JP3200628B2 - Code division multiplex transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code division multiplex transmission for transmitting a low-speed information signal by simultaneously multiplexing and transmitting a low-speed information signal at the same time using a plurality of spread codes, thereby transmitting an overall high-speed information signal. It is about the method.

[0002]

2. Description of the Related Art As a measure for transmitting a high-speed information signal with low distortion in a multi-wave propagation environment such as mobile communication,
2. Description of the Related Art There is a code division multiplex transmission system in which low-speed information signals are multiplexed and transmitted in parallel using a plurality of spread codes, and an overall high-speed information signal is transmitted. FIG. 1 shows an outline of the code division multiplex transmission system. In FIG. 1, a high-speed information data code 1 is first converted into a plurality of low-speed information data signals 3 by a serial-parallel converter 2. Thereafter, the low-speed data signal of each channel is multiplied by the code generated by the spread code generators 4, 5, and 6 by the multiplier 7 to become a signal 17 spread by the code. The signal spread in each channel is applied to a code division multiplexing circuit 9.
, Becomes a signal 10 multiplexed by code division,
1 is transmitted to the receiving side.

On the other hand, in a receiving system, a receiving antenna 12
The code 4, which is multiplied by the transmission information data signal on the transmission side with respect to the code division multiplexed signal 13 received by
The data is demodulated by a code correlator 14 including 5, 6 and an integrator 15. The demodulated data 16 is converted to a parallel / serial data.
8 , the high-speed information data signal 1 is obtained.

In this code division multiplex transmission system, large-capacity transmission can be expected by increasing the number of multiplexes.
However, when the number of multiplexes is increased, transmission characteristics deteriorate due to mutual interference between a plurality of spreading codes to be used, and as a result, the number of multiplex channels is limited. Therefore, reducing the mutual interference between spreading codes as much as possible leads to an improvement in transmission characteristics and, consequently, an increase in the number of multiplex channels. There are various codes that have no mutual interference, that is, codes that maintain orthogonality. For example, a method using orthogonal codes composed of Walsh functions, Manchester-coded orthogonal sequences (Habuchi, Hasegawa, Hakura, Haneishi: “Code division multiplexing method using Manchester-coded orthogonal sequences”, IEICE Transactions, B-11, J74-B-11, No. 5, 1991
May), and a method called an M-sequence with DC bias (called a modified M-sequence) (Sumiyoshi, Tanimoto, Komai:
`` Theoretical study of synchronous spread spectrum multiplexing communication '',
IEICE Technical Report, CS81-11, 19
April 1981). However, a method using an orthogonal code composed of a Walsh function and a Manchester code or an orthogonal sequence generally becomes orthogonal only in a specific synchronization state, and there is a cross-correlation value outside the synchronization state. Focusing on the fact that the autocorrelation value of an M sequence having a code length N is -1 / N at positions other than the synchronization point, a bias α is added to the existing M sequence to obtain Α is a reference (Sumiyoshi, Tanimoto, Komai: “Theoretical study of synchronous spread spectrum multiplexing communication”, IEICE Technical Report, CS81-1
1, April 1981), a function of the code length N, and when N = 15, α = 0.2. FIG.
7 shows an example of a sequence and a modified M-sequence, and an example of its autocorrelation function. In a method of cyclically shifting such a modified M sequence as another code and assigning it as a spread code, no mutual interference between codes occurs. However, this α is set to the existing M
Adding a bias as a sequence means that from the viewpoint of digital signal processing, an integer value such as 1 or -1 has been used to represent one spreading code. At the time of 15, this 1,-
Since α = 0.2 is added to 1, a processing system that must be expressed to the lower order of 1.2, −0.8 is required. In other words, it is necessary to introduce a processing system with a high resolution, and it is undeniable that the apparatus becomes complicated and expensive. Further, there is no distinction between α and the noise level, and a system having noise cannot sufficiently exhibit the advantages of α.

[0005] In a code division multiplexing transmission system capable of transmitting a high-speed information signal by multiplexing low-speed information signals in parallel using a plurality of spreading codes and transmitting a high-speed information signal in total, in addition to the problem of interference between spreading codes, There is an odd correlation problem. FIG. 3 illustrates the problem in detail. In FIG. 3, a three-stage M sequence ( code
Length 7 ) (codes are 1, 1, 1, 0, 0, 1,
0), 1, 1, 0, 0,
1 is spread and transmitted. Hereafter, if 1 is represented by 1 and 0 is represented by −1, the information data is spread by a code at this time, so that 1, 1,
The spread data of 1, -1, -1, 1, -1 is output. In addition, it outputs data -1, -1, -1, 1, 1, -1, 1 having the opposite characteristic to the data -1. It is assumed that spread data created according to such a rule is being transmitted, and the spread code 1, which was used at the time of transmission on the receiving side,
Correlation is taken at 1, 1, -1, -1, 1, -1. In particular, look at the correlation data where the transmission information data signals 1, 1, 0, 1, 1, 1 and 1 are continuous. And the synchronization point 29, a very high correlation characteristic is obtained. In other cases, only the autocorrelation function is obtained, so that the characteristic is -1 / N (N
Is the code length). However, where the transmission information data signal 26 changes from 1 to 0 or changes from 0 to 1, the used code is inverted in the middle, so that the correlation characteristic originally has the -1 / N characteristic of the M sequence. No longer. When a delayed wave due to a multiplex wave arrives at a portion where the correlation value changes, an error occurs in estimation of a radio wave propagation path.

Further, in a code division multiplexing transmission system capable of transmitting a high-speed information signal by multiplexing and transmitting low-speed information signals in parallel using a plurality of spreading codes, there is a problem of interference between spreading codes. In addition to the problem of odd correlation, there is a problem that the number of spreading codes having good correlation characteristics is small. At present, a Gold code is known as a spread code having relatively good interference characteristics between spread codes and a large number of codes. However, in the case of a Gold code having a code length of 63,
Only a maximum of 62 sequences having good correlation characteristics can be taken. In this case, it will be difficult to cope with an increasing number of users in the future, and it will be difficult to allocate a large number of codes to each user to realize high-speed transmission.

[0007]

In a conventional code division multiplexing transmission system capable of transmitting a high-speed information signal by multiplexing low-speed information signals in parallel using a plurality of spreading codes and transmitting an overall high-speed information signal. In addition to the problem of inter-code interference and the problem of odd correlation, there is a problem that the number of spreading codes having good correlation characteristics is small. Therefore, interference between spread codes is small even in a synchronous state and an asynchronous state, and there is no need to provide a complicated and expensive circuit from the viewpoint of digital signal processing. The problem is to realize a spreading code having a large number of spreading codes.

[0008]

In order to achieve the above object, the code division multiplex transmission system of the present invention has a transmission system and a reception system shown in FIG. In the cyclic extension code generation period 33, the M-sequence generated by the generator 32 is first cyclically added to the M-sequence for one cycle as the number of forward extension chips by the allowable number of chips for the synchronization shift, and then After the sequence for one cycle of the code, the number of backward extension chips obtained by adding the number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of redundant chips used for adjusting to the transmission clock is cyclically added. A first means for generating a cyclic extension spreading code for cyclically extending the code length, and (b) a cyclic shift circuit 34 for cyclically expanding the spreading code by the number of chips corresponding to the maximum delay time of the delay wave for which the cyclic extension spreading code is to be allowed. (C) third means for scrambling the transmission information signal by a scramble circuit 31 by regarding the shifted one as another code and performing code division multiplexing transmission using this cyclic extension cyclic shift type code; And (d) fourth means for synchronizing the received signal itself or the received signal with the basic spreading code (M-sequence) in the code synchronization circuit 35 in (d) spread demodulation on the receiving side;
(E) After the synchronization is established, the complex delay profile estimator 36 is obtained by using the sequence of the cyclic extension type spreading code included in the received signal from which the redundant chip is omitted and one cycle of the basic spreading code before extension.
(E) sixth means for demodulating the received data with the code correlator 15 and then descrambling the demodulated data with the descrambling circuit 37;
In the asynchronous state or the quasi-synchronous state where there is a synchronization error with respect to the code, the interference between the spreading codes is the same as that in the case of using the modified M-sequence which has orthogonality but requires a complicated circuit. In addition, in addition, the code length can freely correspond to the processing speed at which the signal processing is being performed, and the problem of the odd correlation can be solved if it is within a certain range of the delay wave.
A code division multiplexing transmission system capable of generating a plurality of sequences from one code sequence and increasing the number of usable codes has been realized.

Further, in a code division multiplexing transmission system for transmitting a high-speed information signal by multiplexing and transmitting a low-speed information signal in parallel using a plurality of spreading codes, a delay distortion due to a multiplex wave is received. The transmission information signal transmission using the cyclic extension cyclic shift type code generated by the first means and the second means for accurate estimation, separation and synthesis on the side as a spreading code of the code division multiplex transmission system Also, one of the cyclic extension cyclic shift type codes is universally code-division multiplexed with a transmission information signal at any time as a known data code and transmitted, and on the receiving side, synchronization is established by the fourth means. After that, correlation reception is performed using a sequence in which the redundant chip of the cyclic extension spreading code included in the received signal is omitted and one cycle of the basic spreading code before extension of the known data code used on the transmission side, Estimate the delay distortion that specifies the time position and magnitude from the synchronization point of the multiplex wave existing in the extended range and the phase difference from the transmission data, and then use it as a code division multiplex with the reception signal when transmitting the transmission signal. A fifth means is used to determine the correlation value of the obtained cyclic extension cyclic shift type code with the basic spreading code before extension at the estimated position of the multiplexed wave, and the transmission data of the delayed wave estimated for each correlation value To the phase at the time of transmission using the phase difference from
Finally, by synthesizing the correlation values of all the phases, correcting the distortion of the transmission signal due to the multiplex wave, and detecting the transmission information signal using the sixth means, the radio wave propagation can be stably performed even in the multiplex wave environment. As a result, a code division multiplexing transmission system that enables high quality transmission has been realized.

In a code division multiplexing transmission system for transmitting a high-speed information signal by multiplexing and transmitting a low-speed information signal in parallel using a plurality of spreading codes, a delay distortion due to a multiplex wave is received. The transmission information signal transmission using the cyclic extension cyclic shift type code generated by the first means and the second means for accurate estimation, separation and synthesis on the side as a spreading code of the code division multiplex transmission system Also, one of the cyclic extension cyclic shift type codes is code-division multiplexed in parallel with a code spreading a transmission information signal at a certain time interval as a known data code and transmitted. After the synchronization is established by means of (1), a sequence in which the redundant chip of the cyclic extension type spreading code included in the received signal is omitted and one cycle of the basic spreading code before extension of the known data code used on the transmission side are used. Correlation reception is performed at fixed time intervals when the knowledge data code is inserted, and delay distortion that specifies the time position and size from the synchronization point of the multiplex wave existing in the extended range and the phase difference from the transmission data is estimated. Then, by using the delay distortion data appearing at certain time intervals, the distortion due to the delay wave of the entire time is estimated, and thereafter, the received signal is extended as a code-division multiplex and the cyclic extension cyclic shift type code used during transmission signal transmission is extended. The correlation value with the previous basic spreading code is obtained by the fifth means at the estimated position of the multiplexed wave, and the phase difference from the transmission data of the delayed wave estimated for each of the correlation values is used at the time of transmission. By returning the phase, and finally synthesizing the correlation values having the same phase, correcting the distortion of the transmission signal due to the multiplex wave, and detecting the transmission information signal using the sixth means. Also stably estimated radio propagation path in a multi-path environment, also always realized known data symbols may code division multiplex transmission system characteristics in terms of power consumption because not carrying.

In a code division multiplexing transmission system for transmitting a high-speed information signal by multiplexing low-speed information signals in parallel by using a plurality of spreading codes and receiving delay distortion due to a multiplex wave. The transmission information signal transmission using the cyclic extension cyclic shift type code generated by the first means and the second means for accurate estimation, separation and synthesis on the side as a spreading code of the code division multiplex transmission system Also, one of the cyclic extension cyclic shift type codes is transmitted as a known data code without transmitting a code for spreading the transmission information signal at certain time intervals, and the receiving side performs the fourth After the synchronization is established by the means, a sequence of the cyclic extension type spreading code included in the received signal, from which the redundant chip is omitted, and one of the basic spreading codes before extension of the known data code used on the transmission side.
Correlation reception is performed at regular intervals with known data code inserted using the period, and the time position and size from the synchronization point of the multiplex wave existing in the extended range and the phase difference from the transmission data are specified. The estimated delay distortion is estimated, and the distortion caused by the delay wave of the entire time is estimated by using the delay distortion data that appears at certain time intervals, and then the cyclic extension cyclic used during transmission of the transmission signal as a received signal and code division multiplexing. The correlation value between the shift type code and the basic spreading code before extension is obtained by the fifth means at the estimated position of the multiplex wave, and the phase difference from the transmission data of the delay wave estimated for each correlation value is calculated. To return to the phase at the time of transmission,
Finally, by synthesizing the correlation values of all the phases, correcting the distortion of the transmission signal due to the multiplex wave, and detecting the transmission information signal using the sixth means, the radio wave propagation can be stably performed even in the multiplex wave environment. Since the channel is estimated and the known data code is not always transmitted, a code division multiplexing transmission system with good characteristics from the viewpoint of power consumption is realized.

In a code division multiplexing transmission system for transmitting a high-speed information signal by multiplexing and transmitting a low-speed information signal in parallel using a plurality of spreading codes, the method is adapted to the condition of the propagation path. A code division multiplexing transmission system using a cyclic extension cyclic shift type code generated by the first means and the second means as a spreading code comprises a base station and a large number of mobile stations. In the downlink that transmits information from the base station to the mobile station, the allowable number of chips for the delay wave and the number of cyclic shifts are larger than the expected maximum delay time of the delay wave. It is transmitted by the code division multiplexing transmission system using the cyclic extension cyclic shift spreading code, and the mobile station uses the delay distortion due to the multiplexed wave estimated at the mobile station and the maximum delay time of the delayed wave to transmit the signal from the mobile station. The number of allowable chips for the delay wave required for constructing the cyclic extension spreading code used in the uplink to the station, and the cyclic shift number of the cyclic extension cyclic shift code are adaptively adjusted according to the maximum delay time. Decide,
A cyclic extension cyclic shift type code is configured using the number of allowable chips and the number of cyclic shifts for the determined delay wave, and transmitted by code division multiplexing using the configured spreading code, so that the optimum A code division multiplex transmission system capable of transmission has been realized.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In the present invention, an M-sequence is used as a basic spreading code sequence as shown in FIG.
First, before the sequence for one cycle, the number of chips to be forwarded is extended cyclically by the number of allowable chips for the synchronization shift. Next, it corresponds to the maximum delay time of the delayed wave to be allowed after the sequence for one cycle of the code. A cyclic extension type spreading code that cyclically adds the number of backward extended chips obtained by adding the number of redundant chips used to match the transmission clock to the number of chips to be transmitted and cyclically extends the code length as a whole is used. Equivalent to the maximum delay time of delayed waves for which extended spreading codes are to be allowed
A code obtained by adding 1 to the number of chips to be cyclically shifted is regarded as another code, and code division multiplex transmission is performed using the cyclic extension cyclic shift type code. FIG. 5 shows an example of this cyclic extension cyclic shift type code. In FIG. 5, a 5-stage M-sequence having a code length of 31 is used, the number of chips allowed for synchronization shift is 2, the number of chips corresponding to the maximum delay time of a delay wave to be allowed is 2, and the number of redundant chips to match the transmission clock. The minute is 2. As shown in FIG. 5, two chips corresponding to the allowable number of chips 43 for the synchronization deviation are cyclically added to the beginning of the M sequence from the end of the M sequence of five stages, and from the beginning of the M sequence of five stages. A total of four chips including the number of chips corresponding to the maximum delay time of the delay wave to be tolerated and the redundant chips for adjusting to the transmission clock are cyclically added to the end of the M sequence. Maximum delay wave you want to allow
A code cyclically shifted from the beginning of the M-sequence by adding 1 to the number of chips corresponding to the delay amount is regarded as another code,
Code division multiplex transmission is performed using this cyclic extension cyclic shift type code. As for the code having the code length 31 in FIG. 5, the number of chips corresponding to the maximum delay time of the delayed wave is two, and the number of chips corresponding to the maximum delay time of the delayed wave is added by one chip, that is, an integer multiple of three chips. Is cyclically shifted, even if a delayed wave corresponding to the maximum delay time comes, other cyclic codes can sufficiently avoid the influence of the delayed wave. By setting the number 39 of cyclic shift chips to 3 in this way, ten different cyclically shifted signals can be generated from one sequence. In spreading demodulation of this signal on the receiving side, after establishing synchronization with the received signal itself or the received signal and the spreading code, a sequence excluding the redundant chip of the cyclic extension type spreading code included in the received signal and the basic spreading before expansion. Correlation reception is performed using one cycle of the code. FIG. 6 shows this state. FIG. 6 shows that a high correlation value is obtained at the synchronization point.
A code that is cyclically extended by the number of chips obtained by adding the number of chips corresponding to the maximum number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of chips equivalent to the maximum delay time of the delay wave to be allowed before and after the synchronization point and a redundant chip used to match the transmission clock. On the receiving side, correlation reception is performed using the sequence of the cyclic extension type spreading code included in the received signal without redundant chips and one cycle of the basic spreading code before extension. The original autocorrelation of the M-sequence can be maintained for the allowable number of chips for the synchronization deviation and the number of chips corresponding to the maximum delay time of the delay wave to be allowed (this is referred to as an observation time 47). However, this value is not zero, and when the code length is N, the correlation value is given by −1 when the correlation value at the synchronization point is 1.
1 / N.

Next, code division multiplexing is performed using the generated cyclic extension cyclic shift type code sequence. FIG. 7 shows the cross-correlation between the synchronous extended code sequence using the cyclic extension cyclic shift code sequence and the cyclic extended cyclic shift code sequence in the asynchronous case and one cycle of the basic spreading code before extension. Indicates a value. Here, a case where 1 of four channels is transmitted as a transmission information data signal is considered, and a case where a received signal is correlated with code 1 on the receiving side at that time is considered. In FIG. 7, focusing on a portion corresponding to the number of chips corresponding to the synchronization shift around the synchronization point and the number of chips corresponding to the maximum delay time of the delay wave to be allowed, the original autocorrelation of the M-sequence is within this range. Since it is maintained, when 1 is transmitted as transmission data, it is always -1 / N except at the synchronization point due to the autocorrelation of the M sequence. Also, when the transmission information data signal is 1 in other spread channels, the correlation value takes a correlation value of -1 / N except for the synchronization point, so that the excess correlation value restricts transmission on other channels. In particular, the correlation value at the synchronization point of one channel is subject to interference due to correlation values other than the synchronization point of the other channel, and the correlation value level at the synchronization point eventually decreases.

In order to avoid such accumulation of cross-correlation values, the transmission data is scrambled, and
+1 and -1 can be generated with equal probability . FIG. 8 shows transmission information data signals of four channels 1, −1,
The cross-correlation value between the cyclic extended cyclic shift type code sequence and the one cycle of the basic spreading code before extension in the case where 1, -1 is transmitted using the code division multiplexing transmission system of the present invention. Is shown. In FIG. 8, paying attention to a portion corresponding to the number of chips corresponding to the synchronization deviation around the synchronization point and the number of chips corresponding to the maximum delay time of the delay wave to be allowed. What is always -1 / N except for the synchronization point due to correlation is transmitted by code division multiplexing, so that the number of chips allowed for synchronization deviation around the synchronization point and the maximum allowable delay wave Since the portion corresponding to the number of chips corresponding to the delay amount is always + 1 / N except for the synchronization point, it can be seen that the cross-correlation value is canceled. By scrambling the transmission information data signal when performing code division multiplex transmission in this manner, the cross-correlation value between codes can be reduced. On the receiving side, it is necessary to descramble the transmission information data signal after correlation demodulation.

According to the present invention, a plurality of spread codes are used to multiplex and transmit low-speed information signals in parallel, and a plurality of spread-codes are used in a code division multiplex transmission system for transmitting an overall high-speed information signal. In order to reduce the mutual interference between spreading codes, an M-sequence is used as a basic spreading code sequence, and a chip is used as a minimum unit in time of the sequence. Previously, it is added cyclically as the number of forward expansion chips by the allowable number of chips for synchronization deviation,
Next, after the sequence for one cycle of the code, the number of backward extension chips obtained by adding the number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of redundant chips used for adjusting to the transmission clock is cyclically added. A first means using a cyclic extension spreading code that cyclically extends the code length as a whole, and (b) cyclically shifting by the number of chips corresponding to the maximum delay time of a delay wave for which the cyclic extension spreading code is to be allowed. Is considered as another code, and second means for performing code division multiplex transmission using the cyclic extension cyclic shift type code, (c) third means for scrambling the transmission information signal, and (d) spread demodulation on the receiving side A fourth means for synchronizing the received signal itself or the received signal with a spread code, and (e) after establishing synchronization, a sequence excluding a redundant chip of a cyclic extension type spread code included in the received signal and before extension. A fifth means for performing correlation reception using one cycle of the basic spreading code, and (e) a sixth means for descrambling the demodulated data after demodulating the received data, are used. This is a code division multiplex transmission system.

FIG. 9 shows the resistance of the cyclic extension type code sequence according to the present invention to odd correlation. FIG.
As shown in, the data to be transmitted is 1, 1 or -1,
When the same digital data as -1 continues,
It can be seen that even when digital data different from 1, -1, 1 is transmitted, a high correlation value is obtained at the synchronization point 29 after the correlation processing on the receiving side. A code that is cyclically extended by the number of chips obtained by adding the number of chips corresponding to the maximum number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of chips equivalent to the maximum delay time of the delay wave to be allowed before and after the synchronization point and a redundant chip used to match the transmission clock On the receiving side, correlation reception is performed using the sequence of the cyclic extension type spreading code included in the received signal without redundant chips and one cycle of the basic spreading code before extension. It can be seen that the autocorrelation inherent in the M-sequence is maintained for the allowable number of chips with respect to the synchronization deviation and the number of chips corresponding to the maximum delay time of the delay wave to be allowed.

A similar method uses a modified M-sequence, and cyclically adds the modified M-sequence as the number of forward extension chips before the one-cycle sequence by the allowable number of chips for synchronization deviation. Then, after the sequence for one cycle of the code, the number of backward extension chips obtained by adding the number of chips corresponding to the maximum delay time of the delay wave to be allowed is cyclically added, and the code length is cyclically extended as a whole. Using a cyclic extension spreading code to perform, the cyclic extension spreading code using the modified M-sequence is regarded as another code by cyclically shifting only the maximum value of the delay time of the delay wave to be allowed by the multiplex wave, A method of performing spread spectrum communication while maintaining orthogonality in a quasi-synchronous state by allocating to a plurality of users using this cyclic extension cyclic shift type code (Japanese Patent Laid-Open No. Hei 8-9774).
As can be seen in 9), in the present invention, a modified M-sequence that requires a more complicated circuit to implement the device is not used, but a normal M-sequence that is easy to implement is used, and the M-sequence is cyclically extended. It is characterized by performing code division multiplex transmission using codes. By using the M-sequence, unlike the modified M-sequence, orthogonality cannot be maintained in an asynchronous state, and intersymbol interference occurs,
When code division multiplexing is performed, depending on the transmission information data signal, intersymbol interference is accumulated and increased. However, by performing code division multiplexing and transmitting the randomized transmission information data signal, a code generated in each multiplex channel is obtained. A technique of canceling the inter-symbol interference value and reducing inter-symbol interference in the entire code division multiplexing is used. FIG. 10 shows an improvement in characteristics due to randomization. FIG. 10 shows a Doppler frequency of 320H
In the presence of two-wave equal-level Rayleigh fading of z, a cyclic extended cyclic shift type code is produced using the M sequence shown in FIG. 5, and a cyclic extended cyclic shift type code is produced using the modified M sequence. And 256 for each channel using 9
It is a relation between the ratio of the energy per bit of the signal and the noise power density when the code division multiplex transmission is performed at kbps, and the data error rate of the transmission information data signal. M as in the present invention
When a cyclic extension cyclic shift type spreading code is created using a sequence, and then code division multiplexing is performed using the spreading code and transmitted, a cyclic extension cyclic shift type spreading code is created using a modified M sequence, and then the spreading code is used. When all the transmission information data signals are 1, the data error rate is significantly degraded as compared with the case where the data is transmitted by code division multiplexing. However, by randomizing the transmission information data signal by the scrambling circuit, it is possible to obtain almost the same characteristics as in the case of using the modified M sequence.

In addition, in the present invention, a cyclic extension type spreading code to which a redundant chip is added in order to match the transmission clock as well as the number of chips corresponding to the maximum delay amount of the delayed wave to allow the number of backward extension chips is used. The cyclic extension spreading code is regarded as another code that is obtained by cyclically shifting only the maximum value of the delay time of the delay wave to be allowed by the multiplex wave as another code, and code division multiplex transmission is performed using this cyclic extension cyclic shift code. Then, on the receiving side, after code synchronization is established, transmission data is obtained by performing correlation reception using a sequence in which the redundant chip of the cyclic extension type spreading code included in the received signal is omitted and one cycle of the basic spreading code before extension. , And a configuration in which a cyclic extension of redundancy for adjusting to the system clock of the signal processing system is performed. It is an important feature of the present proposal that the redundant chips are cyclically extended, and it has been proposed in a spread spectrum communication system using a cyclically extended code based on a modified M-sequence (Japanese Patent Laid-Open No. Hei 8-97749). If only the maximum value of the delay time of the delay wave to be tolerated is cyclically shifted, the code length may become odd in some cases, and the affinity for the signal processing clock in the device is reduced. Therefore, the affinity with the signal processing clock in the device can be always increased only by performing the circulation in consideration of the redundant chips. As described above, there is no example in which a redundant chip and a code constituting a cyclic extension cyclic shift type code are used from the viewpoint of realization of an apparatus. Further, the present invention specializes in a code division multiplexing transmission system for transmitting a high-speed information signal by multiplexing and transmitting low-speed information signals in parallel using a plurality of spreading codes, and basically transmitting the information signal. Since a plurality of generated cyclically extended cyclic shift type spreading codes are transmitted synchronously from one user, the system is different from a system which performs a spread spectrum communication by allocating a plurality of generated cyclically extended cyclic shift type spreading codes to a plurality of users. Is drawn.

FIG. 11 is a block diagram showing an embodiment of the code division multiplex transmission system of the present invention . FIG. 11 shows a configuration on the transmission side (method of generating a code division multiplex transmission signal) and a configuration on the reception side (method of demodulating a code division multiplex transmission signal).

In the transmission system, N + 1 channel code division multiplexing transmission is performed using a cyclic extension cyclic shift type sequence, one of which is used as a pilot channel for channel estimation, and the N channel is used for data transmission. Used as a channel. First, the high-speed transmission information data signal 1
Are converted into random data by the scramble circuit 31 and converted into low-speed N-channel information data by the data serial-to-parallel converter 2. Then, the signals of the respective channels are generated by the baseband signal generator 58 to generate quadrature modulated signals such as QPSK. The generated signal of each channel is multiplied by a cyclic extension cyclic shift type sequence generated through an M sequence generator 32, a cyclic extension code generator 33, and a cyclic shift circuit 34. In the pilot channel, the pilot transmission data generated from pilot data generator 59 is similarly spread by a code different from that of the transmission information channel by a cyclic extension cyclic shift type sequence. Then, all signals generated in each channel are code division multiplexed by the code division multiplexing circuit 9 and transmitted from the transmission antenna 11.

FIG. 11 shows the configuration of the receiving system. On the receiving side, first, a signal received by the receiving antenna 12 is subjected to quasi-synchronous detection by a quasi-synchronous quadrature detector 61 and band limitation by a low-pass filter 62 after a desired signal is extracted by a band-pass filter 60, and then analog / digital conversion is performed. The oversampling is performed by the device 63 at several times the transmission speed of the chip. The sampled data is synchronized with the received signal itself or the received signal by the basic spreading code in the code synchronization circuit 35, and then input to the complex delay profile estimator 36. In the delay profile estimator, in order to measure a complex delay profile, after synchronization is established, a sequence without redundant chips of a cyclic extension spreading code included in a received signal and a basic spreading before cyclic extension corresponding to a pilot channel are performed. A correlation is obtained using one cycle of the code, and a complex delay profile is measured. Here, this correlation work is performed on both in-phase and quadrature channels. However, when measuring the complex delay profile, receiver noise and the like are added, so that the signal-to-noise power ratio of the pilot channel becomes low, and it is not possible to accurately grasp the propagation path condition. Therefore, the signal-to-noise power ratio is improved by adding the delay profiles measured for several consecutive symbols (one or more symbols). Then, using the output of the complex delay profile estimator, the path timing detector 65 selects L paths from the one with the largest power. Then, the output of the analog / digital converter is converted to the downsampler 6 by using the synchronization timing of the code obtained by the code synchronization circuit.
4, down-sampling is performed at the transmission rate of the spread sequence. The resulting signal is then passed to the correlator and maximum ratio combining circuit 6
6, the demodulated waveforms of the L paths are combined at the maximum ratio, and the received data is demodulated. The parallel data demodulated in each channel by the parallel / serial conversion unit 8 is converted into serial data. The descrambled circuit 37 reproduces the transmitted signal.

Next , another embodiment of the code division multiplex transmission system of the present invention will be described.
FIG. 12 shows a configuration diagram of the embodiment . FIG. 12 shows a configuration on the transmission side (method of generating a code division multiplex transmission signal) and a configuration on the reception side (method of demodulating a code division multiplex transmission signal).

In the transmission system, N + 1 channel code division multiplexing transmission is performed using a cyclic extension cyclic shift type sequence, one of which is used as a pilot channel for channel estimation, and the N channel is used for data transmission. Used as a channel. First, the high-speed transmission information data signal 1
Are converted into random data by the scramble circuit 31 and converted into low-speed N-channel information data by the data serial-to-parallel converter 2. Then, the signals of the respective channels are generated by the baseband signal generator 58 to generate quadrature modulated signals such as QPSK. The generated signal of each channel is multiplied by a cyclic extension cyclic shift type sequence generated through an M sequence generator 32, a cyclic extension code generator 33, and a cyclic shift circuit 34. In the pilot channel, the pilot transmission data generated from pilot data generator 59 is similarly spread by a code different from that of the transmission information channel by a cyclic extension cyclic shift type sequence. However, the known data spread by the cyclic extension cyclic shift type sequence is not always transmitted, but is transmitted at regular time intervals by the timing switch 67. Then, all signals generated in each channel are code division multiplexed and transmitted.

FIG. 12 shows the configuration of the receiving system. On the receiving side, first, a signal received by the receiving antenna 12 is subjected to quasi-synchronous detection by a quasi-synchronous quadrature detector 61 and band limitation by a low-pass filter 62 after a desired signal is extracted by a band-pass filter 60, and then analog / digital conversion is performed. The oversampling is performed by the device 63 at several times the transmission speed of the chip. The sampled data is synchronized with the received signal itself or the received signal by the basic spreading code in the code synchronization circuit 35, and then input to the complex delay profile estimator 36. In the delay profile estimator, in order to measure a complex delay profile, after synchronization is established, a sequence without redundant chips of a cyclic extension spreading code included in a received signal and a basic spreading before cyclic extension corresponding to a pilot channel are performed. A correlation is obtained using one cycle of the code, and a complex delay profile is measured. Here, this correlation work is performed on both in-phase and quadrature channels. In this embodiment, since the pilot channel is transmitted only from the transmitting side at a certain time, this complex delay profile is also obtained at a certain time interval. But,
When measuring this complex delay profile, the receiver noise and the like are added, so that the signal-to-noise power ratio of the pilot channel becomes low, so that the propagation path condition cannot be accurately grasped. Therefore, the accuracy of delay profile estimation is improved by adding the measured delay profiles in several symbols (one or more symbols) or by interpolating the delay profile obtained from the delay profile characteristics of the area where pilot data was not transmitted. Let it. Then, using the output of the complex delay profile estimator, the path timing detector 65 selects L paths from the one with the largest power. The down-sampler 64 down-samples the output of the analog / digital converter at the transmission rate of the spread sequence using the synchronization timing of the code obtained by the code synchronization circuit. The obtained signal is then sent to the correlator and maximum ratio combining circuit 66, where the demodulated waveforms of the L paths are combined at the maximum ratio to demodulate the received data. The data is converted to serial data,
Thereafter, the serial data is descrambled by the descrambling circuit 37 to reproduce the transmitted signal.

Next , another embodiment of the code division multiplex transmission system of the present invention will be described.
FIG. 13 shows a configuration diagram of the embodiment . FIG. 13 shows the configuration on the transmission side (method of generating a code division multiplex transmission signal) and the configuration on the reception side (method of demodulating a code division multiplex transmission signal).

In the transmission system, N + 1 channel code division multiplexing transmission is performed using a cyclic extension cyclic shift type sequence, one of which is used as a pilot channel for channel estimation, and the N channel is used for data transmission. Used as a channel. First, the high-speed transmission information data signal 1
Are converted into random data by the scramble circuit 31 and converted into low-speed N-channel information data by the data serial-to-parallel converter 2. Then, the signals of the respective channels are generated by the baseband signal generator 58 to generate quadrature modulated signals such as QPSK. The generated signal of each channel is multiplied by a cyclic extension cyclic shift type sequence generated through an M sequence generator 32, a cyclic extension code generator 33, and a cyclic shift circuit 34. In the pilot channel, the pilot transmission data generated from pilot data generator 59 is similarly spread by a code different from that of the transmission information channel by a cyclic extension cyclic shift type sequence. However, the known data spread by the cyclic extension cyclic shift type sequence is not always transmitted, but is transmitted at regular time intervals by the timing switch 67. When transmitting data on the pilot channel, no information data is transmitted from the N channels for data transmission. Then, all signals generated in each channel are code division multiplexed and transmitted.

FIG. 13 shows the configuration of the receiving system. On the receiving side, first, a signal received by the receiving antenna 12 is subjected to quasi-synchronous detection by a quasi-synchronous quadrature detector 61 and band limitation by a low-pass filter 62 after a desired signal is extracted by a band-pass filter 60, and then analog / digital conversion is performed. The oversampling is performed by the device 63 at several times the transmission speed of the chip. The sampled data is synchronized with the received signal itself or the received signal by the basic spreading code in the code synchronization circuit 35, and then input to the complex delay profile estimator 36. In the delay profile estimator, in order to measure a complex delay profile, after synchronization is established, a sequence without redundant chips of a cyclic extension spreading code included in a received signal and a basic spreading before cyclic extension corresponding to a pilot channel are performed. A correlation is obtained using one cycle of the code, and a complex delay profile is measured. Here, this correlation work is performed on both in-phase and quadrature channels. In this embodiment, since the pilot channel is transmitted only from the transmitting side at a certain time, this complex delay profile is also obtained at a certain time interval. But,
When measuring this complex delay profile, the receiver noise and the like are added, so that the signal-to-noise power ratio of the pilot channel becomes low, so that the propagation path condition cannot be accurately grasped. Therefore, the accuracy of delay profile estimation is improved by adding the measured delay profiles in several symbols (one or more symbols) or by interpolating the delay profile obtained from the delay profile characteristics of the area where pilot data was not transmitted. Let it. Then, using the output of the complex delay profile estimator, the path timing detector 65 selects L paths from the one with the largest power. The down-sampler 64 down-samples the output of the analog / digital converter at the transmission rate of the spread sequence using the synchronization timing of the code obtained by the code synchronization circuit. The obtained signal is then sent to the correlator and maximum ratio combining circuit 66, where the demodulated waveforms of the L paths are combined at the maximum ratio to demodulate the received data. The data is converted to serial data,
Thereafter, the serial data is descrambled by the descrambling circuit 37 to reproduce the transmitted signal.

Next , code division adapted to the propagation environment of the present invention
FIG. 14 is a conceptual diagram and a configuration diagram of an embodiment of a multiplex transmission system .
And 15. Here, FIG. 14 shows a conceptual diagram of a code division multiplex transmission system adapted to a propagation environment. Also,
FIG. 15 shows an example of a code division multiplexing transmission method adapted to the propagation environment, in which the number of chips allowed for delayed waves and the number of backward extended chips obtained by adding a redundant chip for adjusting to the system clock are fixed and the number of chips allowed for delayed waves is two. , 3,4
A method of transmitting data while changing it in a form adapted to a chip and a propagation environment is shown, and a conceptual diagram thereof is shown.

The code division multiplex transmission system adapted to the propagation environment is a system in which the allowable chip 69 for the delay wave is adaptively changed with respect to the maximum delay amount 68 of the delay wave in the multiplex wave propagation environment as shown in FIG. is there. As described above, by adaptively changing the allowable chip 69 for the delay wave, the number of cyclic extension type cyclic shift type sequences generated from one spreading code is optimized according to the propagation path. By using the cyclic extension type cyclic shift type sequence generated in (1), efficient information transmission can be performed.

FIG. 15 shows an example of an embodiment of the code division multiplexing transmission system adapted to the propagation environment, in which the number of backward extension chips 69 is fixed and the number of allowable chips 69 for the delayed wave is 2, 3 or 4 chips. FIG. 5 shows a conceptual diagram in the case of changing the shape in the following manner. Here, the reason why the number of backward extension chips is fixed is that, if the sequence length of the cyclic extension type cyclic shift type is different each time adaptive transmission is performed, the clock for code transmission changes due to the implementation of the device. This is to increase the complexity. Therefore, in order to avoid this complication, the example of FIG.
(The number of cyclic shift chips is 5). First, in the downlink 72 from the base station 70 to the mobile station 71, in order to effectively estimate even the largest delay amount, the allowable chip for the delay wave is set to 4 and transmitted. The mobile station makes use of the allowable chips for the four delayed waves, and estimates the delayed waves up to four chips by correlation processing. Therefore, the maximum delay amount is calculated, the allowable number of chips for the most appropriate delay wave is selected to cover the amount of delay, and the mobile station uses the cyclic extension type cyclic shift type sequence according to the allowable chip number for the delay wave. To the base station from the base station. At this time, as shown in FIG. 15, if 4 (the number of cyclic shift chips is 5) is selected as the allowable number of chips for the delayed wave, the same six types of cyclic extension type cyclic shift type sequences as those for the downlink are used. If 3 (the number of cyclic shift chips is 4) is selected as the allowable number of chips for the delay wave, seven types of codes are selected. If the allowable number of chips for the delay wave is 2, 2 (the number of cyclic shift chips is 3) is selected. In this case, ten kinds of codes can be used. As a result, transmission with higher code use efficiency can be performed.

Next , another code division multiplex transmission system of the present invention will be described.
1 shows an embodiment . This embodiment basically does not change the above configuration . The only change is that the basic spreading code is simply replaced with all spreading code sequences generally used in spread spectrum communication, such as an orthogonal code obtained from a M sequence and a Gold sequence or a Walsh function. By changing the M-sequence to another code, the orthogonality between each spreading code is lost and the accuracy of channel estimation is reduced. However, due to the characteristics of the cyclic extension type cyclic shift type sequence, multiple codes are generated from one code. can do. As a result, effective use of the code can be expected.

[0033]

According to the code division multiplexing transmission system using the cyclic extension type cyclic shift type sequence of the present invention, a complicated circuit is required but a case where a modified M sequence having orthogonality is used and interference between spreading codes. Can obtain the same characteristics, and the code length can freely correspond to the processing speed at which the signal processing is performed. In addition, the problem of the odd correlation can be solved if it is within the range of a fixed delay wave. A plurality of sequences can be generated from one code sequence and the number of usable codes can be increased, and a very good code division multiplex transmission system can be realized from the viewpoint of effective use of codes and from the viewpoint of reducing interference. Become.
Further, by changing the allowable chip for the delay wave of the proposed spreading code adaptively in accordance with the state of the multi-path, the transmission with higher code efficiency can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a conventional code division multiplex transmission system related to the description of the conventional technology .

FIG. 2 is a diagram showing a difference between an M-sequence and a modified M-sequence relating to the description of the related art .

FIG. 3 is a diagram showing the influence of an odd correlation on the description of the prior art, using a spread signal using an M-sequence (1110010) in three stages .

FIG. 4 is a diagram showing a schematic diagram of a code division multiplex transmission system using a cyclic extension cyclic shift type code of the present invention .

FIG. 5 is a diagram showing an example of a cyclic extension cyclic shift type code according to the present invention .

FIG. 6 is a diagram showing a correlation characteristic of the cyclic extension cyclic shift type code of the present invention .

FIG. 7 is a diagram showing a correlation characteristic on the receiving side when the transmission information data signals of the code division multiplexing parallel transmission system using the cyclic extension cyclic shift type code of the present invention are all 1 ;

FIG. 8 is a diagram showing a correlation characteristic on the receiving side when scrambling is applied to a transmission information data signal of the code division multiplexing parallel transmission system using the cyclic extension cyclic shift type code of the present invention .

FIG. 9 is a diagram illustrating resistance to odd correlation when a code division multiplexing parallel transmission system using a cyclic extension cyclic shift type code according to the present invention is used .

FIG. 10 is a diagram illustrating a transmission error rate when the code division multiplexing parallel transmission system using the cyclic extension cyclic shift type code of the present invention is used .

FIG. 11 is a configuration diagram of a transmission side and a reception side according to another embodiment of the present invention .

FIG. 12 is a configuration diagram of a transmission side and a reception side according to another embodiment of the present invention .

FIG. 13 is a configuration diagram of a transmission side and a reception side according to another embodiment of the present invention .

FIG. 14 is a conceptual diagram of a code division multiplex transmission system adapted to a propagation environment according to another embodiment of the present invention .

FIG. 15 is a configuration diagram of a code division multiplex transmission system adapted to a propagation environment according to another embodiment of the present invention .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 High-speed information data signal 2 Serial-parallel converter 3 Low-speed information data signal 4 Code generator used in 1st channel 5 Code generator used in 2nd channel 6 Code generator used in 3rd channel 7th power Product 8 Parallel / serial converter 9 Code division multiplexing circuit 10 Code division multiplexed signal 11 Transmit antenna 12 Receiving antenna 13 Received code division multiplex signal 14 Code correlator 15 Integrator 16 Demodulated data 17 Spread signal 18 Spreading code length (code length is N) 19 Minimum unit of spreading code 1 chip 20 M sequence (spreading code length: 15) 21 Modified M sequence (spreading code length: 15) 22 DC bias (spreading code length: 15) In case of 0.
2) 23 Simplified display of M-sequence 24 Autocorrelation function of M-sequence 25 Autocorrelation function of modified M-sequence 26 Transmission information data signal 27 Data signal after spreading by code 28 Sliding correlation using M-sequence 1110010 used at transmission Unit 29 synchronization point 30 output of sliding correlator 31 scramble circuit 32 M-sequence code generator 33 cyclic extension code generator 34 cyclic shift circuit 35 code synchronization circuit 36 complex delay profile estimator 37 descramble circuit 38 code of cyclic extension code Length 39 Cyclic shift chip 40 Using a 5-stage M sequence, two allowable chips for synchronization deviation, two allowable chips for delayed waves, and two redundant chips for adjusting to the system clock. The 4th code 41 The second code of the cyclic extension type code when the allowable chip for the delay wave is 2, the allowable chip for the delay wave is 2, and the redundant chip for adjusting to the system clock is 2 is used. The tenth code of the cyclic extension type code when the number of chips is 2, the number of allowable chips for delayed waves is 2, and the number of redundant chips for adjusting to the system clock is 43. Allowable chips for synchronization deviation 44. Allowable chips for delayed waves 45. System clock A redundant chip 46 for use with the M-sequence of 5 stages, the number of allowable chips for synchronization shift is 2, the number of allowable chips for delay waves is 2, and the number of redundant chips for adjusting to the system clock is 2. One code 47 Observation time of delay profile 48 Tolerance for synchronization deviation using 5-stage M-sequence The second code, the allowable chip for the delay wave is 2, and the redundant chip for adjusting to the system clock is 2, the third code of the cyclic extension type code. The second code of the cyclic extension type code when the allowable chip for delay wave is 2 and the redundant chip for adjusting to the system clock is 2 50 Synchronization points for the first cyclic spreading sequence 51 Sum after parallel transmission 52 Data signal after spreading by cyclic extension type code 53 Data transmission characteristic of cyclic extension type code using modified M sequence (transmitting randomized data as transmission data) 54 Cyclic extension type code using M sequence 55 (transmission of randomized data as transmission data) 55 Data transmission characteristic of cyclic extension type code using modified M-sequence (transmission 56 Data transmission characteristics of cyclic extension type code using M-sequence (transmit all 1 data as transmission data) 57 Theoretical value of data transmission characteristic of cyclic extension type code 58 Baseband Signal generator 59 Pilot data generator 60 Band-pass filter 61 Quasi-synchronous quadrature detector 62 Low-pass filter 63 Analog-to-digital converter 64 Downsampler 65 Path timing detector 66 Correlator and maximum ratio combining circuit 67 Timing switch 68 Maximum delay wave Delay amount 69 Allowable number of chips for delayed waves 70 Base station 71 Mobile station 72 Down link 73 Up link

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2000-26986 (JP, A) JP-A-8-97749 (JP, A) JP-A-9-8770 (JP, A) JP-A-10-294715 (JP, A) IEICE Technical Report, Vol. 98, No. 452, 1998-12-10, pp. 15-22, RCS98-43 IEICE Technical Report, Vol. 95, No. 491, 1996-1-26, pp. 61-68, RCS95-133, IEICE Technical Report, Vol. 99, No. 271, 1999-8-26, pp. 9-18, RCS99-79 Proceedings of the 1996 IEICE General Conference, Communications 1, 1996-3-11, p. 396 (58) Cl. ⁷ , DB name) H04B 1/69-1/713 H04J 13/00-13/06

Claims (49)

(57) [Claims] 1. A transmission system having a transmission side cyclic extension cyclic shift type code generation unit, and a reception system having a reception side cyclic shift type code generation unit, wherein a code for spread spectrum communication is a basic spread code (hereinafter, referred to as a base spread code). A code division multiplexing transmission system in which the minimum unit of time of the basic spreading code is referred to as “chip”.) (A) The transmission-side cyclic extension cyclic shift type code generation unit includes:
A basic spreading code generator, and a cyclic extension cyclic shift unit, wherein the basic spreading code generator generates the basic spreading code, and the cyclic extension cyclic shift unit is generated by the basic spreading code generator. A cyclic extension cyclic shift type code obtained by cyclically shifting the basic spreading code by an integer multiple of the number of cyclic shift chips, and extending the number of forward extension chips forward and the number of backward extension chips backward. 1) The number of forward extension chips at the head of the cyclic extension cyclic shift type code is equal to the number of forward extension chips at the end of the result of cyclically shifting the basic spreading code. (2) The number of the rear extension chips at the end of the cyclic extension cyclic shift type code is equal to the number of the rear extension chips at the head of the one obtained by cyclically shifting the basic spreading code. (3) The number of front extension chips is an allowable number of chips with respect to synchronization deviation. (4) The number of backward extension chips is the sum of the number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of redundant chips used to match the transmission clock. (5) The cyclic shift chip number is obtained by adding 1 to the chip number corresponding to the maximum delay time of the delay wave to be allowed. (B) the transmission system further includes a scrambling unit, a serial-to-parallel conversion unit, a plurality of product units, and a code division multiplex transmission unit. The scrambling unit scrambles a transmission information signal, the serial-to-parallel conversion unit serially / parallel converts the signal scrambled by the scrambling unit to generate a plurality of signals, and the plurality of products Each of the units is one of a plurality of cyclic extension cyclic shift codes generated by the transmission side cyclic extension cyclic shift type code generation unit in one of the plurality of signals generated by the serial-parallel conversion unit. The other product is multiplied by a product different from the product, the code division multiplexing transmission unit receives as an input a plurality of signals resulting from the multiplication by the plurality of product units, Mark (C) the reception-side cyclic shift type code generation section includes a basic spreading code generation section and a plurality of cyclic shift sections; and the basic spreading code generation section includes the basic spreading code generation section. Each of the plurality of cyclic shift units generates a code, and the basic spread code generated by the basic spread code generation unit is an integer multiple of the number of cyclic shift chips, and the other cyclic shift units perform cyclic shift. (D) generating a cyclic shift type code that is cyclically shifted by the number of chips different from the number of chips to be transmitted; (d) the receiving system includes a synchronization unit, a plurality of code correlation units,
A parallel-to-serial conversion unit, and a descrambling unit, the synchronization unit receives the signal transmitted from the transmission system, and synchronizes the signal with the signal itself or the basic spreading code; Each of the plurality of code correlation units is any one of the plurality of cyclic shift codes generated by the reception side cyclic shift code generation unit for the signal synchronized by the synchronization unit. Demodulating using a different code correlator from that used by the other code correlator, the parallel-serial converter generates a signal obtained by parallel-serial-converting a plurality of signals resulting from demodulation by the code correlator, A code division multiplex transmission system, wherein the descramble section detects a transmission information signal by descrambling the signal generated by the parallel / serial conversion section. 2. The code division multiplex transmission system according to claim 1, wherein said basic spreading code is an M-sequence code. 3. The code division multiplex transmission system according to claim 1, wherein said basic spreading code is a Gold code. 4. The code division multiplex transmission system according to claim 1, wherein said basic spreading code is an orthogonal code obtained from a Walsh function. 5. The code division multiplexing transmission system according to claim 1, wherein: (e) the receiving system further includes a delay distortion estimating unit; Performing correlation reception using the basic spreading code with respect to the signal obtained as a result of synchronization by the synchronization unit, and obtaining a delayed multiplexed wave existing in a portion of the result signal that does not correspond to the basic spreading code. Each of (1) a time shift from a synchronization point, (2) a magnitude of the delay multiplex wave, and (3) a phase difference of the delay multiplex wave is specified to estimate delay distortion. Each of the code correlator units: (1) It was determined that there was no shift of the delay multiplex wave from the respective shifts and magnitudes of the delay multiplex wave estimated by the delay distortion estimator and the basic spreading code. Find the correlation value of the case, ( ) From said each of the phase difference between the delayed multiple waves estimated by delay distortion estimation unit, aligning the delayed multiple waves in phase, (3) each of the obtained correlation values of the delayed multiple waves,
And using the aligned phases, combining the respective signal components of the delayed multiplex wave and the signal components of the direct wave to correct distortion of the transmission signal due to the delayed multiplex wave. Division multiplex transmission method. 6. The code division multiplexing transmission system according to claim 5, wherein: (f) in the receiving system, the delay distortion estimating unit comprises:
By performing correlation reception at regular time intervals, for each of the delayed multiplexed waves, a shift estimated at the constant time period,
A code characterized by identifying a delay, a magnitude and a phase difference of a time longer than the fixed time (hereinafter referred to as “whole time”) from the magnitude and the phase difference and estimating delay distortion. Division multiplex transmission method. 7. The code division multiplexing transmission system according to claim 6, wherein the delay distortion estimating unit adds a shift, a magnitude, and a phase difference estimated at each fixed time, and A code division multiplexing transmission method characterized in that the entire time lag, magnitude and phase difference are specified. 8. The code division multiplexing transmission system according to claim 6, wherein the delay distortion estimating unit interpolates a shift, a magnitude, and a phase difference estimated at each fixed time, and A code division multiplexing transmission method characterized in that the entire time lag, magnitude and phase difference are specified. 9. The code division multiplexing transmission system according to claim 5 , wherein : (g) in the transmission system, each of the plurality of multiplication units.
This is because "a plurality of signals generated by the serial-parallel
Signal or pilot signal containing a known data code "
The transmission side cyclic extension cyclic shift type code generator
Multiple cyclic extended cyclic shift codes generated by the component
Which is different from the product
Code division multiplexing transmission system characterized by multiplying the same by multiplication . 10. The code division multiplexing transmission system according to claim 9, wherein: (h) the transmission system further includes a pilot timing unit, wherein the pilot timing unit is one of the plurality of product units. Or the signal obtained by multiplying the pilot signal by the cyclic extension cyclic shift type code by at least one of
A code division multiplex transmission system, wherein the code division multiplex transmission is provided as one of inputs to the code division multiplex transmission unit at predetermined time intervals. 11. The code division multiplex transmission system according to claim 9, wherein: (i) said transmission system transmits a signal obtained as a result of multiplication by said plurality of multiplication units to said code division multiplex transmission unit. Further comprising a timing unit provided as an input, wherein the timing unit is configured to multiply a pilot signal including the known data code by at least one of the plurality of multiplication units, A code division multiplexing transmission system characterized in that, when one of signals multiplied by a multiplication unit is provided as an input to the code division multiplex transmission unit, the other is not provided as an input. 12. The code division multiplexing transmission system according to claim 5, wherein the reception system and the transmission system are configured to transmit the delay distortion estimated by the delay distortion estimation unit. From the above, determine a new number of cyclic shift chips, the transmitting side cyclic extension cyclic shift type code generator, and the receiving side cyclic shift type code generator, after the new cyclic shift chip number is determined Is a code division multiplex transmission system for generating a cyclic extension cyclic shift type code and a cyclic shift type code using the new number of cyclic shift chips, respectively. 13. The code division multiplexing transmission system according to claim 5, wherein the reception system and the transmission system are configured to include a delay distortion estimated by the delay distortion estimation unit. From, to determine a new generated code number, the transmission side cyclic extension cyclic shift type code generation unit, and the reception side cyclic shift type code generation unit, after the new generated code number is determined, A code division multiplexing transmission system characterized by generating a cyclic extension cyclic shift type code having the new generated code number and a cyclic shift type code having the new generated code number. 14. The code division multiplexing transmission system according to claim 1, wherein in the transmission system, each data of each signal of each chip of a signal obtained as a result of scrambling by the scrambling unit is provided. A code division multiplex transmission system characterized in that the appearance probabilities are almost equal. 15. A transmission system in the code division multiplex transmission system according to any one of claims 1 to 14. 16. A receiving system in the code division multiplex transmission system according to claim 1. 17. A mobile communication system comprising a base station and a mobile station communicating therewith, wherein the base station is a mobile communication system according to any one of claims 1 to 14. A mobile communication system, wherein transmission is performed using a transmission system, and the mobile station performs communication by receiving using a reception system in the code division multiplex transmission system. 18. A mobile communication system having a base station and a mobile station communicating therewith, wherein the mobile station is a mobile communication system according to any one of claims 1 to 14. A mobile communication system, wherein transmission is performed using a transmission system, and the base station performs communication by receiving using a reception system in the code division multiplex transmission system. 19. A code having a transmission side cyclic extension cyclic shift type code generation step, wherein a code for spread spectrum communication is a basic spreading code (hereinafter, the minimum time unit of the basic spreading code is referred to as "chip"). A transmission method for transmitting by division multiplex transmission, wherein: (a) the transmitting-side cyclic extension cyclic shift type code generation step includes a basic spreading code generation step and a cyclic extension cyclic shift step; In the step, the basic spreading code is generated, and in the cyclic extension cyclic shifting step, the basic spreading code generated in the basic spreading code generating step is cyclically shifted by an integer multiple of the number of cyclic shift chips, and A cyclic extension cyclic shift type spreading code extended by the number of forward extension chips and backward by the number of rear extension chips, and has the following conditions: (1) The leading end of the cyclic extension cyclic shift type code The number of the front extended chips at the beginning is equal to the number of the front extended chips at the end of the result of cyclically shifting the basic spreading code. (2) The number of the rear extension chips at the end of the cyclic extension cyclic shift type code is equal to the number of the rear extension chips at the head of the one obtained by cyclically shifting the basic spreading code. (3) The number of front extension chips is an allowable number of chips with respect to synchronization deviation. (4) The number of backward extension chips is the sum of the number of chips corresponding to the maximum delay time of the delay wave to be allowed and the number of redundant chips used to match the transmission clock. (5) The cyclic shift chip number is obtained by adding 1 to the chip number corresponding to the maximum delay time of the delay wave to be allowed. Generating a plurality of cyclic extension cyclic shift codes satisfying all of the following, (b) the transmission method further comprises: a scrambling step, a serial / parallel conversion step, a multiplication step, and a code division multiplex transmission step, In the scrambling step, the transmission information signal is scrambled.In the serial-to-parallel conversion step, a plurality of signals are generated by serial-to-parallel conversion of the signal scrambled in the scrambling step, and in the multiplying step, Any one of the plurality of signals generated in the serial-to-parallel conversion step is multiplied without duplication with any one of the plurality of cyclic extension cyclic shift codes generated in the transmitting side cyclic extension cyclic shift code generation step. In the code division multiplex transmission step, a plurality of signals obtained as a result of the multiplication in the multiplication step are received as input, and are transmitted by code division multiplex transmission. Transmission method. 20. The transmission method according to claim 19, wherein said basic spreading code is an M-sequence code. 21. The transmission method according to claim 19, wherein said basic spreading code is a Gold code. 22. An apparatus according to claim 19, wherein said basic spreading code is an orthogonal code obtained from a Walsh function.
Transmission method described in. 23. A receiving side cyclic shift type code generating step, wherein a code for spread spectrum communication is used as a basic spreading code (hereinafter, referred to as a basic spreading code).
The temporal minimum unit of the basic spreading code is called a “chip”. (C) the receiving-side cyclic shift type code generating step includes a basic spreading code generating step and a cyclic shifting step; In the step, the basic spreading code is generated. In the cyclic shifting step, the basic spreading code generated in the basic spreading code generating step is cyclically shifted by an integer multiple of the number of cyclically shifted chips and different from each other. Generating a plurality of shifted cyclically shifted codes; and (d) the receiving method includes a synchronization step, a code correlation step,
The method further includes a parallel-serial conversion step and a descrambling step. In the synchronization step, the transmitted signal is received, and the transmitted signal is synchronized with the signal itself or the basic spreading code, and the code correlation step is performed. In the above, the signal synchronized in the synchronization step is demodulated using each of the plurality of cyclic shift codes generated in the receiving side cyclic shift code generation step, and the parallel-serial conversion is performed. In the step, a signal obtained by parallel-to-serial conversion of a plurality of signals obtained as a result of demodulation in the plurality of code correlation steps is generated. In the descrambling step, the signal generated in the parallel-to-serial conversion step is descrambled. Receiving method for detecting a transmission information signal. 24. The receiving method according to claim 23, wherein said basic spreading code is an M-sequence code. 25. The receiving method according to claim 23, wherein said basic spreading code is a Gold code. 26. An apparatus according to claim 23, wherein said basic spreading code is an orthogonal code obtained from a Walsh function.
Receiving method described in. 27. The receiving method according to claim 23, wherein: (e) the receiving method further includes a delay distortion estimating step; Performing correlation reception using the basic spreading code for the signal of the result synchronized in the step, and for each of the delayed multiplex waves present in a portion of the result signal that does not correspond to the basic spreading code (1) a temporal shift from a synchronization point; (2) a magnitude of the delayed multiplexed wave; and (3) a phase difference of the delayed multiplexed wave is specified to estimate delay distortion. (1) From the respective shifts and magnitudes of the delayed multiplexed wave estimated in the delay distortion estimation step and the basic spreading code, the correlation value when there is no shift of the delayed multiplexed wave is calculated. (2) the delay From each of the phase difference of the estimated delayed multiple waves at strain estimation step, aligning the delayed multiple waves in phase, (3) each of the obtained correlation values of the delayed multiple waves,
And using the aligned phases to combine the respective signal components of the delayed multiplexed wave and the signal components of the direct wave to correct the distortion of the transmission signal due to the delayed multiplexed wave. Method. 28. The receiving method according to claim 27, wherein: (f) in the delay distortion estimating step, correlation reception is performed at predetermined time intervals, and for each of the delay multiplexed waves,
Estimated deviation, magnitude, and
A reception method characterized in that a delay distortion is estimated by specifying a shift, a magnitude, and a phase difference of a time longer than the predetermined time (hereinafter, referred to as “whole time”) from the phase difference. 29. The reception method according to claim 28, wherein, in the delay distortion estimating step, a shift, a magnitude, and a phase difference estimated at regular intervals are added, and the entire time is calculated. A receiving method characterized by specifying a shift, a magnitude, and a phase difference of the received signal. 30. The reception method according to claim 29, wherein, in the delay distortion estimation step, a shift, a magnitude, and a phase difference estimated at regular intervals are interpolated to obtain the entire time. A receiving method characterized by specifying a shift, a magnitude, and a phase difference of the received signal. 31. The transmission method according to claim 19, wherein: (g) in the multiplying step, in addition to the plurality of signals generated in the serial-parallel conversion step, , A pilot signal including a known data code is also multiplied by the cyclic extension cyclic shift type code. 32. The transmission method according to claim 31, wherein (g) the transmission method further includes a pilot timing step, wherein in the pilot timing step, the pilot signal is transmitted in the multiplication step. A transmission method characterized in that a signal obtained by multiplying a cyclic extension cyclic shift code is given as one of inputs to the code division multiplex transmission step at predetermined time intervals. 33. The transmission method according to claim 31, wherein (h) in the transmission method, a plurality of signals resulting from the multiplication in the multiplication step are provided as inputs to the code division multiplex transmission step. Further comprising a timing step, wherein, in the timing step, a signal obtained by multiplying the pilot signal including the known data code in the multiplying step, and a signal obtained by multiplying the signal , One of which is given as an input to the code division multiplex transmission step,
A transmission method characterized in that the other is not given as an input. 34. The transmission method according to any one of claims 19 to 22, and 31 to 33, wherein a new number of cyclic shift chips is calculated from delay distortion estimated in the previous code division multiplex transmission. The transmitting side cyclic extension cyclic shift type code generation step further includes a step of determining the number of chips to be determined, and after the new number of cyclic shift chips is determined, cyclic extension using the new number of cyclic shift chips. A transmission method characterized by generating a cyclic shift type code. 35. The reception method according to claim 23, wherein a new number of cyclically shifted chips is determined from the delay distortion estimated in the delay distortion estimation step. The method further includes the step of: in the receiving-side cyclic shift code generation step, after the new cyclic shift chip number is determined, using the new cyclic shift chip number, to generate a cyclic shift code. Characteristic receiving method. 36. The transmission method according to any one of claims 19 to 22, and 31 to 33, wherein a new number of generated codes is determined from delay distortion estimated in previous code division multiplex transmission. The transmitting side cyclic extension cyclic shift type code generation step further includes: after the new generation code number is determined, generating a cyclic extension cyclic shift type code of the new generation code number. Transmission method. 37. The receiving method according to claim 23, wherein a code number determining step of determining a new generated code number from the delay distortion estimated in the delay distortion estimating step. The receiving method further comprises: generating a cyclic shift type code having the new generated code number after the new generated code number is determined in the receiving side cyclic shift code generation step. 38. Claims 19 to 22, 31 to 33, 3
37. The transmission method according to any one of Claims 4 and 36, wherein the appearance probability of each data in each chip of the signal scrambled in the scrambling step is substantially equal. 39. Any one of claims 23 to 30, 35
The reception method according to claim 1, wherein the appearance probability of each data in each chip of the signal of the signal descrambled by the scrambling corresponding to the descrambling in the descrambling step is substantially equal. Method. 40. A basic spreading code generator provided in a transmitting side cyclic spreading cyclic shift type code generator in a code division multiplexing transmission system according to any one of claims 1 to 14, a cyclic extension cyclic shifting section, A transmitting-side cyclic spreading cyclic shift type code generation apparatus characterized by having: 41. A base spreading code generator included in a receiving side cyclic shift type code generator in the code division multiplex transmission system according to any one of claims 1 to 14, and a plurality of cyclic shift units. A receiving-side cyclic shift type code generation device. 42. A transmitting side cyclic spreading cyclic shift comprising a basic spreading code generating step and a cyclic extension cyclic shifting step included in the transmitting side cyclic extension cyclic shift type code generating step according to claim 19. Type code generation method. 43. A receiving side cyclic shift type code generation method, comprising: a basic spreading code generation step and a cyclic shift step included in the receiving side cyclic shift type code generation step according to claim 23. 44. The method according to claim 1, wherein
A code division multiplex transmission system, (G) In the transmission system, each of the plurality of product units
This is the " Multiple signals generated by the
Signal or pilot signal containing a known data code "
The transmission side cyclic extension cyclic shift type code generator
Multiple cyclic extended cyclic shift codes generated by the component
Which is different from the product
Division multiplexing transmission method characterized by multiplying
formula. 45. The code division multiplex transmission method according to claim 44.
Expression, (H) the transmission system further includes a pilot timing unit.
Have The pilot timing section includes a plurality of product sections.
The pilot signal is
The signal resulting from the multiplication of the cyclic extension cyclic shift code is
Input to the code division multiplex transmission unit at predetermined time intervals;
Code division multiplex transmission characterized by being given as one of
method. 46. A code division multiplex transmission method according to claim 44.
Expression, (I) the transmission system is multiplied by the plurality of multiplication units;
The resulting signal is applied as an input to the code division multiplex transmission section.
It further has a timing section The timing unit may include any one of the plurality of product units.
At least one pilot including the known data code
The signal resulting from the multiplication of the signal and the other product
One of the signals resulting from the multiplication
When given as an input to the split multiplex transmission unit, the other
A code division multiplexing transmission method characterized by not giving 47. The method according to claim 44, wherein
Code division multiplex transmission system described above, In the transmission system, the scrambling unit
Data of each chip of the resulting signal
Division multiplexing characterized by the fact that the appearance probabilities of
Transmission method. (48) The method according to any one of (44) to (47).
Transmission in the code division multiplex transmission system Shinkei. (49) The method according to any one of (44) to (47).
The receiving system in the code division multiplex transmission system described above.