JP2987720B2 - Spread spectrum communication method - Google Patents

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 for transmitting a predetermined PN sequence to a transmission line, and transmitting the PN sequence to the transmission line in accordance with a state value of information data to be transmitted. .

[0002]

2. Description of the Related Art Conventionally, in a local area network system, a home control system, and the like, in which a transmission line is laid in a building to transmit an information signal or a control signal, the cost of laying the transmission line is reduced. In order to do so, it has been considered to use a power line or the like already laid in a building as a transmission line for communication. Conventionally, impedance characteristics and the like have not been taken into account as such a communication line, and a communication method suitable for use in a circuit having a lot of noise is NEC Technical Report vo1.42 NO.9 / 1989:
C as described in "High performance SS power line modem"
A spread spectrum communication method called the SK method has been developed. In this communication method, as shown in FIG. 7, the modulators T are PN sequences PN having the same period length and a small correlation value.
₀ and PN ₁ are prepared respectively. When the status value of the information data to be transmitted is “0”, the PN sequence PN ₀ is used. When the status value of the information data to be transmitted is “1”, the PN sequence PN ₀ is prepared. PN
It sends the sequence PN ₁ to power line 1. On the other hand, the demodulation device R comprises a PN sequence generator G _R1 to generate the PN sequence PN ₀ PN sequence generator G _R0 to generate the same PN sequence and, and the PN sequence PN ₁ with the same PN sequence , A correlation value between the output signal of the PN sequence generator G _R0 and the received signal is calculated using a correlator H _0, and a voltage corresponding to the calculated value is output. comparator C _r is the reset state "0" to the RS flip-flop 2 in the case of exceeding the _a [V]. Similarly, the correlation value between the output signal of the PN sequence generator G _R1 and the received signal is obtained using the correlator H ₁ , and when the correlation value exceeds the reference voltage V _a [V], the comparator C _s Sets the RS flip-flop 2 to the set state "1" to obtain the original information data from the output terminal of the RS flip-flop 2.

For example, when the modulator T sequentially transmits the PN sequence PN ₀ or PN ₁ corresponding to each state value of the information data “110...” Of the bit length _Ta [s] to the power line 1, the demodulator R correlator H ₀ outputs the correlation peak waveform at the third cycle as shown in FIG. 8 (a), also correlator H ₁
Since outputs the correlation peak waveform at the first and second periods, respectively, as shown in FIG. 8 (b), demodulator R correlator H ₀ and either side of the output voltage level of the reference voltage of an H ₁ By detecting whether V _a [V] has been exceeded, the original information data “110...” Can be demodulated. Therefore, according to this communication method, the transmission signal of the modulation device T is affected by the transmission characteristics of the power line or the like, and the correlator H _0.
And H ₁ even if the output waveforms are distorted, if a correlation peak can be detected from the output waveform of each correlator, the demodulator R
Can obtain the original information data, so that a power line or the like that is not originally intended for communication can be used as a communication transmission line.

However, in this communication method, a large delay deviation and a large amplitude deviation occur in the transmission characteristics of a transmission line such as a power line, and the correlation is originally required at the first and second periods as shown in FIG. When the level of the correlation peak waveform to be output from the demodulator is deteriorated as shown in FIG. 8 (c), the difference between the level of the correlation peak waveform and the level of the other waveforms becomes small. It is very difficult to detect the presence or absence of the correlation peak waveform, and there is a problem that the communication error rate increases.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem of the spread spectrum communication method. A large delay deviation and amplitude deviation occur in the transmission characteristic of a transmission line, and the correlation of the output waveform of a correlator is obtained. An object of the present invention is to provide a spread spectrum communication method capable of increasing the communication error rate and demodulating the original information data by increasing the communication error rate even if the difference between the level of the peak waveform and the level of the other waveforms is small. I do.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is configured as follows. That is, after outputting a predetermined PN sequence for a required period, a means for performing communication using a spread spectrum signal modulated so as to output the PN sequence corresponding to a state value of information data to be transmitted,
The same PN sequence as the modulating side and the location transmitted from the modulating side
To determine the arrival of the received signal by a periodic signal corresponding to the signal speed of the information data extracted from the correlation signal between the main period of the PN sequence, the information data received via the transmission path
Of the required period transmitted from the modulation side before transmitting the
The PN sequence is stored in a memory, and in the subsequent data demodulation, a correlation value is obtained using the PN sequence in the memory.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing an embodiment of a modulator and a demodulator according to the spread spectrum communication method of the present invention. In the figure, T is a modulator,
PN having a small correlation value and a period length of, for example, 31 bits
PN sequence generator G _{TO for} generating sequences PN ₀ and PN _{1 respectively}
And comprising a G _T1, when the bit rate is 300 PN sequences PN ₀ in the case of the state value of the transmission information data to be a [b / s] is "0", and the status value is "1" and performs spread spectrum modulation by sending a PN sequence PN ₁ respectively power line 1. That is, the modulator T
Supplies to the control terminal of the switch S ₁ via the synchronizing circuit 4 information data is supplied to the control terminal of the switch S ₂ a transmission request signal RS through the timing generator CL _A. Further, the timing generator CL _A is 9.3 [kHz].
And a clock signal of 300 [Hz] which is the same as the bit rate of the information data synchronized with the clock signal, and supplies the clock signal of 300 [Hz] to the clock input terminal of the synchronization circuit 4. At the same time, the 9.3 [kHz] clock signal is supplied to each clock input terminal of the PN sequence generators G _TO and G _T1 . Furthermore,
Modulator T is the terminal c connected to the output terminals of the PN sequence generator G _TO and G _T1 of each switch S ₁ to the terminal a and b
The well as connected to a terminal d of the switch S _2, and connected to the power line 1 to the terminal e through an amplifier 5 and transformer 6, it is configured to deliver a spectrum spread signal from the terminal e.

On the other hand, R is a demodulation device, which is a PN sequence generator G _R0 for generating the same PN sequence as the PN sequence PN ₀ and a PN sequence generator G _R1 for generating the same PN sequence as the PN sequence PN _1. A signal received through the power line 1 is converted into a transformer 7, an amplifier 8 and a pass band 1
A / A through a band-pass filter 9 of ~ 9.3 [kHz]
It is supplied to the input terminal of the D converter 3. Further, the output signal of the A / D converter 3 is output to the correlators H ₀ , H ₁ and the synchronous addition circuit 1.
The output terminal of the synchronous adding circuit 10 is supplied to the input terminals as well as connected to the input terminals of the memory M ₀ and M ₁ 0, wherein the respective output terminals of the memory M ₀ and the PN sequence generator G _R0 The other input terminal of the correlator H _{0 and} the memory M ₁
And each output terminal of the PN sequence generator G _R1 is connected to the other input terminal of the correlator H ₁ . Further, the demodulator R connects the output terminals of the clock oscillator CL _B for generating a clock signal of 18.6 [kHz] to the correlators H ₀ , H ₁ and A.
/ D is connected to the clock input terminals of the converter 3, the output terminals of the switches S ₃ and S ₄ comprises a respective correlator terminal g of the terminals f and the switch S ₄ of the switch S ₃ H ₀ and H ₁ And the terminal h of the switch S ₃ is connected to the square circuit 11,
With respectively connected to one input terminal of the adder 13 and the comparator 14 via a high pass filter 12 than the cut-off frequency is 300 [Hz], the terminal i of the switch S ₃ to the input terminal of the low-pass filter 12 Connecting.
Further, the switch S ₄ terminals j the square circuit 15, with respectively connected to the other input terminal of the adder 13 and the comparator 14 via a high pass filter 16 than the cut-off frequency is 300 [Hz] , the terminal k of the switch S ₄
Is connected to the input terminal of the low-pass filter 16. Furthermore, the demodulation device R wherein each supplying an output signal of the adder 13 to one control terminal of the input terminal and the clock oscillator CL _B of the timing extraction filter 17 via the processing circuit 18, in the said processing circuit 18 The original information data is output from the output signal of the comparator 14 and the output signal of the timing extraction circuit 17, and the output signals of the adder 13 and the timing extraction circuit 17 are supplied to the carrier detection circuit 19, respectively, and the output terminal From the carrier detection signal CD.

[0009] The spread spectrum signal thus configured
Operate as follows. Destination
The modulator T transmits the transmission request signal RS to the timing generator.
CL_A To switch S_Two Terminal e to terminal d
And the timing generator CL_A And make
This timing generator CL_A PN sequence generator based on
G_T0And G_T1 From each PN series PN₀ And PN₁ Each
1 bit per 1/9300 [s]
Close. And then switch S₁ Terminal c to terminal a
Then PN series PN₀ Is the first bit for 60 periods, for example.
From the power line 1 repeatedly, and then switch S₁ 
Of the PN series PN₁ For 60 cycles
The signal is repeatedly transmitted to the power line 1 sequentially from the first bit. So
After that, the modulator T converts the information data to be transmitted to a synchronization circuit.
4 and the timing generator CL_A Occurs 300
Every 1/300 [s] based on a clock signal of [Hz]
To the switch S sequentially.₁ Supply to
I do. Also, switch S₁ Is for each bit of the information data
If the state value is "0", the switch S₁ Terminal c
Connect to terminal a, and if the status value is "1", connect to terminal b
PN series PN of one cycle by connecting₀ Or PN₁ The beginning
The bits are transmitted to the power line 1 sequentially from the bit. Where the modulator
T is a PN sequence PN as shown in FIG.₀ To light line 1
Considering the case of transmission, the PN as shown in FIG.
Series PN₀ Will be transmitted to the power line 1.
However, the signal arriving at the demodulation side is affected by the transmission characteristics.
The one whose amplitude and phase are deformed as shown in FIG.
Becomes The modified signal at this time and the PN sequence PN₀ When
3 shows the correlation peak waveform level as shown in FIG.
Of the correlation peak waveform and other waveforms.
The bell difference is small and the original
Data is difficult to obtain. Also, the PN series PN₁ About
It is the same as above.

Next, the operation of the demodulator R according to the present invention will be described below. First, the demodulation device R is connected to the switch S ₃ terminals f and the switch S ₄ terminals g respectively terminals h and the terminal j using a control means (not shown) prior to receiving the transmission signal modulation unit T Together with the clock oscillator CL
Make _B work. Thereafter, the demodulation device R transmits the data 60 before the modulation device T supplies the information data to the synchronization circuit 4.
When the PN sequence PN _{0 having a} period and the PN sequence PN ₁ having a period of 60 are sequentially received as shown in FIG. 4A, the received signal is amplified to a required level by using an amplifier 8 and a filter 9. Remove unnecessary signal components. Also shows the amplitude value of the output signal of the A / D converter 3 based on the clock signal of the clock generator CL _B using 1/18600 [s] for each filter 9, for example, in FIG. 2 (c) As shown in FIG.
_{0 to} DA ₆₁ and the correlator H
₀ and using H ₁ a correlation value between the output signal of the sampling data and the PN sequence generator G _R0 and G _R1 respectively seeking, correlator H ₀ is the received signal, as shown in FIG. 4 (b) 1
In the period from the cycle to the 60th cycle, a correlation waveform is output as shown in FIG. Further, the correlator H ₁ also outputs a similar correlation waveform at the 61 th cycle to 120 th cycle of the received signal as shown in FIG. 4 (c). Further, the demodulator R squares the output signals of the correlators H ₀ and H ₁ by squaring circuits 11 and 15, respectively, and smoothes them by low-pass filters 12 and 16, as shown in FIGS. 4 (d) and 4 (e). As shown in FIG.
A correlation peak waveform having a higher level than the correlation peak waveforms shown in (b) and (c) is output, and the output signals of the low-pass filters 12 and 16 are added using the adder 13 and FIG. 4 is generated from the output signal of the adder 13 using the timing extraction circuit 17 as shown in FIG.
A signal component of 300 [Hz] as shown in (g), that is, a signal component of the same data rate as the information data is extracted, and the adder 1 is extracted by using a carrier detection circuit 19.
3 and from each output signal of the timing extraction circuit 17,
When the level of the signal of 00 [Hz] continuously exceeds a predetermined value for, for example, 20 [ms], it is determined that the signal is transmitted from the modulation device T. The demodulator R compares the output signal levels of the low-pass filters 12 and 16 with each other using a comparator 14. If the output signal level of the low-pass filter 12 is higher than the output level of the low-pass filter 16, the comparator R When the output level of the low-pass filter 16 is large, the comparator 14 outputs the signal of the state value "1", and the comparator 14 outputs the signal of the state value "1". And generate
Using the processing circuit 18, the state value of the output signal of the comparator 14 when the output signal of the timing extraction circuit 17 is 0 [V] is output from the processing circuit as shown in FIG. From the state value, the received signal is converted to the PN sequence PN ₀ or PN
Determining any _one of the.

The demodulation device R determines, using the carrier detection circuit 19, that a signal is being transmitted from the modulation device T, and determines that the received signal is a PN sequence PN ₀ by the output of the processing circuit 18. After the determination from the signal, the timing extraction circuit 17 is controlled by using a control means (not shown).
The output signal is 0 [V] on the basis of the timing for generating by which the clock signal of the clock generator CL _B, also the output signal of the A / D converter 3, i.e., sampling data DA ₀ of the PN sequence PN ₀ To DA ₆₁ are sequentially input to the synchronous addition circuit 10 over a predetermined M period from the first bit, and the sampling data is sequentially added every period of the PN sequence PN ₀ . This synchronous addition circuit 1
0 is for removing random noise contained in the received signal, and its principle is described in the literature: Shinji Ozawa, "Digital Signal Processing," PP. 114-121, which is described in Practical Textbook of Engineering Science and Engineering, so the description is omitted, but by using the synchronous addition circuit, the S / N can be reduced to 10 logM [dB].
Can be improved. Thus, the demodulation device R sequentially stores the sampling data DA _{0 to} DA _{61 from} which noise has been removed in the memory M ₀ as a PN sequence PN ₀ ^′ , and then uses a PN sequence generator using control means (not shown). The supply of the output signal of G _R0 to the correlator H ₀ is stopped, and the memory M
_While supplying the PN sequence PN ₀ ^′ in ₀ to the correlator H ₀ ,
Connecting terminal f of the switch S ₃ to the terminal i. Further, after that, the demodulation device R sets the modulation device T to the PN sequence PN of 60 cycles.
Also, when it is determined from the output signal of the processing circuit 18 that ₁ has been transmitted, the sampling data DB _{0 to} DB ₆₁ of the PN sequence PN ₁ from which noise has been removed using the synchronous addition circuit 10 as described above are converted to the PN sequence PN. ₁ ^' as sequential memory M
After allowed stored in _1, stop using the control means not shown to supply the output signal of the PN sequence generator G _R1 to the correlator H _1, connects the terminal g of the switch S ₄ to the terminal k I do.

Thereafter, the modulation device T sets the PN of the 60 cycle
Series PN₁ After sending out, for example, as shown in FIG.
One cycle PN sequence PN₀ And information data "110"
PN sequence PN corresponding to each state value of "..."₁ , PN₁ , P
N₀ ,... To the power line 1 sequentially, the demodulation device R
Using the A / D converter 3 as described above, FIG.
As shown, the amplitude value of the received signal is changed every 1 / 1,600 [s].
Sequential data D (1)₀ Or D (1)₆₁, D (1)₀ Or
D (1)₆₁, D (1)₀ Or D (1)₆₁, D (0)₀ No
To D (0)₆₁As sampling. Also, the correlator H₀ 
And H₁ And the memory M
₀ PN sequence PN as shown in FIG.₀ ^' And memory
M₁ PN sequence PN as shown in FIG.₁ ^'Correlation with
Find the value for each. Here, the memory M₀ PN sequence PN within
₀ ^'Is the PN sequence PN transmitted by the modulator T as described above.₀ 
The received signal corresponding to is sampled using the A / D converter 3.
Ringed data DA₀ Or DA₆₁And data
TA DA₀ And D (0)₀ , DA₁ And D (0)₁ …… DA₆₁
And D (0)₆₁Are the transmission characteristics of the power line 1 with each other.
Same if not fluctuating, and memory M₁ PN sequence within
PN₁ ^'The same holds for the correlator H₀ Is the figure above
4 (d), the correlation peak waveform is higher than the correlation peak waveform.
Correlation with far greater level difference between waveform and other waveforms
As shown in FIG. 5 (e), the peak waveform
Occurs in the fourth cycle. Similarly, the correlator H₁ FIG. 5
In the second and third cycles as shown in FIG.
Outputs a correlation peak waveform. The demodulator R is a modulator.
T is the PN sequence PN of the 60 periods.₁ Sent that on
After the determination using the processing circuit 18 as described above, the comparison
Output of low-pass filters 12 and 16 using a filter 14
The signal levels are compared with each other and using the processing circuit 18
The output of the timing extraction circuit 17 as shown in FIG.
State value of the output signal of the comparator 14 when the force signal is 0 [V]
Is output from the processing circuit as shown in FIG.
First, the PN sequence PN₀ To detect that
Then, the signal transmitted by the modulation device T thereafter becomes the aforementioned information.
The PN sequence according to the status value of the broadcast data
After that, the original information data is
Are demodulated.

Therefore, according to this communication method, a large delay deviation and a large amplitude deviation occur in the transmission characteristics of a transmission line such as a power line, and the conventional communication method has a large communication error rate when demodulating the original information data. Even so, on the demodulation side, the level difference between the correlation peak waveform obtained by each correlator and the other waveforms can be increased, and the original information data can be demodulated normally. Even if the transmission characteristics of the transmission path fluctuate, the data in the memory and the sampling data of the received signal have different amplitude values, but the number of data having different polarities is small. Can be made much smaller than in the conventional method, and the data error rate when demodulating the original data can be reduced.

In the above-described embodiment, when the transmission characteristic of the transmission line gradually changes with time, such as a distribution line,
Before transmitting a PN sequence corresponding to information data to be transmitted every time communication is performed, PN sequences PN ₀ and PN ₁ having a predetermined period are transmitted.
In order to update the data in the memories M ₀ and M ₁ . In the above-described embodiment, when the attenuation of the transmission line is large and the received signal level is lowered, the demodulation side normalizes the signal obtained by synchronously adding the sampling data of the received signal and sets the signal so that the level exceeds the predetermined value. It will be obvious that a signal generated by multiplying by the coefficient of (1) should be stored in the memory. Further, in the above-described embodiment, the noise included in the received signal is removed by using the synchronous addition circuit. However, the present invention is not limited to this, and other noise suppressing means may be employed. It should be obvious that they can be provided as needed. Further, an intermediate processing circuit such as an absolute value circuit, a squaring circuit, or a filter may be provided at the subsequent stage of each correlator as necessary to increase the level difference between the correlation peak waveform and other waveforms. It would be obvious. In the above embodiment, the frequency of the clock signal of the clock oscillator on the demodulation side is set to twice the frequency of the clock signal of the clock oscillator on the modulation side. However, the present invention is not limited to this, and the frequency on the demodulation side is equal to the reception signal. It is self-evident that any frequency required to sample is used.

Further, in the above-mentioned embodiment, the modulation side sends one of two types of PN sequences to the transmission line according to the state value "0" or "1" of the information data to be transmitted, and the demodulation side transmits the PN sequence. The original information data was obtained from this transmission signal.
The present invention need not be limited to this. For example, the present invention may be modified as described below. That is, as shown in FIG. 6, the modulator T generates a PN sequence PN ₀ based on the clock signal of the timing generator CL _A as described above.
Comprising a sequence generator G _T0, sends the PN sequence PN ₀ of a predetermined period after sending the power line 1, the PN sequence PN ₀ only when the state value of the information data to be transmitted is "0" in the power line 1 Thus, the spread spectrum modulation is performed. On the other hand, the demodulation device R includes the A / D converter 3, the synchronous adder 10, the correlator H ₀ , the memory M ₀ , the PN
Sequence generator G _R0 , clock oscillator CL _B , switch S
₃ , squaring circuit 11, low-pass filter 12, comparator 1
4, a PN sequence PN transmitted before the modulator T transmits the PN sequence to the power line 1 according to the state value of the information data, as described above, including the processing circuit 18, the timing extraction circuit 17, and the carrier detection circuit 19. ₀ , a periodic signal corresponding to the signal speed of the information data is extracted from the correlation signal between the sampling data of the received signal and the output signal of the PN sequence generator G _R0 , and from the correlation signal and the periodic signal, The arrival of the received signal is determined. Also, it allowed to store sampling data of the received signals to remove noise by using a synchronous adding circuit in the memory M _0. Thereafter, the demodulation device R which receives a signal modulating apparatus T is sent in accordance with the state value of the information data through the power line 1, using said correlator H ₀ and the sampling data of the received signal memory M the correlation value between the sampling data in _0, obtain the original information data by correlation value using a comparator 14 to determine whether exceeds a predetermined reference voltage V _a [V]. In this way, even if the transmission characteristics of the transmission line such as a power line are poor, it will be convenient for performing the above spread spectrum communication with a very simple configuration. Further, the present invention inverts the phase of the PN sequence PN ₀ with respect to the state value “0” of the information data to be transmitted on the modulation side and the phase of the PN sequence PN _{0 with} respect to the state value “1” by 180 degrees. The above-described spread-spectrum communication can also be performed by a simple configuration in the same manner as described above, in which the original information data is demodulated by transmitting the signal and detecting whether or not the phase of the correlation value is inverted. That will be self-evident.

In the above-described embodiment, the information data to be transmitted is binary data. However, the present invention is not limited to this, and the information transmitted by the modulation device according to the number of state values of the information data is not limited to this.
By increasing the number of types of N sequences, assigning data state values to each PN sequence, increasing the number of correlators, memories, etc., the demodulation side compares the output signal values of each correlator with each other,
If it is assumed that the state value corresponding to the PN sequence having the maximum value is demodulated data, it can be obviously applied to information data having a large number of state values. Further, in the above-described embodiment, the values of the output signals of the correlators are compared with each other, and the state value corresponding to the PN sequence having the maximum value is used as the demodulated data. The present invention is not limited to this as long as the information data is demodulated. For example, the original information data may be demodulated depending on whether any of the output signal values of each correlator has exceeded a predetermined reference value. May be.
It will be obvious that the present invention is also applicable to wireless communication means.

[0017]

As described above, according to the present invention, the modulation side outputs a predetermined PN sequence for a required period and then modulates to output the PN sequence in accordance with the state value of the information data to be transmitted. The spread spectrum signal is sent to the transmission line, and the demodulation side transmits the same PN sequence as the modulation side and the modulation side.
The arrival of the received signal is determined by the periodic signal corresponding to the signal speed of the information data extracted from the correlation signal with the PN sequence of the required period and received via the transmission path.
Before transmitting the information data before transmitting from the modulation side
The PN sequence of the required period is stored in the memory, and in the subsequent data demodulation, a correlation value is obtained using the PN sequence in the memory, and the information data is demodulated according to the correlation value. Even if the level difference between the correlation peak waveform and other waveforms becomes small due to poor transmission characteristics, the correlation waveform necessary to demodulate the original information data can be obtained, and the communication error rate can be obtained. This is effective in providing a spread spectrum communication system capable of reducing the frequency.

[0018]

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a waveform chart for explaining an embodiment of the present invention.

FIG. 3 is a waveform chart for explaining an embodiment of the present invention.

FIG. 4 is a waveform chart for explaining an embodiment of the present invention.

FIG. 5 is a waveform chart for explaining an embodiment of the present invention.

FIG. 6 is a configuration diagram showing a modified embodiment of the present invention.

FIG. 7 is a configuration diagram for explaining a conventional spread spectrum communication method.

FIG. 8 is a waveform chart for explaining a conventional spread spectrum communication method.

[Explanation of symbols]

T modulator R demodulator 1 power line GT ₀ , GT ₁ , GR ₀ and GR ₁ PN sequence generator CL _A and CL _B clock oscillators S _{1 to} S ₄ switches H ₀ and H ₁ correlator M ₀ and M ₁ memory Reference Signs List 3 A / D converter 10 Synchronous adder 11 and 15 Square circuit 12 and 16 Low-pass filter 13 Adder 14 Comparator 17 Timing extraction circuit 18 Processing circuit 19 Carrier detection circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 1/707

Claims (16)

(57) [Claims] After outputting a predetermined PN sequence for a required period,
Means for performing communication using a spread spectrum signal modulated so as to output the PN sequence corresponding to the state value of information data to be transmitted, wherein the PN sequence is the same as the modulation side and is transmitted from the modulation side. Place
Before the transmission of the information data received via a transmission line, the arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the correlation signal with the PN sequence having a required period.
A spread spectrum communication method , wherein a PN sequence of the required period transmitted from a modulation side is stored in a memory, and when demodulating data thereafter, the received signal is despread using the PN sequence in the memory. 2. A method for outputting a plurality of PN sequences having the same period length and a small cross-correlation value in a required cycle in a predetermined order, and then outputting the PN sequences corresponding to the state values of information data to be transmitted.
Means for performing communication using a spread spectrum signal modulated so as to output any of the sequences, wherein each of the same PN sequence as the modulation side and a correlation signal between the PN sequence output in the predetermined order, The arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the signal obtained by adding all the PN sequences.
Before transmitting the information data received via the transmission line by determining which of the N
A plurality of PN sequences of the required period transmitted from the modulation side;
Storing the people in the memory, a correlation value each determined using the PN sequence in the memory when thereafter data demodulation, spread spectrum, characterized in that so as to demodulate the information data in accordance with the correlation values Communication method. 3. The information data is demodulated by determining a level of a correlation signal at a timing based on the periodic signal or by comparing levels of correlation signals of the plurality of PN sequences. Range 1 and 2
The spread spectrum communication method described in the paragraph. 4. A method for outputting a plurality of PN sequences having the same period length and a small cross-correlation value in a required period in a predetermined order, and then outputting the PN sequences in accordance with the state value of the information data to be transmitted.
Means for performing communication using a spread spectrum signal modulated so as to output any of the sequences, wherein each of the same PN sequence as the modulation side and a correlation signal between the PN sequence output in the predetermined order, The arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the signal obtained by adding all the PN sequences.
Before transmitting the information data received via the transmission line by determining which of the N
A plurality of PN sequences of the required period transmitted from the modulation side;
In the subsequent data demodulation, the respective correlation values obtained by using the respective PN sequences in the memory are compared with each other, and the state value corresponding to the PN sequence having the maximum value is output. A spread spectrum communication method characterized in that information data is demodulated. 5. The information data is demodulated by outputting a state value corresponding to the PN sequence having the maximum value at a timing based on the periodic signal. The spread spectrum communication method as described. 6. After outputting a plurality of PN sequences having the same cycle length and a small cross-correlation value in a required cycle in a predetermined order, the PN sequence corresponding to the state value of information data to be transmitted is outputted.
Means for performing communication using a spread spectrum signal modulated so as to output any of the sequences, wherein each of the same PN sequence as the modulation side and a correlation signal between the PN sequence output in the predetermined order, The arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the signal obtained by adding all the PN sequences.
Before transmitting the information data received via the transmission line by determining which of the N
A plurality of PN sequences of the required period transmitted from the modulation side;
In the subsequent data demodulation, correlation values are obtained using each PN sequence in the memory, and the information data is obtained by detecting which of the correlation values exceeds a predetermined reference value. A spread spectrum communication method characterized in that demodulation is performed. 7. The information data is demodulated by detecting, at a timing based on the periodic signal, which one of the correlation values exceeds a predetermined reference value. 7. The spread spectrum communication method according to claim 6. 8. After outputting a predetermined PN sequence for a required period,
In the means for communicating with whether a spread spectrum signal modulated define a corresponds to the state value of the information data to be transmitted sends the PN sequence, modulates the modulated side and the same PN sequence The location sent from the side
Before the transmission of the information data received via a transmission line, the arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the correlation signal with the PN sequence having a required period.
The PN sequence of the required period transmitted from the modulation side is stored in a memory, and in the subsequent data demodulation, a correlation value is obtained using the PN sequence in the memory, and whether or not the correlation value exceeds a predetermined reference value is determined. And demodulating the information data by detecting the information spread. 9. The information data is demodulated by detecting whether the correlation value exceeds a predetermined reference value at a timing based on the periodic signal. The spread spectrum communication method described in the paragraph. 10. After outputting a predetermined PN sequence for a required period, the PN sequence corresponding to the state value of information data to be transmitted is obtained.
In means for performing communication using a spread spectrum signal modulated so as to invert the phase of a sequence by 180 degrees, the same PN sequence as that on the modulation side and the part transmitted from the modulation side are used.
Before the transmission of the information data received via a transmission line, the arrival of a received signal is determined by a periodic signal corresponding to the signal speed of the information data extracted from the correlation signal with the PN sequence having a required period.
The PN sequence of the required period transmitted from the modulation side is stored in a memory, and in the subsequent data demodulation, a correlation value is obtained using the PN sequence in the memory, and it is determined whether or not the phase of the correlation value is inverted. A spread spectrum communication method, characterized in that the information data is demodulated by detecting. 11. The information data is demodulated by detecting whether or not the phase of the correlation value is inverted at a timing based on the periodic signal. The spread spectrum communication method as described. 12. A method according to claim 1, wherein said PN sequence stored in said memory is a signal obtained by synchronously adding said PN sequence received via a transmission line for a predetermined period. Spread spectrum communication method. 13. The apparatus according to claim 1, wherein a reception signal supplied to said correlation signal generation means and a PN sequence signal output from said memory are synchronized with each other based on said periodic signal. 13. The spread spectrum communication method according to claim 12. 14. A plurality of PNs having the same cycle length and a small cross-correlation value corresponding to the state value of information data to be transmitted.
In the spread spectrum communication means for transmitting any of the sequences to the transmission line, the modulating side transmits each of the plurality of PN sequences for a plurality of predetermined periods before transmitting the PN sequence corresponding to the state value of the information data. The demodulation side includes correlation means for obtaining a correlation value between a received signal and each of the PN sequences, and corresponds to a predetermined PN sequence from the correlation value and a periodic signal of the PN sequence extracted from the correlation signal. To determine the arrival of a received signal to be transmitted and transmit it from the modulation side before transmitting information data via the transmission path.
The received signal of the received PN sequence is synchronously added for a predetermined period.
The respective signal waveform values obtained by the above are stored in a memory, and in the subsequent data demodulation, a correlation value is obtained by using the stored signal waveform value, and each correlation value is determined by a timing signal detected from the sum of the correlation values. A spread spectrum communication method, wherein the state value of the information data is demodulated by comparing magnitudes. 15. A spread spectrum communication method according to claim 14, wherein the demodulation side comprises a correlation means for obtaining a correlation value between a received signal and the PN sequence to be received first. From the value of the value and the means for detecting the period of the correlation signal, the arrival of the received signal based on the PN sequence to be received first is determined, and the PN transmitted from the modulation side before transmitting the information data is determined.
Performing a process of storing a signal waveform value obtained by synchronously adding a received signal based on a sequence in a memory allocated to the correlating means, and a predetermined time interval after the arrival determination of the received signal based on the PN sequence After performing a process of storing a signal waveform value obtained by synchronously adding a reception signal of the other PN sequence sequentially received at the predetermined period in a memory allocated to the correlation means for all of the other PN sequences. Calculating the correlation value between the received signal and the signal waveform value stored in the memory of each of the correlation means, and comparing the state value of the information data with the timing signal detected from the magnitude comparison between the correlation values and the sum of the correlation values. A spread spectrum communication method characterized in that demodulation is performed. 16. Information data "1" or "0" to be transmitted.
In the spread communication means for transmitting one cycle length of one type of PN sequence or one cycle length of a PN sequence in which the sign of the PN sequence is inverted to the transmission line, the modulation side corresponds to the information data. Prior to transmitting the PN sequence, transmitting the PN sequence in a plurality of periods, the demodulation side includes means for obtaining a correlation value between the received signal and the PN sequence, and means for detecting the magnitude of the correlation value and the period of the correlation signal; From the PN sequence to determine the arrival of the received signal, and the PN transmitted from the transmitting side before transmitting the information data.
Performing a process of storing a signal waveform value obtained by synchronously adding a received signal of a series in a predetermined period in a memory allocated to the correlating means, and a received signal and a signal waveform stored in a memory of each of the correlating means. A spread spectrum communication method, wherein a correlation value between the information data is obtained, and the information data is demodulated by a magnitude of the correlation value and a timing signal obtained from a means for detecting a period of the correlation signal.