JP2000324021A - Spread spectrum communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spread spectrum communication apparatus that adopts an FH system to attain synchronization acquisition with high accuracy at high speed. SOLUTION: A transmitter is provided with an FH code generating section 14, a high-speed switching frequency synthesizer section 13 that switches a frequency of a local signal at high speed on the basis of an FH code, a DS code generating section 18 that generates a DS code, and a data control section 20 or the like that outputs FH code pattern data and DS code pattern that decide the FH code and the DS code in use. A receiver has an FH code generating section 24, a high-speed switching frequency synthesizer section 23 that switches the frequency of the local signal at high speed on the basis of the FH code generated by the FH code generating section 24, an FH demodulation section 22 that outputs a SYNC data modulation signal and outputs a usual signal, and a DS demodulation section 27 or the like that outputs the SYNC data on the basis of the DS code and passes the usual signal as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication apparatus using the FH system.

[0002]

2. Description of the Related Art In a spread spectrum communication apparatus using the FH system, when a sliding system, which is a general synchronization system, is used, the timing of the frequency change of the received signal and the timing of the frequency change of the local signal based on the FH code coincide. In addition to this, there is a problem that time is required until the synchronization is performed, and if the synchronization timing is missed due to the influence of noise or the like, a re-search is required, and it takes more time to complete the synchronization.

Hereinafter, this problem will be described with reference to FIGS. FIG. 7 is a block diagram showing a receiving apparatus of a conventional spread spectrum communication apparatus using the FH method.
FIG. 8 is an explanatory diagram showing a relationship between a received input signal of the receiving device and a local signal.

In FIG. 7, reference numeral 1 denotes an input terminal of a reception input signal a from an antenna (not shown) for receiving a radio signal;
2 is a frequency hopping (hereinafter referred to as “F
H) demodulation unit, 3 is a high-speed switching frequency synthesizer unit that outputs a local signal b, 4 is an FH code generation unit that controls the high-speed switching frequency synthesizer unit 3, and 5 is a clock generation unit that controls the timing of FH code generation. , 6 is a data control unit for controlling which FH pattern is used to generate the FH code, 7 is a detection unit for detecting an intermediate frequency signal output from the FH demodulation unit, and 8 is a carrier for FH spread modulation. A carrier detection unit 9 receives a detection signal from the detection unit 7 and outputs a reception data c.
Is an output terminal for the received data c.

The operation of the receiving apparatus of the spread spectrum communication apparatus configured as described above will be described. F
The H-spread-modulated RF signal is input to the FH demodulation unit 2 as a reception input signal a via an antenna. FH demodulation unit 2
Is the input signal a and the high-speed switching frequency synthesizer 3
With the local signal b. Here, the phase of the local signal b is made to slide so that the timing of the local signal b coincides with that of the received input signal a. The phase sliding of the local signal b is performed by controlling the fast switching frequency synthesizer unit 3 by the FH code generation unit 4. The output signal (intermediate frequency signal) of the FH demodulation unit 2 is level-detected through the detection unit 7. This intermediate frequency signal is input to the carrier detection unit 8, which detects the timing at which the carrier becomes maximum, and outputs a carrier detection signal indicating the timing to the clock generation unit 5. When detecting the timing at which the maximum value is reached, the clock generator 5 recognizes that the FH synchronization has been completed, and stops the phase sliding. When the FH synchronization is completed (when phase sliding is stopped), the frequency of the output signal of the FH demodulation unit 2 becomes a fixed frequency, is detected by the detection unit 7, and the detection signal from the detection unit 7 is received by the reception data unit 9. Is output from the output terminal 10 as received data c. The data control unit 6 sets the FH code pattern so as not to interfere with another FH code pattern.

FIG. 8 shows a temporal transition of a carrier detection signal and a phase relationship between a received input signal a and a local signal b as an example of an actual FH synchronization detection operation. At time T1, the timing of the received input signal a does not match the timing of the local signal b, and the carrier detection signal is almost zero. However, at the time T2 at which the timing of the received input signal a matches the timing of the local signal b, a predetermined time is reached. A level carrier detection signal is generated.

[0007]

However, in the above-mentioned conventional spread spectrum communication apparatus, a sliding system is used for synchronization acquisition in the FH system. If a long code length is required, it takes time to acquire synchronization. To
If the time constant of carrier detection is increased to increase the accuracy of synchronization acquisition, high-speed FH operation cannot be realized,
Conversely, if the time constant is shortened, there is a problem that the synchronization acquisition becomes unstable.

In this spread spectrum communication apparatus, FH
There is a demand for high-speed and high-accuracy synchronization acquisition in the system.

An object of the present invention is to provide a spread spectrum communication apparatus capable of performing high-speed and high-accuracy synchronization acquisition in the FH system.

[0010]

In order to solve the above-mentioned problems, a spread spectrum communication apparatus according to the present invention comprises a transmitting apparatus and a receiving apparatus, and is a spread spectrum communication apparatus using the FH system. A transmission FH code generator for generating an FH code, a transmission high-speed switching frequency synthesizer for rapidly switching the frequency of a local signal based on the FH code, a transmission DS code generator for generating a DS code, FH for determining code and DS code
A transmission data control unit for outputting code pattern data and DS code pattern data;
A transmission data section that outputs sync data composed of H code pattern data and outputs a normal signal; a DS modulation section that modulates sync data based on the DS code and passes the normal signal as it is; The sync data modulation signal is modulated by a fixed frequency local signal to output a sync data spread modulation signal, and the normal signal output from the DS modulator is modulated by a local signal whose frequency changes based on the FH code. An FH modulator for outputting a signal spread modulation signal, and a transmission clock generator for generating a clock for controlling the timing of generating the DS code in the transmission DS code generator and the timing of generating the FH code in the transmission FH code generator. And a sync data spread modulation signal and a normal signal spread modulation signal output from the FH modulator as radio signals. A receiving antenna for receiving a radio signal including a sync data spread modulation signal and a normal signal spread modulation signal; a reception FH code generation unit for generating an FH code; Receiving high-speed switching frequency synthesizer for rapidly switching the frequency of a local signal based on an FH code generated by a receiving FH code generator, and demodulating a sync data spread modulation signal output from a receiving antenna with a fixed frequency local signal. An FH modulation unit that outputs a normal signal by modulating the normal signal spread modulation signal output from the receiving antenna with a local signal whose frequency changes based on the FH code, and outputs a normal signal. A receiving DS code generating unit for generating a sync data modulated signal based on the DS code A DS demodulator that outputs and passes a normal signal as it is, a clock reproducer that reproduces system synchronization data based on sync data output from the DS demodulator, and a timing of generating a DS code in a receiving DS code generator. A receiving clock generator for generating a clock for controlling the timing of generating the FH code in the receiving FH code generator based on the reproduction system synchronization data; and a receiving FH code generator based on the FH code pattern data and the normal data And a receiving data control unit for controlling the receiving DS code generating unit.

As a result, a spread spectrum communication apparatus capable of performing high-speed and high-accuracy synchronization acquisition in the FH system is obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spread spectrum communication apparatus according to a first aspect of the present invention comprises a transmitting apparatus and a receiving apparatus, and is a spread spectrum communication apparatus using the FH system, wherein the transmitting apparatus uses an FH code. A transmitting FH code generator to be generated, a high-speed switching frequency synthesizer for transmitting the local signal at high speed based on the FH code, a transmitting DS code generator for generating a DS code, and an FH code and DS to be used. A transmission data control unit for outputting FH code pattern data and DS code pattern data for determining a code, a transmission data unit for outputting sync data including system synchronization data and FH code pattern data and outputting a normal signal, D that modulates sync data based on the DS code and passes a normal signal as it is
An S modulator and a sync data modulation signal output from the DS modulator are modulated with a fixed frequency local signal to output a sync data spread modulation signal, and a normal signal output from the DS modulator is based on the FH code. An FH modulator that outputs a normal signal spread modulation signal by modulating with a local signal whose frequency changes, a DS code generation timing in the transmission DS code generator, and a FH code generation timing in the transmission FH code generator A transmission clock generating unit for generating a clock for controlling the signal, a transmitting antenna for radiating a sync data spread modulation signal and a normal signal spread modulation signal output from the FH modulation unit as radio signals, and A receiving antenna for receiving a radio signal including a data spread modulation signal and a normal signal spread modulation signal, and a reception antenna for generating an FH code; A code generation unit, a high-speed switching frequency synthesizer for reception that switches the frequency of a local signal at high speed based on the FH code generated by the reception FH code generation unit, and a fixed sync data spread modulation signal output from the reception antenna An FH that demodulates with a local signal of frequency to output a sync data modulated signal, and modulates a normal signal spread modulation signal output from a receiving antenna with a local signal whose frequency changes based on an FH code to output a normal signal A modulator, a receiving DS code generator for generating a DS code, a DS demodulator for demodulating a sync data modulation signal based on the DS code, outputting sync data, and passing a normal signal as it is, A clock recovery unit for recovering system synchronization data based on the output sync data, and generation of a DS code for reception A receive clock generating section for generating, based on the reproduction system synchronization data clock for controlling the timing of the FH code generation at the timing the reception FH code generation unit of DS code generation in, FH
FH for reception based on code pattern data and normal data
A reception data control unit for controlling the code generation unit and the reception DS code generation unit is provided.

[0013] With this configuration, synchronization acquisition using the DS method is performed at the beginning of the frame, and as a result, synchronization acquisition of FH is performed.

According to a second aspect of the present invention, in the spread spectrum communication apparatus according to the first aspect, the frequency switching timing of a local signal output from the high-speed switching frequency synthesizer for reception is shifted. A reception level control unit that detects the in-band noise to be received, the reception data control unit controls the reception DS code generation unit when FH code pattern data is input, and the reception data control unit when a normal signal is input. The clock generated by the receiving clock generator is controlled based on the level detected by the level detector.

With this configuration, the receiving clock generator is controlled even during the input of the normal signal, and the proper operation can be performed even if the clock generating cycle of the receiving clock generator is low.

A spread spectrum communication apparatus according to a third aspect of the present invention is the spread spectrum communication apparatus according to the second aspect, further comprising a level conversion section for outputting a phase error signal based on a detection level of the level detection section. The high-speed switching frequency synthesizer outputs a local signal whose frequency changes based on the FH code from the receiving FH code generator and whose frequency changes based on the phase error signal.

According to this configuration, the frequency of the local signal is controlled even during the input of the normal signal, and the proper operation is performed even when the frequency of the local signal is low.

A spread spectrum communication apparatus according to a fourth aspect of the present invention is the spread spectrum communication apparatus according to the first aspect, wherein the output is performed by a reception data control section instead of the high-speed switching frequency synthesizer section for reception. A frequency ROM table for controlling the frequency and a high-speed D / A converter for D / A-converting a signal output from the frequency ROM table at a high speed and outputting a high-speed local signal;
FH from the D synthesizer unit and the FH code generation unit for reception
A high-speed switching frequency synthesizer unit for outputting a medium-high-speed local signal based on a code, and a high-speed switching frequency synthesizer unit for reception having a mixer for mixing the high-speed local signal and the medium-high-speed local signal. .

With this configuration, the frequency of the medium-to-high-speed local signal changes at a medium-to-high speed, the frequency of the high-speed local signal changes at a high-speed, and the mixer determines the difference between the frequency of the medium-to-high-speed local signal and the frequency of the high-speed local signal. It has the effect of outputting the sum local signal.

According to a fifth aspect of the present invention, in the spread spectrum communication apparatus according to the fourth aspect, the data control section includes a frequency ROM table section and a medium / high speed switching frequency synthesizer section each having a plurality of frequencies. Is controlled so as to output a high-speed local signal of a plurality of frequencies and a medium-speed local signal of a plurality of frequencies.

With this configuration, a high-speed local signal whose frequency changes rapidly in a narrow band is output from the DD synthesizer section, and a medium-high-speed local signal whose frequency changes in a medium-high speed in a wide band is output from the medium-high speed switching frequency synthesizer section. It has the effect of outputting.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a block diagram showing an FH spread spectrum communication apparatus according to Embodiment 1 of the present invention.

In FIG. 1, A is a transmitting device, B is a receiving device, 11 is a transmitting antenna, 12 is an FH modulator, 13 is a high-speed switching frequency synthesizer for transmission, 14 is a frequency hopping code generator for transmission, and 15 is a transmitting frequency hopping code generator. A transmission clock generation unit, 16 is a transmission timing control unit, 17 is a direct spreading (hereinafter, referred to as “DS”) modulation unit, 18 is a transmission direct spreading (DS) code generation unit, 19 is a transmission data unit, 20
Is a transmission data control unit, 21 is a reception antenna, 22 is F
H demodulation section, 23 is a high-speed switching frequency synthesizer section for reception, 24 is an FH code generation section for reception, 25 is a clock generation section for reception, 26 is a timing control section for reception, and 27 is a DS for reception.
A demodulation unit, 28 is a reception DS code generation unit, 29 is a clock recovery unit, 30 is a reception data unit, and 31 is a reception data control unit.

The operation of the spread spectrum communication apparatus configured as described above will be described with reference to FIG.
FIG. 2A is a format diagram showing the format of one frame of a reception input a for explaining the operation of the spread spectrum communication apparatus of FIG. 1, and FIG. 2B is a diagram illustrating the operation of the spread spectrum communication apparatus of FIG. 1 of the demodulated signal d for
FIG. 3 is a format diagram showing a format of a frame.
2, 51 is a DS operation area, 52 is an FH operation area, 53 is a synchronization establishment area, and 54 is a data area. As shown in FIG. 1, the spread spectrum communication apparatus includes a transmitting apparatus A and a receiving apparatus B. In the description of the operation in the present embodiment, transmitting apparatus A is a transmitting apparatus on the other side, and receiving apparatus B is a local apparatus. Will be described.

First, in transmitting apparatus A, sync data composed of system synchronization data and FH code pattern data is rate-converted by transmission data section 19 and input to DS modulation section 17. The DS modulation unit 17 transmits the transmission DS
The transmission data (sync data at this timing) is DS-modulated at the head timing of the data before being subjected to the FH processing by the transmission timing control unit 16 by using a spreading code determined between the devices in advance from the code generation unit 18. I do. DS
The modulated signal is then input to the FH modulator 12,
At this DS modulation timing, the FH code output from the transmission FH code generator 14 is fixed, and the output frequency of the transmission high-speed switching frequency synthesizer 13 is also fixed,
Therefore, the output signal from the FH modulator 12 is output from the transmission antenna 11 without being subjected to FH spread modulation. Next, FH
True data shown in the operation area 52 (that is, a normal signal to be subjected to FH spread modulation, hereinafter referred to as a “normal signal”) is similarly rate-converted by the transmission data section 19 and DS-modulated
At this time, the transmission DS code generator 18
For example, all “L” or all “H” is output so that the DS modulator 17 directly outputs the normal signal without setting the S code. The output signal of this DS modulator 17 is F
The signal is input to the FH modulator 12 as an H target signal. Also,
By the code control from the transmission FH code generator 14 arbitrarily set, the transmission high-speed switching frequency synthesizer 13
Converts the local signal whose frequency switches at high speed to the FH
The signal is input to the FH modulator 12 at the same time as the target signal. As a result, the output signal of the DS modulator 17 is subjected to FH spread modulation by the local signal from the transmission high-speed switching frequency synthesizer 13 and output from the transmission antenna 11.

Next, the receiving apparatus B will be described. In the receiving apparatus B, first, the DS-modulated sync data (DS modulated sync data) from the transmitting apparatus A is received by the receiving antenna 21 and input to the FH demodulation unit 22. F
The H demodulation unit 22 receives a predetermined fixed local signal from the reception high-speed switching frequency synthesizer unit 23,
The DS modulation sync data is converted into an intermediate frequency signal (IF signal) d as a demodulated signal. This intermediate frequency signal d is DS
The data is input to the demodulation unit 27 and demodulated to sync data d ₁ by a predetermined DS code from the reception DS code generation unit 28. The demodulated sync data d ₁ is input to the reception data unit 30 and the clock recovery unit 29, respectively. First, the clock recovery unit 29 recovers system synchronization data synchronized with the FH timing on the transmission side, sends this system synchronization data to the clock generation unit 25, and uses it for FH demodulation when an FH spread modulation signal is input. The reception data unit 30 reproduces the same FH code code as the FH code pattern data on the transmission side, and sends it to the reception data control unit 31. The reception data control unit 31 controls the reception FH code generation unit 24 based on the FH code code to cause the local signal b of the reception high-speed switching frequency synthesizer unit 23 to perform the FH operation. That is, the high-speed switching frequency synthesizer for reception 23 outputs a local signal whose frequency changes in accordance with a change in the FH code. Next, the FH spread modulated normal signal (FH spread modulated normal signal) a is received by the antenna 21 from the transmitting apparatus A and output to the FH demodulation unit 22. At this time, the local signal b is in accordance with the same FH code pattern data as that of the transmitting apparatus A by the sync data arranged at the head of the frame, and the acquisition of FH synchronization has been established with high accuracy. Then, after capturing the FH synchronization, the FH synchronization is maintained by the high output frequency accuracy of the clock generator 25. The FH demodulation unit 22 that has received the FH spread modulation normal signal a converts the frequency using the local signal and outputs an intermediate frequency signal d including the normal signal. The intermediate frequency signal d is not DS demodulation process in DS demodulator 27, is converted directly to the normal signal d _2, after being rate conversion by the reception data unit 30, is output as the actual received data c.

As described above, according to the present embodiment,
Synchronous acquisition using the DS method is performed at the beginning of the frame, and the DS
Since the high-accuracy reception clock generation unit 25 maintains synchronization after performing synchronization acquisition using codes, an area 54 of a normal signal subjected to FH code spread modulation is formed after the area 53 for establishing synchronization. In the case of such a data format (see FIG. 2B), synchronization with a normal signal can be established with high speed and high accuracy, and high-speed and high-accuracy synchronization acquisition can be performed in the FH system.

(Embodiment 2) FIG. 3 is a block diagram showing a receiving apparatus of a spread spectrum communication apparatus according to Embodiment 2 of the present invention.

In FIG. 3, a receiving antenna 21, an FH demodulation unit 22, a reception high-speed switching frequency synthesizer unit 23,
FH code generator 24 for reception, clock generator 2 for reception
5, the DS demodulation unit 27 and the reception data unit 30 are the same as those in FIG. Also,
The receiving device in FIG. 3 includes all the components of the receiving device in FIG. 1, but the description is partially omitted. That is, in FIG. 3, the reception timing control unit 26, the reception DS code generation unit 28, and the clock reproduction unit 29 are omitted. 31A is a reception data control unit, 32 is a level detection unit for detecting a noise level, and 33 is an A / D conversion circuit.

With respect to the receiving device configured as described above,
The operation will be described.

The data control unit 31 A
After the FH synchronization capture by the DS-modulated system synchronization data in the synchronization establishment area 53 (see FIG. 2B) input from the A / D conversion circuit 33 at the timing of the data area 54 (see FIG. 2B). inputting data corresponding to the normal signal d ₂ (described later). Receiving antenna 21
Are input to the FH demodulation unit 22 and FH demodulated by the local signal b from the high-speed switching frequency synthesizer unit 23 for reception. The FH-demodulated signal d is input to the noise level detector 32 through the DS demodulator 27. The noise level detection unit 32 uses the FH
From the demodulated signal (ie, the normal signal) d ₂ , the level of in-band noise generated when the frequency switching timing of the local signal b of the FH system (ie, the local signal whose frequency changes) is shifted. A noise level signal indicating the level of the detected noise is input to the A / D conversion circuit 33, and is converted from an analog signal into digital data (data corresponding to the noise level signal). This digital data is input to the data control unit 31A, and controls the clock frequency of the reception clock generation unit 25 so that the noise level is minimized. The high-speed switching frequency synthesizer for reception 23 outputs a local signal in response to a clock from the reception clock generator 25 via the reception FH code generator 24, so that the FH demodulator 22 stably outputs FH demodulation even after FH synchronization capture. The signal d is output.

As described above, according to the present embodiment, the receiving clock generator 25 can be used even while the normal signal d ₂ is being input.
Can be controlled, the receiving clock generator 2
The FH demodulation unit 22 can output the FH demodulation signal d stably even if the clock cycle (clock frequency) of the fifth clock is low.

(Embodiment 3) FIG. 4 is a block diagram showing a receiving apparatus of a spread spectrum communication apparatus according to Embodiment 3 of the present invention.

In FIG. 4, a receiving antenna 21, an FH demodulator 22, a receiving FH code generator 24, a DS demodulator 2
7, the reception data unit 30, the data control unit 31, and the level detection unit 32 are the same as those in FIGS. Further, the receiving device in FIG. 4 has all the components of the receiving device in FIG. 1, but the description is partially omitted. That is, in FIG. 4, the receiving clock generator 25, the receiving timing controller 26,
The receiving DS code generator 28 and the clock reproducer 29 are omitted. 23A is a high-speed switching frequency synthesizer for reception, 34 is a level converter, 35 is a voltage controlled oscillator,
36 is a divider, 37 is a phase comparator, 38 is an adder, 3
9 is a loop filter.

With respect to the receiving device configured as described above,
The operation will be described.

First, the data control unit 31
The FH code acquisition unit 24 controls the FH code generation unit 24 based on the FH code pattern data while performing FH synchronization acquisition using DS-modulated system synchronization data in the synchronization establishment area 53 (see FIG. 2B) input from 0. This operation is the same as that of FIG. 1 except that the FH code output unit 24 outputs F
The difference is that the operation of the divider 36 is controlled based on the H code. As a result, the local signal b corresponding to the FH code is output from the reception high-speed switching frequency synthesizer 23A. The FH spread modulated signal a from the receiving antenna 21 corresponding to the FH area 52 in FIG.
2 and a high-speed switching frequency synthesizer section 2 for reception.
FH demodulation is performed by the local signal b from 3A. The FH-demodulated signal d is input to the noise level detector 32 through the DS demodulator 27. The noise level detector 32 calculates the FH demodulated signal (that is, the normal signal) d ₂
The level of the in-band noise generated when the frequency switching timing of the H-system local signal (that is, the local signal whose frequency changes) b is shifted is detected. A noise level signal indicating the level of the detected noise is sent to the level converter 34. The level converter 34 does not convert the noise level signal into a digital signal, but amplifies the detection signal in an analog manner, adjusts the offset, or performs level conversion of the noise level signal. The level-converted signal is input to the adder 38 of the high-speed switching frequency synthesizer 23A for reception. The high-speed switching frequency synthesizer 23A for reception comprises a general phase-locked loop (PLL) including a voltage-controlled oscillator 35, a divider 36, a phase comparator 37, and a loop filter 39, and a reference from outside. A stable local signal is obtained by comparing the phase with the frequency. In this loop, the converted signal of the noise level signal from the level converter 34 is added as the phase error signal e through the adder 38, so that the deviation of the FH synchronization can be followed. As a result, an FH demodulated signal is obtained.

As described above, according to the present embodiment,
The high-speed switching frequency synthesizer section 23A receives the FH signal for reception.
A local signal based on the FH code from the code generator 24
b can change the frequency and level conversion
Local signal b based on the phase error signal e from
Can be changed, so that the normal signal d _Two
The frequency of the local signal b is controlled even during the input of
High-speed switching frequency synthesizer 2 for reception
It is safe even if the oscillation accuracy of the voltage controlled oscillator 35 of 3A is low.
An FH demodulated signal having a fixed frequency can be generated.

(Embodiment 4) FIG. 5 is a block diagram showing a receiving apparatus of a spread spectrum communication apparatus according to Embodiment 4 of the present invention.

In FIG. 5, the receiving FH code generating section 2
4, the received data section 30, the voltage controlled oscillator 35, the divider 36, the phase comparator 37, the adder 38, and the loop filter 39 are the same as those in FIGS. I do. Although the receiving device in FIG. 5 includes all of the components of the receiving device in FIG. 1, the description is partially omitted. That is, in FIG. 5, the reception antenna 21, the FH demodulation unit 22, the reception clock generation unit 25, the reception timing control unit 26, the DS demodulation unit 27,
The receiving DS code generator 28 and the clock reproducer 29 are omitted. Reference numeral 23B denotes a middle-high speed switching frequency synthesizer unit, 35 denotes a voltage controlled oscillator, 36 denotes a divider, 37 denotes a phase comparator, 38 denotes an adder, and 39 denotes a loop filter. In FIG. 5, reference numeral 23B denotes a middle / high-speed switching frequency synthesizer (DD synthesizer) unit, 23C denotes a direct digital synthesizer unit, 23D denotes a receiving high-speed switching frequency synthesizer unit, 31B denotes a data control unit, and 40 denotes a frequency R unit.
An OM table unit, 41 is a high-speed D / A converter, 42 is a mixer that outputs a signal having a frequency difference or the sum of two input signals, and 43 is a band-pass filter.

With respect to the receiving device configured as described above,
The operation will be described.

A medium / high speed switching frequency synthesizer 23 as a phase locked loop frequency switching synthesizer comprising a voltage controlled oscillator 35, a divider 36, a phase comparator 37, an adder 38 and a loop filter 39.
B outputs a local signal (middle high-speed local signal) in a wide frequency band to the mixer 42 by switching between medium and high speeds (meaning of medium high speed). On the other hand, the frequency ROM table section 4
In the DD synthesizer section 23C composed of 0 and the high-speed D / A converter 41, the frequency ROM table section 40 uses the FH code pattern data from the data control section 31B.
Outputs data indicating the frequency corresponding to the FH code. Based on this frequency data, the high-speed D / A converter 41 inputs a local signal (high-speed local signal) in a narrow frequency band (narrow band) to the mixer 42 by high-speed switching. The two types of local signals (medium and high-speed local signals and high-speed local signals) are converted by the mixer 42 into new local signals having the frequency of the difference or the sum of the two types of local signals, input to the band-pass filter 43, and finally converted. The signal is output as a local signal b for FH demodulation with unnecessary frequencies removed. As described above, the local signal is covered at a medium to high speed by the phase locked loop circuit constituted by the voltage controlled oscillator 35 and the like, and the direct digital synthesizer constituted by the high speed D / A converter 41 and the like in the narrow band. (DD synthesizer) unit 23C provides high-speed coverage, thereby enabling wide-band and high-speed switching as a whole.

As described above, according to the present embodiment, the medium-high-speed local signal can change the frequency at medium-high speed, and the high-speed local signal can change the frequency at high speed. A new local signal of the difference or the sum between the frequency of the medium-high-speed local signal and the frequency of the high-speed local signal can be output.

(Embodiment 5) FIG. 6 is a frequency characteristic diagram for explaining the operation of the receiving apparatus of the FH spread spectrum communication apparatus according to Embodiment 5 of the present invention.

In FIG. 6, reference numeral 44 denotes the direct
Digital synthesizer (DD synthesizer) unit 23C
Generated first FH patterns (f11 to fmn), 4
Reference numeral 5 denotes a second FH pattern (f1 to fn) generated by the medium-to-high speed switching frequency synthesizer 23B using the voltage controlled oscillator 35 of FIG.

The operation of the receiving apparatus having such a function will be described. A high-speed switching frequency synthesizer 23 composed of two oscillators, a direct digital synthesizer 23C and a medium-high-speed switching frequency synthesizer 23B as a phase-locked loop circuit.
In D, a first FH pattern (f11 to fmn) 44 and a second FH pattern (f1 to fn) 45 are given to the two oscillators 23B and 23C, respectively. This allows the code length to be shorter than the case where one FH code covers the entire frequency band.
By combining 3B and 23C, in the case of one loop, many types of FH codes are required,
FH patterns of the same number as the above many types can be obtained with a small number of types.

As described above, according to the present embodiment, DD
Since the synthesizer unit 23C can output a high-speed local signal whose frequency changes rapidly in a narrow band, and the medium-high speed switching frequency synthesizer unit 23B can output a medium-speed local signal whose frequency changes in a wide band in a medium-high speed. In the case of one loop, many types of FH codes are required, but FH patterns of the same number as the above-mentioned many types can be obtained with a small number of types.

[0048]

As described above, according to the spread spectrum communication apparatus of the first aspect of the present invention, the spread spectrum communication apparatus which comprises a transmitting apparatus and a receiving apparatus and uses the FH system is provided. A transmission FH code generator for generating an FH code, a transmission high-speed switching frequency synthesizer for rapidly switching the frequency of a local signal based on the FH code, a transmission DS code generator for generating a DS code, F that determines the FH code and DS code to be used
A transmission data control unit that outputs H code pattern data and DS code pattern data, a transmission data unit that outputs sync data including system synchronization data and FH code pattern data and outputs a normal signal, A DS modulator for modulating the sync data and passing the normal signal as it is, and modulating the sync data modulated signal output from the DS modulator with a local signal of a fixed frequency to output a sync data spread modulation signal and a DS
An FH modulator that modulates a normal signal output from the modulator with a local signal whose frequency changes based on the FH code to output a normal signal spread modulation signal, and a timing of generating a DS code in a transmission DS code generator A transmission clock generator for generating a clock for controlling the timing of FH code generation in the transmission FH code generator, and a sync data spread modulation signal and a normal signal spread modulation signal output from the FH modulator as radio signals. A transmitting antenna for radiating,
The receiving apparatus includes a receiving antenna for receiving a radio signal including a sync data spread modulation signal and a normal signal spread modulation signal, a reception FH code generation unit for generating an FH code, and an FH code generated by the reception FH code generation unit. A high-speed switching frequency synthesizer for reception that rapidly switches the frequency of a local signal based on a code, and a sync data spread modulation signal output from a reception antenna is demodulated with a fixed frequency local signal to output a sync data modulation signal. An FH modulator for modulating a normal signal spread modulated signal output from the receiving antenna with a local signal whose frequency changes based on the FH code to output a normal signal, and a receiving DS code generator for generating a DS code Demodulates the sync data modulation signal based on the DS code, outputs the sync data, and restores the normal signal as it is. A DS demodulation unit, a clock recovery unit that reproduces system synchronization data based on sync data output from the DS demodulation unit, a DS code generation timing in the reception DS code generation unit, and a reception FH code generation unit. Receiving clock generator for generating a clock for controlling the timing of FH code generation based on reproduced system synchronization data, FH code generator for reception and DS code generator for reception based on FH code pattern data and normal data And a receiving data control unit for controlling the synchronization with the DS system at the beginning of the frame, and after the synchronization with the DS code, synchronization with the high-accuracy receiving clock generation unit. Therefore, synchronization with normal signals can be established at high speed and with high accuracy, and high-speed and high-precision synchronization can be obtained in the FH system. Advantageous effect can be performed is obtained.

According to the spread spectrum communication apparatus of the second aspect, in the spread spectrum communication apparatus of the first aspect, when the frequency switching timing of the local signal output from the high-speed switching frequency synthesizer for reception is shifted. The reception data control unit controls the reception DS code generation unit when the FH code pattern data is input, and inputs the normal signal. At times, by controlling the clock generated by the reception clock generator based on the detection level of the level detector, the reception clock generator can be controlled even during normal signal input. Advantageously, the FH demodulation unit can stably output the FH demodulation signal even when the clock generation period of the clock generation unit for use is low in accuracy. Effect can be obtained.

According to a third aspect of the present invention, there is provided the spread spectrum communication apparatus according to the second aspect, further comprising a level converter for outputting a phase error signal based on a detection level of the level detector. The receiving high-speed switching frequency synthesizer outputs a local signal whose frequency changes based on the FH code from the receiving FH code generator and whose frequency changes based on the phase error signal, so that a normal signal can be input. Since the frequency of the local signal can be controlled even when the frequency is high, an advantageous effect that an FH demodulated signal having a stable frequency can be generated even if the oscillation accuracy of the high-speed switching frequency synthesizer for reception is low. .

According to the spread spectrum communication apparatus of the fourth aspect, in the spread spectrum communication apparatus of the first aspect, the reception data control section is replaced with the high-speed switching frequency synthesizer section of the first aspect. ROM table section whose output frequency is controlled by
A high-speed D / A conversion unit that performs high-speed D / A conversion of a signal output from the M table unit and outputs a high-speed local signal, and a FH code from a reception FH code generation unit. By providing a high-speed switching frequency synthesizer section for outputting a medium-high-speed local signal, and a high-speed switching frequency synthesizer section for reception having a mixer for mixing the high-speed local signal and the medium-high-speed local signal,
The frequency of the medium-to-high-speed local signal is changed at medium-to-high speed, the frequency of the high-speed local signal is changed at a high speed, and the mixer outputs a new local signal of the frequency difference or the sum of the medium-to-high-speed local signal and the high-speed local signal. Therefore, an advantageous effect that a wide band and high-speed switching can be realized as a whole is obtained.

According to the spread spectrum communication apparatus of the fifth aspect, in the spread spectrum communication apparatus of the fourth aspect, the data control section includes a plurality of frequency ROM table sections and a plurality of medium / high speed switching frequency synthesizer sections. Is controlled to output a high-speed local signal having a frequency of
Since a high-speed local signal whose frequency changes rapidly in a narrow band is output from the D synthesizer section, and a medium-high-speed local signal whose frequency changes in a medium-high speed in a wide band can be output from the medium-high speed switching frequency synthesizer section, In the case of one loop, many types of FH codes are required. However, an advantageous effect is obtained in which a small number of types can obtain the same number of FH patterns as the large number of types.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an FH spread spectrum communication apparatus according to a first embodiment of the present invention.

2A is a format diagram showing the format of one frame of a received input for explaining the operation of the spread spectrum communication apparatus of FIG. 1; FIG. 2B is a demodulation for explaining the operation of the spread spectrum communication apparatus of FIG. 1; Format diagram showing the format of one frame of a signal

FIG. 3 is a block diagram showing a receiving device of the spread spectrum communication apparatus according to the second embodiment of the present invention.

FIG. 4 is a block diagram showing a receiving device of a spread spectrum communication apparatus according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a receiving apparatus of a spread spectrum communication apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a frequency characteristic diagram for explaining the operation of the receiving apparatus of the FH spread spectrum communication apparatus according to the fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a receiving apparatus of a conventional spread spectrum communication apparatus using the FH method.

FIG. 8 is an explanatory diagram showing a relationship between a received input signal and a local signal of the receiving device of FIG. 7;

[Explanation of symbols]

REFERENCE SIGNS LIST 11 transmission antenna 12 FH modulation section 13 high-speed switching frequency synthesizer section for transmission 14 transmission FH code generation section 15 transmission clock generation section 16 transmission timing control section 17 DS modulation section 18 transmission DS code generation section 19 transmission data section 20 Transmission data control unit 21 Reception antenna 22 FH demodulation unit 23, 23A, 23D High-speed switching frequency synthesizer unit for reception 23B Medium-high speed switching frequency synthesizer unit 23C DD synthesizer unit 24 FH code generation unit for reception 25 Clock generation unit for reception 26 Reception Timing control unit 27 DS demodulation unit 28 DS code generation unit for reception 29 clock recovery unit 30 reception data unit 31, 31A, 31B reception data control unit 32 level detection unit 33 A / D conversion circuit 34 level conversion unit 35 voltage control Type oscillator 36 divider 7 the phase comparator 38 the adder 39 the loop filter 40 frequency ROM table unit 41 D / A converter 42 mixer 43 the band-pass filter

Claims (5)

[Claims] 1. A spread spectrum communication apparatus comprising a transmitting apparatus and a receiving apparatus and using an FH system, wherein the transmitting apparatus includes: a transmitting FH code generating unit for generating an FH code; A high-speed switching frequency synthesizer for transmission for switching the frequency of the local signal, a transmission DS code generator for generating a DS code, and FH code pattern data and DS code pattern data for determining an FH code and a DS code to be used are output. A transmission data control unit, a transmission data unit that outputs sync data composed of system synchronization data and FH code pattern data, and outputs a normal signal after outputting the sync data; and transmits the sync data based on the DS code. A DS modulator for modulating and passing the normal signal as it is,
The sync data modulation signal output from the DS modulator is modulated with a fixed frequency local signal to output a sync data spread modulation signal, and the frequency of the normal signal output from the DS modulator is changed based on the FH code. An FH modulator that modulates with a changing local signal and outputs a normal signal spread modulation signal; a timing of generating a DS code in the transmission DS code generator; and an FH modulator in the transmission FH code generator.
A transmission clock generator for generating a clock for controlling the timing of H code generation; and a transmission antenna for radiating a sync data spread modulation signal and a normal signal spread modulation signal output from the FH modulator as radio signals. A receiving antenna for receiving a radio signal including the sync data spread modulation signal and the normal signal spread modulation signal; a reception FH code generation unit for generating an FH code; A high-speed switching frequency synthesizer for reception that switches the frequency of a local signal at high speed based on an FH code generated in the section, and a demodulation of a sync data spread modulation signal output from the reception antenna with a local signal of a fixed frequency. A normal data spreading modulation output from the receiving antenna while outputting a sync data modulation signal. An FH modulator for modulating a tuning signal with a local signal whose frequency changes based on the FH code and outputting a normal signal; a receiving DS code generator for generating a DS code; A DS demodulation unit that demodulates a data modulation signal and outputs the sync data and passes the normal signal as it is; and a clock regeneration unit that reproduces the system synchronization data based on the sync data output from the DS demodulation unit. A receiving clock generator for generating a clock for controlling the timing of generating the DS code in the receiving DS code generator and the timing of generating the FH code in the receiving FH code generator based on the reproduction system synchronization data; And the reception FH based on the FH code pattern data and the normal signal.
A spread spectrum communication apparatus, comprising: a code generation unit; and a reception data control unit that controls the reception DS code generation unit. 2. A level detecting section for detecting in-band noise generated when a frequency switching timing of a local signal output from the high-speed switching frequency synthesizer section for reception is shifted, wherein the data control section for reception comprises: When the FH code pattern data is being input, the reception DS code generation unit is controlled. When the normal signal is being input, the reception clock generation unit is based on the level detected by the level detection unit. 2. The spread spectrum communication apparatus according to claim 1, wherein the clock generated by the control unit is controlled. 3. A level converter for outputting a phase error signal based on a level detected by the level detector, wherein the high-speed switching frequency synthesizer for reception is based on an FH code from the FH code generator for reception. 3. The spread spectrum communication apparatus according to claim 2, wherein a local signal whose frequency changes based on the phase error signal is output. 4. A frequency ROM table section whose output frequency is controlled by said reception data control section and a signal output from said frequency ROM table section are replaced with the high-speed switching frequency synthesizer section for reception according to claim 1. D /
A DD synthesizer section comprising a high-speed D / A converter for A-converting and outputting a high-speed local signal; and a medium-high-speed switching frequency synthesizer for outputting a medium-high-speed local signal based on the FH code from the reception FH code generator. 2. The spread spectrum communication apparatus according to claim 1, further comprising a high-speed switching frequency synthesizer for reception having a mixer and a mixer for mixing the high-speed local signal and the medium-high-speed local signal. 5. The data control section according to claim 1, wherein each of said frequency ROM table section and said medium-to-high-speed switching frequency synthesizer section outputs a high-speed local signal having a plurality of frequencies and a medium-high-speed local signal having a plurality of frequencies. The spread spectrum communication apparatus according to claim 4, wherein the apparatus performs control.