JP2012134738A - Radio receiver, radio reception method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily execute frequency diversity.SOLUTION: In a radio receiver 110, an A/D conversion unit 156 converts RF signals of a prescribed frequency band received by one reception unit 154 to digital RF signals at once, a plurality of mixer function units 170 respectively convert the digital RF signals to IF signals corresponding to the RF signals of different carrier frequencies, an identicalness determination unit 176 determines whether or not program contents of one IF signal converted by the mixer function unit 170a specified as the one performing conversion to the IF signal corresponding to the RF signal of the carrier frequency corresponding to operation input of a user by a specifying unit 172 and program contents of IF signals converted by the other mixer function part 170b are identical, and a composition unit 180 generates a composite program signal by combining the one, two or more IF signals determined as identical, and makes the composite program signals be outputted to a sound output unit.

Description

  The present invention relates to a radio receiver, a radio reception method, and a program.

  In wireless communication, diversity technology is used to improve communication quality. Diversity technology includes, for example, antenna diversity in which a plurality of antennas are arranged at different positions on the receiving side, and the antenna having the best reception state is selected for reception, or the same on multiple transmitting carriers on the transmitting side. There is frequency diversity in which a data signal is transmitted and a receiving side selects a carrier wave having the best reception state or synthesizes data signals of a plurality of carrier waves.

  As a technique using antenna diversity, for example, in a receiving device that demodulates RF signals respectively received by two receiving units (tuners) through one antenna and combines and displays the obtained two video data, 2 A technique for controlling the direction of an antenna so that a suitable reception state can be obtained in one receiving unit is disclosed (for example, Patent Document 1).

  In addition, as a technique using frequency diversity, for example, a digital data receiver that synthesizes reception signals with different carrier frequencies received by tuners provided for each of a plurality of antennas is disclosed (for example, Patent Documents). 2).

JP 2006-165926 A JP 2007-165961 A

  By the way, recently, a technology (Wide Band RF technology) has been developed that can receive an RF signal with a bandwidth of 20 MHz or more via one antenna and A / D convert the received RF signal with a bandwidth of 20 MHz or more at a time. Has been. In a radio receiver using this technology, RF signals of a plurality of carrier frequencies (carrier frequencies) included in a bandwidth of 20 MHz, which are broadcast by one or a plurality of radio broadcasting stations, are transmitted by one antenna and one tuner. Can be demodulated at once.

  Therefore, the present invention provides a radio receiver, a radio, and a radio that can perform frequency diversity using a technology that can acquire RF signals of carrier frequencies of one or a plurality of radio broadcast stations at one time with one antenna and one tuner. It is an object to provide a receiving method and a program.

  In order to solve the above-described problems, a radio receiver according to the present invention includes one receiving unit that receives an RF signal in a predetermined frequency band, and converts the RF signal in the predetermined frequency band received by the receiving unit into a digital RF signal. 1 A / D conversion unit, a plurality of mixer function units for converting digital RF signals into IF signals corresponding to RF signals having different carrier frequencies, and a user operation input among the plurality of mixer function units A specifying unit for specifying a mixer function unit that converts the IF signal corresponding to the RF signal of the corresponding carrier frequency, a program content of the IF signal converted by the specified mixer function unit, and another mixer function unit The same determination unit for determining whether or not the program content of the converted IF signal is the same, the IF signal converted by the specified mixer function unit, and the IF signal determined to be the same by the same determination unit Together A combining unit for generating a composite program signal by the synthesis program signal, characterized in that it comprises a voice control unit to output to the audio output unit.

  The radio receiver further includes a detection function unit that detects a plurality of IF signals converted by the mixer function unit, and the same determination unit determines whether or not the program content is the same by the detected IF signal. You may judge.

  In order to solve the above problems, a radio reception method of the present invention receives an RF signal of a predetermined frequency band, converts the received RF signal of the predetermined frequency band into a digital RF signal, and a plurality of mixer function units The digital RF signal is converted into an IF signal corresponding to an RF signal having a different carrier frequency, and is converted into an IF signal corresponding to an RF signal having a carrier frequency corresponding to a user operation input among a plurality of mixer function units. The program content of the IF signal converted by the specified mixer function unit is determined to determine whether the program content of the IF signal converted by another mixer function unit is the same. The IF signal converted by the mixer function unit and the IF signal determined to be the same are combined to generate a combined program signal, and the combined program signal is output to an audio output unit.

  In order to solve the above-described problem, a program according to the present invention provides a computer mounted on a radio receiver that receives an RF signal of a predetermined frequency band, and converts the RF signal of the predetermined frequency band received by the receiving unit into a digital RF signal. One A / D conversion unit for converting the digital RF signal, a plurality of mixer function units for converting the digital RF signal into IF signals corresponding to RF signals having different carrier frequencies, and a user operation among the plurality of mixer function units Identification unit for identifying a mixer function unit that converts an IF signal corresponding to an RF signal having a carrier frequency according to the input, program content of the IF signal converted by the identified mixer function unit, and other mixer functions The same determination unit for determining whether or not the program content of the IF signal converted by the unit is the same, and the IF signal converted by the specified mixer function unit are the same by the same determination unit A synthesizing unit which synthesizes a constant IF signal to generate a combined program signals, a synthesis program signal, characterized in that to function as a voice control unit to output to the audio output unit.

  The components based on the technical idea of the radio receiver described above and the description thereof can also be applied to the radio reception method and program.

  According to the present invention, it is possible to perform frequency diversity using a technology that can acquire RF signals of carrier frequencies of one or a plurality of radio broadcast stations at one time with one antenna and one tuner.

It is explanatory drawing which showed the rough connection relation of the radio reception system. It is the functional block diagram which showed the schematic structure of the radio receiver. It is the functional block diagram which showed the specific structure of the receiving part, A / D conversion part, a mixer function part, an identification part, and a detection function part. It is explanatory drawing for demonstrating the process of the same determination part. It is the flowchart explaining the flow of the process of the radio reception method.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Radio reception system 100)
FIG. 1 is an explanatory diagram showing a schematic connection relationship of the radio reception system 100. The radio reception system 100 includes a plurality of radio broadcast stations 102, a plurality of broadcast towers 104, and a radio receiver 110.

  The radio broadcasting station 102 provides terrestrial radio broadcasting, for example, an analog RF signal, a digital RF signal, and a hybrid RF signal that simultaneously provides an analog method and a digital method. Further, the radio broadcast station 102 can superimpose a data signal on an audio signal in the RF signal. For example, in an example described later, RDS (Radio Data System) information in Europe is superimposed as a data signal on a digital RF signal.

  A plurality of broadcast towers 104 are arranged at different positions and transmit a plurality of RF signals broadcast by a plurality of radio broadcast stations 102.

  The radio receiver 110 receives a plurality of RF signals broadcast by a plurality of radio broadcasting stations 102 via the broadcast tower 104, converts the received RF signals into IF (Intermediate Frequency) signals, and Audio data included in the program data obtained by demodulating the IF signal is output to an audio output unit including a speaker or the like.

  Here, when the radio receiver 110 is mounted on the moving body 106 such as a vehicle, a necessary received radio wave intensity may not be ensured depending on the position of the radio receiver 110. Therefore, in terrestrial radio broadcasting in Europe, the radio broadcasting station 102 broadcasts the same program using carrier waves of a plurality of frequencies.

  On the other hand, a technology (Wide Band RF technology) has been developed that can receive an RF signal with a bandwidth of 20 MHz or more via one antenna and convert the received RF signal with a bandwidth of 20 MHz or more into a digital RF signal at a time. ing. In the radio receiver 110 using this technology, a plurality of RF signals broadcast by one or a plurality of radio broadcasting stations 102 can be acquired at a time using one antenna and one tuner.

  Therefore, in the present embodiment, the above-described technology that can acquire RF signals of a plurality of carrier frequencies (carrier frequencies) broadcast by one or a plurality of radio broadcast stations 102 at a time using one antenna and one tuner is used. An object of the present invention is to provide a radio receiver 110 capable of frequency diversity in the radio receiver 110. Hereinafter, a specific configuration of the radio receiver 110 will be described, and then a radio reception method using the radio receiver 110 will be described in detail.

(Radio receiver 110)
FIG. 2 is a functional block diagram illustrating a schematic configuration of the radio receiver 110. FIG. 3 illustrates a reception unit 154, an A / D conversion unit 156, a mixer function unit 170, a specifying unit 172, and a detection function unit 174. It is the functional block diagram which showed the specific structure of these. In FIG. 2 and FIG. 3, the signal flow is indicated by solid arrows, and the control flow is indicated by broken arrows.

  As illustrated in FIG. 2, the radio receiver 110 includes an operation unit 150, one antenna 152, one reception unit 154, one A / D conversion unit 156, a memory 158, and a central control unit 160. And an audio output unit 162.

  The operation unit 150 includes operation keys, a cross key, a joystick, a jog dial, a touch panel, and the like, and accepts user operation inputs. The antenna 152 receives an RF signal in a wide frequency band including RF signals of a plurality of carrier frequencies for terrestrial radio broadcasting, and converts the RF signal into a signal that can be processed by the receiving unit 154.

  As shown in FIG. 3, the receiving unit 154 includes a first amplifier 154a that amplifies the RF signal, a band pass filter (BPF) 154b that narrows the bandwidth of the RF signal, and a second amplifier 154c. And receiving an RF signal in a predetermined frequency band (for example, 87.5 MHz to 108.0 MHz) including RF signals of a plurality of carrier frequencies broadcast by a plurality of radio broadcasting stations 102. The RF signal received by the reception unit 154 is output to the A / D conversion unit 156 described later.

  The A / D conversion unit 156 converts an RF signal in a predetermined frequency band received by the reception unit 154 into a digital RF signal (A / D conversion) at a time.

  In this embodiment, the A / D conversion unit 156 assumes a sampling frequency of 40 MHz or higher, and can convert an RF signal having a bandwidth of 20 MHz or higher into a digital RF signal at a time. Therefore, the A / D converter 156 can convert an RF signal of 87.5 MHz to 108.0 MHz, which is a frequency band of a carrier wave of terrestrial radio broadcasting used in Europe, into a digital RF signal at a time, for example. It becomes possible.

  The memory 158 includes a RAM (Random Access Memory), a flash memory, an HDD (Hard Disk Drive), and the like, and holds various types of information necessary for processing of each functional unit of the central control unit 160.

  The central control unit 160 manages and controls the entire radio receiver 110 by a semiconductor integrated circuit including a central processing unit (DSP or CPU), a ROM storing programs, a RAM as a work area, and the like. In the present embodiment, the central control unit 160 also functions as a plurality of mixer function units 170, a specifying unit 172, a detection function unit 174, an identical determination unit 176, a switch 178, a synthesis unit 180, and a voice control unit 182.

  As shown in FIG. 3, the mixer function unit 170 (indicated by 170a and 170b in the figure) includes a mixer 184a, an oscillator (local oscillator) 184b, and a low pass filter (LPF) 184c. The digital RF signal converted by the A / D conversion unit 156 is converted to an intermediate frequency (IF). Here, a configuration in which the central control unit 160 includes two mixer function units 170 will be described as an example.

  Specifically, referring to FIG. 3, for example, when the band of the digital RF signal converted by the A / D conversion unit 156 is 87.5 MHz to 108.0 MHz and there are two mixer function units 170, the mixer function The unit 170a converts the IF signal corresponding to the RF signal of the carrier frequency according to the operation input to the operation unit 150 by the user. More specifically, when the user sets the carrier frequency of the radio broadcast station 102 through the operation unit 150, the operation unit 150 transmits the set frequency to the mixer function unit 170a. Then, the mixer function unit 170a converts the digital RF signal into an IF signal corresponding to the RF signal having the transmitted frequency as a carrier wave. The mixer function unit 170b sequentially extracts digital RF signals, for example, every 50 kHz in the 87.5 MHz to 108.0 MHz band, and converts a digital RF signal having a signal strength equal to or higher than a predetermined threshold into an IF signal.

  Here, by changing the oscillation frequency of the signal output from the oscillator 184b to the mixer 184a, the mixer 184a can convert digital RF signals having different carrier frequencies into IF signals having the same frequency (for example, 1 MHz).

  In addition, since the central control unit 160 of the present embodiment is configured to include, for example, two mixer function units 170, the mixer function unit 170b changes the oscillation frequency of the signal output from the oscillator 184b to the mixer 184a. All the digital RF signals of the carrier frequency included in the bandwidth of 87.5 MHz to 108.0 MHz are converted into IF signals, but the central control unit 160 determines the number of carrier waves of the radio broadcast station 102 (for example, 400). Only the mixer function unit 170 may be provided, and the frequency of the oscillator 184b of each mixer function unit 170 may be fixed. Further, when the central control unit 160 includes three or more mixer function units 170, one mixer function unit 170 converts the IF signal corresponding to the RF signal of one carrier frequency according to the operation input to the operation unit 150 by the user. The other mixer function unit 170 converts the digital RF signal included in the bandwidth obtained by dividing the bandwidth of 87.5 MHz to 108.0 MHz by the number of the other mixer function units 170 into an IF signal. The oscillator 184b of each mixer function unit 170 may change the oscillation frequency.

  The specifying unit 172 is an arbitrary mixer function unit that converts an IF signal corresponding to an RF signal having a receivable carrier frequency in accordance with an operation input by the user through the operation unit 150 among the plurality of mixer function units 170. 170 (here, the mixer function unit 170a) is specified.

  A detection function unit 174 (indicated by 174a and 174b in the figure) is provided for each mixer function unit 170, and detects a plurality of IF signals.

  The identity determination unit 176 determines whether the program content of the IF signal converted by the mixer function unit 170a specified by the specification unit 172 is the same as the program content of the IF signal converted by the other mixer function unit 170b. To determine. In the present embodiment, the same determination unit 176 determines whether the IF signal program content converted by the mixer function unit 170a and the mixer function unit 170b depend on whether or not the waveforms of the detected IF signals in a predetermined time range are substantially the same. It is determined whether or not the program content of one IF signal sequentially extracted from the plurality of IF signals converted by is identical. Specifically, the same determination unit 176 detects one IF signal sequentially extracted from the IF signal converted by the mixer function unit 170a and the plurality of IF signals converted by the mixer function unit 170b, detected in a predetermined time range. When the mean square error of the waveform is smaller than a predetermined value, it is determined that the error is the same, or from the IF signal converted by the mixer function unit 170a detected in the predetermined time range and the plurality of IF signals converted by the mixer function unit 170b When the correlation value of the waveform of one IF signal extracted sequentially becomes equal to or greater than a predetermined value, it is determined that they are the same.

  FIG. 4 is an explanatory diagram for explaining the processing of the same determination unit 176. For example, the identity determination unit 176 squares the waveform of the IF signal converted by the mixer function unit 170a shown in FIG. 4A and the waveform of the IF signal converted by the mixer function unit 170b shown in FIG. 4B. An average error is calculated, and when the mean square error is smaller than a predetermined value, these IF signals are determined to have the same program content. Further, the same determination unit 176 squares the waveform of the IF signal converted by the mixer function unit 170a shown in FIG. 4A and the waveform of the IF signal converted by the mixer function unit 170b shown in FIG. 4C. An average error is calculated, and the mean square error is larger than a predetermined value, so that these IF signals are determined not to have the same program content.

  When receiving unit 154 receives an RF signal of a European terrestrial radio broadcast wave, identity determining unit 176 determines whether the PI (Program Identification) code of the RDS information superimposed on the RF signal is the same. It can also be determined whether or not the program contents are the same. The PI code is an identifier indicating an individual program and a country where the program is broadcast. Therefore, if the PI code is the same, it can be determined that the program content is also the same.

  Further, the same determination unit 176 compares the results of the fast Fourier transform (FFT) of the IF signal as they are, determines whether the difference is within a predetermined range, and determines whether the program contents are the same. It may be determined.

  If the same determination unit 176 determines that the program content is the same, the switch 178 is closed.

  The combining unit 180 combines a plurality of IF signals determined to be the same to generate a combined program signal. The audio control unit 182 detects (demodulates) the generated synthesized program signal and outputs it to the audio output unit 162.

  The audio output unit 162 includes a speaker or the like, and converts the detected synthesized program signal into audio in accordance with a control command from the audio control unit 182.

  As described above, according to the radio receiver 110 according to the present embodiment, an RF signal in a predetermined frequency band is once transmitted by one antenna 152 and one tuner (receiving unit 154 and A / D conversion unit 156). Because it can be converted into digital RF signals, it is easy to use the same IF signal as the selected IF signal among the generated IF signals without preparing multiple antennas or multiple tuners. And it becomes possible to extract rapidly.

  In addition, since the combining unit 180 generates a combined program signal by combining the IF signals determined to be the same by the same determining unit 176, the SNR (Signal of the same IF signal is compared with each IF signal before combining). to Noise Ratio) can be increased.

  In addition, a program that causes a computer to function as the radio receiver 110 and a computer-readable flexible disk, magneto-optical disk, ROM, EPROM, EEPROM, CD (Compact Disc), DVD (Digital Versatile Disc) on which the program is recorded A storage medium such as a BD (Blu-ray Disc) is also provided. Here, the program refers to data processing means described in an arbitrary language or description method.

(Radio reception method)
FIG. 5 is a flowchart illustrating the processing flow of the radio reception method. Here, the case where the band of the RF signal converted by the A / D conversion unit 156 is 87.5 MHz to 108.0 MHz will be described as an example. In the present embodiment, the radio reception method operates as an interrupt process according to a 40 MHz interrupt signal. As illustrated in FIG. 5, the A / D conversion unit 156 of the radio receiver 110 converts an RF signal in a predetermined frequency band received by the reception unit 154 into a digital RF signal at one time (S202).

  Then, the mixer function unit 170a converts the digital RF signal converted in the A / D conversion step S202 into an IF signal corresponding to the receivable carrier frequency RF signal according to the operation input through the operation unit 150 by the user. Then, the identifying unit 172 identifies the mixer function unit 170a that is converting the IF signal corresponding to the RF signal of the carrier frequency according to the user's operation input from among the plurality of mixer function units 170 (S204). The detection function unit 174a detects the IF signal converted by the mixer function unit 170a specified in the specifying step S204 (S206).

  On the other hand, the mixer function unit 170b sets 87.5 MHz, which is the minimum frequency of the band of the RF signal, as the carrier frequency of the digital RF signal attempting to convert to the IF signal (S208), and converts the digital RF signal of 87.5 MHz. Extracted and converted to IF signal (S210). The detection function unit 174b detects the IF signal converted in the IF conversion step S210 (S212).

  Then, the same determination unit 176 detects the IF signal detected in the detection step S206 (the IF signal converted by the mixer function unit 170a specified by the specifying unit 172) and the IF signal detected in the detection step S212 (the mixer function unit 170b It is determined whether or not the converted IF signal is the same (S214).

  If it is determined that the program content of the IF signal detected in detection step S212 is the same as the program content of the IF signal detected in detection step S206 (YES in S214), the IF converted in IF conversion step S210 The signal is held in the memory 158 (S216). Then, for example, 50 kHz is added to the carrier frequency of the digital RF signal to be converted to the IF signal (S218), and the carrier frequency of the digital RF signal from which the IF signal is converted is the maximum frequency of the band of the RF signal. It is determined whether or not the frequency is 0 MHz (S220). If the frequency is not the maximum frequency (NO in S220), the processing after IF conversion step S210 is performed.

  If it is determined that the program content of the IF signal detected in the detection step S212 is not the same as the program content of the IF signal detected in the detection step S206 (NO in S214), the IF signal is recorded in the memory 158. First, the processing after the frequency changing step S218 is performed. In this way, it is possible to confirm the presence or absence of an IF signal having the same program content as the IF signal converted by the mixer function unit 170a for every 50 kHz which is the carrier bandwidth of the radio broadcast station 102.

  If the carrier frequency of the digital RF signal from which the IF signal is converted is the maximum frequency in the band of the RF signal (YES in S220), that is, all the carrier frequencies included in the bandwidth of the RF signal received by receiver 154 When determining whether or not the program content of the IF signal corresponding to the RF signal is the same as the program content of the IF signal detected in the detection step S206, the central control unit 160 stores the IF signal in the memory 158. It is determined whether or not it is held (S222), and if held (YES in S222), the synthesizing unit 180 synthesizes all IF signals held in the memory 158 in the holding step S216 and combines them. The signal is generated (S224), and the audio control unit 182 detects the synthesized program signal and outputs it to the audio output unit 162 (S226). In the memory determination step S222, if the IF signal is not held in the memory 158 (NO in S222), the voice control unit 182 outputs the IF signal detected in the detection step S206 to the voice output unit 162 (S226).

  As described above, also in the radio reception method according to the present embodiment, the RF signal of the carrier frequency of one or a plurality of radio broadcast stations 102 is converted into one antenna 152 and one tuner (reception unit 154 and A / D conversion unit). 156), it is possible to easily perform frequency diversity using the technology that can be acquired at once.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  Note that each step of the radio reception method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include parallel or subroutine processing.

  The present invention can be used for a radio receiver, a radio reception method, and a program.

DESCRIPTION OF SYMBOLS 110 ... Radio receiver 150 ... Operation part 152 ... Antenna 154 ... Reception part 156 ... A / D conversion part 158 ... Memory 160 ... Central control part 162 ... Audio | voice output part 170 ... Mixer function part 172 ... Specific | specification part 174 ... Detection function part 176... Same determination unit 178... Switch 180... Synthesis unit 182.

Claims (4)

One receiving unit for receiving an RF signal of a predetermined frequency band;
One A / D converter that converts the RF signal of the predetermined frequency band received by the receiver into a digital RF signal;
A plurality of mixer functional units that respectively convert the digital RF signal into IF signals corresponding to RF signals having different carrier frequencies;
Among the plurality of mixer function units, a specifying unit that identifies a mixer function unit that converts an IF signal corresponding to an RF signal having a carrier frequency according to a user operation input;
The same determination unit that determines whether the program content of the IF signal converted by the specified mixer function unit and the program content of the IF signal converted by another mixer function unit are the same,
A combining unit that combines the IF signal converted by the specified mixer function unit and the IF signal determined to be the same by the same determination unit to generate a combined program signal;
An audio control unit for outputting the synthesized program signal to an audio output unit;
A radio receiver comprising: A detection function unit for detecting the plurality of IF signals converted by the mixer function unit;
Further comprising
The radio receiver according to claim 1, wherein the same determination unit determines whether or not the program content is the same based on the detected IF signal. Receiving an RF signal of a predetermined frequency band,
The received RF signal of the predetermined frequency band is converted into a digital RF signal,
In a plurality of mixer function units, the digital RF signal is converted into IF signals corresponding to RF signals having different carrier frequencies, respectively.
Among the plurality of mixer function units, specify a mixer function unit that converts the IF signal corresponding to the RF signal of the carrier frequency according to the user's operation input,
Determine whether the program content of the IF signal converted by the specified mixer function unit and the program content of the IF signal converted by another mixer function unit are the same,
A synthesized program signal is generated by synthesizing the IF signal converted by the specified mixer function unit and the IF signal determined to be the same,
A radio reception method, comprising: outputting the synthesized program signal to an audio output unit. A computer mounted on a radio receiver that receives an RF signal of a predetermined frequency band,
One A / D converter that converts the RF signal of the predetermined frequency band received by the receiver into a digital RF signal;
A plurality of mixer functional units that respectively convert the digital RF signal into IF signals corresponding to RF signals having different carrier frequencies;
Among the plurality of mixer function units, a specifying unit that identifies a mixer function unit that converts an IF signal corresponding to an RF signal having a carrier frequency according to a user operation input;
The same determination unit that determines whether the program content of the IF signal converted by the specified mixer function unit and the program content of the IF signal converted by another mixer function unit are the same,
A combining unit that combines the IF signal converted by the specified mixer function unit and the IF signal determined to be the same by the same determination unit to generate a combined program signal;
A program for causing the synthesized program signal to function as an audio control unit for outputting to an audio output unit.

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