JPH10107684A - Spread spectrum communication method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the spread spectrum communication by which a plurality of bits per frame are transmitted even when a clock signal at a transmitter side is not in matching with a clock signal at a receiver side. SOLUTION: A delay time t1 is decided in response to digital data in 5-bit. A frame signal PN2 is outputted in a delay of t1 sec after a frame signal PN1 is outputted. Moreover, other delay time t2 is decided based on digital data in a succeeding 5-bit. Then a frame signal PN3 is outputted with a delay of t2sec. At a receiver side, the delay times t1, t2 are converted into the original digital data, and then a plurality of bits per frame are transmitted in this communication method.

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 method and a communication apparatus employing the method. In particular, the present invention relates to a direct spread spectrum spread spectrum communication method and apparatus.

[0002]

2. Description of the Related Art Spread spectrum communication is a communication method in which a signal is spread over a band wider than the frequency bandwidth of data to be transmitted and transmitted, and is resistant to interference, has signal confidentiality, and has high resolution measurement. It has the advantage that it can be distanced. Spread-spectrum communication is used in areas such as satellite communication and land-based communication, and in recent years it has been expected to improve the efficiency of frequency utilization and coexist with existing systems. The application of is progressing.

[0003] Typical methods for realizing spread spectrum communication include a direct sequence (DS) method and a frequency hopping (FH) method. The DS method spreads an occupied frequency band by directly modulating spread code pulses onto data modulated by a carrier wave. On the other hand, the FH method uses a wide occupied frequency band by switching (ie, hopping) the carrier frequency of modulated data according to a spreading code pulse.

[0004] In the spread spectrum communication system of the DS (Direct Spreading) system, communication is classically performed as follows.

For example, when data to be transmitted is digital data, the value of which is represented by "1" or "0" and a PN code sequence is used as a spread code sequence,
Spread modulation is performed by multiplying digital data by a PN code. Specifically, in order to transmit one bit of digital data in one cycle of the PN code, one cycle of the PN code is multiplied by one bit (either “0” or “1”) of the digital data. It is. One cycle of the PN code is called one frame.

As a result, when the digital data to be transmitted is "1", the phase of the PN code is maintained as it is, and when the digital data is "0", the polarity of the PN code is inverted. is there.

On the receiving side, the original digital data "0" or "1" is restored depending on whether or not the polarity of the PN code of this one frame (one cycle of the PN code sequence) is inverted. Specifically, on the receiving side, the determination is made based on whether the peak signal is positive or negative when the position of one frame included in the received signal is detected by the matched filter.

As described above, in the conventional spread spectrum communication method, one bit of digital data is transmitted in one frame.

However, in such a classic spread spectrum communication system, since only one bit of digital data is transmitted in one frame time, there is a problem that transmission efficiency is poor. To solve this problem, various proposals have been made for transmitting a plurality of bits of digital data in one frame.

FIG. 5 is a diagram illustrating various measures for transmitting digital data of a plurality of bits in one frame.

First, there has been proposed a technique in which a PN code included in one frame is cyclically rotated to express a data value. Here, rotation means a so-called rotation. As described above, Japanese Patent Application Laid-Open No. 4-273632 discloses a technique in which a PN code is rotated cyclically in one frame to represent a plurality of bits of digital data by the amount of rotation and to transmit a plurality of bits. (Hereinafter referred to as Document A) and Japanese Patent Application Laid-Open No. 7-46222 (hereinafter referred to as Document B). Document A shows a polyphase spreading section 12 on the transmitting side to rotate the PN code cyclically, and FIG. 2 of Document A shows a detailed block diagram of this polyphase spreading section. I have. Document A also shows that the receiving side is provided with a cyclic matched filter 16 for detecting the phase of the PN code (detecting the amount of rotation) in addition to the synchronous detection matched filter 17 for obtaining frame synchronization. Have been. FIG. 3 of Document A shows a detailed configuration diagram of this recursive matched filter. Also, in Document B, since multiple bits of data are transmitted in one cycle of the PN code, P is determined according to the combination of the multiple bits of data.
It is shown that only the phase of the N code is shifted and transmitted as a spread spectrum signal ("000" in Document B).
7 "). Information data 2 is included in “0009” of Document B.
Bit combination "11""10""01""00"
It is described that the PN code is delayed by a predetermined amount in the above four cases.

It is also conceivable to shift the center position of the PN code included in one frame, instead of rotating it cyclically. Such a technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-79133 (hereinafter referred to as Document C). According to the communication method disclosed in Document C, in addition to performing 1-bit data communication in one frame by a normal spread spectrum communication method using the DS system, the center position of the PN code word in one frame is set to 8 bits. By changing among the eight positions, eight signal states are available. As a result, according to the technique described in this document C, it is shown that three additional bits are carried.

[0013]

In the examples shown in the above three types of documents, the length and position of one frame are constant in any of the examples. By detecting a change in the phase of the PN code in one frame, transmission of a plurality of bits of digital data is realized in one frame. For example, in Document C, additional bits are transmitted by detecting how much the center position of the PN code is shifted from the original position of one frame. Therefore, the above 3
In any of the techniques described in the literatures, the clock on the transmitting side and the clock on the receiving side need to completely match each other. To match this clock, for example, Document A describes that a PN code for synchronization is transmitted. It should be noted that this reference B or C does not specifically mention this synchronization. However, Document B
It is self-evident that frames need to be synchronized also in C and C.

As described above, in the conventional spread spectrum communication system, it is necessary to always secure synchronization of one frame between the transmitting side and the receiving side. Since it is necessary to detect the phase, there is a problem that the entire apparatus becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a communication method capable of transmitting a plurality of bits of digital data in one frame, wherein the communication between the transmitting side and the receiving side does not need to be synchronized. Is to provide a way.

[0016]

According to a first aspect of the present invention, in order to solve the above-mentioned problems, a spread code sequence having a predetermined period is used, and the spread modulation sequence corresponding to one period of the spread code sequence is used. In a spread spectrum communication method for sequentially transmitting a frame signal as a signal, a time conversion step of converting a value of data to be communicated into a time length, and the frame signal is temporally preceding the frame signal. And delaying the other frame signal by a predetermined time, wherein the predetermined time includes a time delay amount adding step which is an amount of time converted in the time conversion step.

In the present invention, since data is represented by a time difference between occurrences of frames, data of a plurality of bits can be transmitted per frame.

According to a second aspect of the present invention, there is provided a spread spectrum communication method according to the first aspect, wherein
The time conversion step is a spread spectrum communication method, wherein the value of the data is converted into a time length in units of a code chip time.

It is preferable that the difference (delay amount) between the occurrence times of the respective frames is performed in units of the code chip time.

According to a third aspect of the present invention, there is provided a spread spectrum communication method according to the first aspect, wherein
The time conversion step includes a time length conversion step of converting the value of the data into a time length, and an offset addition step of adding a predetermined offset time to the time converted in the time length conversion step. It is characterized by.

By giving the delay time an offset, the delay time can be set to a value equal to or longer than a predetermined time.
As a result, the number of superimposed and transmitted frames can be suppressed to a certain value or less.

According to a fourth aspect of the present invention, there is provided a spread spectrum communication method according to the third aspect, wherein
The offset addition step is a spread spectrum communication method, characterized in that at least half of a time length of the frame signal, which is a cycle of the spread code sequence, is added as the offset time.

Since at least one half of the frame period is used as the offset time, the number of superimposed and transmitted frames can be suppressed to at most two.

According to a fifth aspect of the present invention, there is provided a spread spectrum communication method according to the fourth aspect, wherein
The time delay adding step includes a first frame signal outputting step of starting outputting a first frame signal after a lapse of the time converted in the time converting step after output of a predetermined other frame signal is started. A second frame signal that starts outputting the second frame signal after a lapse of the time converted in the time conversion step after the output of the first frame signal is started in the first frame signal generation step Generating the second frame signal, wherein the predetermined other frame signal is a second frame signal temporally preceding the first frame signal in the second frame signal generating step. Is the way.

According to the present invention, frames are generated alternately using two processes, so that the delay time between frames can be set efficiently.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problem, a spread code sequence having a predetermined period is used to sequentially receive a signal corresponding to one period (one frame) of the spread code sequence. In the spread communication method, a frame arrival time detecting step of detecting a time at which the frame signal is received, a time interval calculating step of calculating a time interval of arrival times of frames temporally adjacently detected, and the time interval Converting data into corresponding data,
It is characterized by including.

According to the present invention, the arrival time of each frame is stored, and the original data can be demodulated from the difference between the arrival times. Therefore, data of a plurality of bits can be efficiently received in one frame time.

According to the seventh to twelfth aspects of the present invention,
To the sixth invention are represented as an apparatus, and the essential operation is the same as that of the first to sixth inventions.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a timing chart showing the timing of transmitting and receiving a frame signal in the spread spectrum communication method according to the present invention. First, FIG.
(A) shows at what timing a frame signal is transmitted in the present embodiment.

A feature of the present embodiment is that digital data to be transmitted is represented by a time difference between temporally adjacent frame signals. As shown in FIG. 1A, the frame signal PN2 is transmitted t1 seconds after the transmission of the frame signal PN1. On the receiving side, an occurrence time difference (t1) between the frame signal PN1 and the frame signal PN2.
, The original digital data is restored from this length of time.

The frame signal PN1 and the frame signal PN
In order to detect an occurrence time difference (t1) with respect to 2, it is preferable to detect an interval between peaks of a matched filter output. FIG. 1B is a time chart schematically showing an output signal of the matched filter on the receiving side. By detecting the time interval between the peak signals of the matched filter output, it is possible to detect the time difference (t1) between the frame signal PN1 and the frame signal PN2.

Similarly, the next digital data is represented by the time difference between the frame signal PN2 and the frame signal PN3. The frame signal PN2 and the frame signal PN
The next digital data can be restored on the receiving side from the time difference (t2) with respect to 3.

As described above, in the spread spectrum communication method according to the present embodiment, unlike the conventional spread spectrum communication method as shown in FIG. Are transmitted with an overlap. However, since the spread code sequence has a certain degree of orthogonality, even when signals are transmitted with some overlap, each frame signal (PN1, PN2, PN
It is possible to distinguish 3).

Further, the partial correlation value of the portion where the code overlaps is sufficiently smaller than the in-phase autocorrelation value, and does not cause much problem in the demodulation process.

The frame signal PN1 and the frame signal P
The time difference t1 from N2 is preferably set to be shorter than the length of the frame signal (that is, one cycle of the spread code sequence). However, as shown by the broken line in FIG. It is also possible to make the occurrence time difference larger than one cycle. The frame signal PN2 'in FIG. 1A is generated with a time longer than one cycle of the spread code than the preceding frame signal PN1. Even in the case where the delay occurs longer than one cycle as described above, the original digital data can be restored by detecting the peak of the output of the matched filter.

The time differences t1, t as shown in FIG.
2 and the like are times in units of the code chip time. For example, in order to transmit 5-bit digital data with one delay time amount (t1 or t2), the delay time amount is set so that 32 types of delay time lengths can be selected. Therefore, one code (codeword) of the spread code sequence that forms the basis of the frame signal needs to include 32 or more code chip times. The code chip time included in the spread code, the number of bits of digital data that can be represented by one delay time amount, and the like are appropriately selected according to the purpose and application of the communication method.

In FIG. 1, the delay times t1 and t2
Is expressed as the time difference between the first bits of each frame signal, but the amount of delay time may be determined with reference to any chip of the PN code. As shown in FIG. 1, it may be the first chip or the last chip of the frame signal.

Further, one time delay amount (for example, t1) is 5
In the case of expressing digital data of bits, 32 kinds of delay times are required as described above. For example, as the 32 types of lengths, it is conceivable to employ a delay time amount of 1 to 32 with the code chip time as a time unit. In this manner, the digital data to be transmitted is divided into 5 bits, and the amount of delay time proportional to the value of the 5 bits is determined by each frame signal (PN1, PN2, etc.).
In this case, digital data of a plurality of bits can be transmitted in one frame period, which contributes to improvement of transmission efficiency.

In the above example, the length of time from 1 to 32 in units of the code chip time is selected as the amount of delay time for 5-bit digital data. However, when the amount of the delay time becomes very short, the number of frame signals to be superimposed and transmitted at the same time increases. For example, when the amount of delay time (such as t1) is approximately の of the period of the spread code sequence, the number of frame signals transmitted in an overlapping manner is about 2 (+1 on the correlator).
However, the same applies to the following description). However, when the value of the delay time amount becomes about 1/3 of the period of the spread code sequence, the number of frames transmitted in an overlapping manner becomes about three. Therefore, when the delay time corresponding to 5 bits cut out from the data to be transmitted is small, the overlap of the frame signals increases, and the reception state greatly varies depending on the value of the data.

Therefore, it is preferable to provide a predetermined offset time in the amount of delay time (such as t1) in order to reduce fluctuations in the reception state and realize stable reception. For example, the offset time is 1 / of the period of the spreading code sequence.
If the time of 2 is used, the time difference between the generation of the frame signal PN1 and the generation of the frame signal PN2 is always equal to or more than の of the period.

The transmitter and as described on the receiver configuration, the delay time amount of offset is added to the number of the frame signal to be transmitted overlap at most 2
FIG. 2 is a block diagram showing the configuration of the transmitter when the number is one. As shown in the figure, digital data to be transmitted is first supplied to a serial / parallel converter 10 and converted into a 5-bit parallel signal. The parallel signal for every 5 bits is supplied to the code generator 12. As shown in FIG. 2, the code generator 12 includes two code generators 12a and 12b.
These two code generators 12a and 12b are independently operable code generators. In the present embodiment, the code generator 12 includes two code generators 12a and 12a.
The reason for having b is that the number of frame signals transmitted in an overlapping manner is at most two. That is, each of the code generators 12a and 12b operates independently, and independently generates one frame signal. The frame signals generated independently by the code generators 12a and 12b are added in an adder 14, and a superimposed signal is output. The signal on which the plurality of frame signals are superimposed is multiplied by a predetermined carrier in the multiplier 16 and converted into a radio signal in a desired frequency band in the RF unit 18. Thus, finally, it is radiated into the air at the antenna 20.

A characteristic of the transmitter shown in FIG. 2 is that the code generator 12 has two code generators 12a,
12b. These code generators 12
Reference numerals a and 12b denote outputs of the frame signal delayed by a time corresponding to the supplied 5-bit digital signal. FIG. 3 is a block diagram showing the configuration of the code generators 12a and 12b.

FIG. 3 shows the code generator 12.
FIG. 4 is a block diagram showing the configuration of A, and the same applies to the configuration of the code generator 12b.

First, the adder 30 adds the 5-bit digital data supplied to the code generator to a predetermined offset. This offset is the offset generator 3
2 is generated. In the present embodiment,
The offset generated by the offset generator 32 is set to の of the cycle of the spread code sequence. in this way,
Since the offset is half of the period, the number of frame signals output by superposition is at most two, and two code generators are sufficient as described in FIG.

The output of the adder 30 is supplied to a comparator 34. The comparator 34 compares the input 5-bit data with the output signal of the timer 36. This timer 36 is a timer that starts counting timers in response to the other (code generator 12b) start signal. The output signal indicates the time since the frame signal was generated in the other code generator.

With such a configuration, the comparator 34
Determines that the output signal of the timer 36 and the output signal of the adder 30 match, outputs a match signal (start signal) to the outside. When the codeword generator 38 detects this coincidence signal, it sequentially generates one frame signal. In other words, the codeword generator 38 is a one-shot frame signal generator. That is, when the codeword generator 38 finishes outputting the frame signal of one frame,
Next, the frame signal is not output to the outside unless the coincidence signal is supplied.

As described above, the code word generator 38 outputs one frame signal based on the coincidence signal from the comparator 34. That is, the coincidence signal indicates the start time of one frame signal. Therefore, this coincidence signal is also a start signal indicating the start of one frame signal. This start signal is supplied to the code generator 12b as a start signal for the other code generator, that is, the code generator 12b.

The code generator 12b has the same configuration as that shown in FIG. 3, and includes a timer 36 for receiving a start signal from the code generator 12a, an offset generator 32, a comparator 34, and the like. A codeword generator 38 for generating one frame signal is provided. The start signal output from the code generator 12b is
In 2a, it is supplied to the timer 36.

As described above, according to the transmitter shown in FIGS. 2 and 3, since the two code generators 12a and 12b are provided, the spread spectrum communication method according to the present invention can be easily realized. It is possible.

The transmitters shown in FIGS. 2 and 3 show an example in which オ フ セ ッ ト of the cycle of the code sequence is used as the offset. However, when the value of the offset is smaller, It is considered that only the code generators 12a and 12b are not enough, and the number of code generators needs to be increased. Further, in the example shown in FIG. 3, the input digital signal is encoded by dividing it into data of every 5 bits, but it is of course preferable to adopt a data width other than 5 bits.

Next, the configuration of a receiver employing the spread spectrum communication method of the present invention will be described. FIG. 4 is a configuration block diagram showing an example of the configuration of such a receiver.

As shown in this figure, the received radio wave is amplified in the RF section 40 and then multiplied by the carrier in the multiplier 42. The carrier is a carrier generation unit 4
4 occurs. As a result, the output signal of the multiplier 42 becomes a signal similar to the output signal of the adder 14 in FIG. However, in the configuration shown in FIG. 4, in order to shape the waveform and reduce data errors,
The processing in the bandpass filter 46 and the processing in the AGC circuit 48 are respectively performed. The output signal of the AGC circuit 48 is supplied to a correlator 50. The correlator 50 is a so-called matched filter, and outputs a predetermined pulse signal when one frame signal is completely input to the correlator 50.

The configuration from the RF unit 40 to the correlator 50 described above is substantially the same as that of the conventional receiver.

Now, the output signal of the correlator 50 should ideally be a pulse signal, but is actually affected by noise and the like, and as shown in FIG. In many cases, the signal is deflected. In order to make this signal easily recognizable, the square detector 52 converts the signal into a pulse on the positive electrode side.

In the spread spectrum communication method according to the present embodiment, the time delay between frame signals represents data to be transmitted. Therefore, it is extremely important to accurately determine the temporal position of the pulse output from the correlator 50. Therefore, the output signal of the square detector 52 is also supplied to the pulse shaping circuit, so that the position of the pulse can be easily detected.

The pulse waveform thus shaped is supplied to the demodulation unit 56. The demodulation unit 56 has a memory for recording the time at which the pulse was input. Then, the delay time between each pulse is calculated from the time at which the pulse is detected. Then, the delay time is converted into the original digital data.

The demodulation unit 56 basically has a memory for storing the time at which a pulse is received, and is basically similar to that of FIG.
Performs the reverse conversion of the code generator shown in FIG. That is, the offset is subtracted from the amount of time delay between each pulse,
The subtracted value is multiplied by the code chip time. The obtained data is the transmitted 5-bit data.

Of course, it is also preferable that the operation of the demodulation unit 56 is realized using a predetermined program and a microprocessor. In this case, the demodulation unit 56 detects the arrival time of the pulse, determines the interval between the program stored in the memory and the time stored in the memory, and decodes the digital data from the time interval, the offset, and the code chip time. And so on.

The receiver shown in FIG. 4 can be used even when the offset time is short unlike the transmitter shown in FIGS. 2 and 3. This is because if the orthogonality of the spreading code sequence is high, one correlator 50 can identify each frame signal.

[0061]

As described above, according to the first aspect of the present invention, the amount of delay time between frame signals is set according to the value of data to be transmitted, and data is expressed by this amount of delay time. ing. Therefore, a plurality of bits can be transmitted in one frame, and it is not necessary to always maintain synchronization with each frame unlike the related art.

As a result, compared to the conventional communication method capable of transmitting a plurality of bits in one frame, the transmission efficiency can be easily improved.

According to the second aspect of the present invention, a time in units of the code chip time is set as the delay time. By using the code chip time as a unit, the receiving side can detect the arrival time of each frame signal using a matched filter having the same configuration as that of the related art. as a result,
It is possible to make the device configuration simpler.

According to the third aspect of the present invention, a fixed offset time is provided for the delay time. Therefore, it is possible to prevent the delay time from becoming too short,
It is possible to keep the number of superimposed frame signals below a certain value. Therefore, it is possible to suppress the rate at which the transmission state / reception state fluctuates depending on the value of data to be transmitted.

According to the fourth aspect of the present invention, at least 1/2 of the time length of the frame signal is used as the offset time. Therefore, the number of superimposed and transmitted frame signals can be suppressed to at most two, and it is possible to prevent fluctuations in the transmission state / reception state.

According to the fifth aspect of the present invention, a frame signal is output in order using two processes. This is because the communication method according to the fourth aspect of the present invention is employed, so that at most two frame signals are superimposed and transmitted. And the timing of outputting the frame signal in the process of the other party is observed,
After a lapse of a predetermined time from the timing at which the frame signal was output in the process on the partner side, the own device also outputs the frame signal.

Although the fifth invention is based on the fourth invention, the frame signal can be generated in two processes in sequence, but more claim signals are superimposed. If there is a possibility that the same process will be transmitted, it is necessary to provide the same processes as many as three or four, which may be transmitted in a superimposed manner.

According to the sixth invention, the arrival time of the frame signal contained in the received spread spectrum signal is detected, and the time interval is obtained. Since the original digital data is restored from the time interval, a communication method capable of efficiently receiving signals transmitted by the first to fifth communication methods according to the present invention is obtained.

The first to seventh embodiments of the present invention
The present invention relates to a transmitter and a receiver for realizing the communication method according to the present invention from the sixth to the sixth inventions, and the effects are essentially the same as those of the first to the sixth inventions.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the principle of the present invention.

FIG. 2 is a configuration block diagram of a transmitter for spread spectrum communication according to the present invention.

FIG. 3 is a configuration block diagram illustrating a configuration of a code generator 12a in FIG.

FIG. 4 is a configuration block diagram of a receiver of the spread spectrum communication method according to the present embodiment.

FIG. 5 is an explanatory diagram showing a conventional technique of spread spectrum communication capable of transmitting a plurality of bits in one frame.

[Explanation of symbols]

10 serial / parallel converter, 12 code generator,
12a, 12b code generator, 14 adder, 16 multiplier, 18 RF section, 20 antenna, 30 adder, 3
2 offset generator, 34 comparator, 36 timer, 38 codeword generator, 40 RF section, 42 multiplier, 44 carrier generation section, 46 bandpass filter,
48 AGC circuit, 50 correlator, 52 square detector,
54 pulse shaper, 56 demodulation unit.

Claims (12)

[Claims] 1. A spread spectrum communication method for sequentially transmitting a signal (hereinafter referred to as a frame signal) corresponding to one cycle (one frame) of the spread code sequence using a spread code sequence having a predetermined cycle. A time conversion step of converting the value of the target data into a time length, and a step of delaying the frame signal by a predetermined time with respect to another frame signal temporally preceding the frame signal, A time delay adding step, wherein the predetermined time is an amount of time converted in the time converting step, and a spread spectrum communication method. 2. The spread spectrum communication method according to claim 1, wherein said time conversion step converts the value of said data into a time length in units of a code chip time. . 3. The spread spectrum communication method according to claim 1, wherein the time conversion step comprises: a time length conversion step of converting the data value into a time length; and a time converted in the time length conversion step. And a offset addition step of adding a predetermined offset time to the spread spectrum communication method. 4. The spread spectrum communication method according to claim 3, wherein the offset adding step adds at least 1/2 of a time length of the frame signal, which is a cycle of the spread code sequence, as the offset time. Characteristic spread spectrum communication method. 5. The spread-spectrum communication method according to claim 4, wherein the time delay adding step includes the step of adding a time delay after a lapse of the time converted in the time converting step from the start of output of another predetermined frame signal. A first frame signal output step of starting output of one frame signal; and a time lapse converted in the time conversion step after the output of the first frame signal is started in the first frame signal generation step A second frame signal generating step of starting output of a second frame signal later, wherein the predetermined other frame signal temporally precedes the first frame signal in the second frame signal generating step. Spread spectrum communication method, wherein the second frame signal is a second frame signal. 6. A spread spectrum communication method for sequentially receiving a signal corresponding to one cycle (one frame) of the spread code sequence by using a spread code sequence having a predetermined cycle, wherein a time at which the frame signal is received is determined. A frame arrival time detecting step of detecting, a time interval calculating step of calculating a time interval between arrival times of frames detected temporally adjacent to each other, and a data restoring step of converting the time interval into corresponding data. A spread spectrum communication method, comprising: 7. A spread spectrum communication apparatus for sequentially transmitting a signal corresponding to one cycle (one frame) of the spread code sequence using a spread code sequence having a predetermined cycle, wherein a value of data to be communicated is Time conversion means for converting to a length of time; and means for delaying the frame signal by a predetermined time with respect to another frame signal temporally preceding the frame signal, wherein the predetermined time is the time conversion. A time delay amount adding unit that is a time amount converted by the unit. 8. The spread spectrum communication apparatus according to claim 7, wherein said time conversion means converts said data value into a time length in units of a code chip time. . 9. The spread spectrum communication apparatus according to claim 7, wherein said time converting means comprises: a time length converting means for converting said data value into a time length; and a time converted by said time length converting means. And a offset adding means for adding a predetermined offset time to the spread spectrum communication apparatus. 10. The spread spectrum communication apparatus according to claim 9, wherein said offset adding means adds at least 1/2 of a time length of said frame signal, which is a cycle of said spread code sequence, as said offset time. Spread spectrum communication equipment. 11. The spread spectrum communication apparatus according to claim 10, wherein said time delay amount adding means is configured to output the time delay after a lapse of time converted by said time converting means from the start of output of another predetermined frame signal. First frame signal output means for starting output of one frame signal; and elapse of time converted by the time conversion means after output of the first frame signal is started by the first frame signal generation means. And a second frame signal generating means for starting output of a second frame signal later, wherein the predetermined other frame signal is a second frame signal in the second frame signal generating means. Spread spectrum communication device. 12. A spread spectrum communication apparatus for sequentially receiving a signal corresponding to one cycle (one frame) of the spread code sequence by using a spread code sequence having a predetermined cycle. A frame arrival time detecting means for detecting, a time interval calculating means for calculating a time interval between arrival times of frames detected temporally adjacent to each other, and a data restoring means for converting the time interval into corresponding data. A spread spectrum communication apparatus characterized by including: