JP2001177445A - Transmitter in spread spectrum communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitter in spread spectrum communication system adopting a frequency hopping system that reduces interference with other systems so as to maintain coexistence of the systems. SOLUTION: A transmitter in the spread spectrum communication system adopts the frequency hopping system, and is provided with an acquisition means (5) that acquires the frequency information of interference waves in existence within a frequency range of a generated frequency hopping pattern, a detection means (5) that detects a hopping position at which the hopping frequency identical to that of the interference waves is generated, and inhibit means (5, 3) that inhibit the transmission operation of a transmission message at the hopping position detected by the detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission apparatus and the like in a spread spectrum communication system using a frequency hopping system.

[0002]

2. Description of the Related Art Conventionally, in a spread spectrum communication system using a frequency hopping method, a hopping pattern is generated from a pseudo-random periodic signal for reasons such as an increase in communication capacity and security. According to this method, since mutual communication is possible by detecting correlation between patterns, simultaneous transmission from a plurality of terminals becomes possible. In recent years, spread spectrum communication systems using a frequency hopping system have been adopted in mobile communication systems.

In some cases, a certain frequency within a frequency band of a hopping pattern of a spread spectrum communication system using a frequency hopping system is assigned to another system. In other words, different systems
They may coexist using the same frequency. This is because, in other systems, even if the assigned frequency exists within the frequency band of the hopping pattern, it can be processed as noise because it is affected by pseudo-random timing.

For example, TA which is a radio navigation support system
CAN (Tactical Air Navigation System) and DME (D
960-121
5 MHz pulsed radio waves (interrogation pulse, response pulse) are used, and this frequency band overlaps with the hopping frequency band of the mobile communication system.

Hereinafter, in the present specification, as an example in which different systems coexist using the same frequency, a case where a radio navigation support system coexists with a mobile communication system at the same frequency will be described as an example. explain.

[0006]

However, although the radio-navigation support system can coexist on the same frequency, if the transmitting and receiving stations in the radio-navigation support system communicating on the same frequency increase the number of interference sources. There is a problem that there is no change and the response rate is reduced.

Further, in the mobile communication system using the frequency hopping method, interference is still occurring at the same frequency in other terminals performing simultaneous transmission, and bit errors and frame errors are not affected. Invite outbreak.

Therefore, in a mobile communication system using the frequency hopping method, it is necessary to consider interference from other systems, so that it is possible to increase the ratio of multiplexing in the system and improve the line use efficiency. It has become difficult.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a spectrum using a frequency hopping system which can reduce interference with other systems and coexist with the systems. An object of the present invention is to provide a transmission device and the like in a spread communication system.

[0010]

The present invention has the following arrangement to solve the above-mentioned problems. A transmitting apparatus in a spread spectrum communication system according to the present invention is a transmitting apparatus in a spread spectrum communication system using a frequency hopping method, wherein a frequency of an interference wave existing within a frequency range of a generated frequency hopping pattern is provided. Acquiring means for acquiring information, detecting means for detecting a hopping position at which a hopping frequency of the same frequency as the interference wave occurs, and prohibiting means for inhibiting transmission of a transmission message at the hopping position detected by the detecting means. It is characterized by having. According to a second aspect of the present invention, in the transmission apparatus of the spread spectrum communication system according to the first aspect of the present invention, the message generating means for generating the transmission message is configured to transmit the generated transmission message. And an identification code for determining whether or not the hopping frequency at the transmission timing of the preceding and following transmission messages is the interference frequency based on the detection result of the detection means. The transmitting apparatus in the spread spectrum communication system according to the invention according to claim 3 is the transmitting apparatus in the spread spectrum communication system according to claim 1 or 2, wherein the message generating means for generating the transmission message includes the detected hopping signal. The transmission message generated at the transmission timing of the frequency is not output to the transmission system at the transmission timing, but is output to the transmission system at a delayed timing. The receiving device in the spread spectrum communication system according to the invention according to claim 4 is a receiving device in a spread spectrum communication system using a frequency hopping method, wherein a message that could not be received is lost due to an identification code of the received message. Or a determination means for determining whether the transmission has not been performed by the transmission control. Claim 5
The spread spectrum communication system according to the invention described in
A spread spectrum communication system using a frequency hopping method, wherein the transmitting device obtains frequency information of an interference wave existing within a frequency range of a generated frequency hopping pattern, and a hopping frequency having the same frequency as the interference wave. Detecting means for detecting a hopping position that generates a hopping position, prohibiting means for prohibiting a transmission operation of a transmission message at the hopping position detected by the detection means, and a hopping frequency at a transmission timing of a transmission message before and after the transmission message. Message generating means for generating by adding an identification code of whether or not the interference frequency based on the detection result of the detection means, the receiving device,
According to another feature of the present invention, there is provided a determining means for determining whether a message that could not be received is a missing message or has not been transmitted by transmission control, based on an identification code of the received message. A spread spectrum communication system according to a sixth aspect of the present invention is the spread spectrum communication system according to the fifth aspect, wherein the message generating means transmits a transmission message generated at the transmission timing of the detected hopping frequency. It is characterized in that it is not output to the transmission system at the timing, but is output to the transmission system at a delayed timing. A transmission frequency control method in a spread spectrum communication system according to the present invention is a transmission frequency control method in a spread spectrum communication system using a frequency hopping scheme, wherein the transmission frequency control method exists within a frequency range of a generated frequency hopping pattern. Obtaining frequency information of the interference wave, detecting a hopping position that generates a hopping frequency having the same frequency as the interference wave, and prohibiting a transmission operation of a transmission message at the hopping position detected by the detection unit. And characterized in that: The transmission frequency control method in the spread spectrum communication system according to the invention according to claim 8 is the transmission frequency control method in the spread spectrum communication system according to claim 7, wherein the transmission message is transmitted at a transmission timing of a transmission message before and after the transmission message. A step of adding an identification code indicating whether or not the hopping frequency is an interference frequency based on a detection result of the step of detecting the hopping frequency to generate the identification code. In the transmission frequency control method for a spread spectrum communication system according to the ninth aspect of the present invention, in the transmission frequency control method for a spread spectrum communication system according to the seventh or eighth aspect, the transmission frequency is generated at the transmission timing of the detected hopping frequency. The transmission message is not output to the transmission system at the transmission timing, but is output to the transmission system at a delayed timing. A reception control method in a spread spectrum communication system according to the invention according to claim 10 is a reception control method in a spread spectrum communication system using a frequency hopping method, wherein a message that could not be received is identified by an identification code of the received message. , And a step of determining whether the transmission has not been performed or has not been transmitted by transmission control.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a main configuration of a transmission apparatus in a spread spectrum communication system using a frequency hopping scheme according to an embodiment of the present invention. In this embodiment, claims 1 to 3 and claims 5 to 5
9 corresponds.

In FIG. 1, the transmitting apparatus according to the present embodiment includes a message generating section 1, a primary modulating section 2, a frequency converting section 3, and a hopping pattern generating section 4, in which a control section 5 is provided. Some functions are added to the message generator 1 and the frequency converter 3.

The message generating section 1 receives a digital signal to be input, generates a transmission message, and generates a primary modulation section 2
Output to At that time, the operation of the present embodiment is performed based on the notification of the hopping position from the control unit 5.

The primary modulation section 2 primary-modulates an input transmission message by an appropriate narrow-band modulation method (for example, FSK), and outputs a primary modulation signal to the frequency conversion section 3.

The hopping pattern generation unit 4 generates a frequency hopping pattern, and outputs the frequency conversion unit 3 and the control unit 5
Output to

The frequency converter 3 converts the primary modulation signal into a radio frequency signal and outputs a radio signal (RF signal) to an antenna system. At this time, when the transmission prohibition signal is input from the control unit 5, the operation of the present embodiment is performed.

The control unit 5 according to the present embodiment
Input interference frequency information and hopping pattern generator 4
Based on the frequency hopping pattern from, the hopping position where the same hopping frequency as the interference wave occurs is detected, and the message generator 1 and the frequency converter 3 are controlled.

The correspondence between the above configuration and the claims is as follows. The acquisition unit and the detection unit include a control unit 5
Corresponds. The prohibition means includes the control unit 5 and the frequency conversion unit 3
The whole corresponds. The message generator corresponds to the message generator.

Hereinafter, the operation of the transmitting apparatus according to the present embodiment will be described with reference to FIGS. Thereby, the configuration and operation of the communication system and the transmission frequency control method of the present embodiment will be clarified. FIG. 2 is an example of a message format. FIG. 3 is an explanatory diagram of the identification code to be added. FIG. 4 is a flowchart of the transmission frequency control process.

In the radio-navigation support system, 9
Certain frequencies from 60 to 1215 MHz are allocated. In that coverage, the specific frequency assigned is used. Therefore, the interference frequency information input to the control unit 5 is obtained as follows.

That is, when the transmitting apparatus according to the present embodiment is provided in a mobile unit, the interference frequency information provided to control unit 5 is obtained from the base station for each covered area. Note that the moving object is an aircraft, a vehicle, a person, or the like.

When the transmitting apparatus is provided in a base station of a mobile communication system or a transmitting station of a land-based fixed communication system, the interference frequency in the area where the base station or the transmitting station is located. Since is already known, the interference frequency information can be set in advance in a storage device in the transmitting apparatus and can be supplied to the control unit 5 without acquiring it again. In this case, it may be set in the storage device of the control unit 5.

The control unit 5 detects a hopping position where the same hopping frequency as the interference frequency occurs in the hopping pattern generated by the hopping pattern generation unit 4 based on the interference frequency information acquired in this manner. Check the transmission timing of.

The control unit 5 outputs to the frequency conversion unit 3 a transmission prohibition signal for stopping the conversion operation at the transmission timing of the corresponding frequency. Further, the control unit 5 notifies the message generation unit 1 of each hopping position including the hopping position that is the same as the interference frequency in the hopping pattern generated by the hopping pattern generation unit 4.

The message generator 1 converts the digital signal from the host computer into a message format according to each hopping position, and outputs it to the primary modulator 2. At this time, the message generation unit 1 sets the transmission timing at the interference frequency notified from the control unit 5 to:
Does not output the generated message. In this case,
The message is temporarily stored in a buffer and output at the next transmission timing, for example. That is, the message generator 1
Outputs a message to the primary modulator 2 at the hopping position avoiding the interference frequency.

Here, the message format is, for example, as shown in FIG.
2, an identification code section 23, and a data section 24.
This is an area added by the identification code unit 23 in the present embodiment.

When converting the message format of the input data, the message generator 1 determines whether the hopping frequencies of the messages before and after the message generated this time are interference frequencies, based on the hopping position information notified from the controller 5. An identification code such as “whether or not” is set in the identification code section 23.

More specifically, the message generator 1 sets a 2-bit identification code, for example, as shown in FIG. In FIG. 3, in a normal message transmitted at a hopping position other than the interference frequency, the identification code is set to “00”. In the message transmitted at the hopping position immediately before the hopping position of the interference frequency, the identification code is set to “01”. Further, in the message transmitted with delay as described above, the identification code is set to “11”.

The identification code set in this way determines on the receiving device side whether the received message is a message whose transmission is prohibited as described later or a message missing due to fading or the like during radio wave propagation. Used to

The formatted message generated and output by the message generator 1 is modulated by an internal local signal in a primary modulator 2, becomes a primary modulated signal, and is input to a frequency converter 3.

The frequency converter 3 converts the carrier frequency of the input primary modulated signal into a frequency at an arbitrary hopping position of the frequency hopping pattern generated by the hopping pattern generator 4 and outputs a radio signal (RF signal). Is output.

At this time, at the transmission timing at the interference frequency, the frequency conversion unit 3 is notified of the transmission inhibition signal from the control unit 5, so that the frequency conversion operation is not performed at this time. Output of the RF signal to the outside is prohibited.

FIG. 4 summarizes the transmission frequency control operation described above. In FIG. 4, when a digital signal is input from a host computer (S1), the message generator 1 generates an output message in a predetermined format. At this time, an identification code is added to the message (S2).

Then, the message generation unit 1
Then, it is determined whether or not the generated message is a message at the timing using the interference frequency based on the notification of the hopping position from (S3). If it is not the interference frequency (S3: No), the generated message is output to the primary modulation section 2 without time delay. The identification code at this time is either “00” or “01”.

On the other hand, if it is the interference frequency (S3:
Yes), the generated message is not output immediately, but is output to the primary modulator 2 with a delay of, for example, one message. The identification code at this time is “11”. Thereby, a primary modulation signal is generated (S4), and the frequency conversion unit 3
Is input to

The frequency conversion unit 3 determines whether or not the transmission prohibition signal is input from the control unit 5, that is, whether or not the input message related to the primary modulation signal is a message at a timing using the interference frequency. Judge (S
6). If it is not the interference frequency (S6: No), the frequency is converted without time delay to generate an RF signal (S7). The above-mentioned delayed message also corresponds to the case where it is not the interference frequency, and is similarly frequency-converted. Thereby, the message is transmitted at all hopping positions other than the hopping position of the interference frequency (S8).

On the other hand, if it is the interference frequency (S6:
Yes), the frequency conversion operation is stopped (S9). As a result, no message is transmitted (RF signal is transmitted) (S10), and interference with the wireless navigation support system is suppressed.

As described above, according to the transmission frequency control of the present embodiment, the transmission operation at the frequency used by the radio-navigation support system is prohibited, and the message whose transmission is prohibited is shifted in timing, Transmit at a frequency other than the frequency. Therefore, coexistence with the wireless navigation support system is achieved, and the effective use of the frequency resources becomes possible.

Further, not only mobile units but also base stations and fixed communication transmitting stations acquire frequency information of the coverage area of the wireless navigation support system, so that interference with the wireless navigation support system is avoided in the coverage area. It is guaranteed that the frequency can be used reliably. Therefore, the multiplexing ratio can be increased with confidence, and the line utilization rate can be improved.

Since the mobile unit obtains frequency information for each radio coverage area of the radio navigation support system as it moves, frequency control can be performed in response to changes in the surrounding frequency usage.

Next, FIG. 5 is a block diagram of a main part of a receiving apparatus in a spread spectrum communication system using a frequency hopping system according to an embodiment of the present invention.
This embodiment corresponds to claims 4, 5, and 10.

Referring to FIG. 5, in the receiving apparatus according to the present embodiment, an identification code judging / message organizing section 11 is provided between a receiving section 12 and an error correcting section 13.

Receiving section 12 performs a despreading process on the received signal received by radio, demodulates the message, and outputs the demodulated received message to identification code judging / message organizing section 11.

Identification code judgment / message arrangement section 11
Determines and arranges the input order and output order of the received message based on the content of the identification code in the input received message, and outputs the arranged received message to the error correction unit 13.

The error correction unit 13 corrects a bit error or the like in the received message and outputs a correct message to the data processing system as received data.

As in the case of the transmitting device, the receiving device may be provided in a mobile unit, or may be provided in a base station or a fixed communication receiving station.

Regarding the correspondence between the above configuration and the claims, the identification code corresponds to the identification code determination / message arrangement unit 11.

Next, the reception control operation of the receiving apparatus according to the embodiment will be described with reference to FIGS. FIG. 6 is an explanatory diagram of the reception control operation.

In FIG. 5, a receiving section 12 performs a despreading process on a radio-received received signal based on the same frequency hopping pattern as a transmitting side, and demodulates a received message. At this time, the receiving device does not know in which area of the radio navigation support system the communication partner is,
It is in a state where the transmitting side does not know at what frequency the transmission is controlled.

Identification code judgment / message arrangement section 11
Searches for the identification code part in the received message to be input, decodes the content of the identification code, and determines whether the message that could not be received was lost due to fading during radio wave propagation or not transmitted by transmission control I do.

A specific reception control operation will be described with reference to FIG. In FIG. 6, since the identification code of the transmission message MSG1 received at the reception timing 1 is “00”, it is determined that the message is transmitted at the normal transmission timing (normal message).

The transmission message MSG2 received at the next reception timing 2 is a normal message, but its identification code is "01". Therefore, at the next reception timing 3, no message is received due to transmission control. Judge.

Since the identification code of the transmission message MSG3 received at the next reception timing 4 is "11", it is understood that the transmission message MSG3 has been delayed because transmission was prohibited at the previous reception timing 3. .

The above is the operation of the identification code judging section of the identification code judging / message organizing section 11. The message organizing section performs the following operation. That is, the message organizing unit outputs the transmission messages MSG1 and MSG2 received at the reception timings 1 and 2 to the error correction unit 13 in that order.

On the other hand, the transmission message MSG3 received at the reception timing 4 can be determined by the identification code "11" to be correctly received after the transmission message MSG2 received at the reception timing 2.

Therefore, in the message organizing unit, the transmission message MSG3 received at the reception timing 4 is
Transmission message MSG2 received at reception timing 2
Error correction unit 1
Output to 3.

In other words, on the receiving side, when there is no identification code, the unreception at the reception timing 3 is determined to be a missing message, and the error correction unit 13 must correct the error.

On the other hand, if there is an identification code of the received message, the continuity of the message can be determined by checking the identification code as described above, and the message can be processed as a continuous message. Processing can be prevented.

As described above, in the receiving apparatus according to the present embodiment, it is possible to determine whether a message that could not be received is a missing message or has not been transmitted by transmission control, based on the identification code in the message. In the case where the transmission has not been performed by the transmission control, it can be expected that reception can be performed at the next reception timing in the above example, so that the reception processing does not become complicated.

In other words, it is preferable to add an identification code to a message. However, if it is not necessary to consider the complexity of the receiving process, it can be said that the identification code is not required.

As is apparent from the above description, the spread spectrum communication system using the frequency hopping system, which is the object of the present embodiment, is not limited to the mobile communication system, and the transmitting station and the receiving station are fixedly arranged. The data communication system to be performed is also an object.

Further, the other coexisting system is not limited to the radio navigation support system, but is of course a system using a fixed frequency.

[0063]

As described above, according to the transmitting apparatus in the spread spectrum communication system using the frequency hopping method according to the present invention, the transmission at the interference frequency can be controlled, and the interference with other systems can be controlled. Can be reduced, and coexistence of the system can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main configuration of a transmission apparatus in a spread spectrum communication system using a frequency hopping scheme according to an embodiment of the present invention.

FIG. 2 is an example of a message format.

FIG. 3 is an explanatory diagram of an identification code to be added.

FIG. 4 is a flowchart of a transmission frequency control process.

FIG. 5 is a block diagram of a main part of a receiving apparatus in a spread spectrum communication system using a frequency hopping scheme according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a reception control operation.

[Explanation of Code] 1 Message generation unit 2 Primary modulation unit 3 Frequency conversion unit 4 Hopping pattern generation unit 5 Control unit 11 Identification code judgment / message arrangement unit 12 Reception unit 13 Error correction unit 21 Header unit 22 Synchronization code unit 23 Identification Code part 24 Data part

Claims (10)

[Claims] 1. A transmitting apparatus in a spread spectrum communication system using a frequency hopping method, comprising: an acquiring unit for acquiring frequency information of an interference wave existing within a frequency range of a frequency hopping pattern to be generated; Detecting means for detecting a hopping position at which a hopping frequency of a frequency occurs, and transmitting means for prohibiting transmission of a transmission message at the hopping position detected by the detecting means. apparatus. 2. A message generating means for generating the transmission message, wherein the detection means detects the identification code indicating whether or not the hopping frequency at the transmission timing of the preceding and following transmission messages is an interference frequency. The transmitting apparatus in the spread spectrum communication system according to claim 1, wherein the transmitting apparatus is generated by adding based on a result. 3. The message generating means for generating the transmission message does not output the transmission message generated at the transmission timing of the detected hopping frequency to the transmission system at the transmission timing, but outputs the transmission message to the transmission system at a delayed timing. 3. The transmitting apparatus in a spread spectrum communication system according to claim 1, wherein 4. A receiving apparatus in a spread spectrum communication system using a frequency hopping method, wherein a determination is made based on an identification code of a message to be received whether a message that could not be received is due to a missing message or has not been transmitted by transmission control. A receiving apparatus in a spread spectrum communication system, comprising: a determination unit for performing the determination. 5. A spread spectrum communication system using a frequency hopping method, wherein a transmitting device acquires frequency information of an interference wave existing within a frequency range of a frequency hopping pattern to be generated; Detecting means for detecting a hopping position that generates a hopping frequency of the same frequency; prohibiting means for prohibiting transmission of a transmission message at the hopping position detected by the detection means; transmission of a transmission message before and after the transmission message Message generating means for adding an identification code for determining whether or not the hopping frequency at the timing is an interference frequency based on the detection result of the detection means, and generating the message. Missing message is due to missing or transmission control Spread spectrum communication system using a frequency hopping scheme, characterized in that it comprises a determining means for transmitting or not. 6. The message generating means outputs a transmission message generated at the transmission timing of the detected hopping frequency to the transmission system at a delayed timing without outputting the transmission message to the transmission system at the transmission timing. A spread spectrum communication system using the frequency hopping method according to claim 5. 7. A transmission frequency control method in a spread spectrum communication system using a frequency hopping method, comprising: acquiring frequency information of an interference wave existing within a frequency range of a frequency hopping pattern to be generated; Detecting a hopping position that generates a hopping frequency of the same frequency; anda transmission frequency in a spread spectrum communication system, comprising a step of prohibiting a transmission operation of a transmission message at the hopping position detected by the detection unit. Control method. 8. A step of generating a transmission message by adding an identification code indicating whether or not the hopping frequency at the transmission timing of the transmission message before and after the transmission message is an interference frequency based on the detection result of the step of detecting the hopping frequency. The transmission frequency control method in a spread spectrum communication system according to claim 7, comprising: 9. The method according to claim 1, wherein the transmission message generated at the transmission timing of the detected hopping frequency is not output to the transmission system at the transmission timing but is output to the transmission system at a delayed timing. 9. The transmission frequency control method in the spread spectrum communication system according to 7 or 8. 10. A reception control method in a spread spectrum communication system using a frequency hopping method, wherein a determination is made based on an identification code of a message to be received whether a message that could not be received is due to loss or not transmitted by transmission control. A receiving control method in a spread spectrum communication system.