JP2001285132A - Spread spectrum communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide spread spectrum communication equipment for realizing asynchronous access without using fast timing control while keeping high speed properties in synchronization acquisition in the case of accessing to a base station from a plurality of transmission stations by using the same spread code and the same frequency band. SOLUTION: A receiver for receiving a transmitted signal which is transmitted asynchronously by using the same spread code and the same frequency band and consists of a transmission frame having a prescribed synchronizing pattern part and a data part has a first symbol matched filter 5 having the tap of each symbol time and performing the correlation detection of each period between a synchronizing pattern part in a received signal by using a prescribed reference pattern and a second symbol matched filter 6 having the tap of each symbol time and performing the common-mode synthesis of each symbol period between the synchronizing pattern part in the received signal by using the prescribed reference pattern in addition to a matched filter 3 corresponding to the spread signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication apparatus which enables asynchronous access,
In particular, using the same spreading code and the same frequency band, a desired signal and a non-desired signal are transmitted asynchronously, and a receiver that enables reception of only the desired signal even when their propagation times overlap, The present invention relates to a spread spectrum communication apparatus characterized by a configuration of a transmission frame corresponding to.

[0002]

2. Description of the Related Art The inventors of the present invention can reduce undetection of a desired signal by eliminating a threshold value for received signal power, and reduce erroneous detection by using a synchronization pattern. (Japanese Patent Application No. 11-062228).
issue). According to this spread spectrum communication apparatus, the transmitting side multiplexes the information signal (spreading code) in order to increase the transmission speed, and the circuit can be simplified as a multiplexing means. A chip interleaver or a modified Barker code without intersymbol interference is used. On the reception side, the output of the correlator and the delay detector
Data is demodulated asynchronously by detecting the peak value and peak position of the system, signal detection (synchronous capture) is performed by pattern matching of demodulated data, and majority decision is made to improve the reliability of peak position detection. In demodulation, synchronization acquisition is performed using the peak value and peak position detection.

A spread spectrum communication system in which a plurality of transmitting stations randomly access a base station using the same frequency and the same spreading code is disclosed in Japanese Patent Laid-Open No. 11-2520.
No. 44 is known. According to this spread spectrum system, each transmitting station spreads the transmission information obtained by adding a pilot pattern having a different code sequence and having orthogonality to each other to transmission data, to each of the transmission stations, and spreads the spectrum with a spreading code to spread the base station. Transmitting to the station. The base station obtains a correlation component by performing in-phase addition of a pilot pattern component in a search range with a code sequence of a pilot pattern received from each transmitting station and a predetermined spreading code, and obtains a desired received signal based on the correlation result. I have. In this spread spectrum communication system, interference of a non-desired signal with a desired signal is prevented by the orthogonality of each pilot pattern.

[0004]

Problems to be Solved by the Invention Japanese Patent Application No. Hei 11-0622
In a spread spectrum communication apparatus as disclosed in No. 28, when a plurality of transmitting stations access a base station using the same spreading code and the same frequency band, the power of the desired signal is superior to the undesired signal. Except in cases where there is a possibility that the propagation times slightly overlap, a frame collision occurs and reception is often impossible. In order to avoid this, in a centralized control network, the burden on the radio base station that controls the transmission time has increased.

In the spread spectrum communication system disclosed in Japanese Patent Application Laid-Open No. H11-252044, in order to obtain a peak of a correlation signal, it is necessary to perform timing control on a chip basis in order to synchronize a spread code generation unit. Become. Also,
Keep the orthogonality of the pilot pattern between multiple transmitting stations,
In order not to cause interference, it is necessary to perform timing control in units of chips or to remove interference in order to synchronize between transmitting stations. The high-speed timing control for synchronization as described above has led to an increase in the scale of a communication device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spread spectrum communication apparatus that can acquire a high speed when accessing a base station from a plurality of transmitting stations using the same spreading code and the same frequency band. Another object of the present invention is to provide a spread spectrum communication device that realizes asynchronous access without using high-speed timing control required for a spread spectrum communication method.

[0007]

According to the first aspect of the present invention,
Among a plurality of transmission signals transmitted asynchronously using the same spread code and the same frequency band, in a spread spectrum communication device that receives only a desired signal, each of the transmission signals has a predetermined synchronization pattern and data. , And the spread spectrum communication apparatus has a receiver for receiving the transmission signal, and the receiver, in addition to the matched filter corresponding to the spread code, the symbol By having a tap for each time and using a predetermined reference pattern corresponding to the synchronization pattern portion of the desired signal, by performing correlation detection for each symbol period with the synchronization pattern portion in the received signal, the desired signal is obtained. A first symbol matched filter that performs synchronization acquisition with respect to, and a tap for each symbol time, based on the synchronization acquisition of the first symbol matched filter, A second symbol matched filter that performs in-phase synthesis for each symbol period with the synchronization pattern portion in the received signal using a predetermined reference pattern corresponding to the synchronization pattern portion of the desired signal. Things.

According to a second aspect of the present invention, in the spread spectrum communication apparatus according to the first aspect, the desired signal is a transmission signal that the receiver desires to receive among transmission signals transmitted from a plurality of transmitting stations. It is characterized by being a signal from a station.

According to a third aspect of the present invention, in the spread spectrum communication apparatus according to the first aspect, the reference pattern of the first symbol matched filter is first stored in the synchronization pattern section, and then the second symbol matched filter is stored in the synchronization pattern section. Are selected and arranged in accordance with the used channel.

According to a fourth aspect of the present invention, in the spread spectrum communication apparatus according to the first aspect, a symbol of a synchronization pattern corresponding to the desired signal is set as a reference pattern in the first symbol matched filter. It is characterized by the following.

According to a fifth aspect of the present invention, in the spread spectrum communication apparatus of the first aspect, the first symbol matched filter comprises a shift register array having a tap for each symbol.

According to a sixth aspect of the present invention, in the spread spectrum communication apparatus of the fifth aspect, the value of the tap is multiplied by a corresponding reference pattern of the first symbol matched filter, and the multiplied value is applied to all taps. It is added, output as the number of pattern matches, and used for synchronization establishment determination.

According to a seventh aspect of the present invention, in the spread spectrum communication apparatus according to the sixth aspect, the receiver compares the number of pattern matches from the first symbol matched filter with a predetermined threshold value. When the number of pattern matches exceeds a predetermined threshold value, it is determined that synchronization has been established, and a threshold value judging device that outputs a synchronization trigger is further provided.

According to an eighth aspect of the present invention, in the spread spectrum communication apparatus according to the first aspect, the second symbol matched filter includes, as a reference pattern, a symbol in a partial section of a synchronization pattern corresponding to the desired signal. It is characterized by being set.

According to a ninth aspect of the present invention, in the spread spectrum communication apparatus according to the eighth aspect, the second symbol matched filter has a tap for each symbol, and all bits of the received signal are input, and the value of the tap is By multiplying by the corresponding reference pattern of the second symbol matched filter, and the multiplied value is added over all taps,
It is characterized in that cyclic addition is performed in synchronization with the in-phase at a symbol period, and the addition result is output as an in-phase composite waveform.

According to a tenth aspect of the present invention, in the spread spectrum communication apparatus according to the fifth aspect, the reference pattern of the first symbol matched filter is divided into a plurality of partial reference patterns, and the synchronization of the transmission frame is performed. The pattern is characterized in that each of the partial reference patterns is multiplied by a predetermined code and combined.

According to an eleventh aspect of the present invention, in the spread spectrum communication apparatus according to the tenth aspect, the taps are grouped corresponding to each partial reference pattern, and a tap value of each tap group corresponds to the corresponding tap value. Multiplying by a corresponding reference pattern of a one-symbol matched filter, the multiplied value is added over all taps of the tap group, output as a pattern matching number, and used for synchronization establishment determination. .

According to a twelfth aspect of the present invention, in the spread spectrum communication apparatus according to the eleventh aspect, the receiver determines whether the number of pattern matches from the first symbol matched filter is within a predetermined synchronization establishment range. And when it is determined that the number of pattern matches for all the partial reference patterns is within the predetermined synchronization establishment range, it is determined that synchronization has been established, and a threshold decision / pattern demodulator that outputs a synchronization trigger is further provided. It is characterized by having.

According to a thirteenth aspect of the present invention, in the spread spectrum communication apparatus according to the thirteenth aspect, the synchronization establishment range is equal to or greater than a predetermined upper threshold value set near a maximum value, or is set to a predetermined value set near a minimum value. It is characterized by being within a range equal to or lower than the lower threshold value.

According to a fourteenth aspect of the present invention, in the spread spectrum communication apparatus according to the thirteenth aspect, the threshold value determination /
The pattern demodulator outputs different codes when the number of matched patterns is equal to or greater than the upper threshold value and when the number of matched patterns is equal to or less than the lower threshold value.

According to a fifteenth aspect of the present invention, there is provided the spread spectrum communication apparatus according to the fourteenth aspect, wherein
A combination of codes corresponding to the total number of pattern matches output from the pattern demodulator is input as a recognition pattern, and a reference pattern of the second symbol matched filter is set based on the input recognition pattern. Things.

As described above, according to the present invention, in addition to the matched filter corresponding to the spreading code, a receiver including two types of symbol matched filters having taps for each symbol time is configured, It is possible to provide a spread spectrum communication apparatus that can acquire only signals at high speed and that has improved multipath resistance.

[0023]

FIG. 1 shows a format of a transmission frame used in a first embodiment of a spread spectrum communication apparatus according to the present invention. The transmission frame includes, in order of time, a power adjustment unit necessary for gain adjustment of the high-frequency unit, a synchronization pattern unit that is unique data for channel identification, and a data unit exchanged with an upper layer. Here, it is assumed that only one type of spreading code having excellent autocorrelation characteristics is used in common by each station. In the synchronization pattern portion, a reference pattern of a first symbol matched filter described later first and a reference pattern of a second symbol matched filter described later are selected and arranged in accordance with a used channel. In the present embodiment, it is assumed that the synchronization pattern is selected mainly according to the destination address, and the channel is identified.

FIG. 2 shows an example of the configuration of a basic receiver used in the present embodiment, and FIG. 3 is a flowchart showing a receiving operation performed in the receiver of FIG.

In the receiver shown in FIG. 2, a reception signal having the frame format shown in FIG. The detection unit 1 includes an A / D converter 2 that converts an analog signal, which is a received signal, into a digital signal, and a matched filter 3 that performs correlation detection of the digital signal using a reference spreading code.
And a delay detector 4. Delay detector 4
, A detection waveform is output for each sampling time (period). As described above, since the spreading code is common, the matched filter 3 is also of one type and common to each station. The detected waveform from the delay detector 4 is supplied to a first symbol matched filter 5 and a second symbol matched filter 6 to be described later, and each symbol matched filter exchanges a symbol unit with a reference pattern assigned to each. Is performed, synchronization establishment determination, in-phase cyclic addition, and propagation path estimation, which will be described later, are performed.

Hereinafter, an operation of receiving data of a desired signal using a spread spectrum communication apparatus according to the first embodiment of the present invention will be described with reference to FIGS.

In the present embodiment, the establishment of synchronization is determined by the threshold value judging unit 8 based on the number of pattern matches output from the first symbol matched filter 5 for the synchronization pattern in the received signal. The threshold value judging unit 8 judges that synchronization has been established when the number of pattern matches exceeds a predetermined threshold value set by the threshold value judging unit 8. Until a predetermined threshold value is exceeded, the number of successive pattern matches is continuously output from the first symbol matched filter 5 to the threshold value judging device 8. When synchronization is established, a peak search (detection of a peak position and a peak level in the in-phase combined waveform) is performed using an in-phase combined waveform output from a second symbol matched filter 6 described later to detect a propagation path (path). . Using the synchronization timing and the peak level obtained here, sampling and combining diversity (synthesis or switching of a plurality of reception signals including the same information) are performed, and the obtained code is output as data.

As described above, the receiver of this embodiment is
In addition to a normal matched filter, a first symbol matched filter 5 and a second symbol matched filter 6 are further provided. The detection waveform output from the delay detector 4 is compressed into a 1-bit code by the encoder and input to the symbol matched filter 5 (S1). This makes it possible to significantly reduce the number of shift register circuits. Before waiting for reception, the symbol of the synchronization pattern corresponding to the desired signal is stored in the first symbol matched filter 5 in the reference pattern (R ₀₀ , R ₀₀₎ .
₀₁ , R ₀₂ , R ₀₃ , R ₀₄ , R ₀₅ , R ₀₆ ). The shift register row on the input signal side constituting the first symbol matched filter 5 has a length corresponding to the reference pattern time in sampling time units (that is, the length of the shift register row is the length of the chip row of the reference pattern). ),
Each symbol has a tap t. The value of the tap is multiplied by the corresponding reference pattern of the first symbol matched filter 5, and the multiplied value is added over all taps t.
It is output to the threshold value judging unit 8 as the number of pattern matches (S2). Although FIG. 2 shows a case where the number of taps is six, the number of taps is not limited to six, and may vary depending on use conditions such as the accuracy of synchronization establishment determination and the length of a shift register row. It is set according to.

FIG. 4 schematically shows the synchronization establishment determination.

FIG. 4 shows the number of pattern matches (the sum of all taps t) output from the first symbol matched filter 5 over time. As shown in FIG. 4, the number of pattern matches shows a waveform that fluctuates with time between the minimum value and the maximum value. When the peak value of this waveform exceeds a predetermined threshold value, It is determined that the synchronization between the synchronization pattern of the first symbol matched filter 5 and the reference pattern of the first symbol matched filter 5 is established.

That is, the threshold value judging unit 8 compares the number of pattern matches output from the first symbol matched filter 5 with a predetermined threshold value, and when the number of pattern matches exceeds the predetermined threshold value. (S3), the threshold trigger 8 outputs a synchronization trigger. Here, the number of pattern matches corresponds to the correlation output when the reference pattern in the synchronization pattern of the received signal and the reference pattern of the first symbol matched filter 5 are correlated over a plurality of symbols (in symbol units). The timing at which the maximum correlation output (the maximum number of pattern matches) is given is when synchronization is established. Here, a threshold value is set, and the timing of providing a correlation output (the number of pattern matches) exceeding the threshold value is when synchronization is established.

As shown in FIG. 2, the second symbol matched filter 6 also has a tap t for each symbol. All bits of the detected waveform are input to the second symbol matched filter 6. As the reference pattern of the second symbol matched filter 6, with the last short section _{(R 10, R 11, R} 12) of the synchronization pattern, similarly to the first symbol matched filter 6, multiplication, an addition is performed. This makes it possible to perform cyclic addition in synchronization with the same phase at the symbol period, and use it for propagation path (path) estimation.
Although FIG. 2 shows a case where the number of taps is three, the number of taps is not limited to three.

After the synchronization trigger is output from the threshold value judging unit 8, the window 9 opens for a certain period (window width), and the in-phase composite waveform output from the second symbol matched filter 6 peaks via the window 9. Searcher 10
(S4). The peak searcher 10 detects peaks (peak positions and peak levels) corresponding to a predetermined number (m) of paths, and holds the peak positions (peak timings) and peak levels in correspondence. . Further, the symbol sampling unit 11 performs sampling for each symbol in accordance with the peak timing of the number of paths held by the peak searcher 10, and performs synthesis in accordance with the peak level of the number of paths held by the peak searcher 10 ( S6). The sign of this output is determined, and is output to the upper layer as data. As a result, data of only the desired signal can be obtained.

Here, when using QPSK, the first and second symbol matched filters 5 and 6 have two systems of I and Q, respectively, and the result of adding their outputs is used for threshold value determination. Thereby, the synchronization pattern is shortened, and the synchronization acquisition time is further reduced.

Next, a second embodiment of the spread spectrum communication apparatus according to the present invention will be described. Note that portions having functions similar to those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The second embodiment relates to the case where the reception of a plurality of synchronization patterns is performed, and FIG. 5 shows the configuration of the receiver in such a case.

If the radio header can be lengthened, a configuration is possible in which a plurality of channels are identified while erroneous detection is suppressed. FIG. 6 shows the frame format at this time.

Here, the first symbol matched filter 5 'on the receiving side is composed of several divided reference pattern portions (hereinafter referred to as partial reference patterns), and the taps of the first symbol matched filter 5' Are also grouped corresponding to each partial reference pattern. On the transmitting side, a transmission frame as shown in FIG. 6 is configured by multiplying a code for representing a destination address for each of the divided partial reference patterns and using the combination as a synchronization pattern.

FIG. 7 is a flowchart showing the receiving operation of the receiver 5 'shown in FIG. 5, and FIG. 8 explains the operation for determining the establishment of synchronization. As the selection of the synchronization pattern in the second embodiment, first, the destination address and the broadcast address of the receiving side are distinguished, and the configuration used for channel identification or in the case of a system having a base station, There is a configuration in which a data demodulation process of a portion provided in parallel is provided in parallel, a synchronization pattern is selected according to a source address, and channel identification is performed.

Hereinafter, the configuration and the receiving operation of the receiver used in the spread spectrum communication apparatus according to the second embodiment will be described with reference to FIGS.

As in the first embodiment, the detected waveform is input to the first symbol matched filter 5 '. The determination of the establishment of the synchronization is made based on each tap group (T1 (corresponding to part 1), T2 (corresponding to part 2), T2) of the first symbol matched filter 5 '.
3 (corresponding to part 3)) is performed based on the number of pattern matches output from the third embodiment, but the number of pattern matches is equal to that of all tap groups (T1, T2, T3).
The difference is that the number of pattern matches is output sequentially until the threshold judgment is satisfied. That is, the number of pattern matches from each tap group (T1, T2, T3) is input to the threshold value judging / pattern demodulator 8 '(S11), and each of them has a predetermined threshold value as in the first embodiment. The comparison is performed (S12). However, as shown in FIG. 8, the threshold value judgment / pattern demodulator 8 ′ of the present embodiment performs the following operations on each partial output of the first symbol matched filter 5 ′.
There are provided two types of determination success ranges, which are equal to or more than an upper threshold value (+) set near the maximum value and equal to or less than a lower threshold value (-) set near the minimum value. When the established range is satisfied (S12), it is determined that synchronization is established, a synchronization trigger is output, and a demodulation pattern described later is determined and a recognition pattern is output (S13).

On the transmitting side, a predetermined code is shown for each part (1, 2, 3), and the destination address is expressed by a combination of the codes given to these parts. The threshold value determination / pattern demodulator 8 'on the receiver side outputs the synchronization trigger to the window 9 as described above, and also, for each partial reference pattern, the number of pattern matches falls within the upper determination range. A sign “+” is output when the value enters, and a sign “−” is output when the value falls within the lower range where the determination is satisfied. The combination of these codes is output to the pattern determiner 13 as a recognition pattern. In the case of FIG. 8, (+), (-),
(+) Is output as the recognition pattern, whereby the destination address is specified.

The pattern decision unit 13 to which the recognition pattern of the output (recognition pattern, synchronization trigger) of the threshold value decision / pattern demodulator 8 'is inputted identifies the destination address by the combination of the demodulated patterns. In response to this, a reference pattern of the second symbol matched filter 6 is set (S14). Thereafter, in the same manner as in the first embodiment, a window is opened for a certain period by a synchronization trigger from the threshold value judgment / pattern demodulator 8 ′, and is input from the second symbol matched filter 6 via the window 9. Using the in-phase synthesized waveform (S15), a peak search is performed by the peak searcher 10 to detect a path, and sampling and synthesis diversity are performed using the obtained synchronization timing and peak level (S17). Is determined (S18) and output to the upper layer as desired signal data.

In the above-described embodiment, the number of divisions of the reference pattern (the number of partial reference patterns and the number of tap groups) is set to three. However, in the present invention, these numbers are not limited to three, and are arbitrary. Obviously, it can be set to

FIG. 9 is an explanatory diagram for explaining the effect of the first symbol matched filter 5 of the present invention. An example in which an undesired signal having a higher level than the desired signal is added will be described.
This is represented by a detection waveform (input waveform of the first symbol matched filter 5).

In the figure, (a) shows a detection waveform of a desired signal, (b) shows a detection waveform of an undesired signal,
(C) shows a state where the desired signal and the undesired signal overlap each other. Since the first symbol matched filter 5 has a tap for each symbol length, the synchronization pattern included in the desired signal can be demodulated. Using the synchronization timing obtained here, the correlation peak of only the desired signal can be captured. . In addition, since the frame synchronization is sequentially determined for each received waveform sample, the synchronization can be acquired at high speed.

FIG. 10 is an explanatory diagram for explaining the effect of the second symbol matched filter 6 of the present invention, and shows a state of in-phase synthesis started from a synchronization trigger. In the figure, (a) shows a detection waveform of a multipath desired signal, and (b) shows an output waveform synthesized in phase by the second matched filter 6. By the in-phase synthesis by the second symbol matched filter 6, noise and interference at the output of the second symbol matched filter 6 are reduced, and the performance of peak search is improved. Further, when the delay time difference of the multipath exceeds one symbol as shown in the figure, the inter-symbol interference can be reduced.

FIG. 11 shows whether or not a desired signal can be received when a desired signal and an undesired signal overlap at the propagation time in the conventional spread spectrum communication system and the spread spectrum communication system of the present invention. is there.

As shown in FIG. 11, in the case of the conventional method, when at least a part of the undesired signal overlaps the desired signal and the reception time, a frame collision occurs and the desired signal cannot be received. . On the other hand, according to the method of the present invention,
The desired signal can be received (extracted) even if the reception times of the desired signal and the non-desired signal overlap. Also, as compared with the conventional spread spectrum receiver that performs multiple access, the number of shift registers in the symbol matched filter is increased, but the load on peripheral circuits is reduced. In particular, the complexity of time control and the like can be eliminated.

As described above, according to the present invention, in addition to a matched filter corresponding to a spreading code, a receiver including two types of symbol matched filters having taps for each symbol time is constituted, It is possible to provide a spread spectrum communication apparatus that can acquire only signals at high speed and that has improved multipath resistance.

As a system using this spread spectrum communication apparatus, it is easy to configure a self-contained distributed network in which there is no deviation in circuit scale among stations. Further, when a central control type network is configured, for example, when an access method based on contention is used, collision can be significantly reduced. Therefore, when this communication device is used for transmission reservation, CDMA (code division multiple access) or TDMA
(Time division multiple access) can be applied as an access method.

[0052]

As described above, according to the present invention, even when the transmission time of a transmission signal having a different synchronization pattern from the transmission signal having a desired synchronization pattern overlaps, only the desired signal can be received. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a format of a transmission frame used in a spread spectrum communication apparatus according to the present invention.

FIG. 2 is a diagram showing a first embodiment of the receiver of the spread spectrum communication apparatus according to the present invention.

FIG. 3 is a flowchart showing a receiving operation performed in the receiver shown in FIG. 2;

FIG. 4 is a schematic diagram showing determination of establishment of synchronization performed in the receiver shown in FIG. 2;

FIG. 5 is a diagram showing a second embodiment of the receiver of the spread spectrum communication apparatus according to the present invention.

FIG. 6 is a diagram illustrating another format of a transmission frame used in the spread spectrum communication apparatus according to the present invention.

FIG. 7 is a flowchart showing a receiving operation performed in the receiver shown in FIG.

FIG. 8 is a schematic diagram showing determination of establishment of synchronization performed in the receiver shown in FIG. 5;

FIG. 9 is a schematic diagram illustrating the effect of the first symbol matched filter provided in the receiver of the spread spectrum communication apparatus according to the present invention.

FIG. 10 is a schematic diagram illustrating an effect of a second symbol matched filter provided in a receiver of a spread spectrum communication apparatus according to the present invention.

FIG. 11 shows whether or not a desired signal can be received when a desired signal and an undesired signal overlap at the propagation time in the conventional spread spectrum communication method and the spread spectrum communication method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detector 2 A / D converter 3 Matched filter 4 Delay detector 5, 5 'First symbol matched filter 6 Second symbol matched filter 7 Encoder 8 Threshold decision unit 8' Threshold decision / pattern demodulator 9 Window 10 Peak searcher 11 Symbol sampler 12 Data decision unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Hashimoto 5-35-2 Hakusan, Bunkyo-ku, Tokyo Clarion Co., Ltd. F-term (reference) 5K022 EE02 EE33 EE36 5K047 AA15 BB01 GG34 HH15 MM12 MM33

Claims (15)

[Claims] 1. A spread spectrum communication apparatus which receives only a desired signal from a plurality of transmission signals asynchronously transmitted using the same spread code and the same frequency band, wherein each of the transmission signals is a predetermined signal. It is composed of a transmission frame having a synchronization pattern part and a data part, and the spread spectrum communication device has a receiver for receiving the transmission signal, and the receiver has a matched filter corresponding to a spreading code. In addition, a tap is provided for each symbol time, and using a predetermined reference pattern corresponding to the synchronization pattern portion of the desired signal, correlation detection is performed for each symbol period with the synchronization pattern portion in the received signal. Thereby, the first symbol matched filter that performs synchronization acquisition for the desired signal, and has a tap for each symbol time, the synchronization acquisition of the first symbol matched filter And a second symbol matched filter that performs in-phase synthesis for each symbol period with a synchronization pattern part in the received signal using a predetermined reference pattern corresponding to the synchronization pattern part of the desired signal. Spread spectrum communication equipment characterized by the above-mentioned. 2. The spectrum according to claim 1, wherein the desired signal is a signal from a transmitting station that the receiver desires to receive among the transmitted signals transmitted from a plurality of transmitting stations. Spreading communicator. 3. A reference pattern of the first symbol matched filter and then a reference pattern of the second symbol matched filter are selected and arranged in the synchronization pattern section according to a channel to be used. The spread spectrum communication device according to claim 1, wherein: 4. The first symbol matched filter includes:
2. The spread spectrum communication apparatus according to claim 1, wherein a symbol of a synchronization pattern corresponding to the desired signal is set as a reference pattern. 5. The spread spectrum communication apparatus according to claim 1, wherein said first symbol matched filter comprises a shift register array having a tap for each symbol. 6. A value of the tap is multiplied by a corresponding reference pattern of the first symbol matched filter, the multiplied value is added over all taps, output as a pattern matching number, and used for synchronization establishment determination. The spread spectrum communication apparatus according to claim 5, wherein: 7. The receiver compares the number of pattern matches from the first symbol matched filter with a predetermined threshold, and determines that synchronization has been established if the number of pattern matches exceeds a predetermined threshold. 7. The spread spectrum communication apparatus according to claim 6, further comprising a threshold value judging unit for judging and outputting a synchronization trigger. 8. The second symbol matched filter includes:
2. The spread spectrum communication apparatus according to claim 1, wherein a symbol in a part of a synchronization pattern corresponding to the desired signal is set as a reference pattern. 9. The second symbol matched filter has a tap for each symbol, receives all bits of a received signal, and multiplies the value of the tap by a corresponding reference pattern of the second symbol matched filter. 9. The spread spectrum communication apparatus according to claim 8, wherein the values are added over all taps, so that cyclic addition is performed in synchronization with the in-phase at a symbol period, and an addition result is output as an in-phase composite waveform. 10. The reference pattern of the first symbol matched filter is divided into a plurality of partial reference patterns, and the synchronization pattern of the transmission frame is obtained by multiplying each of the partial reference patterns by a predetermined code. 6. The spread spectrum communication apparatus according to claim 5, wherein the spread spectrum communication apparatus is configured by combining the above. 11. The taps are grouped corresponding to each partial reference pattern, and a tap value of each tap group is multiplied by a corresponding partial reference pattern of the first symbol matched filter, and the multiplied value is the tap value. 2. The method according to claim 1, wherein the addition is performed over all taps of the group, and the sum is output as the number of pattern matches and used for determining whether synchronization is established.
0 spread spectrum communication apparatus. 12. The receiver judges whether the number of pattern matches from the first symbol matched filter is within a predetermined synchronization establishment range, and determines whether the number of pattern matches for all partial reference patterns is the predetermined number. The spread spectrum communication according to claim 11, further comprising a threshold value judging / pattern demodulator for judging that synchronization is established when it is determined that the synchronization is within a synchronization establishment range and outputting a synchronization trigger. Machine. 13. The synchronization establishment range is a range that is equal to or greater than a predetermined upper threshold value set near a maximum value or equal to or smaller than a predetermined lower threshold value set near a minimum value. A spread spectrum communication device as described. 14. The threshold decision / pattern demodulator according to claim 1,
If each pattern match is above the upper threshold,
14. The spread spectrum communication apparatus according to claim 13, wherein a different code is output when the number of matching patterns is equal to or smaller than the lower threshold. 15. A combination of codes corresponding to the total number of pattern matches output from the threshold value judging / pattern demodulator is input as a recognition pattern, and the second symbol matched filter is input based on the input recognition pattern. 15. The spread spectrum communication apparatus according to claim 14, wherein a reference pattern is set.