JPH06177853A - Spread spectrum transmission and reception system - Google Patents

Abstract

PURPOSE:To improve using efficiency of a frequency, to prevent the disconnection of a line, and to prevent the continuous generation of an error by operating a weighting processing to information to be transmitted according to significance, orthogonally converting and multiplexing each information, operating a spread spectrum by using a PN code, and preparing and transmitting a transmission signal. CONSTITUTION:This system is equipped with a direct spread spectrum transmitter 1 which fetches digital information, and converts it into the transmission signal by a direct spread spectrum system, and a direct spread spectrum receiver 4 which demodulates the digital information. At that time, the direct spread spectrum transmitter 1 fetches the digital information, operates a weighting processing to the digital information, operates the direct spread spectrum to a signal obtained by Hadamard transformation by using the PN code, and prepares the transmission signal. Then, the direct spread spectrum receiver 4 receives the transmission signal, operates the signal processing opposed to the signal processing of the direct spread spectrum transmitter 1, and reproduces the digital information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum transmission / reception system used in transmission and broadcasting of digital signals.

SUMMARY OF THE INVENTION According to the present invention, a digital signal is taken in by a transmitting device side, a weighting process is performed on the digital information, and then a signal obtained by performing orthogonal transform such as Hadamard transform is directly converted into a spectrum. By generating a transmission signal by spreading, receiving the transmission signal by the receiving device side, and performing the signal processing reverse to that of the transmitting device side to reproduce the digital information, while improving the frequency utilization efficiency. Even when the error rate becomes high, the line is not disconnected, and even when the television signal is compressed and transmitted using the DCT method with motion compensation (for example, MPEG), the error is continuously transmitted. This is to prevent this from happening.

[0003]

2. Description of the Related Art Various systems have been studied as systems for transmitting and broadcasting digital signals.

[0004] Among them, a method of transmitting a digital signal by a direct spectrum spread technique capable of effectively using a radio wave resource has attracted attention.

In this direct spread spectrum technique, on the transmitting side, the information to be transmitted is given a unique PN for each transmitting station.
Modulate with a code (spread code) and send it out on the transmission line,
On the receiving side, the modulated signal supplied through the transmission path is demodulated by the same PN code as on the transmitting station side to reproduce the transmitted information.

[0006]

However, in the conventional direct spread spectrum technique, there is a problem that the frequency utilization efficiency is poor because the frequency is spread.

Further, when a digital signal is transmitted using a transmission line whose state changes with the passage of time, in the conventionally known digital signal transmission system, the received signal level is a certain level. Or
When the level of the interfering wave exceeds a certain level, there is a problem that the error rate after demodulation rapidly increases and the line is disconnected.

For this reason, when a television signal is compressed and transmitted using the DCT method with motion compensation (for example, a method such as MPEG), it is transmitted using a transmission line whose transmission state changes with time. At this time, if an error occurs in the intra-coded image, there is a problem that the error continuously occurs until the next intra-coded image is received.

In view of the above circumstances, the present invention can improve frequency utilization efficiency and prevent the line from being disconnected even when the state of the transmission line deteriorates. DCT method (for example,
It is an object of the present invention to provide a spread spectrum transmission / reception system capable of preventing continuous error even when compressed and transmitted using a method such as MPEG.

[0010]

In order to achieve the above object, a spread spectrum transmission / reception system according to the present invention is a spread spectrum transmission / reception for transmitting / receiving a radio signal modulated by a spread spectrum method between a transmitting side and a receiving side. In the system, the transmission side weights information to be transmitted according to importance, orthogonally transforms and multiplexes each information, and spreads spectrum using PN code to generate a transmission signal. And then send,
The receiving side is characterized in that the received signal is subjected to spectrum despreading using the same PN code as the transmitting side to reproduce information, and then the information is subjected to inverse orthogonal transform to reproduce each information. .

[0011]

In the above structure, on the transmitting side, the information to be transmitted is weighted according to the degree of importance, and then each information is orthogonally transformed and multiplexed, and P
The N code is used to spread the spectrum to generate a transmission signal, which is transmitted. At the reception side, the received signal is despread with the same PN code as the PN code on the transmission side to reproduce information. After that, this information is inversely orthogonally transformed to reproduce each information.

[0012]

1 is a block diagram showing a first embodiment of a spread spectrum transmission / reception system according to the present invention.

A spread spectrum transmission / reception system shown in this figure takes in digital information and converts it into a transmission signal by a direct spread spectrum method, and a transmission generated by this direct spread spectrum transmission apparatus 1. A frequency conversion circuit 2a for converting a signal into a high frequency signal, an antenna 2 for transmitting the high frequency signal generated by the frequency conversion circuit 2a as a radio wave, and an antenna for receiving the radio wave transmitted by the antenna 2 and generating a reception signal 3, a frequency conversion circuit 3a for converting a reception signal obtained by the antenna 3 into a baseband signal, and a direct spectrum spread spectrum for taking in the baseband signal obtained by the frequency conversion circuit 3a and demodulating the digital information. It is equipped with a receiver 4 and the spectrum directly The digital information is taken in by the dispersion transmitting device 1, the digital information is weighted, and then the signal obtained by the Hadamard transform is directly spread in spectrum to generate the transmission signal. The digital signal is reproduced by receiving the transmission signal and performing signal processing reverse to that of the direct spectrum spread transmitter 1 while receiving the transmission signal.

As shown in FIG. 2, the spectrum direct spread transmitter 1 includes a layering circuit 5, a check information adding circuit 6, a weighting circuit 7, a matrix circuit 8, a Hadamard transform circuit 9, and a PN code generating circuit 10. And the multiplication circuit 11, which takes in digital information to be transmitted, performs weighting processing on this digital information, performs Hadamard transform to multiplex, and obtains by this multiplexing processing. The spectrum is directly spread on the signal, the frequency conversion circuit 2 a generates a transmission signal, and the transmission signal is transmitted from the antenna 2.

The layering circuit 5 is a circuit for classifying input digital information, takes in digital information to be transmitted, classifies the digital information according to the importance of the information, and m
Individual pieces of digital information S _{1 to} S _m are generated and supplied to the inspection information adding circuit 6.

The inspection information adding circuit 6 uses a parity method or C
Digital information S by RC method, syndrome method, etc.
_{1 to} S _m is a circuit for adding inspection information to each of them, and takes in digital information S _{1 to} S _m output from the layering circuit 5 and corrects the digital information S _{1 to} S _m for error correction. Inspection information is added and supplied to the weighting circuit 7.

The weighting circuit 7 is provided for each of the digital information S ₁ ...
S _m is provided with m coefficient units 12 for weighting amplitude (power) and the like, and the digital information S _{1 to} S _m to which the inspection information output from the inspection information adding circuit 6 is added. With the digital information S
Weighting coefficient K ₁ preset for _{1 to} S _m
.About.K _m are applied to the matrix circuit 8.

In this case, if the importance levels of the digital information S _{1 to} S _m are in the order of “S ₁ > S ₂ > S ₃ >...> S _m ”, the weighting factors K _{1 to} K _m are “ ₁ ”. K ₁ ＞ K ₂ ＞ K ₃
>...> K _m ″, each of these weighting factors K ₁ to
The value of K _m is set.

The matrix circuit 8 is the hierarchical circuit 5
And the order n of the Hadamard transform circuit 9 (however,
(n ≧ m), the digital information S _{1 to} S _m output from the weighting circuit 7 is matrix-processed to generate n pieces of digital information C _{1 to} C _n , which are subjected to Hadamard transform. Supply to the circuit 9.

The Hadamard transform circuit 9 has a Walsh function W ₁ which is a basis function of Hadamard transform for the digital information C _{1 to} C _n output from the matrix circuit 8.
.About.W.sub.n, and _n adder circuits 13 for multiplying, and an adder circuit 14 for adding and multiplexing the digital information output from each of these multiplier circuits 13 to output from the matrix circuit 8. The digital information C _{1 to} C _n to be stored is captured, and the digital information C _{1 to} C _n is subjected to Hadamard conversion to obtain the digital information C _{1 to} C _n.
Are multiplexed to generate a signal, which is supplied to the multiplication circuit 11.

Further, the PN code generation circuit 10 has a PN set for the direct spectrum spread transmitter 1.
A circuit that generates a code, and supplies the generated PN code to the multiplication circuit 11.

The multiplication circuit 11 is a circuit for multiplying the signal output from the Hadamard conversion circuit 9 by the PN code output from the PN code generation circuit 10 to perform direct spectrum spreading, and is obtained by this multiplication processing. The transmitted signal is supplied to the frequency conversion circuit 2a to be converted into a high frequency signal, which is transmitted from the antenna 2.

Further, the direct spread spectrum receiver 4 is
As shown in FIG. 3, a PN code generation circuit 16 and a multiplication circuit 17
, Hadamard inverse transform circuit 18, inverse matrix circuit 19, (m-1) error detection circuits 20, and (m-
1) The switch 21 and the synthesizing circuit 22 are provided to receive the transmission signal transmitted from the spectrum direct spread transmitter 1 and directly despread the received signal obtained by this receiving operation. After that, the Hadamard inverse transformation is performed to reproduce n pieces of digital information C _{1 to} C _n , and this is inverse matrix processed to generate m pieces of digital information S _{1 to} S _m. Error detection is performed on the low digital information S _{2 to} S _m to select digital information having no error, and the digital information obtained by this selection operation and the digital information S _{1 are selected.}
And are combined to reproduce digital information.

The PN code generation circuit 16 is a circuit for generating the same PN code as the PN code set for the direct spectrum spread transmitter 1, and supplies the generated PN code to the multiplication circuit 17.

The multiplying circuit 17 multiplies the received signal obtained by the receiving operation of the antenna 3 and the frequency converting operation of the frequency converting circuit 3a by the PN code output from the PN code generating circuit 16 to directly despread the spectrum. And supplies the signal obtained by this multiplication process to the Hadamard inverse transform circuit 18.

The Hadamard inverse transformation circuit 18 is a circuit which takes in the signal output from the multiplication circuit 17 and performs nth order Hadamard inverse transformation to generate n pieces of digital information C _{1 to} C _n. The digital information C _{1 to} C _n obtained by the processing is supplied to the inverse matrix circuit 19.

The inverse matrix circuit 19 has n pieces of digital information C output from the Hadamard inverse conversion circuit 18.
Inverse matrix processing of _{1 to} C _n is performed for m (however, n ≧
m) is a circuit for converting digital information S _{1 to} S _m of
The digital information S ₁ obtained by this conversion processing is supplied to the synthesizing circuit 22, and the digital information S _{2 to} S _m are supplied.
Is supplied to each error detection circuit 20.

[0028] In this case, the digital information S ₁ to S _m is "S ₁ by the weighting circuit 7 of direct spread spectrum transmission apparatus 1 to be reproduced by the inverse matrix circuit 19>
Since each layer is weighted so that S ₂ > S ₃ >...> S _m ″, the reliability of the digital information S _{1 to} S _m can be obtained even if there is interference or interference noise due to the nature of the direct spread spectrum method. The degree decreases in the order of “S ₁ > S ₂ > S ₃ >...> S _m ”. Therefore, the most weighted digital information S ₁ has the highest reliability and the lowest error rate.

Each error detection circuit 20 takes in each of the digital information S _{2 to} S _m output from the inverse matrix circuit 19, and based on the inspection information contained in each of the digital information S _{2 to} S _m. Each digital information S ₂ ~ S
It is a circuit that checks whether there is an error in _m ,
If there is an error in any of the digital information S _{2 to} S _m by the check processing, the switch 21 corresponding to the digital information in which the error is detected is opened to block the digital information in error, This is prevented from being supplied to the synthesizing circuit 22, and the switch 21 corresponding to the error-free digital information is closed by the check processing to supply this digital information to the synthesizing circuit 22.

The synthesizing circuit 22 selects _{one of the} digital information S ₁ output from the inverse matrix circuit 19 and the digital information S _{2 to} S _m output from each of the switches 21.
This is a circuit that takes in an error-free portion and synthesizes it to reproduce digital information, and outputs the digital information obtained by this synthesis processing.

In this case, “S ₁ > S ₂ ” for each digital information S _{1 to} S _m synthesized by the synthesis circuit 22.
> S ₃ >...> S _m ″ are weighted in this order, so that even if the state of the transmission path deteriorates, the higher the importance of the digital information S _{1 to} S _m , the lower the error occurrence rate. This makes it possible to eliminate the error in the digital information S ₁ and prevent the line from being disconnected even in the worst condition of the transmission path.

Further, in this case, the direct-spread-spectrum transmitter 1 performs Hadamard transform on each digital information C _{1 to} C _n, and the direct-spread-spectrum receiver 4 performs Hadamard inverse transform on the signal obtained by the receiving process. Since the digital information C _{1 to} C _n is reproduced by using the digital information, it is possible to prevent the interference from occurring due to the cross-correlation of the spreading code used when spreading the frequency, thereby improving the frequency utilization efficiency. be able to.

As described above, in this embodiment, the digital information is taken in by the spectrum direct spread transmitter 1, the digital information is weighted, and the signal obtained by the Hadamard transform is subjected to the spectrum direct spread. Then, the transmission signal is generated, and the transmission signal is received by the spectrum direct spread receiver 4, and the digital information is reproduced by performing the signal processing opposite to that of the spectrum direct spread transmitter 1. It is possible to improve the frequency utilization efficiency and prevent the line from being disconnected even when the error rate becomes high.

FIG. 4 is a block diagram showing a second embodiment of the spread spectrum transmission / reception system according to the present invention.

The spread spectrum transmitter / receiver system shown in this figure takes in complex digital information and converts it into a transmission signal by the spread spectrum direct spread method adopting quadrature modulation, and this spread spectrum direct spread transmitter. Frequency conversion circuit 26a for converting the transmission signal generated by 25 into a high frequency signal, antenna 26 for transmitting the high frequency signal generated by this frequency conversion circuit 26a as a radio wave, and the radio wave transmitted by this antenna 26 Antenna 27 for generating a reception signal by the antenna 27, a frequency conversion circuit 27a for converting the reception signal obtained by the antenna 27 into an intermediate frequency, an intermediate frequency signal obtained by the frequency conversion circuit 27a, and the complex digital signal. Direct spread spectrum to demodulate information And a complex digital information is taken in by the spectrum direct spread transmitter 25, and the complex digital information is separated into real number digital information and imaginary number digital information, and then these real number digital information and imaginary number real number digital information are obtained. Each of the information is weighted, and the weighted real digital information and imaginary real digital information are respectively subjected to Hadamard transform and multiplexed, and the signal obtained by this multiplexing is directly spread in spectrum. After that, each of these signals is subjected to quadrature modulation and frequency conversion circuit 26
The transmission signal is generated at a and is transmitted from the antenna 26. Then, the spectrum direct spread receiver 28 receives the transmission signal and performs signal processing reverse to that of the spectrum direct spread transmitter 25 to reproduce the complex digital information.

The direct spectrum spread transmitter 25 is shown in FIG.
A distribution circuit 29, an I-channel circuit 30, a Q
The channel circuit 31 and the quadrature modulation circuit 32 are provided, and while taking in complex digital information and separating this complex digital information into real number digital information and imaginary number digital information, these real number digital information and imaginary number digital information are obtained. On the other hand, each weighting process is performed, and each of the weighted real number digital information and the imaginary number digital information is subjected to Hadamard transform and multiplexed, and the signal obtained by this multiplexing process is directly spread in spectrum, Each of these signals is quadrature-modulated to generate a transmission signal in the frequency conversion circuit 26a, and this is transmitted from the antenna 26.

The distribution circuit 29 takes in complex digital information and separates it into real number digital information and imaginary number digital information. Then, these real number digital information and imaginary number digital information are hierarchized according to their importance, Further, the inspection information is added to each layer to add the real number digital information S
I _{1 to} SI _n and imaginary number digital information SQ _{1 to} SQ _n are generated, and the real number digital information SI _{1 to} SI _n generated by these processes are supplied to the I channel circuit 30 to generate imaginary number digital information SQ. _{1 to} SQ _n are supplied to the Q channel circuit 31.

The I-channel circuit 30 includes the distribution circuit 29.
Captures real digital information SI ₁ ~SI _n output from each with respect to the real digital information SI ₁ ~SI _n, the weighting circuit 33 for weighting processing, real digital information SI output from the weighting circuit 33 ₁
Fetches the ～SI _n, a Hadamard transform circuit 34 which generates a signal by multiplexing these real digital information SI ₁ ~SI _n real digital information SI ₁ ~SI _n performs a Hadamard transform, the direct spread spectrum transmission The signal output from the Hadamard conversion circuit 34 and the first PN code generation circuit 35 that generates the first PN code set for the device 25 are multiplied by the first PN code output from the first PN code generation circuit 35. And a LPF circuit 37 that cuts high-frequency components of the signal output from the multiplication circuit 36 and passes only low-frequency components.

Then, the real number digital information SI _{1 to} SI _n output from the distribution circuit 29 is fetched, weighted for each of the real number digital information SI _{1 to} SI _n , and then Hadamard transform is performed. Along with multiplexing, the signal obtained by this multiplexing process is directly spectrum spread, and then the high frequency component is removed and supplied to the quadrature modulation circuit 32.

Further, the Q channel circuit 31 outputs imaginary digital information SQ _{1 to} SQ _n output from the distribution circuit 29.
And a weighting circuit 38 for weighting each of the imaginary digital information SQ _{1 to} SQ _n .
The imaginary number digital information SQ _{1 to} SQ _n output from the weighting circuit 38 is taken in, and the digital information SQ _{1 to} SQ _n is subjected to Hadamard conversion to multiplex the digital information SQ _{1 to} SQ _n to generate a signal. Hadamard transform circuit 39, second PN code generation circuit 40 for generating the second PN code set for this direct spectrum spread transmitter 25, and Hadamard transform circuit 39
A multiplication circuit 41 for multiplying the signal output from the second PN code generation circuit 40 by the second PN code to perform direct spectrum spreading, and a high frequency component of the signal output from the multiplication circuit 41 to be cut. An LPF circuit 42 that passes only low frequency components is provided.

Then, the imaginary number digital information SQ _{1 to} SQ _n output from the distribution circuit 29 is fetched, and the imaginary number digital information SQ _{1 to} SQ _{n is} weighted and then Hadamard transformed. Along with multiplexing, the signal obtained by this multiplexing process is directly spectrum spread, and then the high frequency component is removed and supplied to the quadrature modulation circuit 32.

The quadrature modulation circuit 32 includes a modulated carrier wave generation circuit 43 for generating two carrier wave signals for quadrature modulation which are 90 degrees out of phase with each other, a signal output from the I channel circuit 30 and the modulated carrier wave generation circuit 43. A multiplying circuit 44 that multiplies the carrier signal of 0 degree phase output from the I channel circuit 30 to modulate the signal output from the I channel circuit 30.
A multiplying circuit 45 that multiplies the signal output from the Q channel circuit 31 and the 90 ° phase carrier signal output from the modulated carrier generation circuit 43 to modulate the signal output from the Q channel circuit 31; An adding circuit 46 for adding and synthesizing the signals output from the respective multiplying circuits 44 and 45 is provided.

The signal output from the I-channel circuit 30 and the signal output from the Q-channel circuit 31 are quadrature-modulated to generate a transmission signal, which is transmitted from the antenna 26.

Further, the spectrum direct spread receiver 28
Is a quadrature demodulation circuit 47, an I channel circuit 48, a Q channel circuit 49, a real number side inverse matrix circuit 50a, and an imaginary number side inverse matrix circuit 50b, as shown in FIG.
And (m-1) error detection circuits 51a and 51b provided on the real number side and the imaginary number side, respectively, and (m-1) switch 52 provided on the real number side and the imaginary number side, respectively.
a and 52b, a real number side synthesis circuit 53a, an imaginary number side synthesis circuit 53b, and a synthesis circuit 99, which receive a transmission signal transmitted from the spectrum direct spread transmitter 25 and receive the same. After separating the received signal obtained by the operation into a real number signal and an imaginary number signal, spectrum direct despreading is performed on each of these real number signal and imaginary number signal, and then Hadamard inverse transform is performed to perform the real number side. and n pieces of digital information CI ₁ ~CI _n of the imaginary side of the n playing the digital information CQ ₁ ~CQ _n, further this inverse matrix processing to m pieces of real digital information SI ₁ ~SI _m And imaginary digital information SQ _{1 to} SQ
_m is generated, and real number digital information SI _{2 to} SI _m and imaginary number digital information SQ ₂ to
Error detection is performed on SQ _m to select error-free digital information, the digital information obtained by this selection operation and the digital information SI ₁ and SQ ₁ are combined, and real number digital information and imaginary number digital information are combined. Reproduce complex digital information by synthesizing.

The quadrature demodulation circuit 47 converts the reception signal obtained by the reception operation of the antenna 27 into the frequency conversion circuit 2.
Separating circuit 54 that takes in an intermediate frequency signal by 7a and separates it, and demodulation carrier wave generating circuit 5 that generates two carrier wave signals for quadrature demodulation whose phases are 90 degrees different from each other.
5, a multiplication circuit 56 that multiplies the signal separated by the separation circuit 54 and the carrier signal of the 0 ° phase output from the demodulation carrier generation circuit 55 to demodulate a real number signal (I signal); The antenna 27 is provided with a multiplication circuit 57 that multiplies the signal separated by the circuit 54 and the 90 ° phase carrier signal output from the demodulated carrier generation circuit 55 to demodulate an imaginary number signal (Q signal). The received signal obtained by the receiving operation is converted into an intermediate frequency, and the signal is captured, separated and demodulated, and the real number signal obtained by the demodulating operation is supplied to the I-channel circuit 48 to obtain an imaginary signal. It is supplied to the Q channel circuit 49.

The I channel circuit 48 receives the real number signal (I signal) output from the quadrature demodulation circuit 47, removes high frequency components and passes low frequency components, and the direct spread spectrum transmitter. A first PN code generating circuit 59 for generating the same PN code as the first PN code set for 25, and a first PN output from the first PN code generating circuit 59 for the real number signal output from the LPF circuit 58. A multiplication circuit 60 that multiplies a code to perform spectrum despreading, and a Hadamard that takes in a real number signal output from this multiplication circuit 60 and performs an nth-order Hadamard inverse transformation to generate n pieces of digital information CI _{1 to} CI _n And an inverse conversion circuit 61, which takes in the real number signal output from the quadrature demodulation circuit 47 and performs direct spectrum despreading. After Tsu, generates n digital information CI ₁ ~CI _n real side by performing Hadamard inverse transform, and supplies it to the inverse matrix circuit 50a.

The Q channel circuit 49 takes in the imaginary number signal (Q signal) output from the quadrature demodulation circuit 47, removes high frequency components and passes low frequency components.
An F circuit 62, a second PN code generation circuit 63 that generates the same PN code as the second PN code set for the spectrum direct spread transmitter 25, and the LPF circuit 6
2 and a multiplication circuit 64 for performing spectrum despreading by multiplying the imaginary number signal output from the second PN code generation circuit 63 by the second PN code, and n And a Hadamard inverse transform circuit 65 for performing the following Hadamard inverse transform to generate n pieces of digital information CQ _{1 to} CQ _{n. The} imaginary number signal output from the quadrature demodulation circuit 47 is taken in, and spectrum direct despreading is performed. after performing, by performing Hadamard inverse transform to generate n digital information CQ ₁ ~CQ _n imaginary side, and supplies it to the inverse matrix circuit 50b.

Inverse matrix circuit 50a or 50b
Are _n pieces of digital information CI _{1 to} CI n output from the I channel circuit 48 or the Q channel circuit 49.
The outputted n pieces of digital information CQ ₁ ~CQ _n inversely matrix processing each of m (where, n ≧ m) real digital information SI ₁ ~SI _m or m pieces of imaginary digital information SQ ₁ ~SQ of This is a circuit for converting to _m , and the real number digital information SI ₁ or the imaginary number digital information SQ ₁ obtained by this conversion processing is combined with the combining circuit 53a or 53b.
To the real digital information SI ₂
˜SI _m or imaginary number digital information SQ _{2 to} SQ _m are supplied to each error detection circuit 51a or 51b.

In this case, the inverse matrix circuit 50a
Or real number digital information SI _{1 to} SI _m or imaginary number digital information SQ _{1 to} S reproduced by 50b.
Q _m is a distribution circuit 29 of the direct spread spectrum transmitter 25.
Since the information is weighted according to the degree of importance, even if there is interference or interference noise due to the nature of the direct spread spectrum method, the more important digital information, the higher its reliability can be improved. The weighted digital information SI ₁ or SQ ₁ has the highest reliability and can be almost error-free.

[0050] Each error detection circuit 51a or 51b takes in each real digital information SI ₂ ~SI _m or imaginary digital information SQ ₂ ~SQ _m output from the inverse matrix circuit 50a or 50b, these digital information SI _{2 to} SI _m or SQ _{2 to} SQ _m based on the inspection information included in each digital information SI _{2 to} SI
a circuit for checking whether there is an error in the _m or SQ ₂ ~SQ _m, if there is an error in any of the digital information SI ₂ ~SI _m or SQ ₂ ~SQ _m by checking processing, error The switch 52a or 52b corresponding to the detected digital information is opened to block the digital information having an error so that it is not supplied to the synthesizing circuit 53a or 53b, and the digital information having no error is processed by the check processing. Switch 52a
Alternatively, 52b is closed and this digital information is supplied to the synthesis circuit 53a or 52b.

The synthesizing circuit 53a outputs the real number digital information SI ₁ output from the inverse matrix circuit 50a and the real number digital information S output from each of the switches 52a.
This is a circuit that takes in a portion that does not contain an error among I _{2 to} SI _m and synthesizes it, and outputs the real number digital information obtained by this synthesizing process to the synthesizing circuit 99.

The synthesizing circuit 53b outputs the imaginary number digital information SQ ₁ output from the inverse matrix circuit 50b and the imaginary number digital information S output from each of the switches 52b.
It is a circuit that takes in an error-free portion of Q _{2 to} SQ _m and synthesizes it, and outputs the imaginary number digital information obtained by this synthesis processing to the synthesis circuit 99.

The synthesizing circuit 99 synthesizes the real number digital information supplied from the synthesizing circuit 53a and the imaginary number digital information supplied from the synthesizing circuit 53b to output m pieces of complex digital information S _{1 to} S _m . To do.

In this case, for each complex digital information S _{1 to} S _m synthesized by the synthesis circuit 99, "S ₁ >"
Since the weighting is performed in the order of S ₂ > S ₃ >...> S _m ″, even if the state of the transmission line deteriorates, each complex digital information S
_The more important information in _{1 to} S _m , the lower the error occurrence rate, which eliminates the error in the complex digital information S ₁ even when the condition of the transmission line is the worst, resulting in line disconnection. It can be prevented from reaching.

In this case, the spectrum direct spread transmitter 25 performs Hadamard conversion for each real number digital information SI _{1 to} SI _n and each imaginary number digital information SQ _{1 to} SQ _n , and the spectrum direct spread receiver 28 receives them. The signals obtained by the processing are separated, and the real number signals and the imaginary number signals obtained by this separation processing are respectively subjected to Hadamard inverse transformation to obtain real number digital information CI _{1 to} CI _n and imaginary number digital information CQ _{1 to} CQ. _{Since the} information is multiplexed so as to reproduce _n , the frequency utilization efficiency can be improved.

As described above, in this embodiment, the complex digital information is fetched by the spectrum direct spread transmitter 25, and the complex digital information is converted into the real digital information SI _{1 to} SI _n and the imaginary digital information SQ _{1 to} SQ.
After separating into Q _n and these real number digital information SI ₁ ~
SI _n and imaginary number digital information SQ _{1 to} SQ _n are weighted respectively, and the weighted real number digital information SI _{1 to} SI _n and imaginary number digital information SQ _{1 to} SQ _n are respectively subjected to Hadamard conversion and multiplexed. In addition, the signals obtained by this multiplexing process are directly spread spectrum, and then each of these signals is quadrature-modulated and transmitted, and the direct-spread spectrum receiver 28 receives the transmission signals, Since the complex digital information is reproduced by performing the signal processing opposite to that of the spread transmitter 25, the frequency utilization efficiency can be improved and the transmission line of the transmission line can be improved as in the first embodiment. Even when the condition deteriorates,
It is possible to prevent disconnection.

FIG. 7 is a block diagram showing a third embodiment of the spread spectrum transmission / reception system according to the present invention.

The spread spectrum transmission / reception system shown in this figure takes in voice information and video information and converts them into a transmission signal by a spread spectrum direct spread system, and this spread spectrum direct spread transmitter 70. A frequency conversion circuit 71a that converts the transmission signal generated by the high frequency signal into a high frequency signal, an antenna 71 that transmits the high frequency signal generated by the frequency conversion circuit 71a as a radio wave, and a radio wave transmitted by the antenna 71 is received and received. An antenna 72 for generating a signal, a frequency conversion circuit 72a for converting a reception signal obtained by the antenna 72 into a baseband signal, a baseband signal obtained by the frequency conversion circuit 72a, and the voice information. , Spread spectrum to demodulate video information and And the audio information and the video information are taken in by the spectrum direct spread transmitter 70, and the audio information and the video information are weighted and then obtained by Hadamard transform. The spread signal is directly spread spectrum to generate a transmission signal, and the transmission signal is received by the spectrum direct spread receiving apparatus 73, and the signal processing opposite to that of the spectrum direct spread transmitting apparatus 70 is performed to perform the audio information and the video. Play information and.

The spectrum direct spread transmitter 70 is shown in FIG.
As shown in FIG.
5, a weighting circuit 76, a matrix circuit 77,
A Hadamard conversion circuit 78, a PN code generation circuit 79,
A multiplication circuit 80 is provided, and the audio information and the video information to be transmitted are fetched, and the video information is hierarchically divided into low-resolution video information and high-resolution video information. Video information, high resolution video information,
While adding inspection information to the voice information,
Weighting processing is performed, Hadamard transformation is further performed for multiplexing, spectrum direct spreading is performed on the signal obtained by this multiplexing processing, a frequency conversion circuit 71a generates a transmission signal, and this is transmitted from the antenna 71.

The video layering circuit 74 is a circuit for layering the input video information into low-resolution video information and high-resolution video information. It takes in the video information to be transmitted and stores this video information. This is hierarchized according to the degree of importance to generate low resolution video information and high resolution video information,
This is supplied to the inspection information adding circuit 75.

The inspection information adding circuit 75 is a circuit for adding inspection information to the audio information, the low resolution video information and the high resolution video information by the parity method, the CRC method, the syndrome method, etc., and the video hierarchy. Conversion circuit 74
The low-resolution video information and the high-resolution video information output from the device are captured, and the audio information to be transmitted is also captured, and the audio information, the low-resolution video information, and the high-resolution video information are respectively captured. , Inspection information is added and supplied to the weighting circuit 76.

The weighting circuit 76 weights the audio information, the low resolution video information and the high resolution video information output from the inspection information adding circuit 75 with a plurality of coefficient units 81 for weighting the amplitude (power) and the like. And the preset weighting factors K _{1 to} K ₃ for the audio information, the low resolution video information and the high resolution video information output from the inspection information adding circuit 75, respectively. Then, it is supplied to the matrix circuit 77.

In this case, audio information, low resolution video information,
If the importance of the high-resolution video information is in the order of “audio information> low-resolution video information> high-resolution video information”, the weighting factors K _{1 to} K ₃ are “K ₁ > K ₂ > K ₃ ”. Thus, the values of these weighting factors K _{1 to} K ₃ are set.

The matrix circuit 77 is a circuit for matching the number of information output from the weighting circuit 76 with the order n of the Hadamard transform circuit 78, and the audio information output from the weighting circuit 76 and the low resolution. The image information and the high-resolution image information are matrix-processed to generate n pieces of information, which are supplied to the Hadamard conversion circuit 78.

The Hadamard transform circuit 78 has n multiplication circuits for multiplying the n pieces of information output from the matrix circuit 77 by Walsh functions W _{1 to} W _n which are the basis functions of the Hadamard transform. An addition circuit for adding and multiplexing the information output from each of these multiplication circuits is provided, and while taking in n pieces of information output from the matrix circuit 77, Hadamard transform is performed on each of these information. And the signals obtained by this multiplexing processing are supplied to the multiplication circuit 80.

Further, the PN code generating circuit 79 is set to the P set for the spectrum direct spread transmitter 70.
This is a circuit that generates an N code, and supplies the generated PN code to the multiplication circuit 80.

The multiplication circuit 80 is a circuit for multiplying the signal output from the Hadamard conversion circuit 78 by the PN code output from the PN code generation circuit 79 to perform spectrum direct spread, and is obtained by this multiplication processing. The transmitted signal is supplied to the frequency conversion circuit 71a and transmitted from the antenna 71.

Further, the spectrum direct spread receiver 73
9 includes a PN code generation circuit 81, a multiplication circuit 82, a Hadamard inverse conversion circuit 83, an inverse matrix circuit 84, an error detection circuit 85, a switch 86, and a synthesis circuit 87. While receiving the transmission signal transmitted from the spectrum direct spread transmitter 70, and directly despreading the received signal obtained by this receiving operation, the Hadamard inverse transform is performed to reproduce n pieces of information, Further, this is subjected to inverse matrix processing to generate audio information, low resolution video information and high resolution video information, and error detection is performed on the high resolution video information to select high resolution video information without error. The high-resolution video information obtained by this selection operation and the low-resolution video information are combined to reproduce the audio information and the video information.

The PN code generation circuit 81 is a circuit for generating the same PN code as the PN code set for the spectrum direct spread transmitter 70, and supplies the generated PN code to the multiplication circuit 82.

The multiplication circuit 82 is a circuit for performing spectrum despreading by multiplying the reception signal obtained by the reception operation of the antenna 72 and the frequency conversion circuit 72a by the PN code output from the PN code generation circuit 81. The signal obtained by this multiplication processing is supplied to the Hadamard inverse transform circuit 83.

The Hadamard inverse transform circuit 83 is a circuit for taking in the signal output from the multiplication circuit 82 and performing nth order Hadamard inverse transform to generate n pieces of information.
The n pieces of information obtained by this conversion processing are supplied to the inverse matrix circuit 84.

The inverse matrix circuit 84 is a circuit for inverse matrix-processing the n pieces of information output from the Hadamard inverse conversion circuit 83 to convert the information into audio information, low resolution video information and high resolution video information. , The audio information obtained by this conversion processing is output as reproduction information, and low-resolution video information is supplied to the synthesizing circuit 87,
Further, the high resolution video information is supplied to the error detection circuit 85.

In this case, the audio information, the low resolution video information and the high resolution video information reproduced by the inverse matrix circuit 84 are "audio information> low resolution video information> high resolution by the weighting circuit 76 of the spectrum direct spread transmitter 70. Since each information is weighted so that it becomes "video information", even if there is interference or interference noise due to the nature of the direct spread spectrum method, the reliability of audio information, low resolution video information, and high resolution video information The degree decreases in the order of “audio information> low resolution video information> high resolution video information”. Therefore, the voice information with the highest weight has the highest reliability and is almost error-free.

The error detection circuit 85 takes in the high resolution video information output from the inverse matrix circuit 84, and there is an error in the high resolution video information based on the inspection information included in the high resolution video information. This is a circuit for checking whether or not there is an error in the high-resolution video information by the check processing, and the switch 86 is opened to block the erroneous high-resolution video information so that it is not supplied to the synthesizing circuit 87. If there is no error in the check processing, the switch 86 is closed to supply the error-free high-resolution video information to the synthesizing circuit 87.

The synthesizing circuit 87 is a circuit for taking in the low resolution video signal output from the inverse matrix circuit 84 and the high resolution video information output from the switch 86, and synthesizing them to reproduce the video information. Yes, the video information obtained by this combining process is output.

In this case, since the low resolution video information and the high resolution video information synthesized by the synthesis circuit 87 are weighted in the order of "low resolution video information> high resolution video information", the state of the transmission path Even if the deterioration occurs, it is possible to reduce the error occurrence rate of the low-resolution video information, which is more important than the high-resolution video information, so that the low-resolution video information can be transmitted even in the worst condition of the transmission path. It is possible to eliminate errors and prevent disconnection.

Further, in this case, the direct-spread-spectrum transmitter 70 side performs Hadamard conversion on the audio information, the low-resolution video information, and the high-resolution video information, and the direct-spread-spectrum receiver 73 performs the reception processing to obtain the information. Since the information is multiplexed so as to perform the Hadamard inverse conversion on the signal to reproduce the audio information, the low resolution video information, and the high resolution video information, it is possible to improve the frequency utilization efficiency.

As described above, in this embodiment, the direct spectrum spread transmitter 70 takes in the audio information and the video information, weights the audio information and the video information, and then Hadamard-converts them. The signal thus obtained is subjected to direct spectrum spread to generate a transmission signal, the transmission signal is received by the spectrum direct spread receiver 73, and the signal processing reverse to that of the spectrum direct spread transmitter 70 is performed to perform the voice information. Since the video information is reproduced, it is possible to improve the utilization efficiency of the frequency and prevent the disconnection of the line even when the error rate becomes high.

FIG. 10 is a block diagram showing a fourth embodiment of the spread spectrum transmission / reception system according to the present invention. In this figure, the same parts as those shown in FIG.
The same reference numerals are attached.

The difference between the spread spectrum transmission / reception system shown in this figure and the system shown in FIG. 7 is that instead of the spread spectrum direct spread receiver 73, a simplified spread spectrum spread receiver 73b is used to spread spectrum spread transmitter 70. That is, the transmission signal transmitted from the device is received to reproduce the audio information and the video information.

As shown in FIG. 11, the spectrum direct spread receiver 73b includes a PN code generating circuit 90 and a multiplying circuit 91.
And a Hadamard inverse transform circuit 92 and an inverse matrix circuit 93, which receives the transmission signal transmitted from the spectrum direct spread transmitter 70 and directly inverts the reception signal obtained by this reception operation to the spectrum direct inverse. After spreading, the Hadamard inverse transform is performed to reproduce n pieces of information, and further this is subjected to inverse matrix processing to generate audio information and low resolution video information and output this.

The PN code generation circuit 90 is a circuit for generating the same PN code as the PN code set for the spectrum direct spread transmitter 70, and supplies the generated PN code to the multiplication circuit 91.

The multiplication circuit 91 multiplies the reception signal obtained by the reception operation of the antenna 72 and the reception circuit (not shown) by the PN code output from the PN code generation circuit 90 to perform spectrum despreading. This is a circuit for performing, and supplies the signal obtained by this multiplication processing to the Hadamard inverse transform circuit 92.

The Hadamard inverse transform circuit 92 is a circuit which takes in the signal output from the multiplication circuit 91 and performs n-th order Hadamard inverse transform to generate n pieces of information.
The n pieces of information obtained by this conversion processing are supplied to the inverse matrix circuit 93.

The inverse matrix circuit 93 is a circuit that inversely matrix-processes the n pieces of information output from the Hadamard inverse transform circuit 92 to convert the information into audio information and low-resolution video information. The audio information thus obtained and the low resolution video information are outputted as reproduction information.

As described above, in this embodiment, the transmission signal transmitted from the spectrum direct spread transmitter 70 is received, and the reception signal obtained by this reception operation is directly despread in the spectrum, and then the Hadamard inverse transform is performed. Since n pieces of information are reproduced, inverse matrix processing is performed on the information, and audio information and low-resolution video information are generated and output, the reception is performed more than in the embodiment shown in FIG. The circuit configuration on the device side can be simplified.

As a result, by mounting the spectrum direct spread receiver 73b on a mobile unit or the like, the transmission signal transmitted from the spectrum direct spread transmitter 70 on the mobile unit is received to obtain audio information and video information. Can be played.

FIG. 12 is a block diagram showing a fifth embodiment of the spread spectrum transmission / reception system according to the present invention.

The spread spectrum transmission / reception system shown in this figure uses a spread spectrum direct transmission apparatus 95 which takes in audio information and video information and converts this into a transmission signal by a direct spread spectrum system, and this direct spread spectrum transmission apparatus 95. A frequency conversion circuit 96a that converts the generated transmission signal into a high frequency signal, an antenna 96 that transmits the high frequency signal generated by the frequency conversion circuit 96a as a radio wave, and a reception signal that receives the radio wave transmitted by the antenna 96. , A frequency conversion circuit 97a for converting the received signal obtained by the antenna 97 into a baseband signal, the baseband signal obtained by the frequency conversion circuit 97a, and the audio information. Direct spread spectrum receiver for demodulating video information And a device 98, fetches an audio information and video information by direct spread spectrum transmitting unit 95, an intra coded picture information is compressed by the motion compensated DCT encoding system video information,
It is separated into predictive-coded video information, and the intra-coded video information, the predictive-coded video information, and the audio information are weighted, and then the signal obtained by Hadamard transform is directly spread in spectrum. Then, a transmission signal is generated and transmitted. Then, the direct-spread-spectrum receiver 98 receives the transmission signal, and the signal processing reverse to that of the direct-spread-spectrum transmitter 95 is performed to reproduce the audio information and the video information.

The direct spread spectrum transmitter 95 is shown in FIG.
3, a DCT encoding circuit 100 with motion compensation,
Inspection information addition circuit 101, weighting circuit 102, matrix circuit 103, Hadamard conversion circuit 104
And a PN code generation circuit 105 and a multiplication circuit 106. The audio information to be transmitted and the video information are taken in, the video information is compressed by the DCT coding method with motion compensation, and the intra code is obtained. After generating the encoded video information and the predictive coded video information, while adding the inspection information to these intra-coded video information, the predictive coded video information, and the audio information, performs weighting processing, Further, Hadamard transform is performed for multiplexing, the signal obtained by this multiplexing processing is directly spread in spectrum, a frequency conversion circuit 96a generates a transmission signal, and this is transmitted from the antenna 96.

The DCT encoding circuit with motion compensation 100
A circuit for compressing input video information by a DCT coding method with motion compensation (for example, a method such as MPEG) to generate intra-coded video information and predictive-coded video information, which is a transmission target. Captured video information is taken in, and the video information is subjected to compression processing by the DCT coding method with motion compensation to generate intra-coded video information and predictive-coded video information, and this is supplied to the inspection information adding circuit 101. To do.

The check information adding circuit 101 is a circuit for adding check information to the audio information, the intra-coded video information, and the predictive-coded video information by the parity method, the CRC method, the syndrome method, or the like. , The intra-coded video information output from the DCT coding circuit with motion compensation 100 and the predictive-coded video information are fetched, and the voice information to be transmitted is also fetched, and these voice information and the intra code are fetched. The inspection information is added to each of the encoded video information and the predictive encoded video information, and the inspection information is supplied to the weighting circuit 102.

The weighting circuit 102 weights the audio information, the intra-coded video information, and the predictive-coded video information output from the inspection information adding circuit 101, such as amplitude (power), respectively. includes a coefficient multiplier 107, and the audio information outputted from said test information adding circuit 101, an intra coded video information, each relative to a predictive coded video information, the weighting coefficient K ₁ which is set in advance To K ₃ respectively, the matrix circuit 103 is multiplied.
Supply to.

In this case, if the importance of the audio information, the intra-coded video information, and the predictive-coded video information is in the order of “audio information> intra-coded video information> predictive-coded video information”, each weighting coefficient K ₁ ~K ₃ is "K _1> K _2>
The values of these weighting factors K _{1 to} K ₃ are set so as to be K ₃ ″.

The matrix circuit 103 is a circuit for matching the number of information output from the weighting circuit 102 with the order n of the Hadamard transform circuit 104, and the voice information output from the weighting circuit 102 and the intra code. The encoded video information and the predictive-coded video information are matrix-processed to generate n pieces of information, which are supplied to the Hadamard transform circuit 104.

The Hadamard transform circuit 104 multiplies n pieces of information output from the matrix circuit 103 by Walsh functions W _{1 to} W _n , which are basis functions, and n multiplication circuits, and each of these multiplication circuits. And an adder circuit for adding and multiplexing information output from the multiplier circuit,
The n pieces of information output from the matrix circuit are taken in, Hadamard transform is performed on each of these pieces of information to be multiplexed, and the signal obtained by this multiplexing processing is supplied to the multiplication circuit 106.

The PN code generation circuit 105 is a circuit for generating the PN code set for the spectrum direct spread transmitter 95, and supplies the generated PN code to the multiplication circuit 106.

The multiplication circuit 106 applies the signal output from the Hadamard conversion circuit 104 to the PN code generation circuit 1
This is a circuit for carrying out direct spectrum spreading by multiplying the PN code output from 05, and the transmission signal obtained by this multiplication processing is supplied to the frequency conversion circuit 96a and transmitted from the antenna 96.

Further, the direct spectrum spread receiver 98
14, the PN code generation circuit 110, the multiplication circuit 111, the Hadamard inverse conversion circuit 112, the inverse matrix circuit 113, the error detection circuit 114, the switch 115, and the motion compensation DCT decoding circuit 116. And receiving the transmission signal transmitted from the spectrum direct spread transmitter 95, and directly despreading the received signal obtained by this reception operation, and then performing Hadamard inverse transform to obtain n Play the information,
Further, this is subjected to inverse matrix processing to generate audio information, intra-coded video information, and predictive-coded video information, and error detection is performed on the predictive-coded video information to perform predictive-coded video without error. Information is selected, and the predictive-coded video information obtained by this selection operation and the intra-coded video information are combined to reproduce the audio information and the video information.

The PN code generation circuit 110 is a circuit for generating the same PN code as the PN code set for the spectrum direct spread transmitter 95, and the generated PN code.
The code is supplied to the multiplication circuit 111.

The multiplication circuit 111 outputs P from the PN code generation circuit 110 to the reception signal obtained by the reception operation of the antenna 97 and the frequency conversion circuit 97a.
It is a circuit that performs spectrum despreading by multiplying by an N code, and supplies the signal obtained by this multiplication processing to Hadamard inverse transform circuit 112.

The Hadamard inverse transform circuit 112 is a circuit that takes in the signal output from the multiplication circuit 111 and performs n-th order Hadamard inverse transform to generate n pieces of information. This information is supplied to the inverse matrix circuit 113.

The inverse matrix circuit 113 performs a reverse matrix process on the n pieces of information output from the Hadamard inverse transform circuit 112 to convert the information into audio information, intra-coded video information, and predictive-coded video information. The audio information obtained by this conversion processing is output as reproduction information, the intra-coded video information is supplied to the motion-compensated DCT decoding circuit 116, and the prediction-coded video information is also detected by the error detection circuit 114. Supply to.

In this case, this inverse matrix circuit 113
The audio information, the intra-coded video information, and the predictive-coded video information reproduced by means of the weighting circuit 102 of the spectrum direct spread transmitter 95 become "audio information> intra-coded video information> predictive-coded video information". Since each information is weighted, the reliability of the audio information, the intra-coded video information, and the predictive-coded video information is "voice information" even if there is interference or interference noise due to the nature of the spectrum direct spread method. > Intra-coded video information> Predictive-coded video information ”. Therefore, the voice information with the highest weight has the highest reliability and is almost error-free.

The error detection circuit 114 takes in the predictive coded video information output from the inverse matrix circuit 113, and based on the inspection information included in the predictive coded video information, the error code detection circuit 114 stores the predictive coded video information in the predictive coded video information. This is a circuit for checking whether there is an error. If there is an error in the predictive coded video information by the check processing, the switch 115 is opened to shut off the predictive coded video information in which the error has occurred, and this is motion compensation. If there is no error in the check processing, the predictive coded video information having no error is supplied to the DCT decoding circuit with motion compensation 116.

The DCT decoding circuit with motion compensation 116
The intra-coded video information output from the inverse matrix circuit 113 and the predictive-coded video information output from the switch 115 are fetched, and DCT decoding processing with motion compensation is performed on them to reproduce the video information. And outputs the video information obtained by this decoding process.

In this case, with respect to the intra-coded video information and the predictive-coded video information decoded by the motion-compensated DCT decoding circuit 116, "intra-coded video information> predictive-coded video information" is in this order. Since they are weighted, the error rate of intra-coded video information, which is more important than the predictive-coded video information, can be lowered even if the condition of the transmission path deteriorates. Even in the worst condition, it is possible to reproduce the video information by eliminating the error in the intra-coded video information.

In this case, on the direct spectrum spread device 95 side, audio information, intra-coded video information,
The Hadamard transform is performed on the predictive coded video information, and the Hadamard inverse transform is performed on the signal obtained by the reception processing by the spectrum direct spread receiver 98 to obtain the audio information, the intra coded video information, and the predictive coded video information. Since the information is multiplexed so as to reproduce, the frequency utilization efficiency can be improved.

Furthermore, in this embodiment, the motion compensated DCT encoding circuit 100 compresses the image information by the motion compensated DCT method to generate intra-encoded image information and predictive-encoded image information, and predicts the same. Since the weight of the intra-coded video information is higher than that of the coded video information for transmission, it is possible to prevent continuous occurrence of error in the video information due to inability to receive the intra-coded video information. You can

As described above, in this embodiment, the direct spectrum spread transmitter 95 takes in the audio information and the video information, and the video information is subjected to the motion compensation DC.
It is compressed by the T encoding method and separated into intra-coded video information and predictive-coded video information, and weighting processing is performed on these intra-coded video information, predictive-coded video information, and audio information. After that, the signal obtained by the Hadamard transform is directly spread in spectrum to generate a transmission signal, and the transmission signal is received by the spectrum direct spread receiving apparatus 98, and the signal processing reverse to that of the direct spread spectrum transmitting apparatus 95 is performed. Since the audio information and the video information are reproduced by performing the above, it is possible to improve the frequency utilization efficiency and prevent the line from being disconnected even when the state of the transmission line deteriorates. DCT with motion compensation
It is possible to prevent continuous errors even when compressed and transmitted using the method.

FIG. 15 is a block diagram showing a sixth embodiment of the spread spectrum transmission / reception system according to the present invention. In this figure, the same parts as those shown in FIG. 12 are designated by the same reference numerals.

The difference between the spread spectrum transmission / reception system shown in this figure and the system shown in FIG. 12 is that instead of the spread spectrum direct spread receiver 98, a simplified spread spectrum spread receiver 98b is used to spread spectrum spread transmitter 95. Receives the transmission signal transmitted from the voice information,
That is, the intra-coded video information is reproduced.

As shown in FIG. 16, the direct spectrum spread receiver 98b includes a PN code generation circuit 120 and a multiplication circuit 1.
21, a Hadamard inverse transform circuit 122, and an inverse matrix circuit 123 are provided to receive the transmission signal transmitted from the spectrum direct spread transmitter 95 and to directly convert the reception signal obtained by this reception operation into a spectrum direct signal. After despreading, Hadamard inverse transformation is performed to reproduce n pieces of information, and further this is subjected to inverse matrix processing to generate audio information and intra-coded video information, and output this.

The PN code generating circuit 120 is a circuit for generating the same PN code as the PN code set for the direct spectrum spread transmitter 95, and the generated PN code.
The code is supplied to the multiplication circuit 121.

The multiplication circuit 121 outputs P from the PN code generation circuit 120 to the reception signal obtained by the reception operation of the antenna 97 and the frequency conversion circuit 97a.
It is a circuit that performs spectrum despreading by multiplying by an N code, and supplies the signal obtained by this multiplication process to Hadamard inverse transform circuit 122.

The Hadamard inverse transform circuit 122 is a circuit which takes in the signal output from the multiplication circuit 121 and performs n-th order Hadamard inverse transform to generate n pieces of information. This information is supplied to the inverse matrix circuit 123.

The inverse matrix circuit 123 is a circuit for performing inverse matrix processing on the n pieces of information output from the Hadamard inverse conversion circuit 122 to convert them into audio information and intra-coded video information. The obtained audio information and intra-coded video information are output as reproduction information.

As described above, in this embodiment, the transmission signal transmitted from the spectrum direct spread transmitter 95 is received, and the received signal obtained by this reception operation is directly despread in the spectrum, and then the Hadamard inverse transform is performed. Since n pieces of information have been played back and inverse matrix processing has been performed on the pieces of information to generate audio information and intra-coded video information and output the information, as compared with the embodiment shown in FIG. The circuit configuration on the receiving device side can be simplified.

As a result, by mounting the spectrum direct spread receiver 98b on a mobile unit or the like, the transmission signal transmitted from the spectrum direct spread transmitter 95 on the mobile unit is received to obtain audio information and video information. Can be played.

Further, in the above-described first to sixth embodiments, the Hadamard transform and the Hadamard inverse transform are used to perform the orthogonal transform and the inverse transform of the information to be transmitted. In addition to the transform, the information may be multiplexed by performing orthogonal transform and inverse transform using, for example, a Parlay matrix.

[0121]

As described above, according to the present invention, it is possible to improve the frequency utilization efficiency and prevent the line from being disconnected even when the state of the transmission line deteriorates. Further, even when a television signal is compressed and transmitted using a DCT system with motion compensation (for example, a system such as MPEG), continuous error can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a spread spectrum transmission / reception system according to the present invention.

FIG. 2 is a block diagram showing a detailed circuit example of the direct spectrum spread transmitter shown in FIG.

FIG. 3 is a block diagram showing a detailed circuit example of the spread spectrum direct receiving apparatus shown in FIG.

FIG. 4 is a block diagram showing a second embodiment of the spread spectrum transmission / reception system according to the present invention.

FIG. 5 is a block diagram showing a detailed circuit example of the spectrum direct spread transmitter shown in FIG.

FIG. 6 is a block diagram showing a detailed circuit example of the spread spectrum direct receiving apparatus shown in FIG.

FIG. 7 is a block diagram showing a third embodiment of the spread spectrum transmission / reception system according to the present invention.

8 is a block diagram showing a detailed circuit example of the spectrum direct spread transmitter shown in FIG. 7. FIG.

9 is a block diagram showing a detailed circuit example of the direct spread spectrum receiving apparatus shown in FIG. 7. FIG.

FIG. 10 is a block diagram showing a fourth embodiment of the spread spectrum transmission / reception system according to the present invention.

FIG. 11 is a block diagram showing a detailed circuit example of the spectrum direct spread receiver shown in FIG.

FIG. 12 is a block diagram showing a fifth embodiment of the spread spectrum transmission / reception system according to the present invention.

13 is a block diagram showing a detailed circuit example of the spectrum direct spread transmitter shown in FIG.

FIG. 14 is a block diagram showing a detailed circuit example of the spectrum direct spread receiver shown in FIG.

FIG. 15 is a block diagram showing a sixth embodiment of the spread spectrum transmission / reception system according to the present invention.

16 is a block diagram showing a detailed circuit example of the spectrum direct spread receiver shown in FIG.

[Explanation of symbols]

1 spectrum direct spread transmitter (transmission side) 2 transmission antenna 2a frequency conversion circuit 3 reception antenna 3a frequency conversion circuit 4 spectrum direct spread receiver (reception side) 5 layering circuit 6 inspection information addition circuit 7 weighting circuit 8 matrix circuit 9 Hadamard transform circuit (multiplexing circuit) 10 PN code generation circuit 11 Multiplication circuit (spread spectrum circuit) 12 Coefficient unit 13 Multiplication circuit 14 Addition circuit 16 PN code generation circuit 17 Multiplication circuit (spectrum despreading circuit) and 18 Hadamard inverse transform Circuit (Inverse Orthogonal Transform Circuit) 19 Inverse Matrix Circuit 20 Error Detection Circuit 21 Switch 22 Compositing Circuit 32 Quadrature Modulation Circuit 33, 38 Weighting Circuit (Weighting Circuit for Multiple Systems) 36, 41 Multiplication Circuit (Spread Spread Circuit for Multiple Systems) 34 , 39 Hadamard conversion circuit Multiple system multiplex circuit) 47 Quadrature demodulation circuit 53 Synthesis circuit 60, 64 Multiplier circuit (multiple system spectrum despreading circuit) 61, 65 Hadamard inverse transform circuit (multiple system inverse orthogonal transform circuit) 74 Video layering circuit 75 Inspection information adding circuit 76 Weighting circuit 78 Hadamard transform circuit (multiplexing circuit) 80 Multiplier circuit (spread spectrum circuit) 82 Multiplier circuit (spectrum despread circuit) 83 Hadamard inverse transform circuit (inverse orthogonal transform circuit) 87 Synthesis circuit 91 Multiplier circuit 91 (Spectrum despreading circuit) 92 Hadamard inverse transform circuit (inverse orthogonal transform circuit) 100 DCT coding circuit with motion compensation 101 Inspection information adding circuit 102 Weighting circuit 104 Hadamard transform circuit (multiplexing circuit) 106 Multiplier circuit (spread spectrum circuit) 111 multiplication circuit (spectrum despreading circuit) 12 Hadamard inverse transformation circuit (inverse orthogonal transform circuit) 116 motion compensated DCT decoding circuit 121 multiplying circuit (spectrum despreading circuit) 122 Hadamard inverse transformation circuit (inverse orthogonal transform circuit)

Claims (12)

[Claims] 1. A spread spectrum transmission / reception system for transmitting / receiving a radio signal modulated by a spread spectrum method between a transmission side and a reception side, wherein the transmission side weights information to be transmitted according to importance. After that, each information is orthogonally transformed and multiplexed, and PN
A spread spectrum transmission / reception system, wherein a spread signal is generated by using a code to generate and transmit a transmission signal. 2. A spread spectrum transmission / reception system for transmitting / receiving a radio signal modulated by a spread spectrum method between a transmission side and a reception side, wherein the reception side uses the same PN code as the PN code of the transmission side for the received signal. A spread spectrum transmission / reception system characterized by despreading the information by using to reproduce the information, and then inverse orthogonally transforming this information to reproduce each information. 3. The hierarchization circuit that takes in digital information as information to be transmitted and hierarchizes it according to the degree of importance, and the transmission side, for each information hierarchized by the hierarchization circuit, A check information adding circuit for adding check information for error detection for each layer, and a weighting circuit for weighting the information added with the check information by the check information adding circuit with a different weight for each layer, A multiplexing circuit for performing orthogonal transformation such as Hadamard transformation on each information weighted by the weighting circuit to multiplex each information, and a PN for the information multiplexed by this multiplexing circuit
The spread spectrum transmission / reception system according to claim 1, further comprising: a spread spectrum circuit that performs direct spread spectrum using a code to generate a transmission signal. 4. The spectrum despreading circuit, which reproduces information by spectrum despreading the received signal using the same PN code as that of the transmission side, on the receiving side. An inverse orthogonal transform circuit that reproduces each information by performing an inverse orthogonal transform such as Hadamard inverse transform, and among the information obtained by this inverse orthogonal transform circuit, the information in which a reception error has occurred is truncated and the information remains. The spread spectrum transmission / reception system according to claim 2, further comprising: a synthesizing circuit that reproduces information based on the information in (1). 5. The weighting circuit of a plurality of systems, wherein the transmitting side takes in digital information as information to be transmitted, hierarchizes it according to importance, and weights it with a different weight for each hierarchy, Multiplexing circuits that multiplex each information by performing orthogonal transformation such as Hadamard transformation on the information of each hierarchy weighted by each weighting circuit, and multiplexing by the multiplexing circuit using mutually different PN codes 2. A plurality of systems of spread spectrum circuits that directly spread each of the generated information, and a quadrature modulation circuit that quadrature modulates the signals generated by these spread spectrum circuits to generate a transmission signal. Spread spectrum transceiver system. 6. The receiving side includes an orthogonal demodulation circuit that orthogonally demodulates a received signal to generate a plurality of systems of signals, and each signal generated by the orthogonal demodulation circuit is the same PN code as the transmitting side PN code. The spectrum despreading circuit of multiple systems that despreads the spectrum to reproduce information, and the information obtained by each spectrum despreading circuit is subjected to inverse orthogonal transformation such as Hadamard inverse transformation to reproduce each information. Inverse orthogonal transform circuits of a plurality of systems, out of the information obtained by each of these inverse orthogonal transform circuits, a combining circuit that discards the information in which a reception error has occurred and reproduces the information based on the remaining information, The spread spectrum transmission / reception system according to claim 2, further comprising: 7. The video layering circuit, wherein the transmitting side takes in a video signal as information to be transmitted, hierarchizes the video signal according to importance, and hierarchizes it into low resolution video information and high resolution video information. , Low-resolution video information and high-resolution video information obtained by the video layering circuit, a test information adding circuit for adding test information for error detection to audio information to be transmitted, and the test information adding circuit A weighting circuit for weighting the added low-resolution video information, high-resolution video information, and audio information with different weights, and low-resolution video information, high-resolution video information, and audio information weighted by the weighting circuit such as Hadamard conversion. A multiplexing circuit that performs orthogonal transformation to multiplex and generate information, and a multiplexing circuit that uses the PN code to multiplex the information. Spread spectrum transmission and reception system according to claim 1, further comprising a spectrum spreading circuit for generating a direct spread spectrum and transmission signal the information, the. 8. The spectrum despreading circuit for the receiving side to reproduce the information by spectrum despreading the received signal using the same PN code as the PN code of the transmitting side, and the spectrum despreading circuit. An inverse orthogonal transform circuit that reproduces low-resolution video information, high-resolution video information, and audio information by performing inverse orthogonal transform such as Hadamard inverse transform, and low-resolution video information and high-resolution obtained by this inverse orthogonal transform circuit. 3. The spread spectrum transmission / reception system according to claim 2, further comprising: a synthesis circuit that discards high-resolution video information in which a reception error has occurred among video information and audio information and reproduces the information based on the remaining information. 9. The receiving side is a spectrum despreading circuit for despreading the received signal using the same PN code as the transmitting side PN code to reproduce information, and the spectrum despreading circuit. The spread spectrum transmission / reception system according to claim 2, further comprising an inverse orthogonal transform circuit that performs an inverse orthogonal transform such as Hadamard inverse transform on the information to reproduce only low-resolution video information and audio information. 10. The DCT with motion compensation, wherein the transmitting side takes in a video signal as information to be transmitted and compresses it by a DCT method with motion compensation to generate intra-coded video information and predictive-coded video information. A coding circuit, an intra-coded video information and a predictive-coded video information obtained by the DCT coding circuit with compensation, and a test information adding circuit for adding test information for error detection to audio information to be transmitted, A weighting circuit for weighting the intra-coded video information and the predictive-coded video information to which the test information is added by the check-information adding circuit with different weights, and the intra-coded video information and the prediction weighted by the weighting circuit. The coded video information and audio information are multiplexed by performing orthogonal transformation such as Hadamard transformation. The spread spectrum transmission / reception system according to claim 1, further comprising: a multiplexing circuit that generates the information, and a spread spectrum circuit that directly spreads the information multiplexed by the multiplexing circuit using a PN code to generate a transmission signal. . 11. The spectrum despreading circuit for despreading the received signal by using the same PN code as the PN code of the transmission side to reproduce information, and the spectrum despreading circuit. An inverse orthogonal transform circuit that reproduces intra-coded video information, predictive-coded video information, and audio information by performing inverse orthogonal transform such as Hadamard inverse transform on the information, and intra-coded video information obtained by this inverse orthogonal transform circuit And a DCT decoding circuit with motion compensation that truncates the predictive-coded video information in which the reception error has occurred among the predictive-coded video information and the audio information, and reproduces the video information based on the remaining error-free information. The spread spectrum transmission / reception system according to claim 2. 12. A spectrum despreading circuit for despreading a received signal using the same PN code as the PN code on the transmitting side to reproduce information, and a spectrum despreading circuit for obtaining the information. The spread spectrum transmission / reception system according to claim 2, further comprising: an inverse orthogonal transform circuit that reproduces intra-coded video information and audio information by performing an inverse orthogonal transform such as Hadamard inverse transform on the information.