JP5942664B2 - Wireless device and spectrum display method - Google Patents

Description

  The present invention relates to a radio apparatus and a spectrum display method.

  In conventional amateur radio, particularly in short-wave communication, in order to remove interference caused by signals in adjacent bands, the upper or lower limit of the intermediate frequency band is variable, the intermediate frequency bandwidth is variable, the intermediate frequency band is moved, A specific frequency within the frequency band is removed.

  For example, Patent Document 1 shown below includes a dot matrix indicator, an IF filter having a narrow band filter characteristic, and a wide band IF filter, and the user can select any of these filters as appropriate. An FM tuner is disclosed. The dot matrix indicator of this FM tuner usually displays the spectrum analysis result in the intermediate frequency band (hereinafter referred to as the spectrum analyzer display), and the filter temporarily selected (for example, several seconds) when the filter is selected by the user. Displays the filter characteristics of.

  In Patent Document 1, it is possible to switch and display an intermediate frequency signal and an intermediate frequency bandwidth. Therefore, the user can avoid interference from adjacent channels by switching the intermediate frequency bandwidth in a timely manner based on the displayed intermediate frequency signal or intermediate frequency bandwidth.

Japanese Utility Model Publication No. 3-79537

  However, the relationship between the actual interference signal and the demodulated signal can be seen from the demodulated signal spectrum, but how to set the above interference cancellation function in the intermediate frequency band. It was necessary to determine whether to do this based on the demodulated sound.

  For example, the FM tuner disclosed in Patent Document 1 is demodulation of a signal modulated by frequency shift, and demodulation of a signal modulated by amplitude modulation such as SSB (Single Side Band) or CW (Continuous Wave). is not. Therefore, normally, a wireless device using such amplitude modulation is not provided with a function corresponding to a T meter. Therefore, in order to set the interference wave removal function so as to remove the interference wave, the user performs an advanced reception such as adjusting the bandwidth of the intermediate frequency band of the received signal based on the demodulated sound. It was necessary to operate.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a radio apparatus and a spectrum display method that make it possible to demodulate a received signal with optimum filter characteristics.

To achieve the above object, the radio apparatus according to the present invention includes a filtering unit for filtering the received signals SSB (Single Side Band), a demodulator for demodulating the received signal the filtering process, the A spectrum calculation unit that calculates a spectrum of a demodulated signal demodulated by the demodulation unit, and the spectrum calculated by the spectrum calculation unit are displayed, and a filter characteristic set in the filter processing unit is superimposed on the spectrum. And a display unit for displaying.

Further, the spectrum display method according to the present invention is to filter the received signals SSB (Single Side Band), demodulating the received signal the filtering process, to calculate the spectrum of the demodulated demodulation signals, the spectrum And displaying the characteristics of the filter set by the filter process superimposed on the spectrum.

  ADVANTAGE OF THE INVENTION According to this invention, the radio | wireless apparatus and spectrum display method which make it possible to demodulate a received signal with the optimal filter characteristic can be provided.

FIG. 1 is a perspective view showing a schematic configuration of a radio apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the radio apparatus shown in FIG. FIG. 3 is a diagram showing an example of a display screen displayed on the display of FIG. FIG. 4 is a diagram showing an example of the reception frequency adjustment knob shown in FIG. FIG. 5 is a diagram showing an example of the upper and lower limit adjustment knobs shown in FIG. FIG. 6 is a diagram illustrating an example of a filter image according to the present embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the following description, each drawing only schematically shows the shape, size, and positional relationship to the extent that the contents of the present invention can be understood. Therefore, the present invention is illustrated in each drawing. It is not limited to only the shape, size, and positional relationship. Moreover, the numerical value illustrated below is only a suitable example of this invention, Therefore, this invention is not limited to the illustrated numerical value.

  FIG. 1 is a perspective view illustrating a schematic configuration of a wireless device according to an embodiment. As shown in FIG. 1, the wireless device 100 is provided with a power switch 141, a button group 142, a reception frequency adjustment knob 143, an upper / lower limit adjustment knob 144, and a display 160 on the front surface 102 of the housing 101. It has a configuration. The power switch 141 is a main power switch of the wireless device 100. The button group 142 includes various buttons for the user to set the switching of the reception frequency band, the modulation method (SSB, CW, etc.), the switching of the main sound / sub sound, and the like. The reception frequency adjustment knob 143 and the upper / lower limit adjustment knob 144 will be described later. Note that various configurations arranged on the front surface 102 may be arranged on the side surface or the back surface of the housing 101. However, the display 160 is preferably arranged on the side facing the user, that is, the front surface 102.

  FIG. 2 is a block diagram showing a schematic configuration of the radio apparatus shown in FIG. As illustrated in FIG. 2, the radio apparatus 100 includes an antenna 114 and a reception unit 110, a spectrum calculation unit 120, a radio control unit 130, an input unit 140, and a display unit 150. The wireless device display unit 130 is configured by, for example, a CPU (Central Processing Unit) and controls each unit in the wireless device 100.

  The receiving unit 110 includes a filter processing unit 111, an interference removal processing unit 112, and a demodulation unit 113. The filter processing unit 111 performs band limitation processing on the received signal received via the antenna 114. The lower limit frequency and the upper limit frequency of the band limit filter used for the band limit process may be set from the radio control unit 130. The interference removal processing unit 112 performs interference removal processing for removing a frequency band in which an interference wave exists in the reception frequency band using a notch filter or the like. Below, the case where a notch filter is used is illustrated. The frequency band to be removed by the interference removal process, that is, the center frequency of the notch filter may be set from the radio control unit 130.

  The demodulation unit 113 demodulates the received signal that has passed through the filter processing unit 111 and the interference removal processing unit 112. Further, the frequency band for performing the filter processing, the interference removal processing, and the demodulation processing may be an intermediate frequency obtained by converting the reception frequency into a predetermined frequency. Hereinafter, even a signal converted to an intermediate frequency is described as a received signal. The received signal may be a signal modulated by amplitude modulation such as SSB or CW. The signal demodulated by the demodulation unit 113 is input as a demodulated signal to an audio output unit (not shown) and to the spectrum calculation unit 120.

  The spectrum calculation unit 120 obtains the power spectrum of the input signal by performing processing such as fast Fourier transform (hereinafter referred to as FFT) using the demodulated signal output from the reception unit 110 as an input. The obtained power spectrum data is input to the display unit 150 as signal spectrum data.

  The display unit 150 includes a display control unit 151 and a display 160. The display control unit 151 is configured by, for example, a CPU. The display control unit 150 generates a screen to be displayed on the display 160 based on the signal spectrum data input from the spectrum calculation unit 120 and various information input from the wireless device control unit 130. Information input from the radio control unit 130 includes the center frequency of the reception frequency band, the lower and upper limit frequencies of the band limiting filter set in the filter processing unit 111 of the reception unit 110, and the interference removal processing unit 112. The filter characteristics of the notch filter are included.

  Specifically, the display control unit 151 includes signal spectrum data of a demodulated signal input from the spectrum calculation unit 120, filter characteristics of various filters set in the filter processing unit 111 and the interference removal processing unit 112 of the reception unit 110, and the like. Is converted into display data (display coordinate system (pixel coordinates)) in accordance with the number of pixels of the display 160 and the like. In converting the signal spectrum data and the filter characteristics to the display coordinate system, the horizontal axis (frequency) of the signal spectrum data is based on the frequency per pixel in the display coordinate system, for example. You may obtain | require by converting into a value. In addition, the signal spectrum data may be obtained by converting the signal intensity into a pixel value on the vertical axis based on, for example, the signal intensity per pixel in the display coordinate system. Note that the frequency band of the demodulated signal is different from the frequency band of filters (such as a band limiting filter and a notch filter) used for the intermediate frequency signal, but they are similar when receiving SSB. Therefore, regarding the frequency on the horizontal axis, the frequency per pixel used when converting the signal spectrum data to the display coordinate system is equal to the frequency per pixel used when converting the filter characteristics to the display coordinate system. be able to. Further, the frequency per pixel for each of the signal spectrum data and the filter characteristics may be given from, for example, the radio control unit 130 or may be set in the display control unit 151 in advance. Similarly, the signal intensity per pixel for the signal spectrum data may be given from, for example, the wireless device control unit 130 or may be set in the display control unit 151 in advance.

  When the LSB is set, the horizontal axis direction may be reversed in the conversion of the filter characteristics into the display coordinate system. Thereby, the display mode at the time of LSB can be matched with the display mode at the time of USB.

  Thereafter, the display control unit 151 generates a screen to be displayed on the display 160 based on the converted data. The radio device control unit 130 may set the number of pixels of the display 160, the display bandwidth, and the like necessary when generating the display screen from the signal spectrum data.

  The display 160 is composed of, for example, an LCD (Liquid Crystal Display) or the like, and displays a display screen input from the display control unit 151. Here, FIG. 3 shows an example of a display screen displayed on the display 160. As shown in FIG. 3, the display screen includes a main display unit 161 that displays the signal spectrum of the demodulated signal and a sub display unit 165 that displays character information such as the center frequency of the reception frequency band.

  In addition to the signal spectrum of the demodulated signal (not shown), the main display unit 161 includes a line 162 that indicates the center frequency position of the reception frequency band, a filter line 163 that indicates the filter characteristics of the band-limiting filter, and interference cancellation. An interference filter image 164 indicating the filter characteristics of the notch filter is displayed. The filter image 164 may be image data such as a bitmap image. Further, the main display unit 161 may display a horizontal axis scale 161a indicating a reception frequency band, a lower limit frequency value (LOCUT) 163a and an upper limit frequency value (HICUT) 163b of the band limiting filter, and the like. The sub display unit 165 may display a center frequency 165a of the reception frequency band, a modulation method display 165b indicating which one of USB (Upper Sideband) and LSB (Lower Sideband) is used. In FIG. 3, the frequency band of the horizontal axis scale 161a is set to 0 to 3000 Hz. However, in the case of an AM radio, for example, the frequency band of the horizontal axis scale 161a may be switched to, for example, 0 to 8 kHz.

  As described above, in this embodiment, as shown in FIG. 3, the signal spectrum of the demodulated signal and the filter characteristics of the filters (band limiting filter, notch filter, etc.) used for the intermediate frequency signal are simultaneously 1 Since they are displayed superimposed on one screen, the user can easily set the optimum filter characteristics using vision.

  Returning to FIG. The input unit 140 includes the power switch 141, the button group 142, the reception frequency adjustment knob 143, and the upper / lower limit adjustment knob 144 shown in FIG. Here, FIGS. 4 and 5 show examples of the reception frequency adjustment knob and the upper / lower limit adjustment knob, respectively.

  As shown in FIG. 4, the reception frequency adjusting knob 143 is configured to be rotatable clockwise / counterclockwise. For example, when the user rotates the reception frequency adjusting knob 143 clockwise, the reception frequency band moves to the high frequency side. On the other hand, when the reception frequency adjusting knob 143 is rotated counterclockwise, the reception frequency band moves to the low frequency band side.

  As shown in FIG. 5, the upper / lower limit adjustment knob 144 includes a lower limit adjustment knob 144a for the user to adjust the lower limit frequency of the band limiting filter, and an upper limit adjustment knob 144b for adjusting the upper limit frequency of the band limiting filter. Including. The lower limit adjustment knob 144a may protrude directly from the housing 101 (see FIG. 1), for example. The upper limit adjustment knob 144b may be slightly smaller than the lower limit adjustment knob 144a and may protrude from the tip of the lower limit adjustment knob 144a. The lower limit adjustment knob 144a and the upper limit adjustment knob 144b may be rotatable clockwise / counterclockwise independently of each other about the same axis. For example, when the user rotates the lower limit adjustment knob 144a clockwise, the lower limit frequency of the band limiting filter moves to the high frequency side. On the other hand, when the user rotates the upper limit adjusting knob 144b counterclockwise, the upper limit frequency of the band limiting filter moves to the low frequency side. Therefore, by adjusting the lower limit adjustment knob 144a and the upper limit adjustment knob 144b, the lower limit frequency, the upper limit frequency and the bandwidth of the band limiting filter can be adjusted.

  When the LSB is set, the frequency of the filter characteristic is inverted. However, it is easier for the user to intuitively adjust the lower one of the demodulated signal as the lower limit adjustment knob 144a and the higher one as the upper limit adjustment knob 144b. Therefore, in LSB, the adjustment target and adjustment direction for the adjustment knob are reversed with respect to the case where USB is set.

  That is, in the case of LSB, when the user rotates the lower limit adjustment knob 144a clockwise, the upper limit frequency of the band limiting filter moves to the low frequency side. On the other hand, when the user rotates the upper limit adjusting knob 144b counterclockwise, the lower limit frequency of the band limiting filter moves to the high frequency side.

  Next, a filter image 164 showing the filter characteristic of the notch filter superimposed on the filter line 163 showing the filter characteristic of the band limiting filter will be described below with some examples. FIG. 6 is a diagram illustrating an example of a filter image according to the present embodiment. 6A shows a first example of the filter image, FIG. 6B shows a second example of the filter image, and FIG. 6C shows a third example of the filter image. FIG. 6D shows a fourth example of the filter image. However, it is not limited to these examples.

  First, the filter image 164 shown in FIG. 6A will be described. As shown in FIG. 6A, in the filter image 164, the filter characteristic of the notch filter may be drawn with a Y-shaped solid line 164a. In FIG. 6A, the outer frame indicates the outer edge of the filter image 164. The position Lvf where the solid line 164a intersects the outer frame of the filter image 164 is set so that the filter line 163 and the solid line 164a are continuous when the filter image 164 is superimposed on the filter line 163 of the band limiting filter. It is good to have. In the filter image 164, a region 164b above the solid line 164a may be opaque and have the same color as the background color of the main display portion 161. Thereby, when the filter image 164 is superimposed on the filter line 163, the filter line 163 in the lower layer of the region 164b can be hidden. On the other hand, the region 164c below the solid line 164a in the filter image 164 may be transparent.

  6B, in the filter image 264, the filter characteristics of the notch filter may be drawn with a groove-shaped solid line 264a. In FIG. 6B, the outer frame indicates the outer edge of the filter image 264, and the position Lvf where the solid line 264a intersects the outer frame of the filter image 264 is set at a position where the filter line 163 and the solid line 264a are continuous. The region 264b above H.264a may be opaque and the same color as the background color of the main display portion 161, and the region 264c below the solid line 264a may be transparent. As shown in FIG. 6C, when the filter characteristic of the notch filter is a groove shape, the bottom of the groove may reach the lowest part of the filter image 264.

  Further, as shown in FIG. 6D, in the filter image 364, the filter characteristics of the notch filter may be drawn with a V-shaped solid line 364a. In FIG. 6D, the outer frame indicates the outer edge of the filter image 364, and the position Lvf where the solid line 364a intersects the outer frame of the filter image 364 is set at a position where the filter line 163 and the solid line 364a are continuous, The region 364b above the 364a may be opaque and the same color as the background color of the main display portion 161, and the region 364c below the solid line 364a may be transparent.

  In addition, the filter image described above is not only the display position corresponding to the setting of the center frequency parameter of the notch filter, but can also be changed when parameters such as the attenuation bandwidth characteristic and attenuation characteristic of the notch filter are varied. It may be drawn as a shape corresponding to a later parameter.

  As described above, in the present embodiment, the radio apparatus 100 having the interference elimination function specialized for amplitude modulation (SSB, CW) can simultaneously display the spectrum waveform of the demodulated signal and the characteristics of the intermediate frequency band. It was. As a result, the user can visually grasp the state of the signal, and therefore can easily perform band limitation and interference removal setting for obtaining the target signal.

  In addition, the above-described embodiment and its modifications are merely examples for carrying out the present invention, and the present invention is not limited to these, and various modifications according to specifications and the like are within the scope of the present invention. Furthermore, it is obvious from the above description that various other embodiments are possible within the scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Radio | wireless apparatus 101 Case 102 Front 110 Reception part 111 Filter process part 112 Interference removal process part 113 Demodulation part 114 Antenna 120 Spectrum calculation part 130 Radio equipment control part 140 Input part 141 Power switch 142 Button group 143 Reception frequency adjustment knob 144 On Lower limit adjustment knob 144a Lower limit adjustment knob 144b Upper limit adjustment knob 150 Display unit 151 Display control unit 160 Display 161 Main display unit 162 Line 163 Filter line 164 Filter image 165 Sub display unit 164a, 264a, 364a Solid line 164b, 164c, 264b, 264c, 364b, 364c region

Claims (7)

A filter processing unit for filtering a received signal of an SSB (Single Side Band) ;
A demodulator for demodulating the received signal the filtering process,
A spectrum calculation unit for calculating a spectrum of a demodulated signal demodulated by the demodulation unit;
A display unit that displays the spectrum calculated by the spectrum calculation unit and superimposes and displays the characteristics of the filter set in the filter processing unit on the spectrum;
A wireless device comprising: The filter processing unit includes a band limiting filter that limits a band of the received signal, and an interference elimination filter that removes a specific frequency in the band,
The radio apparatus according to claim 1, wherein the display unit displays characteristics of the band limiting filter and characteristics of the interference removal filter. The characteristics of the interference elimination filter are drawn with image data,
The radio apparatus according to claim 2, wherein the display unit displays the image data superimposed on the characteristic of the band limiting filter. An adjustment unit for a user to adjust at least one of a lower limit frequency and an upper limit frequency of the band limiting filter;
The radio apparatus according to claim 2, wherein the display unit updates the drawing of the characteristic of the band limiting filter into a shape corresponding to the adjustment by the adjustment unit. An interference elimination filter adjusting unit that varies a parameter of the interference elimination filter;
The wireless device according to claim 3, wherein the display unit updates the drawing of the image data to a position and a shape according to the adjustment by the interference removal filter adjustment unit. When the received signal is LSB (Lower Side Band),
The display unit is a display in which the band limit filter is determined to determine the height on the frequency axis,
The adjusting unit for adjusting the lower limit frequency adjusts an upper limit frequency of the band limiting filter,
The radio apparatus according to claim 4, wherein the adjustment unit that adjusts the upper limit frequency adjusts a lower limit frequency of the band limiting filter. Filter the received signal of SSB (Single Side Band) ,
Demodulating the received signal the filtering process,
Calculating a spectrum of the demodulated demodulated signal;
A spectrum display method comprising: displaying the spectrum and displaying the spectrum by superimposing the characteristics of the filter set by the filter processing on the spectrum.