JP5025198B2 - Radio receiving apparatus and radio receiving method - Google Patents

Description

  The present invention relates to a radio receiving apparatus such as a radar receiver that requires a wide receiving dynamic range and a method thereof.

  In a radio receiving apparatus used in a conventional radar apparatus, a signal received from an antenna is passed through a filter / amplifier / mixer, digitized by an ADC (Analog to Digital Converter), and taken into a signal processor. I am doing so. The dynamic range of the minimum reception level and the maximum reception level required for this wireless reception apparatus normally reaches 110 dB. For this reason, it is extremely difficult to ensure the allowable input range and signal quality of the ADC.

  Therefore, conventionally, the signal level of the receiving system is appropriately controlled using AGC / STC (Auto Gain Control / Sensitivity Time Control), and the signal level input to the ADC is kept constant to some extent. By maintaining it, the necessary dynamic range is secured.

  However, in recent radar apparatuses, it is desired that an optimum ADC input level is instantly associated with all necessary dynamic ranges so that an optimum reception level can always be secured. It is also desired to prevent signal quality degradation due to AGC / STC.

Although not related to the radar device, as a wireless reception device using AGC, Patent Document 1 discloses a mobile phone using an AGC receiver, and the wireless reception signal of an unstable portion due to antenna switching in AGC operation. Has been disclosed. Patent Document 2 describes an invention related to a software defined radio that can control an AGC voltage without imitating a dynamic range when dealing with any of a plurality of wireless communication systems.
JP 2004-328581 A JP 2005-210357 A

  As described above, in the conventional radio receiving apparatus, it is no longer possible to respond to a request for shortening the control time of AGC and a request for reducing signal quality degradation.

  The present invention has been made in order to solve the above-described problem, and can instantly correspond to the optimum ADC input level for all the required dynamic ranges, always ensure the optimum reception level, and at the same time, AGC / STC. An object of the present invention is to provide a radio receiving apparatus and method capable of preventing deterioration of signal quality due to.

  In order to achieve the above object, a radio receiving apparatus according to the present invention includes an unequal demultiplexing unit that demultiplexes radio reception signals into a plurality of systems at different ratios, and the unequal demultiplexing in each of the plurality of systems. A plurality of signal processing means for detecting the signals separated by the wave means independently of each other and converting them into digital signals; and an output means for selectively taking in the processing results of the plurality of signal processing means and demodulating and outputting them. And a gain range of the plurality of systems assigned to the required dynamic range according to the ratio is allocated.

  Further, the radio reception method according to the present invention divides a radio reception signal into a plurality of systems with different ratios at different ratios, and independently detects the signals that are divided with the plurality of systems independently of each other. Then, the digital signal is converted, the processing results of the plurality of systems are selectively fetched and demodulated and output, and the gain range of the plurality of systems is assigned according to the ratio with respect to the required dynamic range. .

  According to the above configuration, systems having different gains are operated in parallel and at the same time, and different dynamic ranges are assigned to each other. Therefore, an optimum ADC input level for all dynamic ranges required in any system. Is obtained. For this reason, it is possible to instantly respond to level fluctuations by switching the system selection, and it is possible to select an optimal system at the time of demodulation output and perform signal processing. In addition, the optimum reception level can always be ensured, and since AGC / STC is not employed, conventional signal quality degradation can be eliminated.

  As described above, the present invention can instantly correspond to the optimum ADC input level for all necessary dynamic ranges, always ensure the optimum reception level, and prevent signal quality deterioration due to AGC / STC. It is possible to provide a wireless receiving apparatus and a method thereof that can be used.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration when the present invention is applied to a radio receiver of a radar apparatus. In FIG. 1, reference numeral 11 denotes an aerial line that captures a radar signal. A predetermined band is cut out by a band pass filter (BPF) 12 from an RF (radio frequency) signal captured by the aerial line 11, and an unequal demultiplexer 13. Are demultiplexed at different levels. Here, as an example, the first and second systems are demultiplexed at a ratio of 0.01: 0.99, and the first system is a low gain system and the second system is a high gain system.

  In one system, the level of the demultiplexed signal is adjusted by the attenuator 16, mixed with the local signal from the local oscillator 15 by the mixer 17, and passed through the band-pass filter (BPF) 18 to convert the frequency to an IF (intermediate frequency) signal. To do. The IF signal is amplified by the amplifier 19 and passed through the band-pass filter 20 again to remove a useless frequency component. The amplifier 21 amplifies the signal again, inputs it to the ADC 22, and converts it into a digital signal.

  The same applies to the other system. The level of the demultiplexed signal is adjusted by the attenuator 23, mixed with the local signal from the local oscillator 15 by the mixer 24, and passed through the band-pass filter (BPF) 25 to obtain an IF (intermediate frequency) signal. Frequency conversion. The IF signal is amplified by the amplifier 26, passed through the band-pass filter 27 again to remove unnecessary frequency components, amplified again by the amplifier 28, input to the ADC 29, and converted into a digital signal.

  The digital signals obtained by the above systems are input to the demodulator / signal processor 30 and selectively demodulated and signal-processed by the internal signal selection circuit 31. The signal selection circuit 31 monitors the input level of the unequal demultiplexer 13 and selectively switches according to the level change. Alternatively, when the required periods of low sensitivity / high sensitivity are divided, switching is performed accordingly.

  In the above configuration, the processing operation will be described below with reference to FIG.

  In the conventional operation, the ADC input level is stabilized by AGC. In contrast, in the system of this embodiment, the received signal level difference is added by the unequal demultiplexer 13 and the attenuators 16 and 23, and the signals are demultiplexed and input to the ADCs 22 and 29, respectively, for parallel operation. Then, the signal selection circuit 31 in the demodulator / signal processor 30 is used to select the optimum gain system so that the signal level is obtained with the optimum dynamic range. Moreover, it is possible to instantly cope with level fluctuations by simply switching the signal selection circuit 31. Moreover, signal quality can be improved by selecting optimal components in the first systems 16 to 22 and the second systems 17 to 29 having different gains. In addition, since AGC / STC is not used, signal quality degradation as in the conventional case does not occur.

  FIG. 2 is a diagram showing the dynamic ranges B and C which the first system and the second system respectively handle for the required dynamic range A in the radio receiving apparatus having the above configuration. The required dynamic range A is about 110 dB, and the dynamic range that can be realized with one ADC is about 70 dB. Therefore, about 30 dB is secured as the range D in which both systems overlap. As a result, it is possible to accurately switch the system selection with respect to the level fluctuation of the received signal.

  Using the above operation, the radar apparatus determines the reception period based on, for example, a transmission / reception switching signal provided from a transmission / reception control apparatus (not shown), and divides the reception period into short-distance use and long-distance use. Then, the first system having a low gain is selected at a short distance where a relatively strong reflected wave returns, and the second system having a high gain is selected at a long distance where the level of the reflected wave is low. In this way, it is possible to efficiently secure an optimal dynamic range.

  Therefore, according to the radio reception apparatus having the above-described configuration, it is possible to obtain a signal level with an optimum dynamic range, and to instantly cope with level fluctuations. Moreover, signal quality can be improved by selecting optimal components separately for the first and second systems having different gains. Further, since there is no AGC / STC, the conventional signal quality degradation does not occur.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The block diagram which shows one Embodiment of the radio | wireless receiver which concerns on this invention. The figure which shows the relationship of the signal dynamic range of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Antenna, 12 ... Band-pass filter (BPF), 13 ... Inequal branching filter, 15 ... Local oscillator, 16 ... Attenuator, 17 ... Mixer, 18 ... Band-pass filter (BPF), 19 ... Amplifier, 20 ... band pass filter, 21 ... amplifier, 22 ... ADC, 23 ... attenuator, 24 ... mixer, 25 ... band pass filter (BPF), 26 ... amplifier, 27 ... band pass filter, 28 ... amplifier, 29 ... ADC, 30 ... Demodulation / signal processor 31... Signal selection circuit.

Claims (4)

Unequal demultiplexing means for demultiplexing radio reception signals into a plurality of systems at different ratios;
A plurality of signal processing means for independently detecting the signals demultiplexed by the unequal demultiplexing means in the plurality of systems and converting them into digital signals;
Output means for selectively capturing and demodulating the processing results of the plurality of signal processing means,
With respect to the entire required dynamic range, the dynamic range of the gain that each of the plurality of signal processing means is responsible for partially overlaps the range of other signal processing means,
A radio receiving apparatus according to claim 1, wherein a gain range assigned to the plurality of systems is assigned according to the ratio.   The radio reception apparatus according to claim 1, wherein the output means switches the selected system according to a reception level of the radio reception signal.   2. The plurality of signal processing means allocate a low gain system for short distance and a high gain system for long distance when the radio reception signal is a radar transmission wave reception signal. Wireless receiver. Divide radio reception signals into multiple systems at different ratios,
Independently demultiplexed signals in each of the plurality of systems are detected independently of each other and converted into digital signals,
Selectively fetching the processing results of the plurality of systems and demodulating them;
With respect to the entire required dynamic range, the dynamic range of the gain that each of the plurality of signal processing means is responsible for partially overlaps the range of other signal processing means,
A radio receiving method according to claim 1, wherein a gain range assigned to the plurality of systems is assigned according to the ratio.

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