JPS6412141B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronization acquisition device for a frequency hopping spread spectrum communication device, and more specifically, the present invention relates to a synchronization acquisition device for a frequency hopping spread spectrum communication device. This invention relates to a synchronization acquisition device that generates a code sequence that is the same as the hopping pattern of a received signal in a frequency hopping type spread frequency communication receiver that performs a frequency hopping method, and finds a phase relationship so that the phases of both codes are in the same phase. .

In any digital communication, it is necessary to ensure synchronization with the communication partner. Synchronization includes "synchronization acquisition" for initial line connection and "synchronization maintenance" for ensuring line synchronization in good condition after initial line connection. Furthermore, in general, "synchronization acquisition" needs to be performed promptly.

A frequency hopping transmitter for frequency spread communication generally has a configuration as shown in FIG. In the transmitter of FIG. 1, the transmission information signal applied from the input terminal 11 is modulated by the modulator 12 to
_i is converted into a modulated signal. This modulated signal of frequency _i is converted to frequency ( _i + _FH ) by balanced modulator 13.
The frequency is converted into a frequency hopping signal. The frequency hopping signal of this frequency ( _i + _FH ) is
It is transmitted from the antenna 15 via the transmitter 14.
Note that the local signal of frequency _FH applied to the balanced modulator 13 is generated by a frequency hopping synthesizer 16 driven by a spreading code generator 17. Further, the reference signal generator 18 generates a timing signal for the spreading code generator 17. Further, the signal generated by the spreading code generator 17 is a hopping pattern.

On the other hand, a frequency hopping type spread frequency communication receiver conventionally has a configuration as shown in FIG. In the receiver of FIG. 2, a received signal received by an antenna 201 is input to a balanced modulator 203 via a receiver 202. The frequency hopping signal of frequency ( _i + _FH ) from the receiver 202 is
The balanced modulator 203 and the subsequent bandpass converter 204 convert the frequency into a demodulated signal of frequency _i . Based on this demodulated signal, the demodulator 205
demodulates the information signal and outputs it to the output terminal 206. A local signal of frequency FH to create a demodulated signal of frequency _i by converting the frequency hopping signal of frequency ( _i + _FH ) _is sent to the spreading code generator 2.
08 is generated by a frequency hopping synthesizer 207 driven by a frequency hopping synthesizer 207. Spreading code generator 2
The signal generated by 08 is a hopping pattern. The synchronization holding circuit 209 provides the spreading code generator 208 with a timing signal for matching the hopping pattern of the received signal with the hopping pattern generated by the receiver when frequency conversion is performed by the balanced modulator 203.

The detector 2101, the low frequency detector 2102, and the correlation detector 2103 constitute a synchronization acquisition circuit 210 for quickly matching the hopping pattern of the received signal and the hopping pattern of the receiver at the time of initial line connection.

Here, the operating principle of synchronization acquisition using general sliding correlation will be explained. This synchronization acquisition is performed by hopping the received signal at frequency ( _i + _FH ).
Patterns and frequencies that operate at different speeds
This is done by correlating with the hopping pattern of _{the FH} local signal, and the correlator consists of a balanced modulator 203, a bandpass filter 204, and a detector 210.
1, a low frequency filter 2102, and a correlation detector 210
3. When both hopping patterns completely match, the signal power passing through the bandpass filter 204 becomes maximum, and therefore the detection output of the lowband filter 2102 also becomes maximum. Conversely, if the two hopping patterns do not match, the signal power passing through the bandpass filter 204 will be small,
The detection output of the low frequency filter 2102 also becomes smaller. Therefore, the correlation detector 2103 monitors the level of the detection output from the low-pass filter 2102, and when the phase relationship that maximizes the detection output level is reached, the diffusion that is the source of the receiver's hopping pattern is detected. Synchronous acquisition can be achieved by making the timing signal that drives the code generator 208 at the same speed as the timing signal of the transmitter's hopping pattern.

This synchronous acquisition method is performed while changing the phase relationship of the hopping pattern, as shown in FIG. Each _j in Figure 3 (where j=1, 2, 3,
..., n) represent the hopping pattern, a represents the hopping pattern of the transmitted signal, b, c,
d and e represent temporal changes in the hopping pattern of the receiver. Therefore, the phase relationships of the hopping patterns are a and b, a and c, a and d, a and e
By taking the integral of each phase relationship,
Correlation can be obtained. Each of these four phase relationships is the case when the phase is changed by 1/2 bit,
Generally, it is sufficient to change the phase by 1/M bits (M is an integer of 2 or more). In order to increase the probability of success in synchronization acquisition, it is necessary to increase M and change the phase by 1/M bits. Here, if the code length of the hopping pattern is N and the integration time of correlation processing is T, then N×M×T time is required as the worst time for synchronization acquisition.

An object of the present invention is to provide a synchronization acquisition device for frequency hopping spread spectrum communication that can significantly shorten the synchronization acquisition time required to achieve the same synchronization acquisition success rate as a conventional frequency hopping spread spectrum communication synchronization acquisition device. It is in.

A specific object of the present invention is to provide a frequency hopping frequency spread communication synchronization acquisition device using a sliding correlation acquisition method that shifts the phase by 1/M bits (M is an integer of 2 or more). Provided is a synchronization acquisition device for frequency hopping spread spectrum communication that reduces synchronization acquisition time to 1/M without deteriorating the synchronization acquisition success rate by performing parallel processing using multiple sliding correlators. It's about doing.

According to the present invention, one spreading code generator that generates a hopping pattern, one frequency hopping synthesizer driven by the spreading code generator, and an output signal of the frequency hopping synthesizer, 1/M (however, M
is an integer of 2 or more); and M balanced modulators each receiving the same received signal at one input terminal. , a band wave detector connected to each output side of the balanced modulator, one wave detector connected to each output side of the band wave wave generator, and each output of the wave detector. one correlation detector connected to each output side of the low frequency detector, one correlation detector connected to each output side of the low frequency detector, and one correlation detector that receives the output signals of the M correlation detectors. The M output signals of the distribution delay means are respectively applied to the other input terminals of the M balanced modulators, and the control switch is configured to control the M correlation modulators. Based on the output signal of the detector,
There is obtained a frequency hopping spread spectrum communication synchronization acquisition device characterized in that the phase of the hopping pattern of the spreading code generator is controlled so as to be in phase with the phase of the hopping pattern of the received signal.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 shows one embodiment of a frequency hopping receiver for frequency spread communication according to the present invention.
The received signal received by the antenna 201 is transmitted to the receiver 2
02 to the power divider 211. The two outputs of the power divider 211 are processed by balanced modulators 2031 and 2032, bandpass filters 2041 and 2042, detectors 21011 and 21012, and low-pass filters 21021 and 2102 in order to perform parallel correlation processing.
2. Provided to the control switch 213 via correlation detectors 21031 and 21032, respectively. A control switch 213 selects the capture detection output of correlator A or the capture detection output of correlator B, and uses the balanced modulator 2031 to adjust the hopping pattern of the received signal to the hopping pattern of the receiver in order to demodulate the information signal. - Control the synchronization holding circuit 209 so that the patterns match. The output signal of the synchronization holding circuit 209 is transmitted to the spreading code generator 208 which is a hopping pattern generation source.
given to. Frequency hopping synthesizer 2
07 is driven by the spreading code generator 208 and outputs a local oscillation signal. The local oscillation signal is distributed by a distributor 214, one of which is distributed by a balanced modulator 20.
31 and the other is added to the balanced modulator 20 through a delay line 212 with a delay amount of 1/2 bit.
Added to 32. Signal demodulation is performed by balanced modulator 203
1 and is despread by a bandpass filter 2041. Based on this demodulated signal, the demodulator 2
05 demodulates the information signal and sends it to the output terminal 206
Output to. In this way, the control switch 213
Based on the outputs of correlators A and B, the phase of the hopping pattern of the receiver is controlled so that the phase of the hopping pattern during signal demodulation is in phase with the hopping pattern of the received signal.

Parallel correlation processing is performed by correlators A and B. If correlator A performs correlation processing on the phase relationships between a and b and a and d in FIG. , a and e are subjected to correlation processing. This is a frequency hopping local oscillation signal that has a delay amount of 1/2 bit due to the delay line 212,
This is because a frequency hopping local oscillation signal with no delay amount is applied to the balanced modulators 2031 and 2032. However, frequency hopping synthesizer 2
07 operates to change the phase of the hopping pattern one bit at a time for one correlation process.

Compared to the synchronization acquisition device shown in FIG. 2, this synchronization acquisition device can reduce the synchronization acquisition time to 1/2 by adding one series of correlators.

Although the above embodiment is applied to a frequency hopping frequency spread communication synchronization acquisition device using a sliding correlation acquisition method in which the phase is shifted by 1/2 bit, the present invention is not limited thereto. That is, when the present invention is applied to a frequency hopping spread spectrum communication synchronization acquisition device using a sliding correlation acquisition method that shifts the phase by 1/M (M is an integer of 2 or more) bits, M sliding correlators are used. By performing parallel processing using the synchronization method, the synchronization acquisition time can be shortened to 1/M without deteriorating the synchronization acquisition success rate.

As explained above, according to the present invention, the synchronization for frequency hopping spread spectrum communication can significantly shorten the synchronization acquisition time required to achieve the same synchronization acquisition success rate as the conventional frequency hopping spread spectrum communication synchronization acquisition device. A capture device is obtained.

[Brief explanation of drawings]

Figure 1 is a block diagram showing a transmitter for frequency spread communication using a general frequency hopping method, Figure 2 is a block diagram showing a receiver for frequency spread communication using a conventional frequency hopping method, and Figure 3 is a block diagram showing a receiver for frequency spread communication using a conventional frequency hopping method.・A diagram showing the phase relationship of patterns. FIG. 4 is a block diagram showing a frequency hopping type spread frequency communication receiver according to the present invention. DESCRIPTION OF SYMBOLS 11... Input terminal, 12... Modulator, 13... Balanced modulator, 14... Transmitter, 15... Antenna, 16... Frequency hopping synthesizer, 17... Spreading code generator, 18... Reference signal generator, 201... Antenna, 2
02... Receiver, 203... Balanced modulator, 204... Bandwidth wave generator, 205... Demodulator, 206... Output terminal,
207...Frequency hopping synthesizer, 208
... Spreading code generator, 209 ... Synchronization holding circuit, 21
0... Synchronization acquisition circuit, 2101... Detector, 2102
...Low frequency detector, 2103...Correlation detector, 2031
...Balanced modulator, 2032 ...Balanced modulator, 2041
...bandwidth wave device, 2042...bandwidth wave device, 210A
...Synchronization acquisition circuit, 21011...Detector, 2102
1...Low frequency detector, 21031...Correlation detector, 21
0B...Synchronization acquisition circuit, 21012...Detector, 21
022...Low frequency detector, 21032...Correlation detector,
211...power divider, 212...delay line, 213...
Control switch, 214...Power divider.

Claims (1)

[Claims] 1 a spreading code generator that generates a hopping pattern; a frequency hopping synthesizer driven by the spreading code generator; an output signal of the frequency hopping synthesizer; 1/M (M is an integer greater than or equal to 2)
a distribution delay means for outputting (M-1) signals whose delay times are increased bit by bit; M balanced modulators each receiving the same received signal at one input terminal; and the balanced modulators a band wave detector connected to each output side of the band wave detector, one wave detector connected to each output side of the band wave wave generator, and one wave detector connected to each output side of the wave detector. a low-pass filter, one correlation detector connected to each output side of the low-pass filter, and one control switch that receives the output signals of the M correlation detectors. Prepare,
The M output signals of the distribution delay means are respectively given to the other input terminals of the M balanced modulators, and the control switch is configured to perform a control switch based on the output signals of the M correlation detectors. , a frequency hopping spread spectrum communication synchronization acquisition device, characterized in that the phase of the hopping pattern of the spreading code generator is controlled so as to be in phase with the phase of the hopping pattern of the received signal.