JP3348212B2 - transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio device, and more particularly to a radio device capable of performing accurate and high-speed tuning with a simple configuration.

[0002]

2. Description of the Related Art For example, in a radio receiver having a function of easily matching the frequency of a partner station with the frequency of the own station when receiving CW or unmodulated waves, the frequency of the own station is matched with the frequency of the partner station received. Therefore, the tuning function is necessary, and the user simultaneously listens to the frequency-dependent outgoing tone of the received signal from the partner station and the corresponding side tone sound generated by the own station, and adjusts the receiving frequency so that there is no difference between the two sounds. It was manually variable. Such a receiver requires considerable skill in judging the difference between two sounds, and it is difficult to make sure that they match.

Therefore, a configuration as shown in FIG. 5, which detects a peak of a received signal and sweeps the received frequency so that the peak is maximized, is used as a wireless device that automatically matches its own frequency to the received signal frequency. Proposed. In FIG. 5, a reception signal to which a frequency signal from a frequency synthesizer 4 is input and received and subjected to predetermined reception processing is output as a sound from a speaker 5 and received by a level detection circuit 6. The signal level (intensity) is detected and supplied to the MPU (microcomputer) 2. MPU
2 adjusts the output frequency of the frequency synthesizer 4 based on the level detected by the level detection circuit 6. That is, the MPU 2 adds and subtracts the output frequency of the frequency synthesizer 4 by a predetermined frequency step α,
The data of the frequency synthesizer 4 is changed while performing frequency addition until the maximum peak is detected. The frequency step α at this time can be set arbitrarily.

As shown in FIG. 6, a reception signal from a reception circuit 3 of a receiver is decomposed into respective frequency components using an FFT circuit 7 that performs frequency processing such as an FFT analyzer, and the MPU 2 There is also a receiver that controls a receiving circuit such as the frequency synthesizer 4 such that a receiving frequency indicating a maximum peak from a received signal decomposed into each frequency component is centered.

[0005]

However, as described above, a radio device that changes the frequency manually requires not only the skill of the user but also the difficulty of high-precision adjustment.

[0006] Further, in the configuration shown in FIG. 5 in which the reception frequency is swept to the target frequency by sweeping the reception frequency, it takes time to sweep the reception frequency. In particular, the frequency step α
If is set finely, accurate peak detection can be performed, but not only the time required for the detection becomes long, but also a sweep reception circuit is required. In addition, if the configuration is such that there is only one receiving circuit and there is no dedicated receiving circuit for sweeping, it becomes impossible to receive while the receiving frequency is being swept.

Further, in the radio equipment using the FFT circuit as shown in FIG. 6, the FFT circuit 7 is required to have a sufficient memory capacity and DSP speed for performing the FFT processing calculation. Since the amount of memory and the speed of the DSP are proportional to the cost, it is expensive to perform processing that satisfies the performance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radio device capable of performing high-speed and high-precision tuning with a relatively simple configuration.

[0009]

In order to solve the above-mentioned problems, a radio device according to the present invention includes a receiving circuit for receiving an input signal based on an output frequency from a frequency synthesizer and outputting the received signal as a received signal; and adaptive filter coefficients having the function of adaptive operation for a frequency having the maximum amplitude in the variable to the received signal, said adaptive filter
The tracking range is set in advance around a preset frequency.
A limiter for restricting the adaptively controlled frequency range to generate the adaptively controlled frequency information based on the coefficient of the adaptive filter, and when the generated frequency information is in a frequency range around a predetermined frequency. And a control circuit for controlling the frequency synthesizer so that a difference between the generated frequency information and a preset frequency becomes zero.

[0010] A wireless device according to another aspect of the present invention includes:
A receiving circuit that receives and processes an input signal based on an output frequency from a frequency synthesizer and outputs the received signal as a received signal, a filter that receives the received signal as an input, and attenuates a signal other than a predetermined frequency, and a coefficient of which is variable. an adaptive filter having the function of adaptive operation outputs the frequency having the maximum amplitude in the output signal of the filter Te, the
The tracking range of the adaptive filter is centered around a preset frequency.
Set a limiter to limit to a preset range.
A control circuit for generating the adaptively controlled frequency information based on the coefficients of the adaptive filter and controlling the frequency synthesizer such that a difference between the generated frequency information and a preset frequency becomes zero. And is provided.

[0011] A wireless device according to still another aspect of the present invention includes a receiving circuit for receiving an input signal based on an output frequency from a frequency synthesizer and outputting the received signal as a received signal;
As input the received signal, and filters the signal other than the predetermined frequency to attenuate, an adaptive filter whose coefficients have variable is the ability to adapt operating output for frequencies having the maximum amplitude in the received signal, the adaptive Filter
The tracking range is set in advance around a preset frequency.
Providing a limiter for limiting to the range, generating the adaptively controlled frequency information based on the coefficients of the adaptive filter, when the generated frequency information is in a frequency range around a predetermined frequency, A control circuit for controlling the frequency synthesizer so that a difference between the generated frequency information and a preset frequency becomes zero.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a wireless device according to the present invention.

The present embodiment has a receiving circuit 3 which receives an output frequency signal from a frequency synthesizer 4, performs a predetermined receiving process on an input signal, and outputs it as a received signal. The signal is output and subjected to IIR filter processing by the adaptive filter 11 constituting the DSP 1. The coefficient information of the adaptive filter 11 is output to the MPU 2 having the frequency judgment processing circuit 21. The frequency determination processing circuit 21 determines the frequency based on the filter coefficient from the adaptive filter 11, and controls the output frequency of the frequency synthesizer 4 so that the determined frequency matches a predetermined frequency. With such a configuration, an auto notch filter is configured.

This auto notch filter has a receiving circuit 3
The automatic notch filter operates so that the notch frequency matches the frequency of the signal having the maximum amplitude in the received signal from the filter, and therefore the filter coefficient is varied.

In FIG. 1, the coefficient of the auto notch filter controlled so that the notch frequency of the auto notch filter matches the frequency of the signal having the maximum amplitude in the received signal is supplied to the frequency determination processing circuit 21 of the MPU 2. .
The frequency determination processing circuit 21 calculates a notch frequency based on the supplied filter coefficient.

The MPU 2 obtains a difference between the calculated notch frequency and a preset frequency, and changes the frequency of the frequency synthesizer 4 so that the signal frequency of the maximum amplitude in the received signal matches the preset frequency. I do. For example, assume that the receiving circuit outputs a beat sound of 800 Hz when receiving a signal of 14.100 MHz. At that time,
If the receiving frequency is shifted by 1500 Hz (14.099
5 MHz) The receiving circuit 3 outputs a 1300 Hz beat sound. At this time, the auto notch filter has the notch frequency 1
The coefficient of 300 Hz is output to the MPU. The MPU 2 obtains a difference from a preset frequency of 800 Hz, and determines that the reception frequency is +500 Hz. The MPU 2 controls the frequency synthesizer 4 so as to make this difference zero, and sets the output frequency of the frequency synthesizer 4 to 500H.
Add z. The reception frequency when the difference becomes zero is 14.
The frequency becomes 100 MHz, which can be matched with the target reception signal frequency.

FIG. 2 is a flow chart showing the operation of the MPU 2 in the above embodiment. Referring to FIG.
The coefficient of the auto notch filter supplied from the adaptive filter 11 of P1 is read (step S1), and the frequency corresponding to the read coefficient is calculated (step S2).
Next, a difference between the frequency indicated by the read coefficient (the frequency calculated in step S2) and a preset frequency is obtained (step S3), and it is determined whether the obtained difference is 0 (step S4). ). If the difference is 0 (True), the process ends. If the difference is not 0 (False), data that makes the difference 0 based on the difference is supplied to the frequency synthesizer 4 (step S5). . continue,
The data created in step S5 is set in the frequency synthesizer 4 to generate a required output frequency (step S6), and the process returns to step S1 to return the frequency indicated by the coefficient of the auto notch filter and the frequency set in advance. The control of the frequency synthesizer is repeated until there is no difference.

With the above configuration, when the strongest signal among the received signals is the target signal, it is possible to accurately follow the target received signal frequency. However, when there is a stronger signal than the target signal near the target signal in the received signal,
Since the auto notch filter follows a strong signal other than the target signal, the reception frequency is separated from the target signal. When a signal that is stronger than the strong signal near the target signal is farther from the target signal, the receiving frequency is further away from the target signal because the auto notch filter follows the stronger signal. Will be.

In order to solve this problem, a filter for narrowing the receiving band of the receiver is used, and the band of the signal input to the auto notch filter is limited to the vicinity of the target receiving signal frequency so that the signals other than the target signal are removed. If you can not receive,
The deviation of the reception signal frequency can be eliminated. But,
If it is impossible to receive signals other than the target signal, after communication (reception) with the station transmitting the target signal is completed, in order to communicate with other stations, the reception band is set to make it easier to find signals from other stations. The problem that an operation to widen the range is required arises.

Therefore, in the present invention, a limiter (W limiter) is provided at the output of the coefficient update process for limiting the follow-up range of the auto notch filter to a preset range centered on a preset frequency. By following the signal, the reception frequency is prevented from deviating from the target signal frequency. Also, by passing the received signal through a filter having a broad characteristic having a peak at a preset frequency and then inputting the signal to an auto notch filter, a signal other than the intended signal is attenuated, and the target signal in the signal input to the auto notch filter is reduced. By reducing the probability that the signal strength other than the signal becomes stronger than the target signal, it is possible to make it difficult to follow the signal other than the target signal.

FIG. 3 shows a configuration diagram of an auto notch filter constituted by an adaptive filter. In the figure,
The notch filter 100 has a transfer function H (z), and the MPU 2 reads the coefficients of the notch filter and performs processing. Filters 200 and 300 having transfer functions G1 (z) and G2 (z) are filters for creating an adaptive signal for updating coefficients. This auto notch filter is
An IIR adaptive notch filter using a stochastic gradient method, the transfer function, H (Z) = (1 + WZ -1 + Z -2) / (1 + rWZ -1 + r 2 Z -2) where, W = over 2cos ( ωn). Here, ωn is the notch angular frequency. r
Is an arbitrary real number satisfying 0 ≦ r <1, and is a coefficient that determines the sharpness of the notch characteristic of the notch filter. In this case, a predetermined value is set in advance.

The coefficient w of the auto notch filter 100
To obtain the frequency, the notch angular frequency ωn is obtained as ωn = cos ⁻¹ (−W / 2), and the notch frequency fn is obtained as fn = 2πωn.

The output of the filters 200 and 300 is
00, the update unit 600 is controlled based on the added output, and the filter coefficients of the filters 100 to 300 are updated. At this time, as described above, when a predetermined frequency range centering on the target frequency is set, the band-pass filter 50 outputs
The signal is subjected to bandpass filtering at 0 and input to the update unit 600. The bandpass filter 500 can prevent the tracking error due to a signal near the target frequency and stronger than the target frequency.

According to the present invention, the output range of the update unit 600 is further limited by the range of the auto notch filter.
A limiter 700 is provided. This W limiter 700
Is the filter 1 updated by the update unit 600
When the coefficient value of 00 is in the coefficient range wl to wh corresponding to the frequencies fl to fh centered on the coefficient w0 near the preset frequency f0, the filters 100 to 300 are updated with the updated coefficient w, and the coefficient w Is not in the coefficient range wl to wh, the filters 100 to 300 are not updated.

The band-pass filter 500 does not attenuate a preset frequency, but functions to gradually increase the signal attenuation as the frequency increases. Therefore, when the target signal matches the frequency set in advance, even when the signal strength other than the target signal is equal to or higher than the target signal, the non-target signal having a frequency different from the target frequency is attenuated, and the automatic Since the target signal is input to the notch filter as the strongest signal, the auto notch filter does not follow other than the target signal. At this time, since the reception band remains wide, after communication (reception) with the station transmitting the target signal is completed, there is no need to perform an operation to widen the reception band, so that other stations nearby can be received quickly. Can be moved manually. In addition, since the reception state of another station can be confirmed even during communication with the target station, it is possible to quickly move to a station having a good communication state. Of course, an equalizer can be used instead of the bandpass filter 500.

In the above embodiment, the adaptive filter portion is constituted by an auto notch filter constituted by an adaptive filter. However, the same goes for an auto peak filter constituted by an adaptive filter.

In order to detect the frequency of the received signal, D
It is also possible to implement the method using FM detection by SP. In the FM detection by the DSP, unlike the analog FM detection, the reception signal frequency can be accurately detected. FIG. 4 shows the configuration diagram.

In FIG. 4, components denoted by the same reference numerals as those in FIG. 1 have the same functions. The signal received by the receiving circuit 3 is the FM detection circuit 1
2, the signal detected by the FM detection is fed to the integration circuit 13
And the frequency information is obtained. The frequency information thus obtained is stored in the frequency determination processing circuit 21 of the MPU 2.
To make it coincide with the other station frequency in the same manner as described above.

[0029]

As described above, in the radio of the present invention, it takes less time to match the reception frequency than in the conventional radio which sweeps the reception frequency. In addition, not only is it possible to output a received sound at the time of frequency tuning even with a single receiver, but also the amount of memory used is small compared to the method using an FFT analyzer, and the DS
The speed of P and MPU is slow. Further, since the circuit is small and the current consumption is small, it can be easily mounted on a wireless receiver. A further specific effect of the wireless device according to the present invention is that the possibility that the reception frequency follows an unintended reception signal is reduced, and quick frequency tuning becomes possible.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of an operation of an MPU 2 in the embodiment shown in FIG.

FIG. 3 is a configuration diagram of an auto notch filter having an adaptive filter configuration according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of another embodiment of a wireless device according to the present invention.

FIG. 5 is a diagram illustrating a configuration example of a conventional wireless device.

FIG. 6 is a diagram illustrating another configuration example of a conventional wireless device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 DSP 2 MPU 3 reception circuit 4 frequency synthesizer 5 speaker 11 adaptive filter 12 FM detection circuit 13 integration circuit 21 frequency judgment processing circuit 100 notch filter 200, 300 filter 400 adder 500 bandpass filter 600 update section 700 W limiter

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H03J ^7/ 00-7/18 H04B 1/06-1/26

Claims (4)

(57) [Claims] An input signal is output from a frequency synthesizer.
Signal based on the input frequency and output as a received signal.
Receiving circuit having a maximum amplitude in the received signal whose coefficient is varied.
Adaptive filter having a function to perform adaptive operation on frequency
When,The tracking range of the adaptive filter is set to a predetermined frequency.
Limiter to limit to a preset range to be minded
Provided, Said The adaptive control is performed based on the coefficients of the adaptive filter.
Frequency information is generated, and the generated frequency information is
When it is in the frequency range around the determined frequency,
Between the generated frequency information and a preset frequency.
Control the frequency synthesizer so that the difference becomes zero.
And a control circuit. 2. An output signal from a frequency synthesizer.
Signal based on the input frequency and output as a received signal.
A receiving circuit, and a signal having a frequency other than a predetermined frequency,
Is a filter to be attenuated, and its coefficient is varied so that the maximum in the output signal of the filter is
Has a function to output adaptive operation for frequencies with amplitude
Adaptive filter,The tracking range of the adaptive filter is set to a predetermined frequency.
Limiter to limit to a preset range to be minded
Provided, Said The adaptive control is performed based on the coefficients of the adaptive filter.
Generate frequency information, and generate the frequency information in advance.
The frequency shift is set so that the difference from the set frequency becomes zero.
And a control circuit for controlling the synthesizer.
Features radio equipment. 3. An output signal from a frequency synthesizer.
Signal based on the input frequency and output as a received signal.
A receiving circuit, and a signal having a frequency other than a predetermined frequency,
Is a filter to attenuate and its coefficient is varied to have the maximum amplitude in the received signal
An adaptive filter that has the function of outputting an adaptive operation
With Ruta,The tracking range of the adaptive filter is set to a predetermined frequency.
Limiter to limit to a preset range to be minded
Provided, Said The adaptive control is performed based on the coefficients of the adaptive filter.
Generate frequency information, and the generated frequency information is predetermined
When the frequency range is centered on the
The difference between the generated frequency information and the preset frequency is
A control for controlling the frequency synthesizer to be zero.
A wireless device comprising a control circuit. 4. The control circuit does not control the frequency synthesizer when the generated frequency information is not in a frequency range centered on a predetermined frequency.
Wireless machine according to 3 from.