JP2011071627A - Radio receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio receiving apparatus capable of automatically setting up reception characteristic data optimal to an area and/or a road where a vehicle is located and acquiring a proper reception environment using the reception characteristic data. <P>SOLUTION: The radio receiving apparatus 10 interlocks with activation of a navigation device 11 to receive radio broadcasting. The radio receiving apparatus 10 includes a reception state monitoring module (tuner 121), a storage module (data storage 113), and a control module (navigation controller 110). The reception state monitoring module monitors the reception state of the radio broadcasting during running of the vehicle. The storage module stores a plurality of reception characteristic parameters defined beforehand according to the reception state. The control module selects a reception characteristic parameter suitable for present location managed by the navigation device 11 among the plurality of reception characteristic parameters stored at the storage module to repeat and perform processing accumulated at the storage module for a predetermined number of runnings, based on the reception state monitored and acquired by the reception state monitoring module. Then, the control module selects one parameter from reception characteristics parameters accumulated at the storage module to perform noise suppression. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radio reception apparatus that receives radio broadcasts in conjunction with the activation of a navigation apparatus, and is particularly suitable for use in an in-vehicle device in which a navigation apparatus and an audio apparatus including an AM / FM tuner are integrally formed. .

  In an FM (Frequency Modulation) tuner, multipaths caused by radio wave reflection and diffraction due to the influence of buildings, topography, etc. are usually taken by a DSP (Digital Signal Processor). In this case, a lot of parameters must be set for adjustment, and it works effectively only on feature points, and does not conform to patterns in every field. The state of the field varies depending on the time and time, and the disturbances are not always the same. For example, FM tuners are frequently generated in places with strong received radio waves, such as in urban areas and mountainous areas. It was very difficult to determine whether or not the function of removing multipath was working effectively.

  On the other hand, an AM (Amplitude Modulation) tuner may easily receive radio waves from a distant broadcasting station due to the influence of the ionosphere depending on the time zone, and tends to receive harsh noise such as beats and interference.

  Conventionally, as a radio receiver, the circuit configuration that removes external noise is usually available, but for all changes in the area, time, or seasonal change, only fixed parameters that have been set in advance can be used for adjustment. It was difficult to cover.

  In order to solve the above-described problem, conventionally, based on the storage means for storing the reception characteristics according to the area, the area identification means for identifying the area where the car exists, and the reception characteristics according to the area where the car exists. An FM stereo receiver having a reception control means for controlling a received signal has been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 3-54923

  According to the technique disclosed in Patent Document 1 described above, reception characteristics are automatically set according to the area where the vehicle is present, and the reception signal is controlled based on the reception characteristics. become. However, although the contents of controlling the reception signal based on the reception characteristics are disclosed, there is no disclosure about how to automatically set the reception characteristics according to the area where the vehicle exists. Also, no noise countermeasures for AM tuners are disclosed.

  The present invention has been made to solve the above-described problems, and receives radio broadcasts in conjunction with activation of a navigation device. In particular, the navigation device and an audio device including an AM / FM tuner are integrally formed. To provide a radio receiver capable of automatically setting optimum reception characteristic data for an area or road where a vehicle is located in an on-vehicle device, and obtaining a good reception environment by using the reception characteristic data. With the goal.

  The present invention has been made to solve the above-described problems, and is a radio reception device that receives a radio broadcast in conjunction with the activation of a navigation device, and receives the radio broadcast while the vehicle is running. A state monitoring unit; a storage unit that stores a plurality of reception characteristic parameters that are predefined according to the reception state; and a reception that is stored in the storage unit based on a reception state that is monitored by the reception state monitoring unit Control means for selecting a reception characteristic parameter suitable for the current location managed by the navigation device from the characteristic parameter table and performing noise removal.

  According to the present invention, a radio broadcast is received in conjunction with activation of a navigation device, and particularly in an in-vehicle device in which a navigation device and an audio device including an AM / FM tuner are integrally formed, an area where a vehicle is located or a road Therefore, it is possible to provide a radio receiving apparatus that can automatically set reception characteristic data that is optimal for the reception, and that can obtain a good reception environment using the reception characteristic data.

It is a block diagram which shows the structure of the radio receiver which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the data structure of the receiving characteristic parameter table shown in FIG. It is a figure which shows the correspondence of a link and a pattern. It is a flowchart which shows the FM learning process (generation of reception characteristic data) of the radio receiver which concerns on Embodiment 1 of this invention. FIG. 5 is a schematic diagram showing the reception characteristic data validity determination processing operation shown in FIG. 4 in time series. It is a flowchart which shows the noise removal process of the radio receiver which concerns on Embodiment 1 of this invention. It is the schematic diagram which showed the area concept of the area determination process (mesh range) shown in FIG. It is a figure which shows an example of the data structure of the reception characteristic parameter table used in Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the radio receiver which concerns on Embodiment 2 of this invention. It is the schematic diagram which showed the validity determination operation | movement of the receiving characteristic data shown in FIG. 6 on the time series.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of the radio receiving apparatus according to the first embodiment. Here, an in-vehicle device in which a navigation device 11 and an audio device 12 including an AM / FM tuner are integrally formed is illustrated as a radio reception device.

  The navigation device 11 includes a navigation control unit 110, a current location acquisition unit 111, a drawing / display control unit 112, a data storage unit 113, and a map DB (Data Base) 114.

The navigation control unit 110 acquires current location information and map information from the current location acquisition unit 111 and the map DB 114, and realizes navigation original functions such as destination search, destination guidance, and current location display.
The navigation control unit 110 also controls an AM / FM tuner (audio device 12) that receives a radio broadcast in conjunction with the activation of the navigation device 11. Specifically, the navigation device 11 manages the reception characteristic parameter table stored in the storage unit (data storage unit 113) based on the reception state obtained by monitoring with the reception state monitoring unit (tuner 121) described later. It also functions as a control means for selecting a reception characteristic parameter suitable for the current location and removing noise.

The current location acquisition unit 111 includes, for example, a GPS (Global Positioning System) receiver, acquires information on latitude, longitude, and precise time acquired from GPS satellites and supplies the information to the navigation control unit 110 for current location measurement. To do.
The drawing / display control unit 112 draws display information generated by the navigation control unit 110 or a radio control unit 120 described later in a display memory (not shown), and displays the drawn display information on the display timing of the display unit 15. Are read out in synchronization with each other and supplied to the display unit 15 to obtain a desired display. The display information here is, for example, an image in which destination information or traffic jam information is superimposed on a map, broadcast station information being viewed, or volume information.

In addition to the program area where the program is stored, the data storage unit 113 is assigned various data such as the reception characteristic parameter table 113a and a work area.
The reception characteristic parameter table 113a is a table in which data for determining each of separation, high cut characteristic, f characteristic, mute, and the like is stored, for example, as shown in FIG.

  In an FM tuner, it is known that in a weak reception electric field environment where noise is relatively large, the S / N ratio is improved by changing from stereo to monaural and attenuating the high frequency level. For this reason, in a weak reception electric field environment, it is well known to control the degree of separation and high cut characteristics, further mute, or change the f characteristic to attenuate the volume according to the reception electric field strength. . The reception characteristic parameter table 113a is used for this purpose.

  In the reception characteristic parameter table 113a, for example, the multipath setting value is “1” in a strong reception electric field environment with a lot of multipath noise, and the multipath setting value is in a weak reception electric field strength environment with a little multipath noise. It is set to be “0”. Several reception patterns (here, patterns # 1 to # 3) including the default pattern “0010” are prepared and stored.

  The navigation control unit 110 selects one pattern based on the travel region or road, and associates the pattern with the data storage unit 113 for each travel region or road (link) as shown in FIG. 3, for example. Remember. In the example of FIG. 3, link A is pattern # 2, link B is pattern # 3, and link C is pattern # 1. Details will be described later.

The map DB 114 stores, for example, meshes divided into prefecture units, municipalities units, or rectangular regions with sides of about 1 km, and road data included in each mesh includes road intersections and T-shaped roads. The link data regarding the node which shows the position of the branch point and bending point containing, and the link which connects between nodes is contained.
This link data includes information such as a link ID, which is a unique identification number for each link, the coordinates of the start point and end point of the link, and the distance from the start point to the end point.

  The data storage unit 113 to which the reception characteristic parameter table 113a and the like are allocated and stored, and the map DB 114 are, for example, a non-volatile storage device (non-volatile semiconductor memory, hard disk device, optical disk device, etc.) or a randomly accessible storage. It is stored in a device (SRAM, DRAM) or the like.

  On the other hand, the audio device 12 includes a radio control unit 120, a tuner 121, a DSP 122, and an audio output unit 123. Here, only blocks related to the AM / FM tuner are extracted and shown in the audio device 12, and other input sources are not shown.

  The radio control unit 120 starts operation in conjunction with the activation of the navigation device 11 triggered by an ignition key operation (ACC power ON), and is a broadcast station designated by the user, or listened to immediately before, or a preset The channel selection operation is executed according to the broadcast station information. The radio control unit 120 also periodically communicates with the navigation control unit 110 to set various parameters necessary for the operation of the DSP 122. The parameters here include the reception characteristic parameters set in the reception characteristic parameter table 113a described above.

  The tuner 121 includes a high-frequency circuit, usually called a front end, that demodulates radio waves received via an antenna. The demodulated signal is supplied to the DSP 122. The tuner 121 also functions as reception state monitoring means for monitoring the reception state of the radio broadcast while traveling and supplying it to the radio control unit 120. The reception state monitored here is a frequency of occurrence of multipath including a received field strength indication (RSSI).

The DSP 122 controls the audio output unit 123 by decoding the demodulated signal supplied from the tuner 121 in accordance with the parameters set by the radio control unit 120.
The audio output unit 123 converts the digital audio signal output from the DSP 122 into an analog signal, and drives the connected speaker 13.

The operation unit 14 includes keys to which various functions are assigned such as a power key, a numeric key, a character key, a direction key, a determination key, and a function key, and these keys are operated by the user. In the case of the operation, a signal corresponding to the operation content is generated and output to the navigation control unit 110 and the radio control unit 120 as a user instruction.
The display unit 15 displays image information such as a map generated by the navigation control unit 110 and drawn in the VRAM area by the drawing / display control unit 112, or broadcast station information and volume information generated by the radio control unit 120. For example, LCDs (Liquid Crystal Display Devices) and organic ELs (Electro-Luminescence) are used as display elements. The

FIG. 4 is a flowchart showing the FM learning process of the radio receiving apparatus according to the first embodiment.
Hereinafter, the operation of the radio receiving apparatus according to the first embodiment shown in FIGS. 1 to 3 will be described in detail with reference to the flowchart of FIG.

According to FIG. 4, first, when the ignition key is operated and the ACC power is turned on (step ST401 “YES”), the navigation device 11 is activated, and at the same time, the FM radio broadcast reception by the audio device 12 is started. (Step ST402).
At this time, in the audio apparatus 12, a channel selection operation by the tuner 121 is executed under the control of the radio control unit 120, and the reception state is monitored every time this channel selection operation is performed (step ST403). Here, it is assumed that the broadcasting station (frequency) selected immediately before is the preset broadcasting station or the broadcasting station that the user frequently views, and the tuner 121 is set to the frequency of the broadcasting station. On the other hand, multipath detection and reception field strength measurement are performed.

When the navigation control unit 110 periodically communicates with the radio control unit 120 by polling or the like and receives the multipath occurrence event detected by the tuner 121 (step ST403 “YES”), the current location acquisition unit 111 And the location where the multipath is generated by the currently traveling area or road (hereinafter referred to as a link) acquired from the map DB 114, and the multipath occurrence status and the received electric field strength are associated with each link and managed. (Step ST404).
Subsequently, the navigation control unit 110 refers to the reception characteristic parameter table 113a set in the data storage unit 113, and sets a pattern for each link in which multipath occurs according to the multipath strength (reception field strength). A plurality (# 1 to # 3) are applied, and a multipath removal process is executed for each to perform a learning process for selecting an optimum pattern (step ST405).

The learning process described above is executed a plurality of times (n times) every time the same link is traveled to increase the reliability (step ST406 “YES”), and the result is associated with the link and the data storage unit 113 each time. (Step ST407). The data stored here is, for example, reception characteristic data indicating a pattern set for each link as shown in FIG. Subsequently, the navigation control unit 110 travels the same link n times and executes the learning process, and then determines the validity of the accumulated data (step ST408). In steps ST401, ST403, and ST406, the determination is repeated until “YES”.
For example, as shown in FIG. 5, the effectiveness is determined by determining whether or not the range (peak-to-peak) of multipath detection levels collected for each link exceeds ± 3 dB set as a threshold. To do.

In FIG. 5, the vertical axis indicates the multipath detection level, the horizontal axis indicates the travel (time), and the transition of the multipath detection level for each of links A, B, and C that changes with travel is shown.
Here, the navigation control unit 110 determines that the pattern of the links (links A and B) that do not exceed the threshold (± 3 dB) is valid (step ST409), and as reception characteristic data for reference when performing noise removal, The data is stored in a predetermined area of the data storage unit 113. If the link (link C) pattern exceeds ± 3 dB, it is determined to be invalid, and the process returns to step ST405 to repeat the collation operation with the reception characteristic parameter table 113a.

  Since the series of processes described above are performed mainly on roads that travel frequently, default values that are generally tuned in advance are used when traveling far away. In addition, since the above-described learning process is performed, the average of the results obtained by n times of traveling is used, and if a certain amount of traveling experience overlaps, the pattern is applied and the processing for actually removing the multipath is executed. It is assumed that a correct reception result is obtained. This processing is performed in consideration of distance factors such as a place where the user frequently travels and commuting. It is also possible to use the distance information to the destination effectively, and check the link density and travel time information in urban and rural areas to select the optimal multipath removal setting. is there.

FIG. 6 is a flowchart showing noise removal processing of the radio reception apparatus according to the first embodiment.
Hereinafter, the noise removal operation of the radio reception apparatus according to the first embodiment shown in FIG. 1 will be described in detail with reference to the flowchart of FIG.

The navigation control unit 110 first refers to the reception characteristic data stored in the data storage unit 113 (step ST601). Then, it is determined whether or not the currently traveling link is included in a predetermined area range on the map mesh.
Here, as shown in an example in FIG. 7, it is determined whether or not the link is included within a radius of 20 km (range A) (step ST602). If the audio device 12 is within the 20 km range (step ST602 “YES”), the multipath removal process included in the audio device 12 is executed using the pattern stored corresponding to the link (step ST603). , (Step ST602 “NO”), the multipath removal process provided in the audio apparatus 12 is executed using the default pattern (step ST604).

  As described above, the radio receiving apparatus according to the first embodiment receives a radio broadcast in conjunction with the activation of the navigation apparatus 11, and the control means (navigation control unit 110) receives the reception state monitoring means (tuner 121). ) To remove noise by selecting a reception characteristic parameter suitable for the current location managed by the navigation device from the reception characteristic parameter table stored in the storage means (data storage unit 113) based on the reception state obtained by monitoring in (1). Is to do. As a result, it is possible to automatically set the optimum reception characteristic data for the area or road where the vehicle is located, and a good reception environment can be obtained by using this reception characteristic data.

  In the radio receiving apparatus according to the first embodiment, the control unit (navigation control unit 110) is selected for each region or road where a multipath monitored by the reception state monitoring unit (tuner 121) occurs. The validity of the reception characteristic parameters stored in the storage means (data storage unit 113) is determined based on the received electric field intensity obtained by monitoring the received broadcast station with the reception state monitoring means. This makes it possible to control the removal of multipath noise with high reliability and fine grain control, to minimize deterioration in sound quality, etc., and to ensure quality. Therefore, it is possible to provide an environment in which the user always listens to the radio in a good state, and in particular, an effect of suppressing the influence of FM multipath can be obtained.

  In the first embodiment described above, in regions and roads where multipath occurrence is high, DSP parameters are set in advance by taking into account characteristic cases, and a plurality of receptions corresponding to learned regions and roads are performed. Multipath is relaxed by selecting an appropriate reception characteristic parameter from characteristic parameter table 113a, and by performing learning, it is more suitable from a plurality of reception characteristic parameter tables suitable for the area and road where the vehicle is running. Multipath noise can be removed by selecting reception characteristic parameters, and detailed settings can be made by operating in conjunction with the navigation device 11, resulting in a good reception environment. can do.

Embodiment 2. FIG.
By the way, when receiving AM broadcasts, depending on the reception time, especially at night, due to the influence of the ionosphere, it is easy to receive radio waves from distant broadcasting stations, and it tends to receive noise such as beats and interference. It has been known. Hereinafter, as Embodiment 2, an example will be described in which AM is also used for noise removal by using the reception characteristic parameter table 113a and selecting an optimum pattern by learning, as in the case of FM multipath.

In the second embodiment described below, the configuration of the radio receiving apparatus (on-vehicle apparatus) shown in FIG. 1 is used as in the first embodiment.
However, as shown in FIG. 8A, the reception characteristic parameter table 113a stored in the data storage unit 113 is added with a reception characteristic parameter related to the bandwidth instead of muting. The bandwidth is set to be “1” in the strong reception electric field environment and “0” in the weak reception electric field intensity environment, as in the other reception characteristic parameters. It is assumed that several reception patterns (here, patterns # 1 to # 3) including the default pattern “0010” are stored as reception characteristic parameters.

Further, in the second embodiment described below, as shown in FIG. 8B, learning is performed in a predetermined area of the data storage unit 113 for each time zone (T1 to T3) during link travel. It is assumed that a threshold for determining the validity of the application pattern obtained by the above is preset, and the pattern applied in the learning process is accumulated for each link.
For example, the application patterns when traveling on link A are # 1, # 1, and # 2, and the threshold is 5 dB in time zone T1, the threshold is 5 dB in time zone T2, and the threshold is 3 dB in time zone T3. Details will be described later.

FIG. 9 is a flowchart showing the operation of the radio receiving apparatus according to the second embodiment. Here, noise for performing noise removal such as beat and interference using the AM learning process and the optimum pattern obtained by the learning process is shown. The removal process is shown.
In the second embodiment described below, it is assumed that the navigation device 11 is activated when the ignition key is operated and the ACC power is turned on, and at the same time, reception of AM radio broadcasts by the audio device 12 is started. . Hereinafter, the operation of the radio reception apparatus according to the second embodiment will be described in detail with reference to the flowchart of FIG.

In FIG. 9, the navigation control unit 110 acquires navigation time information (current time) together with the current location information from the current location acquisition unit 111 (step ST901 “YES”). If the navigation time information cannot be acquired due to radio wave conditions or the like, the current time is acquired from the internal clock.
On the other hand, the navigation control unit 110 periodically communicates with the radio control unit 120 by polling or the like, and collects information regarding the received electric field intensity monitored by the tuner 121 (step ST902).

Subsequently, the navigation control unit 110 associates the current traveling area or road (link) acquired from the current location acquisition unit 111 and the map DB 114 with the received electric field strength, and the reception characteristics set in the data storage unit 113. A pattern learning process for referring to the parameter table 113a and applying a plurality of patterns (patterns # 1 to # 3) for each link according to the received electric field strength and selecting an optimum pattern by performing a noise removal process on each of the patterns. Is performed (step ST903).
The learning process described above is executed for the specified number of times (n times) every time the same link is traveled in order to improve reliability, and after the specified number of times is executed (“YES” in step ST904), the received electric field strength is averaged. (Step ST905) A process of actually removing noise by applying the selected pattern is executed to obtain a good reception environment.

  The result is accumulated in the data storage unit 113 for each link (step ST906). The data stored here is reception characteristic data indicating a pattern set for each link as shown in FIG. 3, for example, as in the first embodiment.

Next, navigation control section 110 determines a time zone based on the current time information acquired previously (step ST907). Here, the time zone T is managed in three stages: T1 (6: 00 to 11:00), T2 (11: 00 to 15:00), and T3 (after 15:00). Yes.
The navigation control unit 110 determines the validity of the data stored in the data storage unit 113 regardless of the above time zone. For example, as shown in FIG. 10, the validity is a value in which the range of the received electric field level collected for each link is set as a threshold value for each time zone of the link, for example, ± 5 dB in the time zone T1, ±± in T2. In 5 dB and time zone T3, it is determined by determining whether it exceeds ± 3 dB (steps ST908, ST910, ST912).

In FIG. 10, the vertical axis represents S / N, the horizontal axis represents time zones T1, T2, and T3 during travel of link A, and changes in received electric field strength at each time are shown.
Here, the navigation control unit 110 determines that the selected pattern is valid when the threshold value (± 5 dB, ± 5 dB, ± 3 dB) set according to the time zone is not exceeded, and confirms the selected pattern. In this case, it is determined to be invalid, and the process returns to the process of step ST902 to repeat the operation after the determination process of the received electric field strength for each link.

  When it is determined that each of the above-described steps ST908, ST910, and ST912 is valid, the navigation control unit 110 refers to the reception characteristic data generated based on the pattern determined for each of the time periods T1, T2, and T3 (step ST909). , ST911, ST913), noise removal processing is executed (step ST914). Here, as shown in FIG. 8B, if the link A is exemplified, the time zone T1 uses the pattern # 1, the time zone T2 uses the pattern # 2, and the time zone T3 uses the pattern # 3. It is assumed that noise removal processing is executed.

  As described above, in the radio receiving apparatus according to the second embodiment, the control unit (navigation control unit 110) performs the following operation for each region or road in which a multipath monitored by the reception state monitoring unit (tuner 121) occurs. For the selected broadcast station, the validity of the reception characteristic parameter accumulated in the storage means (data storage unit 113) is determined based on the received electric field intensity monitored by the reception state monitoring means. As a result, it is possible to automatically set the optimum reception characteristic data for the region where the vehicle is located and the road, and by using this reception characteristic data, it is possible to obtain a good AM reception environment in which beats and interference are suppressed. Can do.

  Further, in the radio receiving apparatus according to the second embodiment, the control means (navigation control unit 110) acquires the current time information, and the reception state monitoring means ( The operation of selecting one of the reception characteristic parameters set based on the received electric field intensity obtained by monitoring with the tuner 121) by learning is executed for each time zone defined based on the acquired current time information, and each is effective. Sex determination is performed. As a result, noise removal reliability such as beat and interference can be controlled with high accuracy and fine grain control, and deterioration of sound quality and the like can be minimized and quality can be ensured. Therefore, it is possible to provide an environment in which the user always listens to the radio in a good state, and in particular, an effect of suppressing the influence of AM beat, interference, and the like can be obtained.

  In the second embodiment described above, the current time acquired by the navigation device 11 is used, the noise component of AM is automatically changed by the variable bandwidth control, the setting of frequency characteristics, etc., and the noise component is reduced. However, it is also possible to automatically switch broadcasting affiliated stations that can be received satisfactorily. In this case, convenience can be provided to the user, and a better reception environment can be provided. In the case of AM, since it becomes easy to be influenced by a broadcasting station located far away after a specific time zone, when it is judged that the frequency of selective use of FM radio is low after a certain time zone, so-called AM By constructing a mechanism for receiving AM instead of FM simultaneously with activation of the navigation device 11 when the listening frequency is high, an effect of removing annoying noise such as beats and interference can be obtained.

  The functions of the control means (navigation control unit 110) shown in FIG. 1 may be realized entirely by software, or at least a part thereof may be realized by hardware. For example, the current location managed by the navigation device from the reception characteristic parameters stored in the storage unit (data storage unit 113) based on the reception state obtained by the control unit monitoring the reception state monitoring unit (tuner 121). Data processing that selects a reception characteristic parameter suitable for the storage means, repeatedly executes the process stored in the storage means for a predetermined number of times, and selects one of the reception characteristic parameters stored in the storage means to remove noise May be realized on a computer by one or a plurality of programs, or at least a part thereof may be realized by hardware.

  DESCRIPTION OF SYMBOLS 11 Navigation apparatus, 12 Audio apparatus, 13 Speaker, 14 Operation part, 15 Display part, 110 Navigation control part (control means), 111 Present location acquisition part, 112 Drawing / display control part, 113 Data storage part (storage means), 113a Reception characteristic parameter table, 114 map DB, 120 radio control unit, 121 tuner (reception status monitoring means), 122 DSP, 123 audio output unit.

Claims (7)

A radio receiver that receives a radio broadcast in conjunction with the activation of a navigation device,
Reception state monitoring means for monitoring the reception state of the radio broadcast while traveling;
Storage means for storing a plurality of reception characteristic parameters defined in advance according to the reception state;
Based on the reception state obtained by monitoring by the reception state monitoring unit, the reception characteristic parameter suitable for the current location managed by the navigation device is selected from the reception characteristic parameter table stored in the storage unit to remove noise. Control means for performing
A radio receiver characterized by comprising: The control means includes
Accumulated in the storage means based on the received electric field strength obtained by monitoring with the reception status monitoring means for the selected broadcasting station for each area or road where the multipath monitored by the reception status monitoring means has occurred. The validity of the received reception characteristic parameter is determined,
The radio receiver according to claim 1. The control means includes
Collecting the multipath intensity monitored by the reception state monitoring means for each region or road, comparing the range of the multipath intensity variation that occurs with the lapse of time associated with traveling and a threshold value, to determine the effectiveness. The radio receiver according to claim 2, wherein the determination is performed. The control means includes
When the area or road where the multipath occurs belongs to a specific area range shown on the map mesh, referring to the reception characteristic parameter selected and determined to be effective, noise removal is performed, 4. The radio receiving apparatus according to claim 1, wherein when the frequency does not belong to the specific range, noise removal is performed with reference to a reception characteristic parameter set as a default. 5. The control means includes
In the reception characteristic parameter table stored in the storage means based on the received electric field strength obtained by acquiring the current time information and monitoring the selected broadcasting station by the reception status monitoring means for each area or road Executing a process for selecting one from each time zone defined based on the acquired current time information to determine each validity,
The radio receiver according to claim 1. The control means includes
The reception electric field strength monitored by the reception state monitoring means is collected for each region or road, and is defined for each range of the reception electric field strength that fluctuates as time elapses during traveling and for each time zone when traveling in the region or road 6. The radio receiving apparatus according to claim 5, wherein the validity determination is performed by comparing with a threshold value to be used. The control means includes
The radio reception apparatus according to claim 5 or 6, wherein when it is determined that the validity is present, noise removal is performed with reference to the reception characteristic parameter selected for each time period.

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