JP4515973B2 - Radio frequency signal recording / reproducing apparatus - Google Patents

Description

  The present invention relates to a radio frequency signal recording / reproducing apparatus.

In general, when developing a radio frequency signal receiver such as a radio for a vehicle, the radio frequency signal during actual running is recorded in a recording device, and the radio frequency signal recorded in the laboratory is reproduced to generate radio waves during running. By reproducing the environment, it is possible to perform experiments efficiently in the laboratory without repeated running experiments. In order to perform such an experiment, the radio frequency signal is received and recorded in an actual environment where the radio frequency signal receiver is used, and the recorded radio frequency signal is reproduced in the laboratory to reproduce the radio environment of the actual environment. A radio frequency signal recording / reproducing apparatus has been proposed (Patent Document 1).
JP 11-183544 A

  By the way, the diversity system is usually used for the antenna of the radio for vehicles, and a radio frequency signal is received from a plurality of antennas, and a radio frequency signal having the maximum reception intensity is selected (selection diversity), or a plurality of antennas are selected. By combining the radio frequency signals received by the antenna (combining diversity), better sensitivity is obtained. When performing radio performance experiments with such diversity antennas in the laboratory by reproducing the radio wave environment during driving, radio frequency signals received by multiple antennas during actual driving are recorded simultaneously and simultaneously in the laboratory. Need to play.

  Here, since a plurality of recorded radio frequency signals are originally the same signal, when simultaneously reproducing a plurality of simultaneously recorded radio frequency signals, the phases of the respective radio frequency signals are recorded and reproduced at the time of recording. Sometimes it is necessary to replay with the same phase. For this reason, it is not possible to reproduce an appropriate radio frequency signal at the time of reproduction by simply recording and reproducing the radio frequency signal received by each antenna independently and simultaneously.

  An object of the present invention is to provide a radio frequency signal recording / reproducing apparatus that simultaneously records a plurality of radio frequency signals and appropriately reproduces the recorded radio frequency signals.

  In order to solve the above-described problem, the invention according to claim 1 is characterized in that a plurality of antennas that simultaneously receive radio frequency signals, a single transmitter that outputs a sine wave signal, and reception of each of the plurality of antennas. A plurality of reception frequency conversion units that convert the frequency of the radio frequency signal based on the radio frequency signal and the output signal of the transmitter and output an intermediate frequency signal; and output from the plurality of reception frequency conversion units A plurality of intermediate frequency signals converted into digital signals and output, and a radio frequency signal recording unit comprising a recording unit for recording the output signal of the AD conversion unit, and recorded in the recording unit A reproduction unit that reproduces and outputs the output signal of the AD conversion unit, and a DA conversion unit that converts the output signal of the reproduction unit into an analog signal and outputs the plurality of intermediate frequency signals. And a plurality of reproduction frequency converters for converting and outputting the frequency of the intermediate frequency signal based on each of the intermediate frequency signals of the plurality of intermediate frequency signals and the output signal of the transmitter. It is characterized by having a part.

  According to the above configuration, radio frequency signals received simultaneously by a plurality of antennas can be recorded and reproduced in phase.

  According to a second aspect of the present invention, there is provided a plurality of antennas that simultaneously receive radio frequency signals, a single transmitter that outputs a sine wave signal, the radio frequency signals received by the antennas of the plurality of antennas, A plurality of reception frequency converters that convert the frequency of the radio frequency signal based on an output signal of the transmitter and output an intermediate frequency signal, and a plurality of intermediate frequency signals output from the plurality of reception frequency converters It is characterized by comprising a radio frequency signal recording unit comprising an AD conversion unit for converting each into a digital signal and outputting, and a recording unit for recording the output signal of the AD conversion unit.

  According to the above configuration, radio frequency signals received simultaneously by a plurality of antennas can be recorded in phase.

  According to a third aspect of the present invention, a radio frequency signal simultaneously received by a plurality of antennas is converted into an intermediate frequency signal, then converted into a digital signal and recorded, and a recording unit recorded on the recording unit. A reproduction unit that reproduces and outputs the digital signal; a DA conversion unit that converts the output signal of the reproduction unit into an analog signal and outputs a plurality of intermediate frequency signals; and one transmitter that outputs a sine wave signal And a plurality of reproduction frequency converters for converting and outputting the frequency of the intermediate frequency signal based on each intermediate frequency signal of the plurality of intermediate frequency signals and the output signal of the transmitter It is characterized by having a part.

  According to the above configuration, radio frequency signals received and recorded simultaneously by a plurality of antennas can be reproduced in phase.

  According to the present invention, it is possible to provide a radio frequency signal recording / reproducing apparatus that simultaneously records a plurality of radio frequency signals and appropriately reproduces the recorded radio frequency signals.

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

  FIG. 1 shows a block diagram of an embodiment of the present invention. In the present embodiment, for the experiment of the reception performance of a radio having a diversity antenna having two antennas, an example of simultaneously recording radio frequency signals received by two antennas and simultaneously reproducing recorded radio frequency signals Will be explained.

  First, the configuration and operation of the radio frequency signal recording unit 100 that records two radio frequency signals simultaneously will be described.

  FIG. 2 shows a block diagram of the radio frequency signal recording unit 100 extracted from the block diagram of FIG.

  Radio frequency signals (Radio Frequency signals, hereinafter referred to as RF signals) received by the antennas 111 and 112 are input to reception frequency converters (so-called down converters) 121 and 122, respectively.

  The reception frequency converters 121 and 122 receive an output signal from a transmitter 310 (so-called local transmitter) that outputs a sine wave signal having a predetermined frequency (signal path 151 in FIGS. 1 and 2).

  In the reception frequency converters 121 and 122, the input RF signal and the output signal of the transmitter 310 are combined and passed through a frequency filter (not shown) provided in the reception frequency converters 121 and 122. The radio frequency signal is converted into a low frequency signal generally called an intermediate frequency signal (IF signal), so-called radio frequency signal down-conversion is performed.

  Reception frequency converters 121 and 122 output the down-converted IF signal to AD converter 130 (signal paths 152 and 153 in FIGS. 1 and 2).

  The AD converter 130 samples each of the two IF signals taken in at a predetermined sampling frequency and converts them into digital signals. The AD conversion unit 130 outputs a plurality of IF signals converted into digital signals to the recording / reproducing unit 320 (the signal path is 154 in FIGS. 1 and 2).

  The recording / reproducing unit 320 controls the AD conversion unit 130 (signal path is 155 in FIGS. 1 and 2), and records the output signal of the AD conversion unit 130, that is, a plurality of IF signals converted into digital signals.

  Through the above operation, the RF signals received simultaneously by the antennas 111 and 112 are down-converted to IF signals by the reception frequency converters 121 and 122, respectively, converted into digital signals by the AD converter 130, and then recorded and reproduced by the recording / reproducing unit 320. To be recorded. Here, when the RF signal is down-converted to the IF signal, a plurality of RF signals are simultaneously down-converted by using one transmitter 310, and therefore recording is performed in a state where the phases of the plurality of down-converted IF signals coincide with each other. Recorded in the playback unit 320.

  Next, the configuration and operation of the radio frequency signal reproduction unit 200 that reproduces the recorded radio frequency signal will be described.

  FIG. 3 shows a block diagram of the radio frequency signal reproduction unit 200 extracted from the block diagram of FIG.

  The recording / reproducing unit 320 controls the DA converting unit 230 (signal path is 252 in FIGS. 1 and 3), and the plurality of IF signals converted into digital signals and recorded in the recording / reproducing unit 320 are sent to the DA converting unit 230. (The signal path is 251 in FIGS. 1 and 3).

  The DA converter 230 converts an output signal of the recording / reproducing unit 320, that is, a plurality of IF signals converted into digital signals, into analog signals. The DA converter 230 outputs a plurality of IF signals converted into analog signals to the reproduction frequency converters 221 and 222, respectively (signal paths are 253 and 254 in FIGS. 1 and 3).

  In the reproduction frequency converters 221 and 222, the input IF signal and the output signal of the transmitter 310 are combined and passed through a frequency filter (not shown) provided in the reproduction frequency converters 221 and 222, and the IF signal Are converted into RF signals, so-called radio frequency signals are up-converted.

  The reproduction frequency converters 221 and 222 output the up-converted RF signal to the antenna input terminal (not shown) of the tester 410 (signal paths are 256 and 257 in FIGS. 1 and 2).

  Through the above operation, a plurality of IF signals converted into digital signals and recorded in the recording / reproducing unit 320 are converted into analog signals by the DA converting unit 230 and then up-converted to RF signals by the reproducing frequency converting units 221 and 222. Are simultaneously output to the testing machine 410. Here, when the IF signal is up-converted to the RF signal, a plurality of IF signals are simultaneously up-converted by using one transmitter 310, so that the test is performed in a state where the phases of the plurality of up-converted RF signals coincide with each other. Is output to the machine 410.

  The recording / reproducing unit 320 corresponds to a recording unit and a reproducing unit in claims.

  By performing the operation as described above, it is possible to record the RF signal simultaneously received by a plurality of antennas by converting the frequency into an IF signal.

  Further, it is possible to simultaneously reproduce a plurality of recorded IF signals by converting the frequency to an RF signal.

  In addition, when a plurality of RF signals are down-converted to IF signals, frequency conversion is performed using one transmitter 310, so that the phases of the converted IF signals can be matched. For this reason, when the RF signals received by the plurality of antennas 110 are frequency-converted into IF signals and simultaneously recorded by the recording / reproducing unit 320, the plurality of IF signals are appropriately recorded without phase shift. In addition, when up-converting a plurality of IF signals into an RF signal, frequency conversion is performed using one transmitter 310, so that the phases of the converted plurality of RF signals can be matched. For this reason, when a plurality of IF signals recorded in the recording / reproducing unit 320 are frequency-converted into RF signals and simultaneously output to the tester 410, the plurality of RF signals are appropriately output without phase shift, which is the same as when traveling. The radio wave environment can be reproduced.

  Furthermore, frequency conversion is performed using a single transmitter for the plurality of reception frequency conversion units 120 and the plurality of reproduction frequency conversion units 220. For this reason, the circuit scale can be greatly reduced as compared with the method in which each reception frequency conversion unit 120 and each reproduction frequency conversion unit 220 are each provided with a transmitter and the phases are matched by synchronizing the transmitters. This can reduce the size and cost of the apparatus.

  As mentioned above, although the Example of this invention was explained in full detail with drawing, an Example is only an illustration of this invention and this invention is not limited only to the structure of an Example. Accordingly, it is a matter of course that the present invention includes any design change within a range not departing from the gist of the present invention.

  For example, the number of antennas is not limited to the number shown in this embodiment, and a larger number of antennas can be supported.

It is a block diagram of the Example of this invention. It is a block diagram of the radio frequency signal recording part 100 of the Example of this invention. It is a block diagram of the radio frequency signal reproduction | regeneration part 200 of the Example of this invention.

Explanation of symbols

100 Radio frequency signal recording unit 110 Antenna 111, 112 Antenna 120 Reception frequency conversion unit 121, 122 Reception frequency conversion unit 130 AD conversion unit 200 Radio frequency signal reproduction unit 220 Reproduction frequency conversion unit 221, 222 Reproduction frequency conversion unit 230 DA conversion unit 310 Oscillator 320 Recording / Reproducing Unit 410 Test Machine

Claims (2)

A plurality of antennas for receiving radio frequency signals,
One transmitter that outputs a sine wave signal;
A plurality of reception frequency converters that convert the frequency of the radio frequency signal based on the radio frequency signal received by each antenna of the plurality of antennas and the output signal of the transmitter and output an intermediate frequency signal;
An AD converter that converts the plurality of intermediate frequency signals output from the plurality of reception frequency converters into digital signals and outputs the digital signals, respectively;
A radio frequency signal recording section and a recording section for simultaneously record the output signal of the AD converter,
A reproduction unit that reproduces and outputs the output signal of the AD conversion unit recorded in the recording unit;
A DA converter that converts an output signal of the reproduction unit into an analog signal and outputs the plurality of intermediate frequency signals;
A radio frequency signal reproduction unit comprising a plurality of reproduction frequency conversion units for converting and outputting the frequency of the intermediate frequency signal based on each intermediate frequency signal of the plurality of intermediate frequency signals and the output signal of the transmitter A radio frequency signal recording / reproducing apparatus comprising: A recording unit received radio frequency signals are recorded simultaneously converted into digital signals after being converted into an intermediate frequency signal by a plurality of antennas,
A reproducing unit for reproducing and outputting the digital signal recorded in the recording unit;
A DA converter that converts an output signal of the reproduction unit into an analog signal and outputs a plurality of intermediate frequency signals;
One transmitter that outputs a sine wave signal;
A radio frequency signal reproduction unit comprising a plurality of reproduction frequency conversion units for converting and outputting the frequency of the intermediate frequency signal based on each intermediate frequency signal of the plurality of intermediate frequency signals and the output signal of the transmitter A radio frequency signal recording / reproducing apparatus comprising:

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