JPH098703A - Transmitting device and receiving device in frequency hopping communication, and error correction method in frequency hopping communication - Google Patents

Abstract

(57) [Summary] [Object] To provide a burst error correction method and apparatus having a simpler configuration and excellent coding efficiency in order to correct burst errors in FH communication. [Structure] The input data is subjected to Reed-Solomon coding in a Reed-Solomon coding circuit 101 of a transmitter 100 of an FH communication device. This Reed-Solomon code has a code length of n symbols and is a code capable of correcting a burst error of t symbols. The encoded data is distributed to each channel for each t symbol in the frequency conversion circuit 103, and t symbol data is transmitted for each hop. When a burst error due to a narrow band interference wave occurs in any one of the channels, the burst error is t symbols, so that the Reed-Solomon decoding circuit 117 performs Reed-Solomon decoding on the receiving side. , T symbol burst error can be corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to error correction for correcting an error in communication data in frequency hopping communication.

[0002]

2. Description of the Related Art A spread spectrum communication system has been widely studied and its use has been promoted. Spread spectrum communication is roughly divided into two systems, a direct spread system and a frequency hopping (hereinafter referred to as FH) system. In this FH method, the output carrier frequency is pseudo-randomly hopped within a wide range of designated frequencies to perform spread spectrum.

In the FH system communication, when a narrow band interference is received, only data in a predetermined communication channel is affected by noise or the like to cause a data error.

In this case, in the so-called high-speed FH system in which hopping is performed at high speed, communication data contains random errors, and for this error correction, (for example)
Random error correction codes such as BCH code and convolutional code by Viterbi decoding are widely used.

On the other hand, in the low-speed FH system in which the FH is low, data of several bits or more is transmitted in one hop, so that the data transmitted in the disturbed channel is generally observed as a burst error. When correcting this burst error, a random error correction code such as a BCH code or a convolutional code by Viterbi decoding cannot be applied as it is. Therefore, the coded data is bit-interleaved and dispersed into a plurality of channels used for frequency hopping, whereby a burst error in one channel is converted into a random error in a plurality of channels. In this way, by converting the burst error into a random error, it is possible to apply a random error correction code such as the BCH code or a convolutional code by Viterbi decoding.

FIG. 3 is a block diagram showing the configuration of an FH communication device using such a conventional burst error correction method. Further, FIG. 4 is an explanatory diagram for explaining the structure of the transmission data of the burst error correction method by the FH communication device shown in FIG.

In FIG. 3, the input data is supplied to the transmitting section 300 of the FH communication device. The supplied input data is first subjected to random error correction coding in the random error coding circuit 301. Since the data coded here has been coded for random error correction, it is distributed to a plurality of channels by the next interleave circuit 302. As shown in FIG. 4, this interleave circuit 302 takes out encoded data for every N bits corresponding to the number of allocated channels. Then, this N-bit data (referred to as one row of data) is extracted for t rows. Then, as shown in FIG. 4, t pieces of data at the same bit position are extracted from each row of data, and t bits of data are extracted. Here, t is the number of bits of data transmitted in each channel.

The interleave circuit 302 has a memory therein, and by writing N-bit data of t rows into the memory and extracting the data at the same bit position from this memory from each row data, the t-bit data is written. Is getting As shown in FIG. 4, the extracted N pieces of t-bit data are distributed to channels 1 to N, and transmitted on each channel.

The data written in the memory in the interleave circuit 302 is the FH pattern generation circuit 306.
1 from the memory in synchronization with the hopping pattern signal of
Data is read column by column. By reading the data column by column, N pieces of t-bit data are obtained. The N t-bit data obtained here are modulated by the modulation circuit 303 and then supplied to the frequency conversion circuit 304.

On the other hand, the FH synthesizer 307 supplies a frequency whose hopping period and hopping channel are controlled by the hopping pattern signal of the FH pattern generation circuit 306 to the frequency conversion circuit 304. As a result, the modulated signal is converted into the transmission frequency and the amplification circuit 305.
Via the antenna 308. At this time, the data transmitted for each hop is one column of t-bit data read from the memory as shown in FIG.

The transmitted wave by FH is received by the antenna 311 of the receiver 310 of the FH communication device. The received transmission wave is amplified by the amplification circuit 312 and then supplied to the frequency conversion circuit 313.

On the other hand, the FH synthesizer 316 supplies the frequency conversion circuit 313 with a hopping cycle synchronized with the transmission wave by the hopping pattern signal of the FH pattern generation circuit 315 and a frequency at which the hopping channel is controlled. As a result, the frequency-converted reception signal is demodulated by the demodulation circuit 314 into the original communication data.

As for the data demodulated by the demodulation circuit 314, N pieces of demodulated data for each hop are written in the memory in the deinterleave circuit 317 as shown in FIG. Each demodulated data for each hop is t-bit data as described above. That is, on the receiving side, N pieces of t-bit data are sequentially written in the memory. In the deinterleave circuit 317, these data written in the memory are read out from the memory column by column in synchronization with the hopping pattern signal of the FH pattern generation circuit 315. As shown in FIG. 4, this reading is performed in the same manner as the transmitting side, and the data is read by collecting the data at the same bit position of each data for each hop. By this, the data interleaved on the transmission side is deinterleaved on the reception side, and the original communication data is obtained. The data obtained in this way is
The random error decoding circuit 318 corrects the data error and outputs the final output data.

At this time, as shown on the receiving side in FIG. 4, when the data transmitted at the frequency of channel 1 due to the interference wave causes an error due to the burst error, the burst error is caused by the deinterleaving. The data is distributed among other data, resulting in random errors. As a result, the random error decoding circuit 318 can effectively correct the narrow band data error.

[0015]

As described above, the conventional F
In the H communication system, the random error correction code is configured to be able to cope with burst errors by bit interleaving. However, this requires a bit interleave circuit, and the delay time of data due to the interleave operation is too large to be ignored.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an error correction method and apparatus capable of handling burst errors with a simpler configuration in FH communication.

Another object of the present invention is to provide a burst error correction method and apparatus with excellent coding efficiency.

[0018]

In order to solve the above problems, the first invention corrects a burst error of a predetermined number of symbols t (t is a positive integer) in a transmitter used for FH communication. Error correction coding means for performing possible error correction coding on communication data, and the communication data after the correction coding is divided into a small symbol group consisting of the symbols of t or less, and this small symbol group is divided. A transmitting device used for FH communication, comprising: an FH transmitting means that allocates to one hop and performs FH communication.

In order to solve the above-mentioned problems, a second aspect of the present invention is a receiving device for receiving communication data transmitted by the transmitting device according to the first aspect of the present invention, based on the FH of the FH transmitting means, FH receiving means for receiving FH,
Error correction decoding means for performing error correction decoding on the communication data received by the FH receiving means based on the error correction coding used in the error correction coding means. It is a receiving device that does.

A third aspect of the present invention, in order to solve the above-mentioned problems, in the transmitting apparatus according to the first aspect of the present invention, the FH transmitting means is a small symbol composed of t / p (p is an integer of 2 or more) symbols. It is a transmission device characterized by allocating a symbol group to one hop and performing FH communication.

In order to solve the above-mentioned problems, a fourth invention of the present invention is characterized in that, in the above-mentioned transmitter of the first invention, the error correction coding means performs Reed-Solomon coding. It is a device.

In order to solve the above-mentioned problems, the fifth invention of the present invention is characterized in that, in the receiving device of the second invention, the error correction decoding means carries out Reed-Solomon decoding. It is a device.

In order to solve the above problems, a sixth aspect of the present invention corrects an error in communication data by performing a predetermined error correction coding on the transmitting side and performing error correction decoding on the receiving side. In the error correction method in FH communication including a receiving step, the transmitting step may include an error correction code capable of correcting a burst error of a predetermined number of symbols t (t is a positive integer) for communication data to be communicated. And a correction coding step of performing coding, and the communication data coded in the correction coding step is divided into small symbol groups consisting of the symbols of t or less, and each small symbol group is assigned to one hop for FH transmission. And an FH receiving step of receiving communication data according to the FH in the transmitting step, and a receiving step in the FH receiving step. The communication data, performs error correction decoding, an error correction method in a FH communications, characterized in that it comprises an error correction decoding step of restoring the original communication data error has been removed, the.

In order to solve the above problems, a seventh aspect of the present invention is the error correction method in FH communication according to the sixth aspect of the present invention, wherein the FH transmission step is t / p (p is an integer of 2 or more). It is an error correction method in FH communication characterized by allocating a small symbol group consisting of the following symbols to one hop and performing FH transmission.

In order to solve the above problems, the eighth invention of the present invention is the error correction method for FH communication of the sixth invention, wherein the error correction coding in the error correction coding step is a Reed-Solomon code. Is an error correction method in FH communication.

[0026]

Since the FH transmitting means in the first aspect of the present invention allocates a small symbol group consisting of symbols of t or less to one hop, even if an error occurs in the data in the channel of one hop, the FH transmitting means is concerned with the receiving side. It is possible to correct the error.

In the second invention, even if a narrow band error occurs in one channel in the communication data transmitted in the first invention, the error can be corrected by the error correction decoding means. .

In the third aspect of the present invention, the small symbol group is set to t / p. Therefore, even if an error occurs in the data in p channels corresponding to p hops, the error can be corrected. This is because the correctable maximum burst error length is t.

Since the correction coding means in the fourth aspect of the present invention is Reed-Solomon coding, burst errors can be corrected more easily.

The correction decoding means in the fifth invention is
Since the Reed-Solomon decoding is performed, the error can be corrected more easily.

The FH transmitting step in the sixth aspect of the present invention is t
A small symbol group including the following symbols is assigned to one hop and FH transmission is performed. Therefore, on the receiving side, even if an interference wave in a narrow band occurs in one channel and an error occurs, the error in one channel can be corrected in the error correction decoding process.

In the seventh aspect of the present invention, since the small symbol group is t / p, even if an interference wave in a narrow band occurs in the p channel, a data error due to the interference wave can be corrected.

In the eighth aspect of the present invention, Reed-Solomon encoding is performed in the correction encoding step. Therefore, it is possible to perform error correction that can more easily correct the burst error.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows F which is a preferred embodiment of the present invention.
A configuration diagram showing the configuration of an H (hereinafter referred to as FH) communication device is shown. As shown in FIG. 1, the transmission unit 100 of the FH communication device performs Reed-Solomon coding on input data by a Reed-Solomon coding circuit 101.

The feature of this embodiment is that Reed-Solomon coding capable of correcting a burst error of a predetermined length is adopted. Since a coding method that can correct a burst error of a certain length is adopted in this way,
It is possible to cope with a burst error due to a narrow band interference wave in one channel without using an interleave circuit.

The data encoded by the Reed-Solomon encoding circuit 101 is modulated by the modulation circuit 102 and then supplied to the frequency conversion circuit 103. F
The H synthesizer 106 includes an FH pattern generation circuit 105.
The hopping pattern signal and the frequency at which the hopping channel is controlled are supplied to the frequency conversion circuit 103. The modulated signal is converted into a transmission frequency by the frequency conversion circuit and transmitted from the antenna 107 via the amplification circuit 104.

The FH transmission wave is received by the receiving section 110 of the FH communication device.
The antenna 111 is received. The received signal is amplified by the amplifier circuit 112 and then amplified by the frequency converter circuit 113.
Is supplied to.

The FH synthesizer 116 uses a hopping pattern signal output from the FH pattern generation circuit 115 to generate a hopping cycle and a hopping period synchronized with the transmission wave.
The frequency with which the channel is controlled and the frequency conversion circuit 11
Supply 3 The frequency-converted received signal is supplied to the demodulation circuit 114, and demodulated into all the decoded data in the demodulation circuit 114. All the decoded data are decoded in the next Reed-Solomon decoding circuit 117 to obtain the final output data.

At this time, in the transmitter 100 of the FH communication device, the Reed-Solomon code is generated as input data for every k symbols of information length as a code of code length n symbols capable of burst error up to t symbols. . As shown in FIG. 2, the period of the code is made to match the period of the hopping pattern, data of t symbols is assigned for each hop, and this data is transmitted for each hop.

As shown in FIG. 2, the characteristic feature of this embodiment is that the Reed-Solomon encoded data is taken out for every t symbol as it is without using the interleave circuit, and the data of each t symbol is taken out. Is transmitted for each channel. The data of t symbol is
It is a block of data called a small symbol group in the claims. Furthermore, in this embodiment,
As the Solomon code, a code capable of burst error up to t symbols is used. Further, the code length of the Reed-Solomon code in this embodiment is n symbols, and the n symbols are selected to be t × N. Where t is the number of symbols transmitted in one hop,
N is the number of frequency channels used in FH. That is, the code length (n symbols) of the Reed-Solomon code in this embodiment is set to a length that matches the period of FH (N channels).

The transmitted wave of FH is received by the receiving section 11 of the FH communication device.
Received at 0. At this time, as shown in FIG. 2, if only the data transmitted at the frequency of channel 1 has a burst error due to the interfering wave, the number of data errors is t symbols. In this case, since the number of data errors is t symbols, it is possible to completely correct the data error by Reed-Solomon decoding.

A characteristic of this embodiment is that the lead
This is to match the maximum symbol length capable of correcting a burst error in the Solomon code with the number of symbols transmitted per hop on each channel. By doing so, even if an interference wave occurs in any channel and the data in that channel becomes an error, the data of t symbols corresponding to that channel is restored by Reed-Solomon decoding. It is possible to

As described above, according to this embodiment, since t-symbol data is assigned for each hop, it is possible to correct a burst error of data due to interference of any one channel of the hopping channel number n. is there. Furthermore, by allocating data of t / p symbols (p ≦ 2) for each hop, it is possible to correct a data burst error due to interference up to p channels of the number N of hopping channels.

[0045]

As described above, according to the FH communication transmitter, receiver, and error correction method of the present invention,
Since the Reed-Solomon code with high coding efficiency is used and the number of bits corresponding to the number of symbols that is less than or equal to the number of error-correctable symbols is set as the number of transmission bits of one hop, a narrow band interference wave is generated in low-speed FH communication It is possible to efficiently correct a data burst error with a simple configuration.

Specifically, according to the first aspect of the present invention, it is possible to obtain a transmitting device capable of correcting a burst error due to a narrow band interference wave of one channel.

Further, according to the second aspect of the present invention, it is possible to obtain a receiving device capable of correcting a burst error due to a narrow band interference wave in one channel.

According to the third aspect of the present invention, it is possible to correct a burst error not only in one channel but also in any p channel.

According to the fourth aspect of the present invention, since Reed-Solomon coding is performed, it is possible to obtain a transmitting apparatus having higher coding efficiency.

According to the fifth aspect of the present invention, it is possible to obtain a receiving apparatus having excellent coding efficiency as in the fourth aspect of the present invention.

According to the sixth aspect of the present invention, there is provided an error correction method in FH communication capable of correcting narrow band burst errors in one channel by performing coding and decoding rapidly with a simpler configuration. It

According to the seventh aspect of the present invention, the burst error in the p channel can be further corrected in the sixth aspect of the present invention.

According to the eighth aspect of the present invention, the error correcting method which is further excellent in coding efficiency in the sixth aspect of the present invention can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an FH communication device according to a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of the FH communication device shown in FIG.

FIG. 3 is a configuration diagram showing a configuration of a conventional FH communication device.

FIG. 4 is an explanatory diagram illustrating an operation of the FH communication device shown in FIG.

[Explanation of symbols]

100 transmitter for FH communication device, 101 Reed-Solomon encoding circuit, 102 modulation circuit, 103 frequency conversion circuit, 104 amplification circuit, 105 FH pattern generation circuit, 106 FH synthesizer, 107 antenna, 11
0 receiver of FH communication device, 111 antenna, 112 amplification circuit, 113 frequency conversion circuit, 114 demodulation circuit, 1
15 FH pattern generation circuit, 116 FH synthesizer, 117 Reed-Solomon decoding circuit, 300 FH
Transmitter of communication device, 301 Random error coding circuit,
302 interleave circuit, 303 modulation circuit, 30
4 frequency conversion circuit, 305 amplification circuit, 306 FH pattern generation circuit, 307 FH synthesizer, 308 antenna, 310 FH communication receiver, 311 antenna, 3
12 amplification circuit, 313 frequency conversion circuit, 314 demodulation circuit, 315 FH pattern generation circuit, 316 FH
Synthesizer, 317 Deinterleave circuit, 31
8 Decoding circuit for random error.

Claims (8)

[Claims] 1. A transmission device used for frequency hopping communication, wherein error correction coding for correcting burst errors of a predetermined number of symbols t (t is a positive integer) is applied to communication data. Means and frequency hopping transmission means for dividing the communication data after the correction coding into small symbol groups consisting of the symbols of t or less, allocating the small symbol group to one hop, and performing frequency hopping communication. A transmitter used for frequency hopping communication, characterized in that 2. A receiver for receiving communication data transmitted by the transmitter according to claim 1, wherein the frequency hopping receiver performs frequency hopping reception based on the frequency hopping of the frequency hopping transmitter, and the frequency. Error correction decoding means for performing error correction decoding on the communication data received by the hopping reception means based on the error correction coding used in the error correction coding means, Receiver. 3. The transmission device according to claim 1, wherein the frequency hopping transmission means assigns a small symbol group consisting of t / p (p is an integer of 2 or more) symbols to one hop and performs frequency hopping communication. A transmitting device characterized by the above. 4. The transmission device according to claim 1, wherein the error correction coding unit performs Reed-Solomon coding. 5. The receiving device according to claim 2, wherein the error correction decoding means performs Reed-Solomon decoding. 6. An error correction method in frequency hopping communication, comprising: a transmitting step of performing a predetermined error correction coding on a transmitting side; and a receiving step of performing error correction decoding on a receiving side to correct an error in communication data. In the transmitting step, the predetermined number of symbols t is applied to the communication data to be communicated.
(T is a positive integer) error-correction encoding process capable of correcting a burst error, and the communication data encoded in the error-correction encoding process is a group of small symbols consisting of t or less symbols. A frequency hopping transmission step of performing frequency hopping transmission by allocating each small symbol group to one hop and performing frequency hopping transmission, wherein the receiving step receives frequency data according to the frequency hopping in the transmitting step. And a step of performing error correction decoding of the communication data received in the frequency hopping reception step to restore the original communication data from which an error has been removed, and the frequency hopping Error correction method in communication. 7. The error correction method in frequency hopping communication according to claim 6, wherein in the frequency hopping transmission step, a small symbol group consisting of symbols of t / p (p is an integer of 2 or more) or less is made one hop. An error correction method in frequency hopping communication, characterized by performing allocation and frequency hopping transmission. 8. The error correction method in frequency hopping communication according to claim 6, wherein the error correction coding in the error correction coding step is Reed-Solomon coding. Method.