JP2901844B2 - Frequency hopping radio - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency hopping radio which performs communication by switching frequencies at a low speed.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional frequency hopping radio, in which 1 is a data input terminal of a transmitter, 2 is a modulator for modulating input data, and 3 is a modulator.
a is a mixer (transmitting mixer), 4 is a transmitting unit, 5a is a frequency synthesizer on the transmitting side, 6a is a pseudo-noise (hereinafter referred to as PN) generator on the transmitting side, 7 is an output terminal, and these are transmitters T. Is composed.

Further, reference numeral 8 denotes a reception input terminal, 9 denotes a reception unit, 3
b is a mixer (reception side mixer), 5b is a frequency synthesizer on the reception side, 6b is a PN generator on the reception side, 10 is a bandpass filter, 11 is a square detector with good detection sensitivity, 12
Is a decision unit, 13 is an acquisition controller, and these are receivers R
Is composed.

Next, the operation will be described. First, data input from the data input terminal 1 is modulated by the modulator 2. Further, the PN generator 6a shifts the PN generator 6a every several data items, and generates a PN signal in synchronization with the data.
The frequency of the frequency synthesizer 5a is switched accordingly, mixed with the modulated wave by the mixer 3a, and output from the output terminal 7 through the transmission unit 4.

On the other hand, in the receiver, a transmission signal received and input from a reception input terminal 8 is amplified by a reception unit 9 and is converted into a local signal in which the frequency of a frequency synthesizer 5b is switched in synchronization with a PN generator 6b. The mixer 3b de-spreads the modulated wave signal. However, since the frequency of the transmission wave is hopping, the signal cannot be detected from the bandpass filter 10 unless the timing matches the local frequency on the receiving side.

For this reason, the output of the bandpass filter 10 is detected by a square detector 11, the presence or absence of a signal is determined by a determiner, and the PN generator 6b is controlled by a capture controller 13 using the determination result. To capture the transmission signal, shift to tracking, and reproduce the data.

[0007]

Since the conventional frequency hopping radio is configured as described above, in the synchronization acquisition operation, the reception side acquires the transmission signal based on the result of the judgment of the presence or absence of the transmission signal. Therefore, when an interference wave from another is mixed in a transmission wave, it is difficult to acquire synchronization, and erroneous synchronization may occur, so that there is a problem that a synchronization time becomes longer. A technique similar to the conventional frequency hopping radio is described in Science and Technology Publishing Company, “Spread Spectrum Communication System”, Mitsuo Yokoyama,
565.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a frequency hopping radio device which can accurately and quickly acquire synchronous signals even when interfering waves are mixed. Aim.

A second object of the present invention is to obtain a frequency hopping radio which can acquire synchronization at high speed even if there is a strong interference wave by searching for a frequency by a sliding method.

A third object of the present invention is to provide a frequency hopping radio which can synchronously capture even very slow frequency hopping by switching the frequency at high speed.

A fourth object of the present invention is to provide a frequency hopping radio which can accurately capture a predetermined transmission wave by using a direct spread signal having good correlation even if there are a plurality of transmitters. I do.

[0012]

According to a first aspect of the present invention, there is provided a frequency hopping radio device which switches and outputs input data or a pseudo-noise signal for direct spreading output from a pseudo-noise generator for direct spreading on a transmission side. A pseudo-noise generator on the transmission side that outputs a pseudo-noise signal for each of a plurality of pieces of modulated output data obtained by modulating the output signal of the switch, and switching by a frequency synthesizer on the transmission side based on the pseudo-noise signal. A mixer that mixes the output frequency and the frequency of the modulated output data signal and outputs the result from the transmitting unit; and a receiving-side frequency synthesizer that outputs a local signal whose output frequency is switched in synchronization with a pseudo-noise generator on the receiving side. ,
A receiving mixer for mixing the local signal and data obtained by a receiving unit; and a despreader for directly outputting an output from the receiving mixer to a pseudo-noise generator for direct spreading on the receiving side. Correlation detection is performed at the timing of the pseudo-noise signal for spreading, and based on the timing, the pseudo-noise generator on the receiving side is controlled by a capture controller to synchronously capture frequency hopping.

A frequency hopping radio according to a second aspect of the present invention uses a despreader to output an output from a mixer on the receiving side to a pseudo noise signal for direct spreading output from a pseudo noise generator for direct spreading on the receiving side. The frequency is gradually switched so that synchronous detection can be performed at the timing described above, and correlation detection is performed.

According to a third aspect of the present invention, in the frequency hopping radio, the output of the mixer on the receiving side is converted by the despreader into the timing of the pseudo-noise signal for direct spreading output from the pseudo-noise generator for direct spreading on the receiving side. The frequency is switched at a high speed so that synchronous detection can be performed, and correlation detection is performed.

According to a fourth aspect of the present invention, in the frequency hopping radio device, the output from the mixer on the receiving side is output by the despreader to the timing of the pseudo-noise signal for direct spreading output from the pseudo-noise generator for direct spreading on the receiving side. In this method, correlation detection is performed using a direct spreading code having good correlation.

[0016]

The frequency hopping radio device according to the first aspect of the present invention performs direct spread modulation within one hop, and obtains an apparent sensitivity at a hop speed for several hops at the time of acquisition, so that an interference wave or the like can be obtained. Hop synchronization can be easily achieved even when a large number of signals of different codes are mixed.

The frequency hopping radio device according to the second aspect of the present invention performs synchronization acquisition of frequency hopping by slightly increasing or decreasing the frequency switching speed of the receiving side with respect to the transmitting side by using a sliding method to search for a transmission frequency for synchronization.

According to the third aspect of the present invention, the frequency hopping radio device searches for the transmission frequency for synchronization by high-speed switching, thereby quickly acquiring the frequency hopping synchronization.

In the frequency hopping radio according to the fourth aspect of the present invention, different direct spreading codes are set for different communication systems, and interference waves are more effectively removed from a plurality of communication systems.

[0020]

[Embodiment 1] An embodiment of the first aspect of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a data input terminal of a transmitter, 2 is a modulator that modulates input data,
3a is a mixer (transmission side mixer), 4 is a transmission unit, 5a
Is a transmitting-side frequency synthesizer, 6a is a transmitting-side pseudo-noise generator, and 7 is an output terminal, which are the same as those shown in FIG. Reference numeral 14a denotes a pseudo noise generator for direct spreading, and 15 denotes a switch for switching and outputting input data or a pseudo noise signal for direct spreading.

Reference numeral 8 denotes a reception input terminal, 9 denotes a reception unit, 3
b is a mixer (receiving mixer), 5b is a frequency synthesizer on the receiving side, 6b is a PN generator on the receiving side, 10 is a bandpass filter, 14b is a pseudo-noise generator for direct spreading on the receiving side, 16 is a despreader, 17 is a timing detector and 13 is an acquisition controller.

Next, the operation will be described. A few hops at the beginning of transmission are not modulated by the input data from the data input terminal 1, but are modulated by the signal from the PN generator 14a for direct spreading according to the code sequence. The switching is performed by the switch 15.

The signal is awaited on the receiving side, correlation detection is performed by the despreader 16 at the timing of the pseudo noise signal from the PN generator 14b for direct spreading, and the timing is acquired by the timing detector 17, Acquisition controller 13
To capture frequency hopping.

In this embodiment, the receiving side waits at a certain fixed frequency with respect to the transmitting side that performs frequency hopping, and if the transmitting and receiving frequencies match and a direct spreading correlation is established,
The capture is completed and the system moves to tracking. This example is shown in FIG.

That is, according to FIG. 2, if the receiving side is waiting at the frequency f ₂ and the same direct spreading modulation code as the transmitting side, when the transmitting side is at the frequency f ₂ , it matches the transmitting / receiving frequency, , The acquisition is completed. After that, the frequency may be switched so as to be the same frequency as the transmitting side, and the frequency may be followed.

Embodiment 2 FIG. Next, the configuration is the same as that of the first embodiment, but FIG. 3 shows an embodiment in which the receiving side also switches the frequency and performs synchronous acquisition. This makes the frequency switching speed of the receiving side slightly faster or slower than that of the transmitting side (sliding method). Then, if the frequency coincides with the transmission and reception and the correlation is established, the acquisition is completed and the process shifts to tracking.

In this case, the transmission and reception frequencies do not need to be exactly the same in time, and the partial correlation can be sufficiently acquired. In Figure 3, toward the receiving side is slightly faster frequency switching speed, but each frequency match gradually, not reach the threshold level L for capture, if the f _4, exceeds the correlation value Therefore, it will shift to tracking subsequently.

Embodiment 3 FIG. FIG. 4 shows an embodiment for very slow frequency hopping. In this case, the frequency on the receiving side is switched at a high speed, the frequency is constantly matched once, the timing at which the correlation is obtained is detected, and the transition from capture to tracking is performed.

Embodiment 4 FIG. FIG. 5 shows an embodiment in which there are a plurality of transmitting stations. In this case, by using a spreading code for direct spreading having a good cross-correlation, even if a plurality of transmission frequencies coincide with each other, the receiving side can accurately capture.

[0030]

As described above, according to the first aspect of the present invention, there is provided a switch for switching and outputting a pseudo-noise signal for direct spreading output from input data or a pseudo-noise generator for direct spreading on a transmission side. A pseudo-noise generator on the transmitting side that outputs a pseudo-noise signal for each of a plurality of modulated output data obtained by modulating the output signal of the switch, and an output frequency that is switched by a frequency synthesizer on the transmitting side based on the pseudo-noise signal. A mixer that mixes the frequency of the modulated output data signal and outputs the mixed signal from a transmitting unit; a receiving-side frequency synthesizer that outputs a local signal whose output frequency is switched in synchronization with a pseudo-noise generator on the receiving side; A receiver mixer for mixing the signal and the data obtained by the receiver is provided, and the output from the receiver mixer is supplied to a despreader by a pseudo for direct spreading on the receiver side. Correlation detection is performed at the timing of the pseudo-noise signal for direct spreading output by the noise generator, and based on the timing, the pseudo-noise generator on the receiving side is controlled so as to synchronously capture frequency hopping by a capture controller. Therefore, there is an effect that a frequency synchronization acquisition can be performed at high speed and reliably without being affected by an interference wave by performing direct diffusion at the time of acquisition and performing acquisition detection.

According to the second aspect of the present invention, the output from the mixer on the receiving side is synchronized with the timing of the pseudo-noise signal for direct spreading outputted from the pseudo-noise generator for direct spreading on the receiving side using the despreader. Since the correlation detection is performed by gradually switching the frequency so that capture is possible, even when there is a strong interference wave, the search for the transmission frequency for synchronization is performed by high-speed switching, so that the synchronization capture of frequency hopping can be performed at high speed. There is an effect that what can be performed is obtained.

According to the third aspect of the invention, the output from the mixer on the receiving side can be synchronously captured by the despreader at the timing of the pseudo-noise signal for direct spreading output from the pseudo-noise generator for direct spreading on the receiving side. Since the configuration is such that the frequency is switched at a high speed and the correlation detection is performed, even if the frequency is hopped due to a very slow switching, there is an effect that a frequency can be quickly acquired.

According to the present invention, the output from the mixer on the receiving side is correlated with the timing of the pseudo-noise signal for direct spreading outputted from the pseudo-noise generator for direct spreading on the receiving side by the despreader. Since it is configured to perform correlation detection using a good direct-spread code, even if there are multiple communication systems, synchronization detection can be performed using different pseudo noise signals, and the desired communication partner can be reliably searched for. This has the effect of obtaining something that can be more reliably performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a frequency hopping radio according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a frequency synchronization acquisition state according to the invention of claim 1;

FIG. 3 is a timing chart showing a frequency synchronization acquisition state according to the invention of claim 2;

FIG. 4 is a timing chart showing a frequency synchronization acquisition state according to the invention of claim 3;

FIG. 5 is a timing chart showing a frequency synchronization acquisition state according to the invention of claim 4;

FIG. 6 is a block diagram showing a conventional frequency hopping radio.

[Explanation of symbols]

 2 Modulator 3a Mixer (transmitter mixer) 3b Mixer (receiver mixer) 4 Transmitter 5a, 5b Frequency synthesizer 6a, 6b PN generator (pseudo noise generator) 9 Receiver 13 Capture controller 14a, 14b For direct spreading Pseudo noise generator 15 Switch 16 Despreader

Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H04B 1/713 H04B 1/707 H04B 7/12

Claims (4)

(57) [Claims] A switch for switching and outputting a pseudo-noise signal for direct spreading output from input data or a pseudo-noise generator for direct spreading on a transmission side; a modulator for modulating an output signal of the switch; Transmitter-side pseudo-noise generator that outputs a pseudo-noise signal in synchronism with the modulated output data for each of a plurality of output data of a transmitter, and a transmitter-side frequency synthesizer whose output frequency is switched based on the pseudo-noise signal A transmitting-side mixer that mixes the output frequency and the frequency of the modulated output signal and outputs the result from a transmitting unit; a receiving unit that receives a transmitting signal from the transmitting unit; and a pseudo-noise generator on a receiving side. A frequency synthesizer on the receiving side that outputs a local signal whose output frequency is switched in synchronization with
A receiving mixer for mixing the local signal and the transmission output data obtained by the receiving unit; and a pseudo-noise for direct spreading output from a pseudo-noise generator for direct spreading on the receiving side. A frequency hopping radio device comprising: a despreader that performs correlation detection at a signal timing; and an acquisition controller that controls the reception-side pseudo-noise generator to synchronously acquire frequency hopping based on the timing. 2. A switch for switching and outputting a pseudo-noise signal for direct spreading output from input data or a pseudo-noise generator for direct spreading on a transmission side, a modulator for modulating an output signal of the switch, Transmitter-side pseudo-noise generator that outputs a pseudo-noise signal in synchronism with the modulated output data for each of a plurality of output data of a transmitter, and a transmitter-side frequency synthesizer whose output frequency is switched based on the pseudo-noise signal A transmitting-side mixer that mixes the output frequency and the frequency of the modulated output signal and outputs the result from a transmitting unit; a receiving unit that receives a transmitting signal from the transmitting unit; and a pseudo-noise generator on a receiving side. A frequency synthesizer on the receiving side that outputs a local signal whose output frequency is switched in synchronization with
A receiving mixer for mixing the local signal and the transmission output data obtained by the receiving unit; and a pseudo-noise for direct spreading output from a pseudo-noise generator for direct spreading on the receiving side. A despreader that performs correlation detection by gradually switching the frequency so that synchronization can be acquired at the timing of a signal, and acquisition control that controls the pseudo-noise generator on the receiving side to acquire frequency hopping synchronously based on the timing. Frequency hopping radio with a device. 3. A switch for switching and outputting a pseudo-noise signal for direct spreading output from input data or a pseudo-noise generator for direct spreading on a transmission side, a modulator for modulating an output signal of the switch, Transmitter-side pseudo-noise generator that outputs a pseudo-noise signal in synchronism with the modulated output data for each of a plurality of output data of a transmitter, and a transmitter-side frequency synthesizer whose output frequency is switched based on the pseudo-noise signal A transmitting-side mixer that mixes the output frequency and the frequency of the modulated output signal and outputs the result from a transmitting unit; a receiving unit that receives a transmitting signal from the transmitting unit; and a pseudo-noise generator on a receiving side. A frequency synthesizer on the receiving side that outputs a local signal whose output frequency is switched in synchronization with
A receiving mixer for mixing the local signal and the transmission output data obtained by the receiving unit; and a pseudo-noise for direct spreading output from a pseudo-noise generator for direct spreading on the receiving side. Despreader that performs correlation detection by switching the frequency at high speed so that synchronization can be acquired at the timing of the signal, and based on the above timing, controls the pseudo-noise generator on the receiving side to acquire the extremely slow frequency hopping synchronously. Frequency hopping radio with an acquisition controller to perform. 4. A switch for switching and outputting a pseudo-noise signal for direct spreading output from input data or a pseudo-noise generator for direct spreading on a transmission side, a modulator for modulating an output signal of the switch, Transmitter-side pseudo-noise generator that outputs a pseudo-noise signal in synchronism with the modulated output data for each of a plurality of output data of a transmitter, and a transmitter-side frequency synthesizer whose output frequency is switched based on the pseudo-noise signal A transmitting-side mixer that mixes the output frequency and the frequency of the modulated output signal and outputs the result from a transmitting unit; a receiving unit that receives a transmitting signal from the transmitting unit; and a pseudo-noise generator on a receiving side. A frequency synthesizer on the receiving side that outputs a local signal whose output frequency is switched in synchronization with
A receiving mixer for mixing the local signal and the transmission output data obtained by the receiving unit; and a pseudo-noise for direct spreading output from a pseudo-noise generator for direct spreading on the receiving side. A despreader that performs correlation detection using a direct spreading code having good correlation at a signal timing, and a capture controller that controls the pseudo-noise generator on the receiving side to synchronously capture frequency hopping based on the timing. A frequency hopping radio equipped with: