JP2010283462A - Diversity receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably receive delivery data of a comparatively large capacity by a receiving antenna not used for receiving a broadcast wave while receiving and demodulating the broadcast wave. <P>SOLUTION: A diversity receiver includes: a received signal selection and determination section (31) for computing each radio wave reception intensity of a plurality of antennas (20) at the present position and a destination predicted and determining antennas to be used as a main antenna and as a sub antenna; a received signal control section (10) for outputting received signals of the main and sub antennas based on the determination result; a first demodulation circuit (40) for demodulating the received signal of the main antenna; a second demodulation circuit (50) for demodulating the received signal of the sub antenna when receiving an instruction of demodulation; and a demodulation instruction section (34) for instructing demodulation to the second demodulation circuit (50) when a continuously selected period of the sub antenna is larger than a predetermined value wherein the continuously selected period is computed based on the radio wave reception intensity computed by the received signal selection and determination section (31). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a diversity receiver that is mounted on a mobile body and receives a signal, and more particularly to a technique that can perform stable reception using an unused reception antenna.

  In receiving a broadcast wave in a mobile body, the reception environment changes greatly due to movement. As a technique for improving reception performance, there is a diversity reception technique using a plurality of reception antennas. This diversity reception technique is characterized by using reception signals from a plurality of reception antennas installed in a mobile body.

  In the conventional diversity receiver, the distance between the transmitting station and each receiving antenna is obtained from the position information of the transmitting station and the position information of each receiving antenna, the difference between the distances is calculated, and the correlation due to this distance difference is minimized. The receiving performance is improved by selecting and instructing the receiving antenna to be (see, for example, Patent Document 1).

JP 2005-348274 A

  In the conventional diversity receiver, the best receiving antenna is selected to receive the broadcast wave. On the other hand, reception antennas that have not been selected are often not used for broadcast wave reception, such as when the power supply is stopped to reduce power consumption or for other purposes. In view of such a problem, an object of the present invention is to stably receive distribution data having a relatively large capacity with a receiving antenna that is not used for receiving a broadcast wave while receiving and demodulating the receiving antenna broadcast wave. To do.

  In order to solve the above problems, the present invention has taken the following measures. That is, a diversity receiver that receives and processes radio waves from a transmitting station received by a plurality of antennas mounted on a mobile body, and obtains information on the current location and traveling direction of the mobile body from a navigation system mounted on the mobile body. Receiving, calculating the radio wave reception intensity of each of the plurality of antennas at the current location and the predicted destination, and determining which of the plurality of antennas should be the main antenna and the sub-antenna based on the calculation result A signal selection determination unit, a reception signal control unit that receives reception signals of a plurality of antennas and outputs a reception signal of the main antenna and a reception signal of the sub-antenna according to a determination result of the reception signal selection determination unit, and a reception signal of the main antenna When receiving a demodulating instruction and a first demodulating circuit for demodulating, the demodulated data is demodulated by demodulating the received signal of the sub-antenna Based on the second demodulating circuit to be recorded in the recording unit and the radio wave reception intensity calculated by the received signal selection determining unit, a period during which the sub-antenna will be continuously selected without switching is calculated, When is larger than a predetermined value, a demodulation instruction unit for instructing demodulation to the second demodulation circuit is provided.

  In this way, by always predicting and grasping the positional relationship between the position of the mobile body and the transmitting station, the optimal receiving antenna to be used for the received signal of the broadcast wave in the strong electric field area can be known in advance. Can be assigned. Thereby, delivery data can be acquired stably without interruption.

  The reception signal control unit may include a diversity combining circuit that combines at least two reception signals of a plurality of antennas to generate at least one of the reception signal of the main antenna and the reception signal of the sub antenna. As a result, a reception signal of the main antenna or a reception signal of the sub-antenna can be generated by appropriately combining a plurality of antennas.

  According to the present invention, it is possible to stably receive distribution data having a relatively large capacity with a receiving antenna that is not used for receiving a broadcast wave while receiving and demodulating the receiving antenna broadcast wave in an optimal combination. .

It is a block diagram of the diversity receiver which concerns on 1st Embodiment. It is a figure which shows the example of arrangement | positioning of a receiving antenna. It is a process flowchart of a received signal selection determination part. It is a schematic diagram which shows the movement plan route of a moving body. It is a schematic diagram of the table which stored the radio wave reception intensity | strength of each antenna in a present location and a movement destination. It is a process flowchart of a demodulation instruction | indication part. It is a block diagram of the diversity receiver which concerns on 2nd Embodiment. It is a figure which shows the example of arrangement | positioning of a receiving antenna. It is a process flowchart of a received signal selection determination part. It is a schematic diagram of the table which stored the radio wave reception intensity | strength of each antenna in a present location and a movement destination. It is a process flowchart of a demodulation instruction | indication part. It is a block diagram of the diversity receiver which concerns on 3rd Embodiment. It is a process flowchart of a received signal selection determination part. It is a block diagram of the diversity receiver which concerns on 4th Embodiment.

(First embodiment)
FIG. 1 shows a configuration of a diversity receiving apparatus according to the first embodiment. The reception signal control unit 10 includes AGC circuits 11-1 and 11-2 and a selector 12. AGC circuits 11-1 and 11-2 amplify reception signals RCV-1 and RCV-2 supplied from antennas 20-1 and 20-2 that receive broadcast waves transmitted from transmitting station 100, respectively. For example, as shown in FIG. 2, the antennas 20-1 and 20-2 are distributed on the roof top of a moving body 200 such as a car. The selector 12 receives the outputs of the AGC circuits 11-1 and 11-2, and selects the reception signal MAINR of the main antenna and the reception signal SUBR of the sub antenna according to the selection instruction SEL from the reception signal selection determination unit 31 in the system control unit 30. Output. Demodulation circuits 40 and 50 receive and demodulate the reception signal MAINR of the main antenna and the reception signal SUBR of the sub antenna, respectively.

  The navigation system 60 recognizes the absolute position of the own vehicle. Specifically, the navigation system 60 recognizes the absolute position of the reference point at the center of the moving body 200 shown in FIG. 2 and the absolute direction of the traveling direction of the host vehicle, and The relative positions of the antennas 20-1 and 20-2 and the position information of the transmitting station 100 are stored.

  FIG. 3 shows a processing flow of the reception signal selection determination unit 31. If the selection determination flag output from the CPU 32 in the system control unit 30 is valid (YES in S11), the current location A point and the predicted B point, C point, and D for the planned movement route as shown in FIG. The own vehicle position information, the own vehicle traveling direction information, the receiving antenna position information, and the transmitting station position information are acquired from the navigation system 60 (S12). Then, the radio wave reception strengths of the antennas 20-1 and 20-2 at the current location A and the radio wave reception strengths of the antennas 20-1 and 20-2 at the destinations B to D are calculated (S13). The results are recorded in the RAM 33 in the system control unit 30 in the table format as shown in FIG. 5 (S14). The received radio wave strengths of the antennas 20-1 and 20-2 at the current location are compared with reference to the table, and a selection instruction SEL is output so as to select an antenna having a high strength as the main antenna (S15, S16, S17). In the example of FIG. 5, the antenna 2 is selected as the main antenna from the point A to the point B, and the antenna 1 is selected as the main antenna from the point B to the point D.

  In addition, the determination of the predicted destinations B to D is limited to a point indicating an intersection in the map data of the navigation system 60 or a point such as 10 minutes or 20 minutes after the current location when the route is set. Rather, it can be set arbitrarily.

  The demodulation circuit 40 demodulates the reception signal MAINR of the main antenna output from the reception signal control unit 10. The video / audio signal processing circuit 70 receives the video / audio signal which is the demodulation result of the demodulation circuit 40 and reproduces video and audio.

  FIG. 6 shows a processing flow of the demodulation instruction unit 34 in the system control unit 30. One of the antennas 20-1 and 20-2 that has not been selected as the main antenna by the received signal selection determining unit 31, that is, the sub-antenna is specified (S21), and the current location A point and the destination B point to D point In step S22, it is determined whether the same antenna is continuously selected as the sub antenna. When it is determined that the sub antenna is switched (NO in S22), the process returns to step S21. On the other hand, when it is determined that the same antenna is continuously selected as the sub-antenna (YES in S22), the continuous period is compared with a predetermined value (S23). If the continuous period is longer than the predetermined value (YES in S23), the download permission flag PFLG is validated and the demodulation circuit 50 is instructed to demodulate (S24). On the other hand, if the continuous period is smaller than the predetermined value (NO in S23), the download permission flag PFLG is invalidated and the process returns to step S21. In the example of FIG. 5, the antenna 1 is selected as the sub-antenna from the point A to the point B, the antenna 2 is selected from the point B to the point D, and the sub-antenna is continuous from the point B to the point D. It is determined. If the continuous period is larger than a predetermined value, the download permission flag PFLG becomes valid.

  The predetermined value is not limited to a setting value that can be freely set by the user or a setting value incorporated in the diversity receiver, and can be arbitrarily set.

  When receiving the instruction for demodulation, the demodulation circuit 50 demodulates the reception signal SUBR of the sub antenna output from the reception signal control unit 10. Then, the data obtained as a result of demodulation is stored in the recording unit 80. The recording unit 80 may be realized by, for example, a non-volatile memory that can keep stored data even when the diversity receiver is turned off.

  The reception signal selection determination unit 31 and the demodulation instruction unit 34 may be realized by program processing. That is, a program for executing the processing flow of the reception signal selection determination unit 31 and the demodulation instruction unit 34 may be held in the ROM 35 of the system control unit 30 and the CPU 32 may execute these programs. In addition to the execution of these programs, the CPU 32 performs control to sequentially record the received radio wave intensity information as shown in FIG. 5 in the recording unit 80, and the information on the same point is already recorded in the recording unit 80. In some cases, update processing is also performed so that the latest state is always obtained.

(Second Embodiment)
FIG. 7 shows the configuration of the diversity receiver according to the second embodiment. The diversity receiver according to the present embodiment selects a receiving antenna that receives the best broadcast wave in an area where the radio wave intensity level of the broadcast wave transmitted from the transmission station 100 is weak. Only differences from the first embodiment will be described below.

  The reception signal control unit 10A includes n AGC circuits 11-1, 11-2, ..., 11-n and a selector 12A. The AGC circuits 11-1, 11-2,..., 11-n respectively receive n antennas 20-1, 20-2,..., 20 that receive broadcast waves transmitted from the transmitting station 100. The received signals RCV-1, RCV-2,..., RCV-n supplied from −n are amplified. The antennas 20-1, 20-2,..., 20-n are distributed on the upper part of the roof of the moving body 200 such as a car as shown in FIG.

  The selector 12A receives the outputs of the AGC circuits 11-1, 11-2,..., 12-n, and diversity-combines a maximum of any m of them according to the selection instruction SEL from the reception signal selection determination unit 31. In addition to outputting to the circuit 13, either one is output as the reception signal SUBR of the sub-antenna. Diversity combining circuit 13 combines the plurality of reception signals output from selector 12A and outputs main antenna reception signal MAINR. Specifically, the diversity combining circuit 13 compares the received signals for each carrier, and performs combining by giving a large weight to the carrier of the receiving antenna having a good CN ratio.

  FIG. 9 shows a processing flow of the reception signal selection determination unit 31. Steps S11 to S14 are as described above. The received radio wave intensity of the antennas 20-1, 20-2,..., 20-n at the current location is compared with reference to the table stored in step S14, for example, the table shown in FIG. A selection instruction SEL is output so as to select the antenna as the main antenna (S15A, S16). On the other hand, if there is no antenna having a high radio wave intensity (NO in S15A), it is determined whether or not the radio wave intensity is increased by combining a plurality of antennas (S18). All the antennas to be combined are selected as main antennas (S17). In the example of FIG. 10, antenna 1, antenna 2, and antenna 3 are selected as the main antenna from point A to point B, and antenna 1 is selected from point B to point D, respectively.

  FIG. 11 shows a processing flow of the demodulation instruction unit 34. Basically, the processing flow is the same as that shown in FIG. 6, but it is determined whether the radio field intensity of the sub-antenna specified in step S21 is not low (S26). If the intensity is low (NO in S26) ), The process returns to step S21. On the other hand, when the intensity is not low (YES in S26), the processes after step S22 are performed. In the example of FIG. 10, since all antennas from point A to point B are used as the main antenna, there is no sub-antenna assignment, and antenna 2 is selected as the sub-antenna from point B to point C. From point C to point D, both antenna 2 and antenna 3 have low radio field strength, so there is no sub-antenna assignment. Thereby, it is determined that the sub-antenna is continuous from point B to point C. If the continuous period is larger than a predetermined value, the download permission flag PFLG becomes valid.

  As described above, according to the first and second embodiments, since the usage time of the receiving antenna that is continuously used as the sub-antenna can be predicted in advance, the distribution data can be stably acquired without interruption by the sub-antenna. Can do. Further, even when the reception of the distribution data is interrupted, the distribution data up to that time remains in the recording unit 80, so that the distribution data can be acquired halfway after the communication is resumed.

(Third embodiment)
FIG. 12 shows the configuration of the diversity receiver according to the third embodiment. The diversity receiving apparatus according to the present embodiment selects a receiving antenna that receives the best distribution data in an area where the radio wave intensity level of the broadcast wave transmitted from the transmitting station 100 is weak. Only differences from the second embodiment will be described below.

  The selector 12B receives the outputs of the AGC circuits 11-1, 11-2,..., 12-n, and diversity-combines a maximum of any m of them according to the selection instruction SEL from the reception signal selection determination unit 31. In addition to outputting to the circuit 13, one of them is output as the main antenna reception signal MAINR. Diversity combining circuit 13 combines a plurality of received signals output from selector 12B and outputs a sub-antenna received signal SUBR.

  FIG. 13 shows a processing flow of the reception signal selection determination unit 31. Steps S11 to S14 are as described above. The received radio wave intensity of the antennas 20-1, 20-2,..., 20-n at the current location is compared with reference to the table stored in step S14, for example, the table shown in FIG. A selection instruction SEL is output so as to select the antenna as the sub-antenna (S15A, S16A). On the other hand, if there is no antenna having a high radio wave intensity (NO in S15A), it is determined whether or not the radio wave intensity is increased by combining a plurality of antennas (S18). All the antennas to be combined are selected as sub-antennas (S17A). In the example of FIG. 10, antenna 1, antenna 2 and antenna 3 are selected as sub-antennas from point A to point B, and antenna 1 is selected from point B to point D, respectively.

  The processing flow of the demodulation instruction unit 34 is as shown in FIG. In the example of FIG. 10, all antennas from point A to point B are used as sub-antennas. Further, the antenna 2 is selected as a sub antenna from the point B to the point D. Thereby, it is determined that the sub-antenna is continuous from point A to point D. If the continuous period is larger than a predetermined value, the download permission flag PFLG becomes valid.

(Fourth embodiment)
FIG. 14 shows the configuration of a diversity receiver according to the fourth embodiment. The diversity receiver according to the present embodiment selects a receiving antenna that receives the best broadcast wave and distribution data regardless of the strength of the radio wave intensity of the broadcast wave transmitted from the transmission station 100. Only differences from the second and third embodiments will be described below.

  The selector 12C receives the outputs of the AGC circuits 11-1, 11-2,..., 12-n, and diversity synthesizes any one of them in accordance with the selection instruction SEL from the reception signal selection determination unit 31. A maximum of any k pieces is output to the circuit 13-1 to the diversity combining circuit 13-2. Diversity combining circuits 13-1 and 13-2 respectively combine a plurality of reception signals output from selector 12C and output main antenna reception signal MAINR and sub-antenna reception signal SUBR.

  The operation flows of the reception signal selection determination unit 31 and the demodulation instruction unit 34 are as shown in FIGS. 9 and 6, respectively. In the example of FIG. 10, antenna 1, antenna 2, and antenna 3 are selected as the main antenna from point A to point B, and antenna 1 is selected from point B to point D, respectively. Further, since all antennas from point A to point B are used as main antennas, there is no assignment of sub-antennas, and antennas 2 and 3 are selected as sub-antennas from point B to point D. Thereby, it is determined that the sub-antenna is continuous from point B to point D. If the continuous period is larger than a predetermined value, the download permission flag PFLG becomes valid.

  As described above, according to the third and fourth embodiments, the usage time of the receiving antenna that is continuously used as the sub-antenna can be predicted and understood in advance, and the received signal is combined by the diversity combining circuit even if the electric field strength is weak. Distribution data can be stably acquired without interruption by the sub-antenna.

  The diversity receiving apparatus according to the present invention can stably receive distribution data having a relatively large capacity with a receiving antenna that is not used for receiving broadcast waves, and is thus useful for a car navigation system, a mobile phone, and the like. .

DESCRIPTION OF SYMBOLS 10 Received signal control part 13 Diversity combining circuit 13-1 Diversity combining circuit 13-2 Diversity combining circuit 31 Received signal selection determination part 34 Demodulation instruction | indication part 40 Demodulation circuit (1st demodulation circuit)
50 Demodulation circuit (second demodulation circuit)

Claims (4)

A diversity receiver that receives and processes radio waves from a transmitting station received by a plurality of antennas mounted on a mobile body,
Receives information on the current location and traveling direction of the mobile body from the navigation system mounted on the mobile body, calculates the radio wave reception intensity of each of the plurality of antennas at the current location and the predicted destination, and A reception signal selection determination unit that determines what should be the main antenna and what should be the secondary antenna among the plurality of antennas,
A reception signal control unit that receives the reception signals of the plurality of antennas and outputs the reception signal of the main antenna and the reception signal of the sub-antenna according to the determination result of the reception signal selection determination unit;
A first demodulation circuit for demodulating a reception signal of the main antenna;
A second demodulating circuit that demodulates the received signal of the sub-antenna and records the demodulated data in a recording unit when receiving a demodulating instruction;
Based on the radio wave reception intensity calculated by the received signal selection determination unit, a period during which the sub antenna is to be continuously selected without being switched is calculated, and when the period is greater than a predetermined value, A diversity receiving apparatus comprising: a demodulation instruction unit that instructs demodulation of the second demodulation circuit. The diversity receiver according to claim 1, wherein
The diversity reception device, wherein the reception signal control unit includes a diversity combining circuit that combines at least two reception signals of the plurality of antennas to generate a reception signal of the sub-antenna. The diversity receiver according to claim 2, wherein
The diversity reception apparatus, wherein the reception signal control unit includes a diversity combining circuit that combines at least two reception signals of the plurality of antennas to generate a reception signal of the main antenna. The diversity receiver according to claim 1, wherein
The diversity reception apparatus, wherein the reception signal control unit includes a diversity combining circuit that combines at least two reception signals of the plurality of antennas to generate a reception signal of the main antenna.

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