JP2916457B1 - Spread spectrum communication equipment - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To reliably acquire synchronization of a multiplexed frame when transmitting the same n spread code strings having different phases in parallel. A frame synchronization signal including a unique word having good autocorrelation is inserted by a frame synchronization signal insertion unit at predetermined intervals and transmitted. On the receiving side, the unique word can be detected by the correlator, so that the frame synchronization signal can be easily reproduced, and the synchronization of the multiplex frame can be more reliably captured without lowering the data transmission efficiency. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting apparatus and a receiving apparatus in a spread spectrum communication system.

[0002]

2. Description of the Related Art In a conventionally known direct spread spectrum communication system, as a method of transmitting more information within a limited band, one spread code sequence is delayed and a plurality of types of spread codes are simulated. There is a method of multiplexing transmission by generating a sequence and spreading a plurality of symbol data by the plurality of spreading code sequences. Further, as a method of increasing the information transmitted while suppressing the number of multiplexing, the present applicant has disclosed in Japanese Patent Application No. 8-97338, selecting r spread code sequences from n spread code sequences synchronized with each other and having different phases. A polarity of + 1 / −1 is given to the selected r codes to generate a plurality of r composite spread spectrum code strings, and for each bit pattern obtained by dividing the input information data into predetermined bits. Has proposed a method of allocating and transmitting r different spreading code strings.

However, in this transmission system, n spread code sequences having different phases are pseudo-negatively regarded as n different spread code sequences and transmitted. In addition, there arises a problem that it is not possible to determine which phase of the received spreading code sequence of n spreading code sequences having different phases. Therefore, in the above proposal, some patterns of the r spreading code strings are allocated for frame synchronization and transmitted. This conventional example will be further described with reference to FIG. In FIG. 15, reference numeral 110 denotes a transmitter, 111 denotes a spread code generator, and 112-1 to 112-n.
-1 is a delay device, 113-1 to 113-n are modulators, 11
4 is a carrier generator, 115 is a serial / parallel converter, 116 is a code selector, and 117 is an adder. Reference numeral 120 denotes a receiver, 122 denotes a correlator, 123 denotes a multiplex frame synchronization unit, and 124 denotes a data demodulation unit.

[0004] The spreading code sequence generated by the spreading code generator 111 is divided into n sequences, and the delay units 112-1 to 11-1 provided for each of the sequences except for the first distributed sequence.
After being delayed by 2-n-1, n spread code strings having mutually different phases as shown in FIG. This n
Spread code strings are provided for each of the modulators 113-1 through 113-1.
At 113-n, primary modulation is performed by the carrier generated by the carrier generator 114. At this time, the modulator 11
The spread code string supplied to 3-2 to 113-n is supplied to the modulator 113-1 by the delay units 112-1 to 112-n-1.
, Τ ₀ , τ ₁ ,.
... It is assumed that the τ _n-1 time phase is shifted. As described above, while the primary modulation is performed by the carrier, the n signals synchronized with each other and having different phases are input to the code selector 116, and r out of the n signals are selected, and each of the n signals is selected. The signal is secondarily modulated to +1 or -1 polarity. On the other hand, such as error correction coding and interleaving,
The information symbol subjected to processing necessary for transmission is input from input terminal 118, and is converted by serial / parallel converter 115 for every m (m ≧ r) bits, which is an integer smaller than r + log ₂ ( _{nC r} ). Is converted to an information symbol. With these m bits, 2 bits composed of r spreading code strings are used.
^{One of the m} combinations is selected and output from the selection modulator 116. This selective modulator 11
The r spread code strings of the pattern selected according to the m bits output from 6 are added by the adder 117, and are transmitted from the transmission output terminal 119 in units of a multiplex frame having the same cycle as the cycle of the spread code string. You.

Further, a pattern consisting of r spreading code strings that are not selected by the selective modulator 116 is output from the selective modulator 116 to the adder 117 at predetermined intervals to synchronize multiplexed frames. Are added by an adder 117, and are output as a multiplexed frame synchronization signal at a transmission output terminal 119.
Sent out. The signal transmitted from the transmission output terminal 119 is received by the reception input terminal 121, subjected to correlation processing in the correlator 122, and then supplied to the multiplex frame synchronization unit 123. In the multiplex frame synchronization unit 123, the correlator 1
A multiplexed frame synchronization signal pattern inserted at the time of transmission is detected from the correlation output obtained from 22, and a multiplexed frame synchronization signal is generated based on the detected timing. The generated multiplexed frame synchronization signal is supplied to the data demodulation unit 124, and the data demodulation unit 124 demodulates the correlation output supplied from the correlator output 122 for each multiplexed frame based on the timing of the multiplexed frame synchronization signal. Thus, the multiplexed m symbols are demodulated and output from the receiving end 125.

[0006]

FIG. 16B shows an example of a multiplexed frame synchronization signal inserted for discriminating the multiplexed frame shown in the above-mentioned transmission system. Where n = 5, r
= 2, m = 5, the transmitted combination pattern is
2 ^m = 32 patterns. The multiplexed frame synchronizing signal is selected from 2 ^r × _n C _r −2 ^m = 8 patterns excluding the 32 patterns. An example shown in FIG. 16B is an example in which two patterns among them are used as a multiplexed frame synchronization signal. Since each pattern is r = 2,
This is a pattern of spread code strings.

[0007] S ₀ , S ₁ , S ₂ , S ₃ , and S ₄ in the transmission code column shown in FIG. 16B indicate five spread code strings input to the code selector 116. As shown in FIG. 16A, there are five spread code strings S _{0 to} S ₄ that are synchronized with each other and have different phases. Note that the spreading code sequence S ₀ is a reference first spreading code sequence {c ₀ , c ₁ ,... C _N },
The second spreading code sequence S ₁ is obtained by shifting the first spreading code sequence S ₀ by time τ ₀ , and similarly, the third spreading code sequence S ₂ is equivalent to τ ₁ , and the fourth spreading code sequence S ₃ is tau ₂ equivalent, fifth spreading code sequence S ₄ is obtained by shifting tau ₃ equivalent, respectively.
In this example, as the multiplexed frame synchronization signal, the first multiplexed frame in which the polarities of the _fourth and fifth spread code sequences S ₃ and S ₄ are +1 and the spread code sequence S ₀ and the spread code sequence S _1. Of the second multiplexed frame whose polarity is set to +1 is successively inserted.

On the receiver side, S ₀ = S ₁ = S ₂ = 0 (no signal), a signal of a pattern of S ₃ = S ₄ = + 1, followed by S ₀ = S ₁ = + 1, S ₂ = S _When it is determined that a signal having a pattern of ₃ = S ₄ = 0 (no signal) has been received, the signal is determined to be a multiplex frame synchronization signal, and a synchronization signal is generated with that time as a multiplex frame start point. I have. The pattern used as the multiplexed frame synchronization signal in this example is a pattern that is not transmitted when information data is transmitted.

However, when information data is transmitted, a similar pattern may appear even if a pattern that is not transmitted is used. In addition, an error may occur due to fading, noise, or the like in the propagation path, and if the above-described pattern matching is used, there is a possibility that the multiplex frame synchronization point may be incorrect. By the way, in the direct spread spectrum transmission system which is generally well known, a method is employed in which pilot signals are multiplexed or inserted at regular time intervals in order to correct for amplitude changes and phase changes received on a propagation path. By multiplexing such pilot signals and correcting the amplitude change and phase change received on the propagation path, it is possible to reduce the possibility of erroneous multiplex frame synchronization points.

However, in this case, multiplexing a pilot signal in addition to multiplexing from the beginning,
This causes deterioration of the reception characteristics. Further, since a multiplexed frame synchronization signal is inserted in order to know the starting point of the multiplexed frame, if a pilot signal is further inserted, the amount of transmission information is reduced. In transmitting information data, data subjected to error correction processing, interleaving, and the like are handled in a data frame unit different from a multiplexed frame. Considering that a data frame synchronization signal for this is inserted. , The effect of inserting a pilot signal is increased. Accordingly, the present invention has been made in view of the above-described problems, and when transmitting a partial combination pattern of n identical spreading code strings having different phases in parallel,
It is an object of the present invention to provide a spread spectrum communication apparatus that can capture synchronization of multiple frames more reliably. It is another object of the present invention to provide a spectrum communication apparatus that can use a multiplexed frame synchronization signal by a synchronization signal of a data frame and can also be used as a pilot signal for removing various effects generated in a propagation path. . A further object of the present invention is to provide a spectrum communication device capable of improving the reception static characteristic on the reception side.

[0011]

In order to achieve the above object, a first spread spectrum communication apparatus according to the present invention comprises a spread code for generating n spread code sequences synchronized in phase and having mutually different phases in parallel. A generating unit and symbol data of an integer α symbol smaller than log ₂ ( _{nC r} ).
A code selection unit that selects a combination of r spreading code sequences from the spreading code sequences, modulates each of the selected r spreading code sequences with each of the symbol data of r symbols, and outputs the result. By adding the r modulation spread code sequences output from the code selection unit, the composite spread spectrum signal sequence having the r-multiplexed modulation spread code sequence having the information amount of (α + r) symbols as a multiplex frame is obtained. By modulating each of the r spread code strings in the combination of the output adder and the spread code string that is not selected in the code selection unit with unique data having a good autocorrelation characteristic, A synchronizing signal generation unit that generates a frame synchronizing signal in units of the multiplexed frame, wherein the frame synchronizing signal is generated by multiplexing data to be transmitted. Are to be transmitted is inserted at predetermined intervals several times.

In the first spread spectrum communication apparatus according to the present invention, the frame synchronization signal may be generated using a plurality of multiplexed frames. Further, the frame synchronization signal may be inserted for each data frame of data. Furthermore, a frame synchronization signal insertion unit for inserting the frame synchronization signal may be provided between the code selection unit and the adder. Furthermore, the spreading code sequence is configured by serially connecting N orthogonal codes each having a length of 1 / N (N is a positive integer) of a required spreading factor, and the n spreading codes. The phase difference of the code sequence may be a phase difference in units of time corresponding to the length of the orthogonal code.

According to the present invention, the above object can be achieved.
The second spread spectrum communication device is log ₂ ( _n C _r )
2 based on the symbol data of the smaller integer α symbol
^{In the α} patterns, the symbol data of the r symbol input following the symbol data of the α symbol, and (n −
a code selector for outputting r (n is an integer) parallel data composed of r) symbols in a non-signal state; and a spreading code for each of the n parallel data output from the code selector. A spreading unit that multiplies the sequence, and a phase of the n spread spectrum signals output from the spreading unit,
(N-1) delayers that are delayed from each other,
By adding n signals out of phase with each other and output from the delay unit, a composite spread spectrum signal sequence having a r-multiplexed modulation spread code sequence having (α + r) symbol information as a multiplex frame is obtained. An adder to be output, and by arranging individual data of a unique word having a good autocorrelation characteristic on each of r signals in a combination that is not selected by the code selection unit, the multiplex frame is defined as a unit. A synchronizing signal generator for generating a frame synchronizing signal to be transmitted, wherein the frame synchronizing signal is inserted and transmitted at predetermined intervals of an integral multiple of a multiplexed frame in which data to be transmitted is multiplexed.

In the second spread spectrum communication apparatus according to the present invention, the frame synchronization signal may be generated using a plurality of multiplex frames. Further, the frame synchronization signal may be inserted for each data frame of data. Further, a frame synchronization signal insertion unit for inserting the frame synchronization signal may be provided between the code selection unit and the spreading unit. Furthermore, each delay time of the (n-1) delay units may be set to an integral multiple of a chip period in the spread code sequence. Furthermore, if the data frame length of the data is
It may be longer than the delay dispersion amount predicted in the propagation path. Furthermore, the spreading code string is formed by adding an orthogonal code having a length of 1 / N (N is a positive integer) of a required spreading factor to N
And (n)
-1) The delay time of each of the delay units may be a delay time in units of time corresponding to the length of the orthogonal code.

[0015]

According to the present invention, the above object can be achieved.
The third spread-spectrum communication device selects a combination of r spreading code sequences from n spreading code sequences based on the symbol data of α symbols, and selects the selected r spreading code sequences by: A spread-spectrum communication apparatus for receiving r-multiplex composite spread-spectrum signals having (α + r) -symbol information generated by performing modulation with each of r-symbol symbol data, wherein the spread-spectrum communication apparatuses are synchronized with each other and have different phases from each other. A spread code generator for generating the n spread code sequences; n correlation codes for correlating the n spread code sequences output from the spread code generator with the received composite spread spectrum signal; And n correlation outputs output from the n correlators and the respective correlation signal powers are compared to estimate r signal symbols. A maximum likelihood determining unit for decoding the α symbol data from the r signal symbol patterns output from the maximum likelihood determining unit, and decoding r symbol data from the r signal symbols And a synchronizing signal generator for generating a frame synchronizing signal based on the timing at which a unique word inserted at predetermined intervals is detected from the received composite spread spectrum signal, and an output from the synchronizing signal generator. The data decoding unit decodes symbol data based on the frame synchronization signal to be transmitted.

In the third spread-spectrum communication apparatus according to the present invention, the synchronization signal generator includes a correlator for correlating with the unique word having a good autocorrelation characteristic, and the correlator has a correlation peak. The frame synchronization signal may be generated based on the timing at which the symbol synchronization signal is output, and the symbol synchronization signal may be generated based on the frame synchronization signal. Further, a frame synchronization signal composed of the unique word is inserted for each data frame having a data frame length longer than the delay dispersion amount predicted on the propagation path, and is used for the correlation peak signal output by the correlator. Propagation path correction means for correcting the influence of the propagation path based on the transmission path may be further provided.

[0018]

According to the present invention, the above object can be achieved.
The fourth spread-spectrum communication apparatus generates (α + r) symbol information generated by delaying the symbol data of r symbols spread by the same spreading code sequence by delay amounts based on the symbol data of α symbols. A spread spectrum communication apparatus that receives a composite spread spectrum signal having a single correlator that correlates a received composite spread spectrum signal with the spread code string,
By comparing the correlation output of the spread code string output from the correlator for one period with the magnitude of the correlation signal power, the transmitted temporal position of r signal symbols is estimated and output. A maximum likelihood determining section, and α from the temporal positions of r signal symbols output from the maximum likelihood determining section.
A data decoding unit that decodes symbol data of a symbol and decodes symbol data of r symbols from r signal symbols, and a timing of detecting a unique word inserted every predetermined period from the received composite spread spectrum signal And a synchronizing signal generator for generating a frame synchronizing signal based on the frame signal. The data decoder decodes the symbol data based on the frame synchronizing signal output from the synchronizing signal generator.

In the fourth spread spectrum communication apparatus according to the present invention, the synchronization signal generating section is provided with a correlator for correlating with the unique word having good autocorrelation characteristics, and the correlator is provided with a correlation peak. The frame synchronization signal may be generated based on the timing at which the symbol synchronization signal is output, and the symbol synchronization signal may be generated based on the frame synchronization signal. Further, a frame synchronization signal composed of the unique word is inserted for each data frame having a data frame length longer than the delay dispersion amount predicted on the propagation path, and is used for the correlation peak signal output by the correlator. Propagation path correction means for correcting the influence of the propagation path based on the transmission path may be further provided.

According to the present invention, by inserting a frame synchronization signal composed of unique words having good autocorrelation, it is possible to more reliably acquire synchronization of multiplex frames without lowering data transmission efficiency. And a spectrum communication device capable of performing such operations. Also, by setting the data frame length longer than the delay dispersion amount predicted on the propagation path and inserting a frame synchronization signal for each data frame, the data frame period can be set to only frame synchronization, symbol synchronization, and multiplex frame synchronization. Instead, it can be used as a signal for propagation path estimation and correction including separation of delayed waves, and the like, and reception characteristics can be improved.

Further, according to the present invention, symbols spread with the same spreading code sequence are delayed and multiplexed, so that it is possible to easily separate a multiplexed wave on the receiving side and to obtain good autocorrelation. By inserting a synchronization signal based on a combination of unselected spreading code sequences modulated by unique words, delayed wave removal by multipath or the like or RAKE
Reception can be performed easily. Furthermore, by making the spreading code sequence a code obtained by connecting N orthogonal codes, it is possible to prevent interference such as interference due to cross-correlation with other symbols having different phases or interference due to partial correlation. Thus, the reception characteristics can be improved. Furthermore,
By using the maximum likelihood determination of selecting r high powers from n or n time position correlator outputs, r numbers of signals determined to be received can always be secured. As a result, the excess or shortage of the signal can be prevented, and the reception static characteristic can be improved by 2 to 3 dB as compared with that obtained by the threshold determination.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a configuration of a transmitting apparatus according to a first embodiment of the spectrum communication apparatus of the present invention. In FIG. 1, reference numeral 11 denotes a PN (Pseudo
Noise), a spread code generator for generating a well-known spread code sequence such as a code, and 12-1 to 12-n-1 denote spread code sequences generated from the spread code generator 11 by τ ₀ , τ ₁ ,
... Delayer for delaying τ _n-2 time, 13 is input terminal 18
A serial / parallel converter that converts serial symbol data input from
Reference numeral 14 denotes a spread code generator 11 and a delay unit 1 based on the symbol data supplied from the serial / parallel converter 13.
2-1 to 12- n- 1 and selecting r spreading code strings from the n spreading code strings supplied from
Code selectors for respectively modulating the spread code strings, 15
Is a frame synchronization signal insertion unit that inserts a frame synchronization signal described later at predetermined intervals, and 16-1 to 16-r are r number of carriers that modulate a carrier with the r spreading code strings output from the frame synchronization signal insertion unit 15. Modulators provided in parallel, 1
Reference numeral 7 denotes an adder for adding and multiplexing the r high-frequency modulated spread code strings output from the r modulators 16-1 to 16-r.

In the transmitting apparatus shown in FIG. 1, the spreading code sequence generated by the spreading code generator 11 is provided for each of the sequences except for the first spreading code sequence S ₀ distributed and distributed to n sequences. Are delayed by the delay units 12-1 to 12-n-1. That is, as shown in FIG. 16 (a), n spread code strings S ₀ , S ₁ ,.
_n-1 . The n spread code strings S _{0 to} S _n−1 that are synchronized but have different phases are input to the code selector 14. At this time, spreading code sequence S ₁ ~S _n-1 supplied to the code selector 14, the delay units 12-1 to 12-n-1,
To the spreading code sequence S ₀ is not inserted in the delay device, respectively tau _0, tau _1, and is assumed to ···· τ _n-2 hours phase shifted. As described above, the n spreading code strings S _{0 to} S _n−1 synchronized with each other and having different phases from each other are input to the code selector 14, and based on the symbol data supplied from the serial / parallel converter 13, n R of the spreading code sequences are selected, and +1 or -1 modulation is performed on each of the selected r sequences in accordance with the symbol data of the symbol data of the r symbols.

More specifically, serial symbol data which has been subjected to processing required for transmission, such as error correction coding processing and interleaving, is input from an input terminal 18, and a serial / parallel converter 13 performs logarithmic symbol data processing. _Two
If the closest integer smaller than ( _n C _r ) is α, then
The data is serial-parallel converted for each (α + r) symbol and converted to parallel symbol data for each α + r = k symbol. Here, as described above, the spread code sequence generated by the spread code generator 11 is generated by the delay units 12-1 to 12-n-1.
Τ ₀ , τ ₁ ,... Τ _n-2 for the spread code sequence S ₀ supplied from the spread code generator 11 directly to the code selector 14
Time phase shifted (n-1) number of spreading sequences S ₁ ~S _n-1
It has been. And the output of the spreading code generator 11;
Delayer 12-1 to 12-n-1 through the total n spread code sequence S ₀ to S _n-1 is the code selector 14, parallel data α symbol of the serial / parallel converter 13 outputs Selects _r spreading code strings L _{0 to} L _r−1 , and further selects the selected spreading code string by the respective symbol data of the parallel data consisting of r symbols in the output of the serial / parallel converter 13. L ₀ ~L _r-1
Are modulated so that each has a polarity of +1 or −1.

Here, taking the case where n = 5 and r = 2 as an example, an input composed of α symbols and r symbols output from the serial / parallel converter 13 and supplied to the code selector 14 FIG. 3A shows the relationship between the symbols and r (= 2) code selector outputs L ₀ and L ₁ output from the code selector 14. Here, the spread code sequence S _0-
S ₄ is as shown in FIG. 16 (a) when that is the n = 5 5
Are spreading code sequences synchronized with each other and having different phases from each other. The data of the five spreading code strings S _{0 to} S ₄ , α and r symbols are two-polarity signals having one of +1 and −1. From n = 5, r = 2, log
₂ ( ₅ C ₂ ) = 3.32, and therefore α = 3 symbols. The information r _{0 of} the illustrated r (= 2) symbol,
The information r ₁ is multiplied by r (= 2) spread code strings selected by the code selector 14 based on the information of α = 3 symbols, and is output. A multiplex frame is formed by the output r modulated spreading code strings. That is, information for three symbols is transmitted by a combination pattern of r (= 2) spreading code strings selected based on information of α = 3 symbols, and r (= 2) spreading code strings are each information r _0. , And information r ₁ , information of two symbols is transmitted. As a result, information for five symbols can be transmitted with a small multiplexing number of two multiplexes in one multiplex frame.

The outputs of the r code selectors 14 that have been selected and modulated as described above are output to the frame synchronization signal insertion unit 1.
5, and the frame synchronization signal insertion unit 15 inserts a frame synchronization signal at a data frame interval of the symbol data input to the input terminal 18. This frame synchronization signal is transmitted to the code selection unit 14 when transmitting the symbol data.
Are generated by 2 ^r × _n C _r −2 ⁽ α ^{+ r)} combinations of several patterns that are not selected in the process of selecting r from n spreading code strings. For example,
For example, in FIG. 3A where n = 5 and r = 2, a combination of r ₀ × S ₀ and r ₁ × S ₁ , r ₀ × S ₃ and r ₁ × S ₄
Is a pattern that is not selected by the code selection unit 14. Therefore, as shown in FIG. 3B, the frame synchronization signal is converted into r using this pattern.
₀ × multiplex frame of S ₃ and _{r 1 × S 4, r 0} × S 0 and r ₁ × S ₁
Multiplexed frames of r ₀ × S ₃ and r ₁ × S ₄ ,
It is generated as a 4-multiplex frame composed of multiplex frames of r ₀ × S ₀ and r ₁ × S ₁ . Further, using one unique word consisting of {+, +,-,-,-, +,-, +} as information r ₀ and information r ₁ , each spreading code sequence S ₀ , S in the four-multiplex frame is used. ₁ , S ₃ and S ₄ are respectively modulated. Thus, the frame synchronization signals are + S ₃ , + S ₄ , −S ₀ ,
_{-S 1, -S 3, + S} 4, -S 0, is a total of eight spreading code sequence by multiplexing four frames + S _1. The frame sync signal is shown as F ₀ sequence and F ₁ sequence to the frame synchronization signal inserter output column of FIG. 3 (b).

That is, in the example shown in FIG. 3B, a frame synchronization signal is transmitted by inserting four multiplexed frames, and j (j ≧ 1) indicates the number of multiplexed frames for transmitting the frame synchronization signal. , # 1 to # 4 indicate the respective multiplex frame numbers in the four multiplex frames. Also,
The unique word is a unique word composed of j × r symbols and having good autocorrelation characteristics. Therefore, the receiving side can easily detect the frame synchronization signal. The outputs F _{0 to} F _r−1 into which the frame synchronization signal has been inserted by the frame synchronization signal insertion unit 15 are supplied to r modulation units 16-1 to 16-r provided in parallel.
In the modulators 16-1 to 16-r, high-frequency modulation is performed on the input r symbol data or the spread code sequence modulated by the unique word using a carrier. The outputs from the modulators 16-1 to 16-r are supplied to an adder 17, where they are added and multiplexed to form a composite spread spectrum signal composed of multiplexed frames and transmitted from an output terminal 19. You.

Here, in the composite spread spectrum signal to be transmitted, the phases of the selected r spread code sequences are different from each other, but the phases of the r symbols for modulating the spread code sequence are completely the same. . On the other hand, a transmission mode in which the phase of a signal modulated by r symbols instead of a spread code string is made different is also conceivable. In this case, before the modulation, the phases of the spreading code sequence and the r symbols are completely the same, but after the modulation, the phases are different between the r symbols. FIG. 2 is a block diagram showing a configuration of a transmission apparatus according to a second embodiment of the spectrum communication apparatus of the present invention that realizes the above transmission method.

In FIG. 2, reference numeral 20 denotes an input end to which serial symbol data is input, 21 denotes a serial / parallel converter for converting the input serial symbol data into parallel symbol data of α symbols and r symbols, 22 Is a code selector that transmits r symbol information to r out of n outputs of the code selector 22 one by one in parallel based on the α symbol information output from the serial / parallel converter 21. Reference numeral 23 denotes a frame synchronization signal insertion unit that inserts a frame synchronization signal at predetermined intervals, 24 denotes a spread code generator that generates a well-known spread code sequence such as a PN (Pseudo Noise) code, and 25-1 to 25-n denote a spread code generator. N parallel multipliers 26-1 to 26-n- for modulating a carrier with n symbol data output from the frame synchronization signal insertion unit 23 1 is a multiplier 25-2 to 25-
output from the n the (n-1) spread the symbols respectively _{τ 0, τ 1, ··· τ} n-2 time delay unit for delaying, 2
7-1 to 27-n are a multiplier 25-1 and a delay unit 26-
N modulators provided in parallel for modulating a carrier with n symbol data output from 1-26-n-1;
An adder 28 adds and multiplexes the n high-frequency modulated spread code strings output from the n modulators 27-1 to 27-n.

In the transmitting apparatus shown in FIG. 2, symbol data subjected to processing required for transmission, such as error correction coding processing and interleaving, is input from an input terminal 20. log ₂
If the closest integer smaller than ( _n C _r ) is α, then
(Α + r) symbols are subjected to serial / parallel conversion to become k parallel data. Here, r is the number of signals selected by the code selector 22. The n pieces of parallel data are supplied to the code selector 22. The code selector 22 transmits r symbol information to r out of the n outputs of the code selector 22 in parallel, one symbol at a time, based on the α symbol information of the parallel output of the serial / parallel converter 21. Is selected. In this case, the number of selected r combinations out of _n is _n C _r , but the code selector 2
The number of combinations used in 2 is 2α.
Then, a no-signal state is sent to the remaining NR outputs. If the input symbol has both +1 and −1 polarity, the no-signal state is zero. This may be realized by arranging n switches and turning off nr outputs that are not selected. A multiplex frame is composed of two symbols output in parallel from the code selector 22.

Here, for example, when α = 3, r = 2, and n = 5, an input symbol composed of an α symbol and an r symbol output in parallel from the serial / parallel converter 21 and a code selector FIG. 4A shows the relationship between n code selector outputs L _{0 to} L ₄ including the signal in the non-signal state output from the signal selector 22. In this figure, taking as an example the case where the α symbols, which are three symbols, are ｛+, +, +｝,
When the α symbol is three symbols of {+, +, +}, _two outputs of the selector outputs L ₀ and L ₂ are selected, and the two outputs L ₀ and L _{2 represent} two symbols r. ₀ and r ₁ are output respectively. Also, the remaining 3 not selected
No signal state 0 is output to each of the selector outputs L ₁ , L ₃ and L ₄ . Similarly, when the α symbol is in another state, two of the n outputs are selected, and the symbols r ₀ and r ₁ are respectively output to the selected two outputs as shown in FIG. The output is 0 in a no-signal state. That is, information of three symbols is transmitted by an r (= 2) output pattern selected based on information of α = 3 symbols, and information r ₀ and information r ₁ are arranged in the r (= 2) output, respectively. Transmits information for two symbols. As a result, information for 5 symbols is stored in 1
It can be transmitted in multiple frames.

In this way, the signal output from the code selector 22 is supplied to the frame synchronization signal insertion unit 23, and the frame synchronization signal is inserted at the data frame interval of the input symbol data supplied to the input terminal 20. The frame synchronization signal to be inserted is composed of j (j ≧ 1) multiplexed frames, that is, a unique word having good autocorrelation characteristics composed of j × (n−r) no-signal states and j × r symbols. It is composed of the modulated j × r signals.

The frame synchronizing signal will be described using a specific example. For example, α = 3, r = 2, n = 5, j = 4, and the unique word is ｛+, +, −, −. ,
Suppose that they are −, +, −, + さ れ. And j multiplex frame # 1 to # 4 outputted from the frame synchronization signal insertion unit 23 of this case, shown in FIG. 4 (b) the relationship between the frame sync signal insertion unit output F ₀ to F _4. In this figure, in the first multiplex frame # 1 of the j multiplex frame, five output F ₀ to F 2 two output F ₃ of the _4, F ₄ is selected, the first two symbols of each unique word { The output is modulated by +, +｝. Unselected outputs F ₀ , F ₁ , F
_{In the case of 2} , no signal 0 is output. In the multiplex frame # 2 of the second frame of the j multiplex frame, 5
Two outputs F ₀ and F ₁ of the two outputs F _{0 to} F ₄ are selected, and the next two symbols {−,.
Modulated by −｝ and output. Unselected outputs F ₂ ,
In F ₃ and F ₄ , 0 in a no-signal state is output. And j
In multi-frame # 3 of the third frame of the multiple frames, five output F ₀ 2 two output F ₃ of the to F _4, F ₄ is selected, the next two symbols of each unique word {-, + ｝ Is modulated and output. The non-selected outputs F ₀ , F ₁ , and F ₂ output 0 in a no-signal state. Furthermore, in the fourth multiplex frame # 4 of the j-th multiplex frame, two outputs F ₀ and F ₁ among the five outputs F _{0 to} F ₄ are selected, and each of the outputs F ₀ and F ₁ is selected next to the unique word. Modulated by two symbols {−, +} and output. In the non-selected outputs F ₂ , F ₃ and F ₄ , 0 in a no-signal state is output.

The n signals into which the frame synchronization signal has been inserted in this manner correspond to the n signals connected to the respective signal paths.
In the multipliers 25-1 to 25 -n, spreading is performed simultaneously by the spreading code sequence generated from the spreading code generator 24. Next, among the outputs of the n multipliers 25-1 to 25-n, n-1 outputs excluding the output of the multiplier 25-1 have delay times of τ ₀ , τ ₁ ,. n- which is τ _n-2
It is supplied to one delay unit 27-1 to 27-n. In addition,
The delay time τ of the delay unit 27-n which is the maximum delay time
_n-2 is a time within the symbol interval T. Then, the (n-1) spreading code sequence M ₁ ~M _n-1 delayed by the delay units 27-1 to 27-n, the spreading code sequence M ₀ output from the multiplier 25-1 mutually phase Will shift. As an example, when the number of parallel signals is 5 (n = 5),
Second spreading code sequence M ₁ with respect to the first spreading code sequence M ₀ is delayed by a time tau ₀ as shown in FIG. 11 (b), third spreading code sequence M to the first spreading code sequence M _{0 2} is delayed by a time tau _1, is delayed relative to the first spreading code sequence M ₀ by a fourth spreading code sequence M ₃ time tau _2, the fifth to the first spreading code sequence M ₀
Spreading code sequence M ₄ is to be delayed by a time tau _3. Note that the illustrated cycle T is the symbol interval.

As described above, the n-1 signals delayed by the delay units 27-1 to 27-n and the n output signals from the multiplier 25-1 are n-phase spread and shifted. signal M ₀ ~M _n-1 is, n pieces parallel provided to a modulator 27-1～
27-n, where high frequency modulation is performed by the carrier. Further, the n signals P _{0 to} P _n-1 output from the modulators 27-1 to 27 -n are multiplexed by being added in the adder 28 to form a composite spread spectrum signal, which is transmitted from the output terminal 29. Is done.

In the multiplexed frame having the period T in the composite spread spectrum signal thus obtained, as can be understood from FIG. 11B, the phases of the spreading code sequence and the spread r symbol completely match each other. However, the phase differs between the r symbols. This is because the symbol data of the r symbol is time-sequentially
1 to 27-n by delay _{0, τ 0, τ 1,} ... are delayed by the tau _n-2 is because it is transmitted in order. That is, the transmitting apparatus according to the first embodiment selects the spread code string to be transmitted, but the transmitting apparatus according to the second embodiment selects n time periods within the period of the symbol interval T. This means that the r time position is selected from the position and transmitted.

Further, in the transmitting apparatus according to the second embodiment of the present invention, as shown in FIG. 5, the time interval at which the frame synchronization signal is May be equal to or longer than the delay time of the wave that arrives latest. According to this, necessary delay waves can be separated. That is, when four delayed waves are required on the receiver side, the desired wave and the frame synchronization signals of the delayed waves 1 to 4 can be detected, respectively. The waves 4 can be separated, and more accurate communication can be realized. In the transmitting apparatuses according to the first and second embodiments described above, an integer smaller and closest to log ₂ ( _{nC r} ) is α, but the present invention is not limited to this. , An integer α may be smaller than log ₂ ( _{nC r} ).

Next, a receiving apparatus suitable for application to the receiving apparatus for receiving the composite spectrum signal transmitted by the spread spectrum communication apparatus according to the first or second embodiment of the present invention will be described. explain. In the transmitting apparatus according to the present invention, r pieces are selected from the n spread code strings, or somewhere in the r time position is selected from the n time positions set within a period of one symbol, and the r pieces are selected. Is transmitted, the receiving apparatus selects which signal among the received signals is r
It is necessary to determine whether or not the number is individual. The most common method for such determination is a method of checking whether or not each of the received signals at n or n time positions that are candidates exceeds a threshold. However, when there are r signals appearing at the correlator output when affected by strong noise or the like on the propagation path, the number of signals exceeding the threshold exceeds r, or the number of signals exceeds r. May not be enough. In that case, an error occurs in units of multiplex frames at the time of data decoding, and the reception performance is unnecessarily deteriorated.

Therefore, in the receiving apparatus according to the present invention, the maximum likelihood decision of selecting r high powers from the correlators output at n or n time positions is used, so that the signal determined to be received is determined. The number is always set to r. As a result, the excess or shortage of the signal can be prevented, and the reception static characteristic can be improved by 2 to 3 dB as compared with that obtained by the threshold determination. FIG.
The third embodiment of the spectrum communication apparatus according to the present invention is preferably applied to a receiver for receiving a composite spread spectrum signal transmitted by the transmitting apparatus according to the first embodiment. FIG. 6 is a block diagram showing the configuration of the receiving apparatus. Hereinafter, a receiving apparatus according to a third embodiment of the spectrum communication apparatus of the present invention will be described with reference to FIG.

In FIG. 6, reference numeral 30 denotes a reception signal input terminal to which a reception signal is input, 31 denotes a demodulator for demodulating the reception signal into a baseband signal, and 32-1 to 32-n denote spread codes generated in the reception device. A correlator for correlating the sequence with the baseband signal; 33, a spread code generator for generating a spread code sequence; 34-1 to 34-n-1, delay devices for delaying the generated spread code sequence; A maximum likelihood decision section 36 selects and outputs r high powers out of the input n correlator outputs, and 36 is data for decoding the α + r symbols multiplexed from the selected and output r signals. A decoding unit 37 is an information symbol output terminal from which the decoded signal is output.

The operation of the receiver shown in FIG. 6 will be described.
The received signal input from the received signal input terminal 30 is demodulated into a baseband signal by a demodulator 31 and n correlators 32
-1 to 32-n. In this case, the spreading code sequence S ₀ generated from spreading code generator 33 is the same spread code sequence as the spread code sequence S ₀ on the transmission side, the correlator 32
The spreading code sequence S ₀ is directly supplied as a reference signal to -1. The correlator 32-2 includes a spreading code generator 33.
Spreading code sequence S ₁ delayed by the delay unit 34-1 connected delay time tau ₀ are supplied to the correlator 32-3 delay time is tau ₁ connected to the spread code generator 33 in is supplied spread code sequence S ₂ that has been delayed by the delay unit 34-2, the following are supplied in the same manner, delay correlators 32-n delay connected to the spread code generator 33 in the tau _n-2 Vessel 3
4-n-1 spreading sequence S _n-1 delayed by is supplied as a reference signal at the time of the correlation. As described above, the n correlator 32-1 to 32-n have the same delayed n spreading code sequences S _{0 to} S as the spreading code sequence used at the time of transmission.
_n-1 will be supplied respectively.

The correlators 32-1 to 32-32 are generated by the n reference signals synchronized with each other and having different phases.
n is correlated with the received baseband signal,
The n correlator outputs CO _{0 to} CO _n−1 are supplied to the maximum likelihood determination unit 35. The maximum likelihood determination unit 35 determines whether the input n
The powers of the correlator outputs CO _{0 to} CO _n−1 are compared, and r powers ML ₀ to ML ₀ to
ML _r−1 is determined as the transmitted r codes, and is output to the data decoding unit 36 in association with the determined r signal polarities. The data decoding unit 36 performs the reverse operation of the code selector 14 in the transmission as shown in FIG. 3A, and decodes and outputs the α + r symbol for each multiplex frame. The signal output to the information symbol output terminal 37 is then subjected to deinterleaving, error correction processing, etc., and is decoded into information data.

In this case, the data decoding unit 36 can be constituted by a table for outputting α + r symbols by r inputs, a logic circuit, or the like. In the case of receiving a composite spectrum signal in which a frame synchronization signal using a unique word is inserted, as in the spread spectrum communication apparatus according to the first embodiment of the present invention,
A frame synchronization signal decoding means is required. In such a case, a frame synchronization signal decoding unit is added to the data decoding unit 36, and the arrival timing of the frame synchronization signal using the unique word is detected by the frame synchronization signal decoding unit. . Then, by generating a multiplexed frame synchronization signal from the timing of the frame synchronization signal transmitted at an integer multiple of the multiplexed frame period, α + r symbols in each multiplexed frame are determined based on the multiplexed frame synchronization signal.
The data is demodulated in the data decoding unit 36.

Next, the fourth embodiment of the present invention, which is preferably applied to a receiving apparatus for receiving a composite spread spectrum signal transmitted by the transmitting apparatus according to the second embodiment of the present invention.
FIG. 7 is a block diagram showing the configuration of the receiving apparatus according to the embodiment. Hereinafter, the receiver according to the fourth embodiment will be described with reference to FIG. In the figure, reference numeral 38 denotes a reception signal input end to which a received reception signal is input, 39 denotes a demodulator for demodulating the reception signal into a baseband signal, 40 denotes a baseband signal and a spread code sequence from a spread code generator 41 41, a spread code generator for generating a spread code sequence similar to that on the transmission side, and 42, selecting r powers having large power from n correlation outputs arranged on the time axis. The maximum likelihood determination unit 43 to be output is a data decoding unit that decodes α + r symbols from the r signals output from the maximum likelihood determination unit 42, and 44 is an information symbol output terminal from which the decoded signal is output.

The operation of the receiving apparatus shown in FIG. 7 will be described.
The received signal input from the received signal input terminal 38 is demodulated into a baseband signal by a demodulator 39 and supplied to a matched filter 40. The spreading code generator 41 generates a spreading code sequence used at the time of transmission, and supplies the generated spreading code sequence to the matched filter 40 as a reference signal for giving a coefficient to the matched filter 40. As a result, the correlation between the spread code sequence generated by the spread code generator 41 in the matched filter 40 and the received baseband signal demodulated in the demodulator 39 is obtained. Since the correlation signal output from the matched filter 40 is transmitted by selecting the r time position from the n time position obtained by dividing the period of the symbol interval T in the transmitting apparatus according to the second embodiment, The signals are arranged on the time axis. This correlation signal is supplied to the maximum likelihood determination unit 42, and the power of each of the n correlation signals arranged on the time axis is compared with each other. doing. The determined r signals are:
The data is output to the data decoding unit 43 in association with the polarity. The data decoding unit 43 performs the reverse operation of the code selector 22 on the transmitting side as shown in FIG. 4A, and decodes and outputs α + r symbols for each multiplex frame. The decoded signal of α + r symbols output to the information symbol output terminal 44 is then subjected to deinterleaving, error correction processing, etc., and is decoded into information data.

Here, a matched filter 4 is used as a correlator.
The reason why 0 is used is that it is convenient to identify the signal of the r symbol appearing on the time series. However, any correlator that can obtain the same effect can be used. good. When receiving a composite spectrum signal into which a frame synchronization signal using a unique word is inserted, as in the spread spectrum communication apparatus according to the second embodiment of the present invention, the frame synchronization signal decoding means is used. Required. Therefore, in such a case, the data decoding unit 43
The frame synchronization signal decoding means is added to the frame, and the arrival timing of the frame synchronization signal using the unique word is detected by the frame synchronization signal decoding means. Then, by generating a multiplexed frame synchronization signal from the timing of the frame synchronization signal transmitted at an integer multiple of the multiplexed frame period, the α + r symbol in each multiplexed frame is decoded based on the multiplexed frame synchronization signal. The signal is demodulated in the unit 43.

Next, a receiving apparatus which is a spread spectrum communication apparatus according to a fifth embodiment of the present invention in which propagation path correction is performed using a received frame synchronization signal modulated by a unique word will be described. 8 will be described.
In the figure, reference numeral 45 denotes a reception signal input end to which a received reception signal is input; 46, a demodulator for demodulating the reception signal into a baseband signal; 47, a baseband signal and a spreading code from a spreading code generator (not shown) A first correlator for correlating with the column, 48 is a first correlator utilizing the autocorrelation of the unique word.
The second correlator 49 outputs a correlation peak output when a frame synchronization signal is received from the correlation output signal of the correlator 47.
A synchronization signal generator for generating a data frame synchronization signal and a multiplexed frame synchronization signal based on the correlation peak signal detected by the correlator 48; Is a maximum likelihood determining unit that selects and outputs r out of n signals output from the channel correcting unit 50, and 52 is a maximum likelihood determining unit. A data decoding unit that decodes the multiplexed α + r symbols from the r signals output from 51, and 53 is an information symbol output terminal from which the decoded signal is output.

The operation of the receiving apparatus shown in FIG.
The received signal input from the received signal input terminal 45 is demodulated into a baseband signal by a demodulator 46 and supplied to a first correlator 47. The first correlator 47 includes the spreading code generator 33, the delay units 34-1 to 34-n-1, and the correlators 32-1 to 32-n shown in FIG. 6, or the matched filter shown in FIG. 40 and a spreading code generator 41. The correlation output obtained by the first correlator 47 is the second
The signal is supplied to the correlator 48 and is correlated with the frame synchronization signal inserted at the data frame interval. In this case, the frame synchronization signal includes j multiplex frames × r signal portions modulated by unique words having good autocorrelation characteristics as described above. Further, since r signal portions in the frame synchronization signal are transmitted in a combination pattern that does not normally appear, the correlation output of the second correlator 48 causes a correlation peak to appear only when the frame synchronization signal is received. become.

Thus, in the second correlator 48, j
Since the correlation is obtained over multiple frames, the influence of random noise can be suppressed, and the C / N of the frame synchronization signal can be improved without increasing the transmission power. Furthermore, since the frame synchronization signal is inserted at the head of the data frame as shown in FIG. 5, for example, the captured correlation peak appears at the head of the data frame. Therefore, the correlation peak can be used as it is as a frame synchronization signal of the data frame. The correlation output of the second correlator 48 is applied to a multiple frame synchronization generator 49.
And a synchronization signal of the data frame, a multiplexed frame synchronization signal of a multiplexed frame that is an integer equal to the data frame period, and a symbol synchronization signal are generated from the timing of the correlation peak.

Since the phase of the correlation peak output from the second correlator 48 is constant, it can be used as a pilot signal for estimating and correcting the influence on the propagation path. For this correction, the output of the second correlator 48 is also supplied to the propagation path correction unit 50. The propagation path correction unit 50 holds the correlation peak value obtained from the second correlator 48 for a time corresponding to the data frame, and transmits the information signal following the frame synchronization signal output from the first correlator 47 to the propagation path. The received amplitude and phase fluctuations are corrected. After the influence on the propagation path is corrected by the propagation path correction section 50, the information symbol output from the first correlator 47 is supplied to the maximum likelihood determination section 51, and the synchronization signal generation section 4
Using the multiplexed frame synchronization signal generated in step 9, the r information signals transmitted for each multiplexed frame are estimated. Next, the r signals estimated by the maximum likelihood determination unit 51 are supplied to a data decoding unit 52, and α + r symbols are decoded. In the data decoding unit 52, the data decoding unit 52 shown in FIG.
The reverse operation of the code selector in the transmission as shown in (a) is performed, and α + r symbols multiplexed for each multiplex frame are generated and output from the information symbol output terminal 53. The symbol data output to the information symbol output terminal 53 is then subjected to deinterleaving, error correction processing, etc., and is decoded into information data.

Next, a first example of the detailed configuration of the second correlator 48 in the receiver according to the fifth embodiment of the present invention will be described. However, in the first example, five spread code strings (n =
5) (r = 2) is selected, and the information symbols are transmitted according to FIG. It is also assumed that the frame synchronization signal is transmitted in four multiplex frames (j = 4) as shown in FIG. In FIG. 9, reference numerals 47-1 to 47-5 denote five correlators provided in parallel, and reference numerals 55-1 to 55-8 denote a coefficient k for the correlator outputs output from the correlators 47-1 to 47-5, respectively. ₀ to k ₇ coefficient multiplier for multiplying, 56-1～56-4 coefficient k ₀ to k ₇ of multiplied two adders for adding the correlator output, 57-
Reference numerals 1 to 57-3 denote delay devices for adjusting the time of the adder output signals output from the adders 56-1 to 56-4, and reference numeral 58 denotes a delay device from the adder 56-2 and the delay devices 57-1 to 57-3. An output adder that adds the signals having the same time and outputs a correlation output; 49-1, a data frame synchronization signal generator that generates a data frame synchronization signal based on the output of the output adder 58; A multiplexed frame synchronization signal generator for generating a multiplexed frame synchronization signal based on a data frame synchronization signal.

The operation of the configuration of the first example shown in FIG. 9 will be described. In the five (n = 5) correlators 47-1 to 47-5, the spread code string S shown in FIG. ₀ correlation between to S ₄ and the baseband signal is taken. Correlator 47-1
The five correlator outputs output from ４７47-5 are supplied to the propagation path correction unit 50 via the correlator output terminal 61, and are also supplied to the second correlator 48. That is, the correlator output from the correlator 47-1 is supplied to a coefficient multiplier 55-1 of coefficient k _2, k _6, the correlator output from the correlator 47-2, the coefficient k ₃ , coefficient of k ₇ multiplier 55-3,
Is supplied to 55-4, the correlator output from the correlator 47-4 is supplied to a coefficient multiplier 55-5,55-6 coefficients k _0, k _4, the correlator output from the correlator 47-5 Is supplied to coefficient multipliers 55-7 and 55-8 for the coefficients k ₁ and k ₅ ,
The correlator output from correlator 47-3 is not supplied to any of them. This means that the frame synchronization signal is the third spreading code string S
_This is because it is transmitted without using ₂ .

Here, the coefficients k _{0 to} k ₇ in the coefficient multipliers 55-1 to 55-8 are set to be the same as the unique words shown in FIG. 3B, and the coefficients k _{0 to} k ₇ are represented by ｛ k ₀ , k ₁ ,
k ₂ , k ₃ , k ₄ , k ₅ , k ₆ , k ₇ ｝ = {+, +, −, −,
−, +, −, +｝. When the coefficient is +, the sign does not change even if multiplication is performed.
_{0, k 1, k 5,} k 7 it is also possible to omit the multiplication coefficient for multiplying the. Then, in the adder 56-1, the coefficient multiplier 5
Coefficients outputted from 5-1 k ₂ (= -) and the correlator output of the correlator 47-1 is multiplied by the coefficient k ₃ output from the coefficient multiplier 55-3 (= -) is multiplied Correlator 47-
The two correlator outputs are added. Thereby, the adder 56
From -1, -S _0, so significant output is output when receiving a second multi-frame # 2 consisting of -S _1.

The adder 56-2 has a coefficient multiplier 55
Coefficient k ₆ output from the 2 (= -) and correlator output multiplied correlator 47-1, the correlation coefficient k ₇ which is output from the coefficient multiplier 55-4 to (= +) is multiplied Table 47-2
And the correlator output are added. Thereby, the adder 56−
From 2, a significant output is output when the fourth multiplex frame # 4 including −S ₀ and + S ₁ is received. Further, in the adder 56-3, the correlator 47 multiplied by the coefficient k ₀ (= +) output from the coefficient multiplier 55-5.
-4 correlator output, the coefficient k ₁ output from the coefficient multiplier 55-7 (= +) is the correlator output multiplied correlator 47-5 is added. Thus from the adder 56-3, + S _3, significant output is to be output when it receives the first multiplex frame # 1 consisting of + S _4. Furthermore, in the adder 56-4, the correlator 47- multiplied by the coefficient k ₄ (= −) output from the coefficient multiplier 55-6.
A correlator output of 4, the coefficient k ₅ output from the coefficient multiplier 55-8 (= +) is the correlator output multiplied correlator 47-4 is added. Thus from the adder 56-4, -S _3, significant output is to be output when it receives the third multi-frame # 3 consisting + S _4.

As described above, four multiplex frames (j = 4)
Are output from the adders 56-1 to 56-4. Next, the significant output output from the adder 56-1 when the second multiplex frame # 2 is received is:
A delay time twice as long as the time T corresponding to the multiplex frame length (2
T) is delayed by the delay unit 57-1. Also, 1
When receiving the multiplex frame # 1, the adder 56-
3 is a significant output from the delay unit 57 for a delay time (3T) three times the time T corresponding to the multiplex frame length.
-2. Further, the significant output output from the adder 56-4 when the third multiplex frame # 3 is received is delayed by the delay unit 57-3 by the time T corresponding to the multiplex frame length. Note that the significant output output from the adder 56-2 when the fourth multiplex frame # 4 is received is not delayed.

By being delayed by the delay units 57-1 to 57-3 in this manner, the significant output is aligned on the time axis with the significant output in the fourth multiplex frame, and this significant time is aligned. Are added in the output adder 58. Therefore, the correlation peak signal is output from the output adder 58 when the fourth multiplex frame of the frame synchronization signal is received. Then, a T frame after the detection of the frame synchronization signal is a multiplex frame on which the information symbol is superimposed, and thereafter, the multiplex frame appears every T time. For example, if the data frame is composed of m multiplexed frames, the correlation peak signal is detected again by the adder 58 after m × T time.

Using this principle, the data frame synchronizing signal generator 49-1 generates a data frame synchronizing signal from the correlation peak signal supplied every mT period, and outputs the data frame synchronizing signal to the output terminal 63.
Output more. Also, a multiplex frame synchronization signal generator 49
In -2, a multiplexed frame synchronization signal having a period T is generated by multiplying the data frame synchronization signal having the mT period by m, and output from the output terminal 64. The correlation peak signal from the output terminal 62, which is the output of the output adder 58, is supplied to the propagation path correction unit 50, and based on the correlation peak signal, the amplitude and phase of the correlator signal appearing at the correlator output terminal 61. Correction is performed.

Next, a second example of the detailed configuration of the second correlator 48 in the receiving apparatus according to the fifth embodiment of the present invention will be described. However, in the second example, five spreading code strings (n =
5) (r = 2) is selected, the information symbol is transmitted according to FIG. 4 (a), and the frame synchronization signal is a 4-multiplex frame (j = 4) as shown in FIG. 4 (b). It shall be transmitted as shown. In FIG. 10, 66 is the first
Matched filter (MF) for realizing the correlator 47, 67
Reference numerals -1 to 67-7 denote cascaded delay devices for delaying the despread output signal output from the matched filter 66 by a predetermined time, and reference numerals 68-1 to 68-8 denote output signals of the matched filter 66 and delay devices. coefficient multiplier for multiplying a coefficient k ₀ to k ₇ each delayed output signal at 67-1～67-7, 69 coefficients k ₀ to k ₇ are multiplied by the coefficient multiplier 68-1～68-8 An adder that calculates and outputs the sum of the output signals, a data frame synchronization signal generator that generates a data frame synchronization signal based on the output of the adder, and a data frame synchronization signal that generates a data frame synchronization signal based on the output of the adder. And a symbol synchronization signal generator 49-3 for generating a symbol synchronization signal based on the multiplexed frame synchronization signal.

The operation of the second example shown in FIG. 10 will now be described. The matched filter 66, which is a correlator, receives the received composite spread spectrum signal and the matched filter 6.
The correlation with the target code (corresponding to the spread code string on the transmission side) set in 6 is calculated, and an output signal despread is output. The output signal from the matched filter 66 is output from the information signal output terminal 73 and supplied to the propagation path correction unit 50, and is also supplied to the second correlator 48. The second correlator 48 includes j × r−1 = 7 delay units 67-1 to 67-7 and j × r = 8 multiplication coefficient units 68
-1 to 68-8 and eight multiplication coefficient units 68-1 to 68-
It is configured as a matched filter type correlator consisting of an adder 69 for calculating the sum of the outputs of the eight outputs.

Before describing the matched filter type second correlator 48, the configuration of the received frame synchronization signal will be described with reference to FIG. FIG. 11 (a)
In the Tx column, frame synchronization signals composed of multiplexed frames # 1 to # 4 transmitted according to the above-described FIG. 4B and modulated with unique words are arranged in chronological order for each multiplexed frame. In the Rx column, each coefficient unit 68- in the second correlator 48 for this frame synchronization signal is shown.
The correspondence relationship of 1 to 68-8 is shown. As shown in the figure, the positional relationship of each symbol of the frame synchronization signal appearing in a time series is as shown in FIG. 3, in which {+, +,-,-} appear adjacently, and the coefficients k ₀ , k ₁ , k ₂ , and k ₃ are set to be adjacent. Further, after the no-signal state continues for six symbols, {−, +, −, +} appear adjacently,
Correspondingly, coefficients k ₄ , k ₅ , k ₆ , and k ₇ are set adjacently. The coefficient k ₀ to k ₇ as shown in Rx column is, so as to correspond to the symbol of the frame synchronization signal appearing on the time axis, the delay time of the delay device 67-1～67-7 is set. That is, the despread output signal output from the matched filter 66 is arranged on the time-series axis with the time and code shown in FIG. T shown in the figure is the cycle of the multiplex frame.

FIG. 11B shows the relationship between the temporal position and the symbol of one multiplex frame transmitted when the number of spread code strings to be multiplexed is five. Symbols are selected at r (= 2) positions from each of the five (n = 5) positions of the first to fifth spreading code strings and transmitted.
At this time, the time difference between the symbol of the first spreading code string transmitted first and the symbol of the second spreading code string transmitted with a delay of τ ₀ adjacent thereto is τ _A , and similarly, the symbol of the second spreading code string a third time difference between the symbols of the spreading code sequence tau _B transmitted adjacent time tau ₁ delay symbol of the fourth spreading code sequence to be transmitted third spreading code sequence symbol and adjacent time tau ₂ delay of Τ _C , the time difference between the symbol of the fourth spreading code sequence and the symbol of the fifth spreading code sequence transmitted with a delay of τ ₃ adjacent thereto is τ _D , the next symbol adjacent to the symbol of the fifth spreading code sequence Τ _E is the time difference from the symbol of the first spreading code string which is the head of the multiplexed frame.

The values of the coefficients k _{0 to} k ₇ in the coefficient multipliers 68-1 to 68-8 are set to be the same as the unique words shown in FIG. 4B, and the coefficients k _{0 to} k ₇ are ｛K ₀ ,
k ₁ , k ₂ , k ₃ , k ₄ , k ₅ , k ₆ , k ₇ ｝ = ｛+, +,
−, −, −, +, −, +｝. When the coefficient is +, the sign does not change even if multiplication is performed.
It is also possible to omit a multiplication coefficient unit for multiplying k ₀ , k ₁ , k ₅ , and k ₇ . Here, in the matched filter type second correlator 48 for correlating with the frame synchronization signal, the symbol {+} of the fourth spreading code string transmitted from the delay unit 67-7 in the first multiplex frame # 1 appears. Suppose you did.
This symbol is multiplied by a coefficient {+} in a coefficient multiplier k ₀ and supplied to an adder 69. At this time, the symbol {+} of the fifth spreading code string transmitted in the first multiplex frame # 1 appearing before the delay time τ _D of the delay unit 67-7 appears from the delay unit 67-6. This symbol is multiplied by a coefficient {+} in a coefficient multiplier k ₁ to obtain an adder 69.
Supplied to

Further, at the same time, the delay device 67-5
Then, the symbol {−} of the first spreading code string transmitted in the second multiplex frame # 2 that appears before the delay time τ _E of the delay unit 67-6 further appears. This symbol is multiplied by a coefficient ｛−｝ in a coefficient multiplier k ₂ and supplied to an adder 69. Furthermore, at the same time, the delay device 67-
4, the symbol {−} of the second spreading code string transmitted in the second multiplex frame # 2 that appears before the delay time τ _A of the delay device 67-5 further appears. This symbol is multiplied by a coefficient ｛−｝ in a coefficient multiplier k ₃ and supplied to an adder 69. Furthermore, at the same time, the delay 67
-3, the delay time T + τ _B +
The symbol {−} of the fourth spreading code string transmitted in the third multiplex frame # 3 that appears before τ _C appears. This symbol is multiplied by a coefficient ｛−｝ in a coefficient multiplier k ₄ and supplied to an adder 69. Furthermore, at the same time, the symbol {+} of the fifth spreading code string transmitted from the delay unit 67-2 in the third multiplex frame # 3 that appears further before the delay time τ _D of the delay unit 67-3. Appears. The symbol in the coefficient multiplier k ₅ coefficients {+} is supplied to the adder 69 are multiplied.

Further, at the same time, the delay device 67
From -1, the symbol {−} of the first spreading code string transmitted in the fourth multiplex frame # 4 that appears before the delay time τ _E of the delay device 67-2 further appears. This symbol is multiplied by a coefficient ｛-｝ in a coefficient multiplier k ₆ to form an adder 69.
Supplied to Further, at the same time, the matched filter 66 further outputs the delay time τ of the delay device 67-3.
The symbol {+} of the second spreading code string transmitted in the fourth multiplex frame # 4 that appears before _A appears. This symbol is multiplied by a coefficient {+} in a coefficient multiplier k ₇ and supplied to an adder 69. Accordingly, at this time, the time is aligned in the adder 69, and the coefficient multipliers 68-1 to 68-1 are set.
Since the multiplied signal in one direction of positive polarity is input from 68-8 and added, a peak appears in the added output. This addition output is a correlation peak signal, and is output at the arrival timing of the second spreading code sequence of the fourth multiplex frame # 4 in the frame synchronization signal. This timing is shown in FIG. 12B, and a correlation peak can be detected a time (T−τ _A ) before the head of the multiplexed frame modulated by the information symbol following the frame synchronization signal.

The correlation peak signal output from the adder 69 is supplied to the data frame synchronizing signal generation section 49-1, and the data having the period mT of the timing shown in FIG. A frame synchronization signal is generated. This data frame synchronization signal is output from the output terminal 75. The data frame synchronization signal is supplied to the multiplex frame synchronization signal generation unit 71,
The multiplexed frame synchronization signal shown in FIG. 12D is generated by multiplying the data frame synchronization signal by m in the multiplexed frame synchronization signal generator 71. In this case, the data frame period is mT, and the multiplex frame synchronization signal is output from the output terminal 76. Further, the multiplexed frame synchronization signal is supplied to the symbol synchronization signal generation unit 72,
When the symbol synchronization signal generation unit 72 sets n = 5 by multiplying the multiplexed frame synchronization signal by n, FIG.
The symbol synchronization signal shown in FIG. 2 (e) is generated. As a result, τ _A ,
tau _B, the symbol synchronization signal · · · tau _D interval is outputted from the output terminal 77.

The data frame synchronizing signal, the multiplexed frame synchronizing signal and the symbol synchronizing signal output from the output terminals 75, 76 and 77 are supplied to the data decoding section 52, the maximum likelihood judgment section 51 and the first correlator 47, Used for position signal extraction and the like. That is, if the output signal of the matched filter 66 shown in FIG. 12A is extracted from the symbol synchronization signal shown in FIG. 12E, a multiplexed frame signal with the information symbol shown in FIG. 12F can be obtained. it can. Also,
12G shows a decoded signal obtained by decoding the multiplexed frame signal shown in FIG. 12F into information symbols of α + r symbols by the data decoding unit 52. The first five symbols of this decoded information symbol are the signals ｛+, shown in FIG.
0, 0, −, 0} are defined as α = {+,
+, −｝, And r ₀ = +, r ₁ = −
Is decrypted.

By the way, the adder 69 shown in FIG.
Has a correlation peak only at the data frame interval mT. Therefore, if this correlation peak signal is used, even if a delayed wave occurs in the propagation path,
Within the time corresponding to the data frame length (mT), it is possible to identify and separate the delayed waves. This will be described in detail with reference to FIG. In the correlation peak signal output from the adder 69 when a delayed wave is present, a correlation peak further appears within a time T _F (= mT) corresponding to the data frame length. For example, as shown in FIG. 13A, a correlation peak whose time difference from the first correlation peak is τ _d appears. This means that there is a delayed wave shown in FIG. 13C which arrives after a delay of τ _d in addition to the desired wave shown in FIG. 13B. Therefore, it is possible to detect the delay time of the delayed wave, and it is possible to separate the received desired wave and the delayed wave.

Thus, in a transmission system in which it is difficult to separate a delayed wave within one symbol without inserting and transmitting a special signal which causes a reduction in transmission capacity, a delayed wave far exceeding one symbol is transmitted. Separation becomes possible, and reception characteristics can be improved. As a condition for this, the data frame length may be set to be equal to or longer than the maximum delay time of the delay wave predicted on the propagation path and considered necessary by the receiving device. The correlation peak signal output from the adder 69 is also supplied to the propagation path correction unit 50, and the amplitude and phase of the correlation signal output from the first correlator 47 are corrected using the correlation peak signal as a reference signal. .

In the spread spectrum communication apparatus of the present invention described above, symbols are spread and multiplexed assuming that one spread code sequence is synchronized with n types of spread code sequences having different phases, or the same spread code sequence is used. Either a plurality of symbols spread with a spreading code sequence are delayed and multiplexed. In such a case, the correlation value between the spread code sequences having different phases or the correlation value between the spread code sequences at the time of being delayed may cause interference and degrade the reception characteristic from the theoretical value. . Particularly, a method of delaying and multiplexing a plurality of symbols spread by the same spreading code sequence has a great effect.

Therefore, a sixth embodiment of the spectrum communication apparatus of the present invention which can solve the above problem will be described with reference to FIG. According to the sixth embodiment of the present invention, in the method of delaying and multiplexing the phase difference between each spread code sequence or a plurality of symbols spread by the same spread code sequence, The delay difference is set to 1 / N of the spreading factor required in the communication system, and a spreading code string using N orthogonal codes is assigned to each 1 / N portion. Note that N is a fixed value.

FIG. 14 shows an example of a spread code sequence in a case where five (n = 5) spread code sequences according to the sixth embodiment are used.
This is shown in FIG. In FIG. 14A, five types of orthogonal codes A to E each including eight chips are prepared, and the orthogonal codes A to E are sequentially assigned for each period τ obtained by dividing the symbol period T into five equal parts. Here, since the orthogonal codes A to E are orthogonal to each other, any part does not interfere with each other in the period τ that is the phase difference interval or the delay difference interval. More specifically, as an example, as shown in FIG. 14 (b), two of a third spreading code sequence and a fifth spreading code sequence are selected and transmitted from five spreading code sequences having phases different from each other by τ. (R = 2). In this case, two of the third spreading code sequence and the fifth spreading code sequence are received at the same time. In this case, for a correlator correlating with the third spreading code sequence, the fifth spreading code sequence is only interference, but 5
Each of the orthogonal codes {D, E, A, B, C} forms five orthogonal codes {B, C, D, E,
Since each of them is orthogonal to A｝, the fifth spreading code sequence does not cause interference as a whole. Similarly, for a correlator correlated with the fifth spreading code sequence, the third spreading code sequence does not cause interference.

In the example shown in FIG. 14C, two symbols (r = 2) spread by the same spreading code string are multiplexed with delay in one of five ways (n = 5). This is an example. In this case, in the first multiplexed frame, the third spreading code sequence delayed by 2τ from the reference first spreading code sequence and the fifth spreading code sequence delayed by 4τ from the reference first spreading code sequence are used.
The multiplexed signal is multiplexed with a spread code sequence and is not delayed in the next multiplexed frame, and is multiplexed with a fourth spread code sequence delayed by 3τ from the reference first spread code sequence. Then, for the signal of the third spreading code string of the first multiplex frame, the orthogonal code A, B, and C parts of the fifth spreading code string of the first multiplex frame and the orthogonal codes of the first spreading code string of the next multiplex frame. The portions of the codes A and B cause interference, but since each spread code sequence is composed of orthogonal codes A to E, they do not cause interference as a result. Also, regarding the signal of the fifth spreading code string of the first multiplex frame, the portions of the orthogonal codes C, D, and E of the third spreading code string of the first multiplex frame and the signals of the first spreading code string of the next multiplex frame. Orthogonal code A,
The portions of B, C, and D and the portion of the orthogonal code A of the fourth spreading code sequence cause interference, but similarly, they do not.

In FIG. 14, an example in which n = 5 and r = 2 has been described. However, the present invention is not limited to this numerical example, and it is possible to prevent interference between spreading code strings. Thus, the orthogonal code is N
By selecting a concatenated code as a spread code string, it is possible to prevent inter-code interference having different phases or interference due to partial correlation, and secure more reliable transmission. In addition,
According to the present invention described above, by selecting a spreading code string that is not multiplexed and inserting a unique word having good autocorrelation by a combination thereof as a synchronization code, it is possible to easily separate a delayed wave on the receiving side. Utilizing this, in the present invention, it is possible to remove delayed waves by multipath or the like,
KE reception may be performed.

[0075]

Since the present invention is configured as described above, the synchronization of a multiplex frame can be achieved without lowering the data transmission efficiency by inserting a frame synchronization signal composed of unique words having good autocorrelation. A spectrum communication device that can more reliably capture can be obtained. Also, by setting the data frame length longer than the delay dispersion amount predicted on the propagation path and inserting a frame synchronization signal for each data frame, the data frame period can be set to only frame synchronization, symbol synchronization, and multiplex frame synchronization. Instead, it can be used as a signal for propagation path estimation and correction including separation of delayed waves, and the like, and reception characteristics can be improved.

Further, according to the present invention, symbols spread with the same spreading code sequence are delayed and multiplexed, so that it is possible to easily separate multiplexed waves on the receiving side, and to obtain good autocorrelation. By inserting a synchronization signal based on a combination of unselected spreading code sequences modulated by a unique quadrature, delay wave removal by multipath or the like or RAKE
Reception can be performed easily. Furthermore, by making the spreading code sequence a code obtained by connecting N orthogonal codes, it is possible to prevent interference such as interference due to cross-correlation with other symbols having different phases or interference due to partial correlation. Thus, the reception characteristics can be improved. Furthermore,
By using the maximum likelihood determination of selecting r high powers from n or n time position correlator outputs, r numbers of signals determined to be received can always be secured. As a result, the excess or shortage of the signal can be prevented, and the reception static characteristic can be improved by 2 to 3 dB as compared with that obtained by the threshold determination.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a transmission device according to a first embodiment of a spectrum communication device of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a transmission device according to a second embodiment of the spectrum communication device of the present invention.

FIG. 3 is a table showing an example of a code selection mode in the transmitting apparatus according to the first embodiment of the spectrum communication apparatus of the present invention.

FIG. 4 is a table illustrating an example of a code selection mode in a transmission device according to a second embodiment of the spectrum communication device of the present invention.

FIG. 5 is a block diagram showing a relationship between a data frame and a delay profile in the spread spectrum communication apparatus according to the present invention.

FIG. 6 is a block diagram illustrating a configuration of a receiving apparatus according to a third embodiment of the spectrum communication apparatus of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a receiving apparatus according to a fourth embodiment of the spectrum communication apparatus of the present invention.

FIG. 8 is a block diagram showing a configuration of a receiving apparatus according to a fifth embodiment of the spectrum communication apparatus of the present invention.

FIG. 9 is a block diagram illustrating an example of a detailed configuration of a second correlator in a receiving device according to a fifth embodiment of the spectrum communication device of the present invention.

FIG. 10 is a block diagram showing another example of the detailed configuration of the second correlator in the receiving apparatus according to the fifth embodiment of the spectrum communication apparatus of the present invention.

FIG. 11 is a chart and a diagram for explaining the operation of the second correlator shown in FIG. 10;

FIG. 12 is a time chart of a first correlator output, a correlation peak signal, each synchronization signal, and the like, for explaining an operation of the second correlator shown in FIG. 10;

FIG. 13 is a diagram illustrating an example of a timing of a frame synchronization signal detected when a delayed wave is received in the spread spectrum receiving apparatus of the present invention.

FIG. 14 is a diagram illustrating a configuration of a spread code string and a configuration of a multiplex frame for describing a sixth embodiment of the spectrum communication apparatus according to the present invention.

FIG. 15 is a diagram showing a configuration of a conventional spread spectrum transmission system using a parallel combination delay multiplex system.

FIG. 16 is a diagram showing a configuration of a multiplexed frame by a parallel combination delay multiplexing method using the same spreading code sequence and a configuration of a conventional multiplexed frame synchronization signal.

[Description of Code] 11 Spreading Code Generator 12-1 to 12-n-1, 26-1 to 26-n-1 Delay Unit 13, 21 Serial / Parallel Converter 14, 22 Code Selector 15, 23 Frame Synchronization Signal insertion units 16-1 to 16-r, 27-1 to 27-r Modulators 17, 28, 56-1 to 56-4, 69 Adders 18, 20 Input terminals 19, 29 Output terminals 25-1 to 25 −n Multipliers 30, 38, 45 Received signal input terminals 31, 39 Demodulators 32-1 to 32-n, 47-1 to 47-5 Correlators 33, 41 Spreading code generators 34-1 to 34-n- 1, 57-1 to 57-3, 67-
1-67-7 Delay unit 35, 42, 51 Maximum likelihood determination unit 36, 43, 52 Data decoding unit 37, 44 Information symbol output terminal 40, 66 Matched filter 47 First correlator 48 Second correlator 49 Synchronous signal generation Unit 49-1 data frame synchronization signal generation unit 49-2 multiplex frame synchronization signal generation unit 49-3 symbol synchronization signal generation unit 50 propagation path correction unit 55-1 to 55-8, 68-1 to 68-8 coefficient multiplier 58 output adder 61, 73 correlator output terminal 62, 63, 64, 74, 75, 76, 77 output terminal

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-64845 (JP, A) JP-A-9-321661 (JP, A) JP-A-2-299334 (JP, A) JP-A-4- 360434 (JP, A) JP-A-5-30079 (JP, A) JP-A-5-130079 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04J 13/00 H04B 7 / 26 H04L 7/00

Claims (18)

(57) [Claims] 1. n synchronized with each other and out of phase with each other
A combination of a spreading code generator that generates a number of spreading code strings in parallel, and a combination of r spreading code strings from the n spreading code strings based on symbol data of an integer α symbol smaller than log ₂ ( _{nC r} ) And a code selecting unit that modulates and outputs each of the selected r spread code sequences with each of the symbol data of r symbols, and r modulated spread signals output from the code select unit An adder for adding a code sequence to output a composite spread-spectrum signal sequence in which an r-multiplexed modulated spread code sequence having an information amount of (α + r) symbols is a multiplex frame; By modulating each of the r spreading code sequences in the combination of spreading code sequences without any error with individual data of unique words having good autocorrelation characteristics, the multiplexed frame is simply multiplexed. A synchronization signal generation unit that generates a frame synchronization signal to be transmitted as a unit, wherein the frame synchronization signal is inserted and transmitted at predetermined intervals of an integral multiple of a multiplexed frame in which data to be transmitted is multiplexed. Spread spectrum communication equipment. 2. The spread spectrum communication apparatus according to claim 1, wherein said frame synchronization signal is generated using a plurality of multiplex frames. 3. The spread spectrum communication apparatus according to claim 1, wherein said frame synchronization signal is inserted for each data frame of said symbol data. 4. The spread spectrum communication apparatus according to claim 1, wherein a frame synchronization signal insertion unit for inserting the frame synchronization signal is provided between the code selection unit and the adder. 5. The spreading code sequence is configured by serially connecting N orthogonal codes each having a length of 1 / N (N is a positive integer) of a required spreading factor and serially connecting the n codes. 2. The spread spectrum communication apparatus according to claim 1, wherein the phase difference of the spread code sequence is a phase difference in units of time corresponding to the length of the orthogonal code. In 6. _{log 2 (n C r) 2} α street pattern based on symbol data integer smaller than alpha symbol,
A code selecting unit that outputs symbol data of r symbols input after symbol data of α symbols and n (n is an integer) parallel data composed of (n − r) non-signal-state symbols A spreading unit that multiplies each of the n pieces of parallel data output from the code selecting unit by a spreading code sequence, and sets the phases of the n spread spectrum signals output from the spreading unit to each other. Delay to shift (n-1)
By adding n delay units and n signals output from the delay units with mutually shifted phases, an r-multiplexed modulation spread code sequence having information of (α + r) symbols is set as a multiplexed frame. An adder that outputs a composite spread spectrum signal sequence, by arranging individual data of a unique word having a good autocorrelation characteristic on each of the r signals in a combination that is not selected by the code selection unit, A synchronization signal generation unit that generates a frame synchronization signal in units of the multiplexed frame, wherein the frame synchronization signal is inserted and transmitted at predetermined intervals of an integral multiple of a multiplexed frame in which data to be transmitted is multiplexed. A spread-spectrum communication device characterized in that: 7. The spread spectrum communication apparatus according to claim 6, wherein said frame synchronization signal is generated using a plurality of multiplex frames. 8. The spread spectrum communication apparatus according to claim 6, wherein said frame synchronization signal is inserted for each data frame of said symbol data. 9. The spread spectrum communication apparatus according to claim 6, wherein a frame synchronization signal insertion unit for inserting the frame synchronization signal is provided between the code selection unit and the spreading unit. 10. The spread spectrum communication apparatus according to claim 6, wherein each of the (n-1) delay units has a delay time that is an integral multiple of a chip period in the spread code sequence. 11. The spread spectrum communication apparatus according to claim 6, wherein a data frame length of said symbol data is longer than a delay dispersion amount predicted on a propagation path. 12. The spreading code sequence is configured by serially connecting N orthogonal codes having a length of 1 / N (N is a positive integer) of a required spreading factor in a serial manner. −
7. The spread spectrum communication apparatus according to claim 6, wherein each of the delay units has a delay time in units of a time corresponding to the length of the orthogonal code. 13. A combination of r spreading code sequences from n spreading code sequences based on the symbol data of α symbols, and the selected r spreading code sequences are:
A spread-spectrum communication apparatus for receiving r-multiplex composite spread-spectrum signals having (α + r) -symbol information generated by performing modulation with each of r-symbol symbol data. A spreading code generator for generating the n spreading code sequences; n correlations for correlating the n spreading code sequences output from the spreading code generator with the received composite spread spectrum signal; And n correlation outputs output from the n correlators,
A maximum likelihood determining section for estimating and outputting r signal symbols by comparing the magnitudes of the respective correlation signal powers; and a symbol of an α symbol from a pattern of the r signal symbols output from the maximum likelihood determining section. A data decoding unit that decodes data and decodes symbol data of r symbols from r signal symbols, based on a timing at which a unique word inserted every predetermined period is detected from the received composite spread spectrum signal. A synchronization signal generation unit for generating a frame synchronization signal, wherein the data decoding unit decodes symbol data based on the frame synchronization signal output from the synchronization signal generation unit. Communication device. 14. The synchronizing signal generating section is provided with a correlator for correlating with the unique word having good autocorrelation characteristics. to generate a spread spectrum communication apparatus according to claim 1 3, wherein it has to symbol synchronization signal is generated based on the frame synchronization signal. 15. A correlation signal output from the correlator, wherein a frame synchronization signal composed of the unique word is inserted for each data frame having a data frame length longer than a delay dispersion amount predicted on a propagation path. Propagation path correction means for correcting the influence of the propagation path based on the peak signal,
It spread spectrum communication apparatus according to claim 1 4, wherein, further provided. 16. A composite spectrum having information of (α + r) symbols generated by delaying symbol data of r symbols spread by the same spreading code sequence by delay amounts based on symbol data of α symbols, respectively. A spread-spectrum communication apparatus for receiving a spread signal, comprising: a single correlator for correlating a received composite spread-spectrum signal with the spread code sequence; and one of the spread code sequences output from the correlator. A maximum likelihood determining section for estimating and outputting the temporal position of transmission of r signal symbols by comparing the magnitude of the correlation signal power with respect to the correlation output over the period; The symbol data of α symbol is decoded from the temporal position of the r signal symbols to be output, and the symbol data of r symbol is decoded from r signal symbols. And a synchronization signal generation unit for generating a frame synchronization signal based on the timing at which a unique word inserted at predetermined intervals is detected from the received composite spread spectrum signal. A spread spectrum communication apparatus, wherein the data decoding unit decodes symbol data based on a frame synchronization signal output from a generation unit. 17. The synchronizing signal generating section includes a correlator for correlating with the unique word having a good autocorrelation characteristic, and a frame synchronizing signal based on a timing at which the correlator outputs a correlation peak. 18. The spread spectrum communication apparatus according to claim 16, wherein a symbol synchronization signal is generated based on the frame synchronization signal. 18. A frame synchronization signal comprising the unique word is inserted for each data frame having a data frame length longer than a delay dispersion amount predicted on a propagation path, and a correlation output by the correlator is provided. Propagation path correction means for correcting the influence of the propagation path based on the peak signal,
The spread spectrum communication apparatus according to claim 17, further comprising: