JP2829850B2 - Dynamic range optimization method for operating devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for optimizing a dynamic range of an operating device for operating an interference canceller, which is used particularly in an amateur radio communication device.

[0002]

2. Description of the Related Art In a conventional superheterodyne receiver, a plurality of band-limiting filters (hereinafter, also referred to as BPFs) and a plurality of local oscillation circuits (hereinafter, referred to as OSCs) used in an intermediate frequency amplification stage or the like. An IF SHIFT circuit (hereinafter, referred to as SHIFT) that removes unnecessary signal components included in the received signal by pseudo-shifting the received signal from the center of the pass band of the band-limiting filter.
That. ) And a plurality of band-limiting filters having different center frequencies, by pseudo-shifting these center frequencies, a pseudo-narrow band filter is generated from a composite value of the pass bandwidths of the different band-limiting filters. In an IF WIDTH circuit (hereinafter, WIDTH) that passes a received signal, or in a circuit that has both functions of these SHIFT circuit and WIDTH circuit, the frequency setting of each circuit is mixed before and after the band-limiting filter. This has been done by varying the oscillation frequency output from the local oscillation circuit.

The operating device for operating the above SHIFT and WIDTH has, for example, a volume. Conventionally, the frequency set by this volume is -1.28kHz to + 1.28kHz with SHIFT
In z and WIDTH, it was fixed at 0 to 1.28 kHz. But SHIF
BPF and O configured in the interference canceller such as T and WIDTH
The frequency range determined by the SC or the like does not always coincide with the frequency range of the volume in which the above-mentioned frequency range is fixed. That is, the dynamic range of the volume becomes wider or narrower depending on the selected BPF, OSC, or the like. In other words, a portion where the frequency can be set and a portion where the frequency cannot be set occur in the electrically variable region of the volume, and the original electrically variable region of the volume is 100%.
In some cases, it was not possible to set the SHIFT or WIDTH frequency by using this function.

[0004]

Therefore, in the present invention,
Even if these filters and the like are arbitrarily selected with a plurality of band-limiting filters having different bandwidths, the dynamic range of the operating device becomes effective over the entire variable range, and the operating function becomes effective. The purpose is to set the resolution appropriately.

[0005]

A plurality of filters that can be selected, a plurality of local oscillators that can be changed at a desired frequency, a plurality of hybrids, and an arithmetic unit that controls the oscillation frequency of the local oscillators. In a radio communication device having an operation means for changing the oscillation frequency in order to remove an unnecessary signal component of a received signal, a characteristic of the selected desired filter and the local oscillator are provided. A dynamic range optimizing method for an operating device, wherein a frequency range in which interference can be removed by the arithmetic unit is calculated from the characteristics described above, and the calculated frequency range is set as a frequency range of the operating means.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1 is a first hybrid, 2 is a first band limiting filter, 3 is a second hybrid, 4 is a second band limiting filter,
5 is a third hybrid, 6 is a local oscillation circuit group, 7 is a first band-limiting filter selecting device, 8 is a second band-limiting filter selecting device, 9 is an operating device for varying the local oscillation frequency, Reference numeral 10 denotes a microcomputer.

In FIG. 1, the received signal is 1 →
It passes through 2 → 3 → 4 → 5.

First, the band limiting filters 2 and 4 are selected by the selecting devices 7 and 8, respectively. When the band limiting filter is selected, the interference rejection mode selected by m (for example, IF SHIFT
And IFWIDTH), the microcomputer 10 calculates and sets the variable width of each local oscillator per one step of the operating device 9.

FIG. 2 shows a conceptual diagram when the IF SHIFT method functions. Here, the horizontal axis is frequency, A is the target signal, B is the center frequency of the band limiting filter, C is the bandwidth of the band limiting filter, and A can pass only the portion surrounded by C. .

FIGS. 2 (2-1a) and (2-1b) show a case where IF SHIFT is operated in a standard state and a maximum variable amount when a filter having a standard band is used as a band limiting filter. is there. In this case, when the bandwidth (f1) / 2 of the band-limiting filter is set to the maximum value of the variable amount as shown in FIG. 2 (2-1b), the target signal comes to the end of the band-limiting filter. It turns out that it is optimized.

Next, FIGS. 2 (2-2a) and (2-2b) show the conventional case where the band limiting filter is switched to a narrower band than a standard one. In this case, if the variable amount maximum value (f1) / 2 is set to the same value as in FIG. 2 (2-1a), the target signal may deviate from the end of the band limiting filter as shown in FIG. 2 (2-2b). Recognize. Therefore, as described above, when the band limiting filter is switched from the standard band width filter to the narrow band width, the setting of the maximum value of the variable amount is changed to change the narrow band width band as shown in FIG. 2 (2-3b). By setting the filter bandwidth (f2) / 2, the operation range is optimized.

FIG. 3 is a conceptual diagram when the IF WIDTH system functions. Here, the horizontal axis is frequency,
A is the target signal, B is the center frequency of the band limiting filter, C
Represents the bandwidth of the first band-limiting filter, D represents the bandwidth of the second band-limiting filter, and A represents a portion surrounded by C and D
Only the common part of the part enclosed by can be passed.

FIGS. 3 (3-1a) and (3-1b) show the case where the IF WIDTH is operated in the standard state and the maximum variable amount, respectively, when a standard band-pass filter is used as the band-limiting filter. is there. In this case, as shown in FIG. 3 (3-1b), the bandwidth (f1) of the first band-limiting filter and the second band-limiting filter
It can be seen that when / 2 is set to the maximum value of the variable amount, the combined bandwidth by the two band limiting filters is minimized, that is, the operation range is optimized.

Next, FIGS. 3 (3-2a) and (3-2b) show the conventional case where the band limiting filter is switched to a narrower band than a standard one. In this case, if the variable amount maximum value (f1) / 2 is set to the same value as in FIG. 3 (3-1a), the common part of the two band limiting filters is lost as shown in FIG. 3 (3-2b). It can be seen that the signal cannot pass. Therefore, as described above, when the band limiting filter is switched from a standard band width filter to a narrow band width, the setting of the maximum value of the variable amount is changed to change the narrow band width as shown in FIG. 3 (3-3b). By setting the filter bandwidth (f2) / 2, the operation range is optimized.

In the case of the IF WIDTH system, it is assumed that the bandwidths of the first band limiting filter and the second band limiting filter are different from each other. An optimum value can be obtained by setting for each combination of the bandwidths of the band limiting filter and the second band limiting filter.

[0016]

According to the present invention, since the variable range of the operating device is a variable range determined by the selected band limiting filter and the interference mode, the operator can always operate the operating device with the optimum dynamic range, and the efficiency can be improved. In addition, interference can be quickly removed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a waveform chart showing an IF SHIFT method.

FIG. 3 is a waveform diagram showing an IF WIDTH method.

[Explanation of symbols]

 2 First band-limiting filter 4 Second band-limiting filter 6 Local oscillator group 7 First band-limiting filter selecting device 8 Second band-limiting filter selecting device 9 Operating device

Claims (1)

(57) [Claims] 1. A system comprising: a plurality of selectable filters; a plurality of local oscillators that can be varied at a desired frequency; a plurality of hybrids; and a calculator for controlling an oscillation frequency of the local oscillator. In the interference canceller, in order to remove unnecessary signal components of the received signal, in a wireless communication device equipped with an operation means for varying the oscillation frequency, from the characteristics of the selected desired filter and the characteristics of the local oscillator, A dynamic range optimizing method for an operating device, wherein the arithmetic unit calculates a frequency range in which interference can be removed, and sets the calculated frequency range as a frequency range of the operating unit.