JP2003283376A - Method for synchronization seizure in spread spectrum communication system and terminal equipment for this system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize small and light-weight terminal equipment, low power consumption, and cost reduction by miniaturizing a circuit scale of a matched filter, and to reduce an average seizure time required for synchronization seizure. <P>SOLUTION: This terminal equipment receives coded data a transmitted after multiplying an information signal by a PN code with a fixed number of bits as a cycle on the transmitting side. A matched filter 100 generates a PN code with fewer bits than the fixed number of bits. Synchronization of the received coded data a is detected by partial matched filter processing. When it is detected with a partial PN code, a diffusion code generator 200 generates a PN code c with a fixed number of bits as a cycle. A sliding correlator 300 generates decoded data d by multiplying coded data which are successively received by the PN code. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization acquisition method in a spread spectrum communication system and a terminal device in the spread spectrum communication system.

[0002]

2. Description of the Related Art So-called spread spectrum communication in which a transmitting side multiplies an information signal by a wide band spreading code, modulates it at a high frequency and transmits it as a radio wave, and a receiving side despreads the received signal back to a narrow band signal The method can detect the original information signal even when the C / N (carrier-to-noise ratio) of the received radio wave is bad, so CDMA (Code Division Mult)
iple Access: Code division multiple access), GPS (Global Po
There is great expectation for its development as an effective method for space communication such as sitioning system: global positioning system), LAN (local area network), and other communication systems.

For example, in IS-95 which is a standard as a spread spectrum communication system for digital mobile phones, a plurality of users can share the same frequency band at the same time. For that purpose, PN (pseudo-random-no), which is a unique pseudo-random noise code for distinguishing each user, is used.
A spreading code consisting of ise) code is used. This IS-95
In the standard system, on the transmitting side, which is a base station, the voice data is multiplied by a spread code having a frequency whose clock frequency is several tens of times higher than the frequency band of the voice data, that is, the information signal to be transmitted. Spread the spectrum.

On the other hand, in the terminal device on the receiving side,
Decoding process that generates the same spread code as the multiplication code on the transmission side, multiplies the information signal received at the same timing as the transmission side to capture synchronization, and restores the original narrowband audio data information signal It can be performed. A matched filter method or a sliding correlation method is used as this synchronization acquisition method.

In the matched filter method, a filter circuit including a shift register such as a delay element, a multiplier (EX-OR; exclusive or), and an adder is provided,
A spreading code having the same number of bits as the spreading code multiplied on the transmitting side is prepared for one period, that is, the number of bits of the spreading code (this is called "the number of chips"), and each spreading code is multiplied by the received information signal. Then, the spreading code having the maximum value (maximum level or minimum level) as a result is determined. In this case,
It takes one cycle of the spread code to acquire synchronization, and
A shift register and a multiplier corresponding to the number of bits of the spread code are required.

On the other hand, in the sliding correlation method, only one spreading code having the same number of bits as the spreading code multiplied on the transmitting side is prepared, and it is multiplied by the received information signal while shifting it by 1 bit, and the The spreading code with the maximum value is determined. In this case, it takes one cycle of the spreading code to obtain the correlation value at a certain timing (phase). Therefore, the average acquisition synchronization time from the state of uncertain synchronization to the completion of acquisition is (2
It is the time multiplied by m-1) / 2. m is the number of bits in one period of the spread code, that is, the number of phases.

[0007]

In the synchronization acquisition method and the terminal device in the conventional spread spectrum communication method, the synchronization of the received information signal is acquired by either the matched filter method or the sliding correlation method. When the matched filter method is used, when the number of bits of the spread code increases, the circuit scale including the shift register and the multiplier also increases. Therefore, there is a problem in that it is an obstacle to the reduction in size and weight of the terminal device and causes a cost increase. For example,
IS-95 requires more than 32,000 shift registers and multipliers, and 3GPP (W-CDMA) requires
Indeed, 260,000 or more shift registers and multipliers are required. Therefore, the power consumption becomes extremely high, and
It is impossible to build because the circuit scale becomes huge.

On the other hand, when the sliding correlation method is used, the number of bits of the spread code increases and the average acquisition time required for synchronization acquisition becomes long, so that there is a problem that the speed of communication is impaired.

Therefore, the present invention has been made to solve such a conventional problem, and aims to reduce the size and weight of a terminal device, reduce the power consumption, and reduce the cost, and reduce the average acquisition time required for the synchronous acquisition. An object of the present invention is to provide a synchronization acquisition method in a spread spectrum communication system and a terminal device in the spread spectrum communication system that can be shortened.

[0010]

A synchronization acquisition method in a spread spectrum communication system according to the present invention solves the above-mentioned problems. Therefore, according to the configuration of claim 1, the transmission side has a spreading code whose cycle is a predetermined number of bits. And an information receiving step of receiving an information signal transmitted by being multiplied by a partially matched filter having a number of bits smaller than the predetermined number of bits, and a synchronous detection by a partially matched filter process for an information signal received in the information receiving step. And a spreading code generating step of generating a spreading code of the predetermined bit for sliding correlation processing when synchronization is detected by the synchronization detecting step, and a spreading code generating step. And a signal decoding process for multiplying an information signal that is sequentially received with a spread code to generate a decoded signal. It is characterized.

According to a second aspect of the present invention, in the synchronization acquisition method in the spread spectrum communication system according to the first aspect, the synchronization detecting step exists only once in one period of the spread code having the predetermined number of bits. It is characterized in that synchronization detection is performed by the matched filter processing using a unique partial spreading code.

According to a third aspect of the present invention, there is provided the first or second aspect of the invention.
In the method for acquiring synchronization in the spread spectrum communication system according to, the synchronization detecting step generates the spreading code when the spreading code generating step detects the maximum value of the part of the information signal multiplied by the partial spreading code. It is characterized in that a shift start command for shifting in units of code bits is issued.

According to a fourth aspect of the present invention, in the synchronization acquisition method in the spread spectrum communication system according to any one of the first to third aspects, the spreading code generating step is performed by using the spreading code shifted in the code bit unit. It is characterized in that synchronization detection is performed by the sliding correlation process by detecting the maximum value of the multiplied information signal.

According to a fifth aspect of the present invention, in the synchronization acquisition method in the spread spectrum communication system according to any one of the first to fourth aspects, the synchronization detection process is the same as the reception channel of the information signal after the synchronization acquisition. The feature is that synchronization detection is performed in the reception channel.

According to a sixth aspect of the present invention, in the synchronization acquisition method in the spread spectrum communication system according to any one of the first to fifth aspects, the spreading code is a pseudo-random noise code (pseudo-random code) having a specific phase. -noise code).

According to another aspect of the present invention, there is provided a terminal device in a spread spectrum communication system for solving the above problems.
In the configuration described in (1), the information receiving means for receiving the information signal transmitted by being multiplied by the spread code having the predetermined number of bits at the transmission side, and the partial matched filter having the number of bits smaller than the predetermined number of bits A synchronization detecting means for performing synchronization detection by partial matched filter processing on the information signal received by the information receiving means, and when the synchronization is detected by the synchronization capturing means, the spread code of the predetermined bit is used for sliding correlation processing. And a signal decoding means for multiplying an information signal to be sequentially received by the spreading code generated by the spreading code generating means to generate a decoded signal.

According to a eighth aspect of the present invention, in the terminal device in the spread spectrum communication system according to the seventh aspect, the synchronization detecting means is unique only once in one period of the spread code having the predetermined number of bits. It is characterized in that synchronization detection is performed by the matched filter processing using the partial spread code of.

According to a ninth aspect of the present invention, there is provided the seventh or eighth aspect.
In the terminal device in the spread spectrum communication system according to, the synchronization detecting means generates the spread code when the spread code generating means detects the maximum value of a portion of the information signal multiplied by the partial spread code. It is characterized by issuing a shift start command for shifting in code bit units.

According to a tenth aspect of the present invention, the seventh aspect is the seventh aspect.
In the terminal device in the spread spectrum communication system according to any one of items 1 to 3, the spread code generation means detects synchronization with the sliding correlation processing by detecting a maximum value of an information signal multiplied by a spread code shifted by the code bit unit. The feature is that detection is performed.

According to the eleventh aspect of the present invention, the seventh aspect is the first aspect.
The terminal device in the spread spectrum communication system described in any one of 0 is characterized in that the synchronization detection means performs synchronization detection on the same reception channel as the reception channel of the information signal after the synchronization acquisition.

According to a twelfth aspect of the present invention, there is provided the seventh aspect.
The terminal device in the spread spectrum communication system described in any one of 0 is characterized in that the spread code generates a spread code of a pseudo-random-noise code having a specific phase.

According to a thirteenth aspect of the present invention, the seventh aspect is the first aspect.
In the terminal device in the spread spectrum communication system according to any one of 2), the number of bits of the partial spread code is determined according to the processing speed of the sliding correlation processing of the spread code generating means.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, the configuration of the embodiment will be described. FIG. 1 shows a schematic of a spread spectrum system. The transmitter side spreads the transmission data, which is an information signal to be transmitted, with a spread code to convert the data into encoded data.
An RF transmitter 2 that modulates the encoded data into a high frequency signal, a transmission antenna 3 that transmits the high frequency signal, and the like are included. On the other hand, the receiving side receives a high-frequency signal from the transmitting side, a receiving antenna 4, an RF receiving unit 5 (information receiving means) that demodulates the received high-frequency signal and extracts encoded data, and decodes the encoded data ( It is composed of a multiplication unit 6 that despreads the original transmission data and a synchronization unit 7 that performs synchronization acquisition for decoding. Note that the multipliers 1 and 6 on the transmitting side and the receiving side are configured by exclusive OR, that is, EX-OR, and when two input logics are different (two logics are “1” and “0”). "1" is output when the two logics are the same (when the two logics are "1" and "1", or "0" and "0").
In case of), "0" is output.

Next, the operation of the configuration of FIG. 1 will be described. On the transmission side, the multiplier 1 is supplied with transmission data, which is transmission information, and a PN code, which is a spreading code, that is, a pseudo random noise code, and multiplies them. This PN code is composed of M-sequence generator polynomials. Where n is P
It is an exponent that determines the number of bits of the N code. The bit of the spread code is called a "chip", but in order to avoid confusion in explanation, it is a general term "bit".
Will be used.

IS-95 system and 3GPP (WC
In a DMA system, a PN code pattern by which 1-bit transmission data is multiplied is defined in advance for each system. As described above, the RF transmitter 2 modulates the coded data, which has been spectrum-spread with the PN code, into a high-frequency signal, which is transmitted as a radio wave from the transmitting antenna 3.

On the receiving side, the high frequency signal received by the receiving antenna 4 is demodulated into coded data by the RF receiving section 5 and input to the multiplying section 6 and the synchronizing section 7. The synchronizing unit 7 generates a PN code having the same pattern as the PN code multiplied on the transmitting side based on the input coded data, and supplies the PN code to the multiplying unit 6. The multiplication unit 6 multiplies the encoded data by the PN code to decode the original transmission data. In this case, the PN on the sending side
The transmission data can be decoded when the PN code having the same timing (phase) as the code pattern is multiplied.

Therefore, it is necessary for the synchronizing section 7 to synchronously generate the PN code at the same timing as the transmitting side, based on the input coded data. This timing adjustment is called synchronous acquisition. When the timing of the generated PN code matches the transmission side, the maximum value (when the transmission data is “1”) or the minimum value (when the transmission data is “0”) output data is obtained. On the other hand, when the timing of the generated PN code deviates from the transmission side, the intermediate value between the maximum value and the minimum value is output from the multiplication unit 6, and the transmission data cannot be reproduced. In addition, the maximum value or the minimum value is generically referred to as a "maximum value".

In the synchronization acquisition method in this embodiment, rough synchronization acquisition is performed in the preceding stage by the matched filter method, and then final synchronization acquisition (generation of a PN code in the embodiment) is performed by the sliding correlation method. Next, the principle of the synchronization acquisition method of the embodiment will be described by taking the case of a "7" bit PN code as an example.

FIG. 2 is a block diagram showing a detailed configuration of the data decoding unit including the synchronization unit 7 and the multiplication unit 6 on the receiving side, that is, the terminal device. The data decoding unit includes a matched filter 100 (synchronization detecting means) and a spread code generator 20.
0 (spread code generating means) and sliding correlator 3
00 (signal decoding means). The matched filter 100 includes three shift registers (SR) 11,1.
2 and 13, three multipliers (EX-OR) 21, 22 and 23 corresponding to the respective shift registers, and an adder 30. The spread code generator 200 includes three shift registers 41, 42, 43 and a multiplier (EX-OR) 5
It consists of zero. The sliding correlator 300 is
7 shift registers (SR) 61 to 67, 7 shift registers (SR) 71 to 77 respectively corresponding to these shift registers, and 7 multipliers (EX) respectively corresponding to both shift register pairs. -OR) 81-8
7 and an adder 90.

Next, the operation of the data decoding section of FIG. 2 will be described. To the matched filter 100 and the sliding correlator 300, coded data a having a period of 7 bits is sequentially input for each bit. In this case, the 7-bit PN code multiplied on the transmitting side is, for example, “0011101”. Therefore, when the data for synchronization acquisition is "1", the coded data a whose cycle is "1100010" in which the logic of the PN code is inverted is repeatedly input. Therefore, on the reception side, by adjusting the timing, that is, the phase of this encoded data "1100010", it is possible to decode the transmission data, that is, the information signal, which is composed of the spread-spectrum voice data and is transmitted subsequently.

In the matched filter 100, the shift registers 11, 12, and 13 temporarily hold consecutive 3-bit encoded data (a period in which a bit of the next encoded data is received). The held 3-bit encoded data is input to the corresponding multipliers 21, 22, 23. In addition, p1, p2,
p3 is input.

Now, assume that p1 = p2 = p3 = 1. That is, it is assumed that the partial PN code “1” is input to each of the multipliers 21, 22, and 23. Therefore, the coded data of each bit of each shift register 11, 12, 13 and the partial PN code “1” are multiplied by each multiplier 21, 22, 23, and the multiplication value is input to the adder 30 and added. To be done.

Therefore, when the coded data a for synchronization acquisition having "1100010" as one cycle is repeatedly input, the following cases occur.

Case (1), shift registers 11, 1
The 3-bit encoded data held in Nos. 2 and 13 is “11
In the case of “0”, the multiplication outputs of the multipliers 21, 22, 23 are “001”, and the addition output of the adder 30 is “1”. In case (2), the held encoded data is "10".
In the case of "0", the multiplication output is "011" and the addition output is "2". In case (3), when the held encoded data is “000”, the multiplication output is “111” and the addition output is “3”. In case (4), when the held encoded data is "001", the multiplication output is "1".
10 ", and the addition output becomes" 2 ". In case (5), when the held encoded data is "010", the multiplication output is "101" and the addition output is "2". In case (6), the held encoded data is "10".
In the case of "1", the multiplication output becomes "010" and the addition output becomes "1". In case (7), if the held encoded data is "011", the multiplication output is "100" and the addition output is "1".

That is, in the case where the coded data a for synchronization acquisition having “1100010” as one cycle is repeatedly input, and when all “1” s are input to each of the multipliers 21, 22 and 23, The maximum value of the addition output of the adder 30 is "3" because the encoded data held in the shift registers 11, 12, and 13 within one cycle is "0".
Only once in the case of "00". Matched filter 1
00 outputs a start signal b (shift start command) to the spread code generator 200 when the addition output of the adder 30 reaches the maximum value “3”.

In the spread code generator 200, the shift registers 41, 42 and 43 have initial values i1 and i, respectively.
2 and i3 are set. For example, i1 = 1, i2
= 0, i3 = 0, when the data shift is started according to the system clock (not shown), the shift registers 41, 42, 42,
The content of 43 changes.

Therefore, at the time of clock 7, the output from the shift register 43, that is, the spread code generator 20.
The PN code output from 0 is "00111010".
7 bits of 1 are set as one cycle, and "00111010011"
It is a continuous bit string of "101001110100111 ...". After that, clock 7 to clock 8, 9,
As shown in FIG. 4, the PN code of one cycle output from the spread code generator 200 is “0
"111010", "1110100", "110100"
1 ”... changes. That is, as is clear from FIG. 4, the spread code generator 200 outputs a bit string in which three consecutive unique 3 bits appear only once in one cycle in any clock state.

On the other hand, as described above, in the matched filter 100, each of the multipliers 21, 22 and 23 has a value of "11".
1 ”is input, and when the timing with the unique 3 bits“ 000 ”in the encoded data a for synchronization acquisition is obtained, 1 of the encoded data a for synchronization acquisition after that is obtained.
The cycle is “1011000”. Therefore, in order to perform synchronization acquisition, the PN code for decoding is set to "01001".
11 ”.

Therefore, as the initial value of the shift registers 41, 42, 43 of the spread code generator 200, i1 =
When 0, i2 = 1 and i3 = 0 are set and the start signal b is input from the matched filter 100, the data shift is started according to the system clock. As a result, the spread code generator 200 outputs “0100111”.
The PN code of the
The PN code for decoding is sequentially set in the 0 shift registers 61 to 67. That is, the synchronization acquisition is completed.

After this, at the stage where the actual transmission data is spread spectrum from the transmission side and the 7-bit coded data a received at the reception side is stored in the shift registers 71 to 77 of the sliding correlator 300, The PN code multiplied by the transmission data on the transmitting side and the PN code set on the receiving side are completely synchronized. Therefore, in the sliding correlator 300, the PNs in the corresponding seven shift registers 61 to 67 are
Code and encoded data a of the shift registers 71 to 77
In the above, in each of the seven multipliers 81 to
It is multiplied by 87 and the decoded data d is output from the output buffer 90.

For example, when the transmission data consisting of the voice data to be transmitted is a repetition of "1" and "0", it is spectrum-spread with the PN code "0100111" and transmitted, and received by the receiving side. The encoded data a stored in the shift registers 71 to 77 of the sliding correlator 300 has a bit array as shown in FIG. Now, the PN code “0100111” is stored in the shift registers 61 to 67 of the sliding correlator 300.
Is set, a constant PN code pattern is obtained for each cycle as shown in FIG. 5B.
87 is input. Therefore, the multiplication result is as shown in FIG.
The bit arrangement shown in (3) is obtained. As a result, from the output buffer 90, as shown in FIG.
The repeated decoded data of "0" is output, and the transmission data on the transmission side is restored.

Even when a 3-bit value other than "111" is input to each of the multipliers 21, 22, and 23 of the matched filter 100, the addition output of the adder 30 becomes the maximum value "3". Is only once in one cycle. For example, when "010" is input to each of the multipliers 21, 22, 23, the maximum value of the addition output of the adder 30 is "3" because the shift registers 11, 1 within one cycle.
There is only the case where the coded data held in Nos. 2 and 13 is “101”. That is, when one fixed 3-bit data is input to each of the multipliers 21, 22, and 23 to receive the coded data a for synchronization acquisition for one period, the addition output of the adder 30 reaches the maximum value " There is always one case where it becomes "3".

The coded data held may be 3 bits or more. In this case, the number of shift registers and multipliers also increases. Further, it is possible to select a combination of bits that is not necessarily consecutive 3 bits but only once in one cycle. Furthermore, it is when the addition output becomes the maximum value or the minimum value, that is, the maximum value that the matched filter 100 synchronously detects the partial PN code, so that the addition output of the adder 30 becomes the minimum value "0". A combination may be selected.

FIG. 6 is a diagram showing the configuration of a data decoding unit in a terminal device that receives an information signal that has been spread spectrum with an n (= 2 ^m -1) bit PN code. The matched filter 100 includes m shift registers 11 to 1
It is composed of m, m multipliers 21 to 2m, and an adder 30. The spread code generator 200 is composed of m shift registers 41 to 4m and a multiplier 50. The spreading code generator 200 shows an example of a circuit configuration, and in the spreading code generator 200 of FIG. 6, only one multiplier 50 operates so that m = 3, 4, 4.
Only in the case of 5, 6, 7, 15, etc., and in the other cases, a plurality of multipliers 50 are required, but the examples thereof will be omitted here.

As described above, according to the above-described embodiment, the encoded data a (information signal), which is transmitted by being multiplied by the PN code having a predetermined number of bits as a cycle on the transmitting side, is received, and the number is smaller than the predetermined number of bits. The partial matched filter consisting of the number of bits performs synchronization detection on the received encoded data a by the partial matched filter processing, and when the synchronization is detected by the partial PN code, a PN code having a predetermined number of bits as a cycle. For the sliding correlation processing, the PN code generated by shifting in bit units is multiplied by the received coded data to generate decoded data.

Therefore, the circuit scale of the matched filter 100 can be reduced to reduce the size and weight of the terminal device, reduce the power consumption, and reduce the cost, and the average acquisition time required for synchronization acquisition in the spread code generator 200 can be shortened. .

Further, in the above embodiment, the unique partial PN code existing only once in one cycle of the PN code having the predetermined number of bits is used to perform the synchronization detection by the matched filter processing. The partial PN code in this case does not necessarily have to be consecutive bits. A unique bit structure that exists only once in one cycle of the PN code may be used.

Therefore, the partial PN code used in the matched filter can be easily specified regardless of the number of bits of the PN code, and the time required for system development can be shortened.

Further, in the above embodiment, when the maximum value (maximum value or minimum value) of the part of the encoded data obtained by multiplying the partial PN code by the matched filter 100 is detected, the PN code is shifted bit by bit. A start signal for the purpose is issued to the spread code generator 200.

Therefore, the structure of the data decoding unit can be made extremely simple, which contributes to reduction of system development time and reduction of product cost.

In the above embodiment, the synchronization detection is performed on the same reception channel as the reception channel of the information signal after the synchronization acquisition.

Therefore, for example, it is not necessary to provide a dedicated channel for synchronization acquisition such as a pilot channel (CPICH) in addition to a channel for receiving an information signal, that is, transmission data. It does not compromise the functionality of some multiple access.

Further, in the above embodiment, when the synchronous acquisition of the partial PN code is completed in the matched filter 100, the start signal b is given to the spread code generator 200 to generate the PN code of a predetermined number of bits. Shift registers 61-67 of sliding correlator 300
However, after the setting, the matching may be performed on the encoded data a for synchronization acquisition having a predetermined number of bits. That is, FIG.
The configuration of FIG. 6 may be configured to confirm that the decoded data in the output buffer 90 becomes “1”. In this case, more accurate synchronization acquisition can be performed.

Further, in the above embodiment, the number of bits of the partial PN code may be determined according to the processing speed of the sliding correlation processing.

With such a configuration, when the processing speed of the sliding correlation processing is slower than the processing speed required for the system, the number of bits of the partial PN code is increased to increase the processing speed required for the system. Can be supplemented.
On the contrary, when the processing speed of the sliding correlation processing is faster than the processing speed required for the system, the number of bits of the partial PN code can be reduced to further reduce the circuit scale.

[0056]

According to the present invention, the transmitting side receives the information signal transmitted by being multiplied by the spread code having the predetermined number of bits as a period, and uses the partially matched filter having the number of bits smaller than the predetermined number of bits. Sync detection is performed on the received information signal by partial matched filter processing, and when synchronization is detected by the partial spread code, a spread code with a predetermined number of bits as a cycle is generated for sliding correlation processing. Since the decoded signal is generated by multiplying the information signal that is sequentially received by the received signal, the circuit scale of the matched filter is reduced, the terminal device is reduced in size and weight, the power consumption is reduced, and the cost is reduced. The acquisition time can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic system on a transmission side and a reception side in a spread spectrum communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a data decoding unit in the case of a 7-bit PN code on the receiving side according to the embodiment.

FIG. 3 is a diagram showing a change in data in a shift register in the spreading code generator according to the above embodiment.

FIG. 4 is a diagram showing changes in the PN code output from the spreading code generator according to the embodiment.

FIG. 5 is a diagram showing a transition of data decoding according to the embodiment.

FIG. 6 is a block diagram showing a configuration of a data decoding unit in the case of a PN code having an n-bit configuration on the receiving side according to the embodiment.

[Explanation of symbols]

1, 6 Multiplier 2 RF transmitter 3 Transmit antenna 4 Receive antenna 5 RF receiver 7 Synchronizer 11-1m, 41-4m, 61-6n, 71-7n Shift registers 21-23, 50, 81-8n Multiplier 30 adder 90 output buffer 100 matched filter 200 spreading code generator 300 sliding correlator a encoded data b start signal c PN code d decoded data i1 to im initial values p1 to pm partial PN data

Claims (13)

[Claims] 1. An information receiving step of receiving an information signal transmitted by being multiplied by a spread code having a predetermined number of bits at a transmitting side, and the information by a partially matched filter having a number of bits smaller than the predetermined number of bits. A synchronization detection step of performing synchronization detection by partially matched filter processing on the information signal received in the reception step, and when synchronization is detected in the synchronization detection step, the spread code of the predetermined bit is used for sliding correlation processing. A spread spectrum communication system characterized by comprising: a spread code generating step to be generated; and a signal decoding step of multiplying an information signal to be sequentially received by the spread code generated by the spread code generating step to generate a demodulated signal. Acquisition method in. 2. The synchronization acquisition method in the spread spectrum communication system according to claim 1, wherein the synchronization detection process uses a unique partial spread code existing only once in one cycle of the spread code having the predetermined number of bits. A synchronization acquisition method in a spread spectrum communication system, characterized in that synchronization detection is performed by the matched filter processing. 3. The synchronization acquisition method in the spread spectrum communication system according to claim 1 or 2, wherein the synchronization detecting step detects the maximum value of a part of the information signal multiplied by the partial spreading code. A synchronization acquisition method in a spread spectrum communication system, characterized in that the generation process issues a shift start command for shifting in code bit units to generate the spread code. 4. The synchronization acquisition method in the spread spectrum communication system according to claim 1, wherein the spread code generating step is a maximum value of an information signal multiplied by a spread code shifted in units of the code bit. A synchronization acquisition method in a spread spectrum communication system, characterized in that the synchronization detection is performed by the sliding correlation processing by detecting the. 5. The synchronization acquisition method in the spread spectrum communication system according to any one of claims 1 to 4, wherein the synchronization detection step performs synchronization detection in the same reception channel as the reception channel of the information signal after the synchronization acquisition. A method for acquiring synchronization in a spread spectrum communication system characterized by the above. 6. The synchronization acquisition method in a spread spectrum communication system according to claim 1, wherein the spread code is a pseudo-random-noise code having a specific phase. A method for acquiring synchronization in a spread spectrum communication system. 7. An information receiving means for receiving an information signal transmitted by being multiplied by a spread code having a predetermined number of bits at a transmitting side, and the information by a partially matched filter having a number of bits smaller than the predetermined number of bits. A synchronization detecting means for performing synchronization detection on the information signal received by the receiving means by partial matched filter processing, and when synchronization is detected by the synchronization detecting means, the spread code of the predetermined bit is used for sliding correlation processing. A spread spectrum communication system comprising: a spread code generating unit for generating; and a signal decoding unit for multiplying an information signal sequentially received by the spread code generated by the spread code generating unit to generate a decoded signal. Terminal equipment in. 8. The terminal device in the spread spectrum communication system according to claim 7, wherein the synchronization detecting means uses a unique partial spread code that exists only once in one cycle of the spread code having the predetermined number of bits. A terminal device in a spread spectrum communication system, wherein synchronization detection is performed by the matched filter processing. 9. The terminal device in the spread spectrum communication system according to claim 7, wherein the synchronization detecting means generates the spread code when the maximum value of a portion of the information signal multiplied by the partial spread code is detected. A terminal device in a spread spectrum communication system, wherein the means issues a shift start command for shifting in code bit units to generate the spread code. 10. The terminal device in the spread spectrum communication system according to claim 7, wherein the spread code generating means multiplies a maximum value of an information signal by multiplying a spread code shifted by the code bit unit. A terminal device in a spread spectrum communication system, characterized by performing synchronization detection by the sliding correlation processing by detecting. 11. The terminal device in the spread spectrum communication system according to claim 7, wherein the synchronization detecting means performs synchronization detection on the same reception channel as the reception channel of the information signal after the synchronization acquisition. And a terminal device in a spread spectrum communication system. 12. The terminal device in the spread spectrum communication system according to claim 7, wherein the spreading code is a pseudo random noise code having a specific phase. A terminal device in a spread spectrum communication system characterized by being generated. 13. The terminal device in the spread spectrum communication system according to claim 7, wherein the number of bits of the partial spread code is determined according to a processing speed of a sliding correlation process of the spread code generating means. A terminal device in a spread spectrum communication system characterized by: