
It has.

The demodulation result from joint detection demodulation section 3 is input to decoding section 12 and decoded bits are output. The decoded bits are input to the error detection unit 11 to perform error detection. The error detection unit 11 includes the decoding unit 1
When an error is detected in the decoded bit from No. 2, control is performed to change the reference value in the delay profile comparison processing unit 2. This control is performed until no error is detected. In the case where the reference value is changed, if the reference value is returned to the initial value after a lapse of a predetermined period after the error is no longer detected, or the value is returned to the value before the change, the situation where the reference value is lost can be avoided.

FIG. 10 is a flowchart showing the operation of each section of the demodulation device according to the present embodiment. As shown in this figure, when an error is detected in the decoded bit obtained by performing the decoding processing, the reference value used in the delay profile comparison processing is changed. The reference value is changed until no error is detected.

As described above, according to the demodulation apparatus of the present embodiment, the reference value used in the delay profile comparison processing is changed according to the error detection result, so that the reception quality can be improved.

(Embodiment 7) FIG.11 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 7 of the present invention. In this figure, the same parts as those in FIGS. 7 and 9 are denoted by the same reference numerals.

The demodulation device of this embodiment is an application of the demodulation device of the sixth embodiment described above, and has a configuration similar to that of the demodulation device of the fourth embodiment except that an error detector 11 is provided.

The delay profile comparison processing unit 2 calculates the amount of change between the delay profile at the start of averaging and the current delay profile. If the amount of change is larger than a set reference value, the averaging is terminated. Is determined to continue. When detecting an error in the decoded bit from the decoding unit 12, the error detection unit 11 performs control to change the reference value in the delay profile comparison processing unit 2. This control is performed until no error is detected. In the case where the reference value is changed, if the reference value is returned to the initial value after a lapse of a predetermined period after the error is no longer detected, or the value is returned to the value before the change, the situation where the reference value is lost can be avoided.

As described above, according to the demodulation apparatus of the present embodiment, the reference value used in the delay profile comparison processing is changed according to the error detection result, so that the reception quality can be improved.

(Embodiment 8) FIG.12 is a block diagram showing a configuration of a demodulation apparatus according to Embodiment 8 of the present invention. In this figure, the same parts as those in FIGS. 8 and 9 described above are denoted by the same reference numerals. The demodulation device of the present embodiment is an application of the demodulation device of the above-described sixth embodiment, and has a configuration similar to that of the demodulation device of the fifth embodiment, except that an error detector 11 is provided.

The delay profile comparison processing unit 2 obtains the amount of change between the previous average delay profile and the current average delay profile, and performs a process of selecting an operation variable used for joint detection demodulation. That is, if the change amount is smaller than the reference value, the previous calculation variable is used, and if the change amount is larger, the selection result of creating a new calculation variable from the current average delay profile is output to the joint detection demodulation unit 3. When detecting an error in the decoded bit from the decoding unit 12, the error detection unit 11 performs control to change the reference value in the delay profile comparison processing unit 2. This control is performed until no error is detected. In the case where the reference value is changed, if the reference value is returned to the initial value after a lapse of a predetermined period after the error is no longer detected, or the value is returned to the value before the change, the situation where the reference value is lost can be avoided.

As described above, according to the demodulation apparatus of the present embodiment, the reference value used in the delay profile comparison processing is changed according to the error detection result, so that the reception quality can be improved.

In the above embodiments, when a new operation variable is not created, the previously created one is used. However, it is not always necessary to use the one created last time. It may be something. In short, if you can use what was created in the past, you can use it.

[0072]

As described above, according to the present invention,
Since the number of creations of operation variables used for joint detection demodulation can be reduced, power saving at the time of demodulation can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a demodulation device according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of a joint detection demodulation unit of the demodulation device according to Embodiment 1 of the present invention.

FIG. 3 is a flowchart showing an operation of the demodulation device according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a demodulation device according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram showing a configuration of a demodulation device according to Embodiment 3 of the present invention.

FIG. 6 is a flowchart showing an operation of the demodulation device according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram showing a configuration of a demodulation device according to Embodiment 4 of the present invention.

FIG. 8 is a block diagram showing a configuration of a demodulation device according to Embodiment 5 of the present invention.

FIG. 9 is a block diagram showing a configuration of a demodulation device according to Embodiment 6 of the present invention.

FIG. 10 is a flowchart showing the operation of the demodulation device according to Embodiment 6 of the present invention.

FIG. 11 is a block diagram showing a configuration of a demodulation device according to Embodiment 7 of the present invention.

FIG. 12 is a block diagram showing a configuration of a demodulation device according to Embodiment 8 of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional demodulation device.

[Explanation of symbols]

 Reference Signs List 1 channel estimation unit 2 delay profile comparison processing unit 3 joint detection demodulation unit 4 operation variable creation unit 5 interference removal operation unit 7 delay profile averaging processing unit 8 buffer 9 rake demodulation unit 11 error detection unit 12 decoding unit

Continued on the front page F term (reference) 5K022 EE01 EE35 5K052 AA01 AA12 BB02 CC06 DD03 EE24 EE38 FF32 5K067 AA02 AA43 BB02 CC10 DD46 EE02 EE10 GG11 HH22 HH23

Claims (14)

[Claims] 1. An operation variable determining means for determining whether an operation variable used for joint detection demodulation is newly created or used in the past according to a predetermined reference value for each reception transmission unit, and said operation Storage means for storing variables, and when a new creation of an operation variable is determined by the operation variable determination means, a new operation variable is newly created in the current reception transmission unit and used for joint detection demodulation. The joint detection demodulation means for storing in the storage means and using the past operation variable stored in the storage means for joint detection demodulation when it is determined to use the one created in the past,
A demodulation device comprising: 2. An operation variable determining means for measuring a change amount of a delay profile between a plurality of transmission units, and determining a change amount of a delay profile of a past reception transmission unit and a change amount of a delay profile of a current reception transmission unit according to a predetermined standard. If the value is equal to or less than the value, the use of the operation variable created in the past reception transmission unit is determined, and if the value is equal to or more than the reference value, the use of the operation variable created in the current reception transmission unit is determined. 2. The demodulation device according to 1. 3. An error detecting means for detecting an error in a decoded signal after joint detection demodulation, and a reference value control means for changing a reference value based on an error detection result from the error detecting means. 2. The method according to claim 1, wherein
Or the demodulation device according to claim 2. 4. A delay profile averaging means for averaging a delay profile among a plurality of transmission units, and a change amount of the delay profile averaged by the delay profile averaging means is measured. Is compared with a predetermined reference value, and if the amount of change between the average value of the past delay profile and the average value of the current delay profile is smaller than the reference value, it is created in the past reception transmission unit. Joint detection demodulation is performed using the calculated operation variable, and if the change amount is larger than the reference value, joint detection is performed by newly creating a calculation variable from the current delay profile and performing joint detection demodulation. And demodulation. 5. An error detecting means for detecting an error of a decoded signal after joint detection demodulation, and a reference value for changing an average length or a reference value of a delay profile based on an error detection result from said error detecting means. The demodulation device according to claim 4, further comprising control means. 6. A delay profile averaging processing means for averaging a delay profile among a plurality of transmission units, a joint detection demodulation means for performing demodulation by joint detection using an average value of the delay profiles, A demodulation device comprising: 7. A reception baseband signal is stored during the delay profile averaging processing by the delay profile averaging processing means, and the reception baseband signal stored after the delay profile averaging processing is performed is jointly processed. 7. The demodulation device according to claim 6, further comprising storage means for supplying the data to the detection demodulation means. 8. Rake demodulation of a received baseband signal,
8. The demodulation device according to claim 7, further comprising a rake demodulation unit that supplies the rake demodulation symbol obtained as described above to the storage unit. 9. A method for measuring an amount of change in a delay profile between a plurality of transmission units, and terminating the averaging of the delay profile if the amount of change in the delay profile is larger than a predetermined reference value; A delay profile comparison processing unit that performs the averaging of the delay unit when the determination result of the delay profile comparison processing unit is the averaging censoring. 9. The demodulation device according to claim 6, wherein joint detection demodulation is performed on the received signal. 10. An error detection means for detecting an error in a decoded signal after joint detection demodulation, and a reference value for changing a reference value for terminating delay profile averaging based on an error detection result from said error detection means. 10. The demodulation device according to claim 9, comprising: a control unit. 11. A radio base station device comprising the demodulation device according to claim 1. Description: 12. A wireless communication terminal device comprising the demodulation device according to claim 1. Description: 13. A demodulation method comprising selecting an operation variable used for joint detection demodulation according to a predetermined criterion, and performing joint detection demodulation using the selected operation variable. 14. An average of delay profiles in a plurality of transmission units, an operation variable used for joint detection demodulation is created using the averaged delay profile, and joint detection is performed using the created operation variable. A demodulation method characterized by performing demodulation.