JP2012005030A - Receiving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiving apparatus capable of obtaining an excellent receiving property by setting a receiving control parameter corresponding to the receiving property, in simple configuration.SOLUTION: A receiving apparatus comprises: a receiving circuit 10 for outputting an intermediate frequency (IF) signal and a detection signal from a received radio frequency signal; a DSP circuit 20 having a processing section 30 for outputting an audio signal in accordance with a receiving control parameter for determining a processing method of the IF signal from the receiving circuit 10 and a detection section 40 for outputting a receiving sensor value representing a receiving state based on the detection signal inputted from the receiving circuit 10; a host microcomputer 50 to which the receiving sensor value is inputted from the detection section 40 of the DSP circuit 20; and a memory 52 for storing a plurality of receiving control parameters corresponding to a plurality of receiving sensor values. The host microcomputer 50 selects an optimal receiving control parameter from among the plurality of receiving control parameter stored in the memory 52 in accordance with the receiving sensor value and transfers the selected receiving control parameter to the processing section 30.

Description

  The present invention relates to a receiving apparatus, and more particularly to a receiving apparatus capable of changing a reception control parameter for controlling a reception state.

  In today's in-vehicle radio or in-vehicle television receivers, reception control of the front end (F / E) unit is performed using a digital signal processor (DSP) capable of high-speed signal processing. As a result, (1) control of stereo separation with respect to fluctuations in electric field strength during movement, (2) automatic gain control (AGC) for setting the electric field strength of the received signal to a desired level, and (3) mixing of noise due to adjacent interference Detection, (4) Stereo separation control for reception interference due to multipath, (5) High cut control of high frequency of audio signal when electric field strength drops to near no electric field strength due to fading, etc. This realizes a receiver capable of reducing the sense of wandering and effectively reducing noise.

  A configuration of a conventional receiving apparatus is shown in FIG. The receiving apparatus 100 includes a receiving circuit 102 that is an F / E section, a DSP circuit 103 that is a back-end (B / E) section, a microcomputer 104, a memory 105, and an amplifier 106. The audio signal output from the amplifier 106 is transferred to the speaker 107, and the audio is output from the speaker 107. With respect to the controls (1) to (5), the reception control parameters that determine how to apply the control are stored in the memory 105, and the memory 105 passes through the microcomputer 104 when the receiving apparatus is activated (when the power is turned on). The data is transferred to the DSP circuit 103. Here, examples of the reception control parameter include an AGC control amount, a soft mute amount, a multipath removal characteristic, and the like.

  In developing the receiving apparatus, it is important how to determine the reception control parameter. However, it is difficult to determine the reception control parameter to a specific value because it is affected by factors such as differences in reception environments such as urban areas, mountainous areas, and plain areas, and vehicle-specific factors such as vehicle movement speed and antenna position. It is. For this reason, in order to determine a reception control parameter that can be averagely applied in any environment, a lot of man-hours are spent on evaluation of reception characteristics by actual vehicle traveling in which the receiver is actually mounted on the vehicle. ing. Specifically, as shown in FIG. 1, a personal computer (PC) 200 is connected to the receiving apparatus 100, and (a) reception control parameters are determined based on accumulated past evaluation results and results, ( b) Evaluation is performed by actual vehicle running in a field such as an urban area or a mountainous area, and if the evaluation is not good, comprehensive judgment is made from the DSP operation log recorded in a time series and the evaluation results on hearing. The reception control parameter is tuned by repeating the routines (a) to (c) in which the reception control parameter is tuned, (c) the tuned result is written in the memory, and the vehicle is run again in the field for evaluation. The accuracy was improved.

  However, the reception control parameter determination method as described above has the following problems. First, since considerable knowledge and experience are required to decode the DSP operation log and tune the reception control parameters, it is very important to have skilled engineers who influence the accuracy of the reception control parameters. However, there is a problem that it takes a long time to train such skilled engineers. In particular, for OEM suppliers of in-vehicle products such as receivers that are compatible with the recent global development of automobile manufacturers, it is a problem how to increase the number of skilled engineers and deploy them to major bases around the world. It was.

  Secondly, in the conventional evaluation method of the reception control parameter, since the evaluator mainly evaluates the received voice based on the audibility while traveling in the field, the DSP operation log, time, vehicle position and reception It has been difficult to accurately associate information such as signal output results (received speech, bit error rate, etc.). Therefore, in the evaluation using only the DSP operation log, sufficient analysis accuracy cannot be obtained, and it is difficult to improve the accuracy of the reception control parameter.

  Third, basically, it is ideal to set reception control parameters for each vehicle type and for each region. However, in general, many in-vehicle receivers are used in consideration of an average system configuration and cost. However, one type of reception control parameter that can be applied on average is set in the product, and there has been a problem that many man-hours are required for updating the reception control parameter according to the reception environment of the market.

  By the way, the coordinates of the vehicle position measured by GPS and the received electric field strength are associated and stored as experience values, and when the environment changes even at the same point, the latest reception control parameters are automatically calculated, A replacement method is known (for example, Patent Document 1). However, in order to realize this function, an arithmetic device having a considerably high computing capacity and processing speed and a large-capacity storage medium are required, resulting in a problem that the product becomes expensive.

  Furthermore, in the prior art described in Patent Document 1, position coordinates and past received information (electric field strength, fluctuation frequency) are stored, and if the traveling electric field strength is different from the past received information, reception control is newly performed. Although the parameters have been corrected, this conventional technique has the following problems. That is, (i) Electric field fluctuations due to climate change such as sudden heavy rain or thunderstorm, (ii) Interference caused by medium wave broadcasting usually encountered when a vehicle traveling in the daytime travels at midnight, (iii) Relay of a broadcasting station When passing near the vehicle, there is a possibility that a problem such as an unexpected reception failure for selecting a reception control parameter which is not necessary originally occurs. Furthermore, in the above case, the reception control parameter differs for each user, and therefore, there is a problem that the reproduction experiment for the reception state failure cannot be performed, and cases where the cause of the failure is unknown increase. .

JP-A-8-149029

  An object of the present invention is to provide a receiving apparatus that can set a reception control parameter corresponding to a reception state with a simple configuration and obtain good reception characteristics.

  The receiving apparatus of the present invention receives a radio frequency signal received by an antenna, outputs an intermediate frequency (IF) signal and a detection signal, and receives an IF signal from the receiving circuit, and determines an IF signal processing method. A DSP circuit having a processing unit that outputs an audio signal according to a reception control parameter, a detection unit that receives a detection signal from the reception circuit and outputs a reception sensor value that represents a reception state based on the detection signal, and a DSP circuit A host microcomputer to which a reception sensor value is input from the detection unit; and a memory for storing a plurality of reception control parameters corresponding to the plurality of reception sensor values. The host microcomputer stores in the memory in accordance with the reception sensor value. An optimum reception control parameter is selected from a plurality of stored reception control parameters and transferred to the processing unit.

  ADVANTAGE OF THE INVENTION According to this invention, the receiving apparatus which can set the receiving control parameter corresponding to a receiving condition with a simple structure and can acquire a favorable receiving characteristic can be provided.

It is a block diagram of the conventional receiver. It is a block diagram of the receiver of this invention. It is a flowchart for demonstrating the setting method of the reception control parameter using the receiver of this invention. It is a block diagram of the receiving system for determining the reception control parameter using the receiver of this invention.

  FIG. 2 shows a configuration diagram of the receiving apparatus of the present invention. The receiver 1 of the present invention receives a radio frequency (RF) signal received by an antenna 101, receives an intermediate frequency (IF) signal and an S meter value, and receives an IF signal from the receiver circuit 10. The processing unit 30 that outputs the audio signal according to the reception control parameter that determines the IF signal processing method, and the S meter value are input from the receiving circuit 10, and the reception sensor value that represents the reception state is output based on the S meter value. A digital signal processor (DSP) circuit 20 having a detection unit 40, a host microcomputer 50 that receives a reception sensor value from the detection unit 40 of the DSP circuit 20, and a reception control parameter that determines a method of processing an IF signal in the processing unit 30 And a memory 52 for storing. The memory 52 stores a plurality of reception control parameters corresponding to a plurality of reception sensor values, and the host microcomputer 50 selects an optimum reception control parameter from the plurality of reception control parameters stored in the memory 52 according to the reception sensor value. Is transferred to the processing unit 30.

  The receiving circuit 10 includes an RF receiving amplifier 11, a comparator 12, an IF signal amplitude controller (AGC) 13, and an oscillator 14. The RF signal received by the antenna 101 is input to the RF receiving amplifier 11 of the receiving circuit 10, amplified, and then output to the comparator 12. The amplification degree in the RF receiving amplifier 11 is controlled by the AGC 13. The amplified RF signal is input to the comparator 12, which outputs an IF signal and an S meter value based on the signal from the oscillator 14. Here, the S meter value includes data on electric field strength, multipath, adjacent interference, and pulse noise.

  The DSP circuit 20 includes a processing unit 30 and a detection unit 40. The processing unit 30 includes an IF filter 31, an IF amplifier 32, a detector 33, a noise canceller 34, a multipath automatic selectivity controller (M-ASC, M-ATC) 35, a de-emphasis circuit (de-Emph) 36, An audio DSP 37 is provided. The IF signal input to the IF filter 31 is amplified by the IF amplifier 32, then the modulation signal is detected by the detector 33, and the noise is removed by the noise canceller 34. Here, multipath is a propagation phenomenon until a radio signal reaches a receiving antenna through two or more paths, and causes harmful interference and a phase shift of the signal. The automatic selectivity controller 35 at the time of multipath reduces the influence of multipath. The de-emphasis circuit 36 functions to restore the emphasized frequency component. The audio DSP 37 performs so-called soft mute, which reduces the input to the audio amplifier when the noise is large. The output signal of the noise canceller 34 is input to the audio amplifier 21 via the automatic selectivity controller 35, the de-emphasis circuit 36 and the audio DSP 37, output from the audio amplifier 21 to the speaker 107, and finally as sound from the speaker 107. Is output.

  The detection unit 40 includes an S meter value detection unit 41 and a reception control parameter storage unit 42. The S meter value detection unit 41 receives the S meter value from the comparator 12 of the reception circuit 10 and outputs a reception sensor value. The S meter value detection unit 41 includes an electric field intensity detection unit 41a, a multipath detection unit 41b, an adjacent disturbance detection unit 41c, and a pulse noise detection unit 41d, and these output data are referred to as reception sensor values. The electric field strength detection unit 41 a detects the electric field strength after being amplified by the RF receiving amplifier 11. The multipath detection unit 41b detects the presence / absence of multipath and the degree of interference. Interference due to multipath may be caused by reflected waves from buildings such as buildings and trees. The adjacent interference detection unit 41c detects the degree of adjacent interference. Adjacent interference is a problem particularly in digital radio broadcasting represented by the IBOC system in which new digital signals are added to both sides of an AM / FM broadcasting allocated band. The reception control parameter storage unit 42 can be configured by a RAM or the like, and stores reception control parameters described later.

  The host microcomputer 50 includes a host microcomputer CPU 51 and a memory 52. The CPU 51 for host microcomputer receives the reception sensor value from the S meter value detection unit 41 and the DSP control operation information from the processing unit 30 of the DSP circuit 20. The memory 52 stores a plurality of reception control parameters 1 to N, vehicle type information, and other information. The reception control parameter is a value determined in advance so as to obtain an optimal reception state according to the reception sensor value. For example, when there is a possibility that a vehicle equipped with a receiving device travels in an urban area, a plain area, or a mountainous area, reception control parameters suitable for those environments are prepared in advance.

  The reception control parameter is a control parameter for improving the reception state when it is determined that the reception state is not good based on the reception sensor value. Examples of reception control parameters include a soft mute amount, an AGC amount, an automatic selectivity control amount, and a filter constant. Soft mute is an operation that lowers the overall volume of received audio and can be used when the electric field strength is low. This is because when the electric field strength is weak, the strength of the audio signal is lowered, so that the noise level is relatively increased and uncomfortable feeling occurs. At this time, uncomfortable feeling can be reduced by using soft mute to lower the level of the audio signal. The soft mute amount is controlled by the audio DSP 37.

  The amount of AGC is for maintaining the output constant by increasing the sensitivity when the received signal is weak and decreasing the sensitivity when the received signal is strong. When the AGC amount is changed, the gain of the RF receiving amplifier unit 11 of the receiving circuit 10 can be changed according to the received electric field strength. That is, when the output signal voltage of the electric field strength detection unit 41a among the reception sensor value outputs is applied to the gain input terminal of the AGC 13 that controls the RF reception amplifier 11, the RF reception amplifier has an antenna input level at the time of weak to medium electric fields. Accordingly, the RF signal can be amplified with a constant gain. On the other hand, due to the characteristics of a general amplifier circuit, the output of the RF receiving amplifier is distorted when the electric field is strong and the input to the amplifier is large. Therefore, if the output signal level exceeds a certain level, Control to keep the gain constant.

  An automatic selectivity control amount (Multipath detect Automatic Separation Control; M-ASC) is a control amount for removing noise caused by multipath. This forcibly approaches stereo to monaural according to the multipath noise to reduce the multipath noise. By controlling the automatic selectivity control amount, the automatic selectivity controller 35 of the processing unit 30 in FIG. 2 can be controlled. The filter constant is used when reducing the level of a high frequency band where unpleasant sound distortion occurs. The filter constant of the IF filter 31 of the processing unit 30 in FIG. 2 can be controlled using the filter constant.

  The vehicle type information represents the type of vehicle, and the other information includes information related to acoustic parameters, equalizers, and the like. The host microcomputer CPU 51 can select an optimal reception control parameter from the memory 52 in accordance with the value of the reception sensor value. The reception control parameter selected by the host microcomputer CPU 51 is stored in the reception control parameter storage unit 42 of the detection unit 40 and then transferred to the processing unit 30 for reception control. The IF signal subjected to reception control according to the reception control parameter is transferred to the audio amplifier 21 and output to the speaker 107.

  In the present invention, the position information of the vehicle is not necessarily required, but the position information can be used supplementarily. In this case, the position may be detected using a car navigation device (navigation) or a mobile terminal having a GPS function. When the navigation is used, the GPS navigation ECU 60 and the GPS antenna 61 may be provided. Moreover, when using a mobile terminal, you may make it use communication ECU70 and the mobile terminal 71 between mobile terminals. The host microcomputer CPU 51 receives vehicle position information from the GPS navigation ECU 60 or the mobile terminal communication ECU 70, and can select the optimum reception control parameter using the position information as an auxiliary.

  Next, the operation method of the receiving apparatus of the present invention will be described. FIG. 3 is a flowchart for explaining a reception control parameter setting method using the receiving apparatus of the present invention. First, in step S101, the power supply of the receiving device 1 is turned on. Next, in step S <b> 102, the host microcomputer CPU 51 reads reception control parameters from the memory 52. Here, N reception control parameters 1 to N are stored in the memory 52, and the host microcomputer CPU 51 selects one reception control parameter from these. In this selection, a navigation or mobile terminal having a GPS function may be used with reference to position information. For example, when the receiving apparatus is mounted on a vehicle that exists in an urban area, it is possible to select a reception control parameter that is set so that optimal reception can be realized in the urban area.

  Next, in step S <b> 103, the host microcomputer CPU 51 transfers the reception control parameter to the processing unit 30. The processing unit 30 processes the IF signal based on the input reception control parameter and outputs sound.

  The S meter value is output as a detection signal from the comparator 12 of the receiving circuit 10 and is input to the S meter value detection unit 41 of the detection unit 40. The S meter value detection unit 41 outputs a reception sensor value based on the input S meter value. The reception sensor value is input to the host microcomputer CPU 51. In step S104, the host microcomputer CPU 51 determines whether or not the reception sensor value is within a predetermined range. Specifically, the size of various data output from the electric field intensity detection unit 41a, the multipath detection unit 41b, the adjacent disturbance detection unit 41c, and the pulse noise detection unit 41d and a predetermined threshold is determined.

  If the host microcomputer CPU 51 determines that the reception sensor value deviates from the predetermined range, an optimal reception control parameter is selected from the memory 52 in step S105. For example, when the reception control parameter suitable for reception in the plain part is read while traveling on the plain part, the output data of the multipath detection unit 41b exceeds the threshold value, and the radio wave interference caused by the multipath increases. Is detected, a reception control parameter suitable for reception in urban areas is selected. Alternatively, when the reception control parameters suitable for reception in the urban area were read when traveling in the urban area, the output data of the electric field intensity detection unit 41a was below the threshold value, and it was detected that the distance from the radio tower was far away. In this case, a reception control parameter suitable for reception in the plain is selected.

  In step S104, the host microcomputer CPU 51 returns to step S104 after a predetermined time after the reception sensor value is within the predetermined range and after replacing with the optimal reception control parameter in step S105. It is determined whether or not the value is within a predetermined range.

  In a vehicle equipped with a navigation system, in addition to the reception sensor value, the switching accuracy of reception control parameters can be improved by linking with position information from GPS navigation or a position information service of a mobile phone. . Specifically, when your vehicle is traveling within a few kilometers of broadcasting equipment or power equipment, it may be affected by adjacent interference or strong electric field noise. In order to avoid the influence, it is possible to switch to a reception control parameter in which a filter constant, a time constant, or the like is changed, so that a reception failure can be predicted at an early stage and this can be dealt with.

  As described above, in the present invention, since the reception control parameter is changed only when the reception sensor value deviates from the predetermined range, the reception control is performed when the reception state is maintained at a constant level. There is no need to change the parameters. Therefore, while maintaining the reception state at a certain level, the necessary reception control parameters can be suppressed to the minimum necessary number, so that the optimum reception can be achieved without significantly increasing the CPU function and memory capacity. A receiving apparatus capable of obtaining an environment can be realized with a simple configuration.

  Next, a procedure for determining reception control parameters using the receiving apparatus of the present invention will be described. FIG. 4 shows a block diagram of a receiving system for determining reception control parameters using the receiving apparatus of the present invention. In this receiving system, a personal computer (PC) 200 is connected to the receiving apparatus 1 shown in FIG. The PC 200 receives the reception sensor value from the host microcomputer CPU 51, collects the sound output from the speaker 107 with the microphone 108, and receives the collected sound signal.

  Specifically, the PC 200 records the received sensor value obtained through the host microcomputer during the test course running test in the field, the DSP operation log information such as the DSP control operation information, and the time series data of the received voice. After the test course running test is completed, the sensor values and received voices obtained in time series are automatically analyzed by the PC, so that the optimum reception characteristics for the field, that is, soft mute amount, AGC amount, M-ASC / ATC Receive control parameters that define characteristics such as characteristics and adjacent interference filter coefficients are automatically calculated. As described above, the effect of the reception control parameter obtained in the test course running is conventionally determined by a skilled engineer based on the sense of hearing, but the received sound is analyzed using a PC. Thus, this work can be automated. For this reason, optimal reception control parameters can be easily set using a PC without depending on a skilled engineer.

  Next, a method for automatically calculating reception control parameters will be specifically described. The soft mute control amount that determines the soft mute control in a weak electric field derives an optimum value from the fluctuation amount of the electric field strength, the modulation degree, and the modulation frequency. The AGC amount of the RF receiving amplifier of the receiving circuit is derived from the optimum value from the electric field strength and the fluctuation amount of the received voice. The M-ASC / ATC control amount at the time of multipath noise detection derives an optimum value from the fluctuation amount of the electric field strength, the multipath detection frequency, and the received voice. Here, M-ATC (Multipath Automatic Tone Control) is used to reduce the noise sensation by suppressing the high frequency and low frequency levels of the received signal with a filter when multipath noise occurs. As for the time constant such as an IF filter used at the time of adjacent interference or multipath detection and the set value of the filter switching time, an optimum value is derived from the fluctuation amount of the electric field intensity and the frequency of adjacent interference detection.

  By using the vehicle equipped with the reception system shown in FIG. 4 and determining the reception control parameters while traveling in various environments such as urban areas, plain areas, and mountainous areas, the reception control parameters suitable for each environment can be obtained. Obtainable. Furthermore, reception control parameters determined by characteristics specific to the vehicle type such as the type of antenna and the presence / absence of an amplifier can be determined in the same manner. By using a PC as described above, the reception control coefficient that can be obtained only after running the test course multiple times in the past is automatically calculated by making two rounds of the test course, including the confirmation of the effect. Is possible.

  In the above embodiment, the on-vehicle receiving device has been described as an example of the receiving device. However, the present invention is not limited to this, and the present invention can also be applied to overseas digital radio, terrestrial digital TV receiving media, and the like. .

1 Receiving Device 10 Receiving Circuit 20 DSP Circuit 30 Processing Unit 40 Detection Unit 41 S Meter Value Detection Unit 50 Host Microcomputer 51 Host Microcomputer CPU
52 memory 200 PC

Claims (5)

A radio frequency signal received by the antenna is input, and a receiving circuit that outputs an intermediate frequency (IF) signal and a detection signal;
The IF signal is input from the receiving circuit, and a processing unit that outputs an audio signal according to a reception control parameter that determines a processing method of the IF signal; and the detection signal is input from the receiving circuit, and based on the detection signal A DSP circuit having a detection unit that outputs a reception sensor value indicating a reception state;
A host microcomputer to which the reception sensor value is input from the detection unit of the DSP circuit;
A memory for storing a plurality of reception control parameters corresponding to a plurality of reception sensor values;
The host microcomputer selects an optimum reception control parameter from a plurality of reception control parameters stored in the memory according to the reception sensor value, and transfers the selected reception control parameter to the processing unit.   The receiving device according to claim 1, wherein the reception sensor value includes at least one of a reception electric field value, a multipath noise detection value, and an adjacent disturbance detection value.   The receiving apparatus according to claim 1, wherein the reception control parameter includes at least one of a soft mute amount, an AGC amount, an automatic selectivity control amount, and a filter constant.   The host microcomputer selects an optimal reception control parameter from a plurality of reception control parameters stored in the memory only when it is determined that a reception state of a certain level or more cannot be maintained based on the reception sensor value, The receiving device according to any one of claims 1 to 3, wherein the receiving device is transferred to a processing unit.   The host microcomputer selects an optimum reception control parameter from a plurality of reception control parameters stored in the memory according to the reception sensor value and position information of the reception device. The receiving device according to item.

Images