JP2008205701A - Digital broadcasting receiver and reception control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcasting receiver capable of improving a receiving state even in a state that a portable apparatus is detatched from an external device such as charging equipment, and capable of inhibiting the increase of power consumption. <P>SOLUTION: The digital broadcasting receiver 18 has a plurality of antennas 1 and 3, a plurality of receiving sections 2 and 4 receiving and processing digital broadcasting signals received by the plurality of antennas 1 and 3 respectively and a synthesizing section 5 synthesizing and processing receiving signals output from the plurality of receiving sections 2 and 4 respectively. The digital broadcasting receiver 18 has a connector 14 detecting the presence/absence of connection between the digital broadcasting receiver 18 and specified charging equipment 19, and a CPU 12 carrying out synthetic processing in the synthesizing section 5 when the presence of the connection with the specified charging equipment 19 is detected by the connector 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiving apparatus and a reception control method, and more particularly to a technique suitable for application to a mobile device such as a mobile phone terminal or a portable information terminal (PDA).

  In recent years, digital broadcasting such as television broadcasting has been carried out, and digital broadcasting can be received using various devices. In Japanese terrestrial digital television broadcasting (ISDB-T), one channel is divided into 13 segments, and 12 segments are assigned in high-definition broadcasting. For mobile devices, the screen is small and the resolution is low, and one segment is allocated. Receiving broadcast waves is relatively easy even for mobile devices that cannot use high-performance antennas or high-performance receivers. It has become.

  However, since the radio wave condition changes every moment when moving, it is not always possible to receive a broadcast in a good state. For example, there is a high possibility that digital broadcasting cannot be viewed in a good state in an environment where the attenuation of received radio waves is large, an environment where fading occurs, or an environment where there is a lot of noise.

  Conventionally, in a general television receiver for home use, when reception environment is poor, diversity reception is performed by connecting a plurality of reception antennas to improve the reception environment. Yes.

For example, Patent Literature 1 discloses that diversity reception is performed when a mobile device receives a broadcast. Specifically, when the antenna is mounted on the charging device and a television broadcast is received while charging with the portable device connected to the charging device, the antenna on the portable device and the antenna on the charging device It is proposed to implement diversity reception using both.
JP 2005-136724 A

  However, in the technique disclosed in Patent Document 1, since diversity reception cannot be performed unless the antenna on the charging device is used, diversity reception may be performed when the portable device is separated from the charging device and used alone. Cannot improve reception status.

  In addition, in the case of a portable device such as a mobile phone terminal, there is a restriction that a high-performance large antenna cannot be mounted. Furthermore, since a battery having a limited power capacity is used as a power source, it is necessary to suppress an increase in power consumption, and there is a problem in complicating the configuration of the receiving circuit.

  The present invention provides a digital broadcast receiving device and a receiving device capable of improving the receiving state even when the portable device is disconnected from an external device such as a charging device and suppressing an increase in power consumption. An object is to provide a control method.

  The digital broadcast receiving apparatus according to the present invention includes a plurality of antennas, a plurality of receiving means for receiving and processing digital broadcast signals received by the plurality of antennas, and a combining process for receiving signals output from the plurality of receiving means, respectively. Diversity processing means for performing an external power supply detection for detecting the connection between the digital broadcast reception apparatus and a predetermined charging device or the connection between the digital broadcast reception apparatus and an external power supply. And a reception control unit that executes a combining process in the diversity processing unit when the external power source detection unit detects that the predetermined charging device or the external power source is connected. And

  The digital broadcast receiving apparatus according to the present invention includes a plurality of antennas, a plurality of receiving means for receiving and processing digital broadcast signals received by the plurality of antennas, and a combining process for receiving signals output from the plurality of receiving means, respectively. And a diversity processing means for detecting whether power is supplied from a predetermined charging device to the digital broadcast receiving device or from an external power source to the digital broadcast receiving device. An external power supply detection means, and a reception control means for executing a combining process in the diversity processing means when the external power supply detection means detects that there is power supply from the predetermined charging device or the external power supply, It is characterized by that.

  With this configuration, when a charging device or an external power source is connected or when a state in which power is supplied from the charging device or the external power source is recognized, diversity reception is possible even when the reception state is not deteriorated. Allow. Therefore, even if the reception state is not particularly deteriorated, the reception state can be improved by diversity reception. When a charging device or external power supply is connected, or when power is supplied from the charging device or external power supply, it is not necessary to consider battery consumption. However, it is considered that there will be no problem.

  In addition, the digital broadcast receiving apparatus of the present invention includes a demodulating unit that demodulates a signal output from the diversity processing unit, and the reception control unit is not connected to the predetermined charging device or the external power source, Alternatively, when the external power supply detection means detects that there is no power supply from the predetermined charging device or the external power supply, based on the magnitude of the bit error rate value of the received signal demodulated by the demodulation means, And controlling the execution of the synthesis process in the diversity processing means.

  With this configuration, the presence or absence of the deterioration of the reception state detected by comparing the bit error rate (BER) with a threshold value prepared in advance is recognized, and depending on whether or not the deterioration of the reception state is detected. The reception control means automatically switches whether to receive diversity. That is, when the reception state deteriorates and diversity reception is performed, the combining process in the diversity processing unit is permitted, and the reception process is performed using the plurality of receiving units. Further, when the reception state has not deteriorated, the combining process in the diversity processing unit is stopped, and the reception process is performed in a state where only one of the plurality of reception units is used and the remaining reception units are stopped.

  Therefore, even if the charging device and the external power source are not connected or the power is not supplied from the charging device and the external power source, diversity reception is performed and the reception state is Can be improved. Also, in an environment where the reception state has not deteriorated, that is, when digital broadcasting can be received in a good state without performing diversity reception, the diversity reception is stopped and one of a plurality of reception means is received. Therefore, increase in power consumption can be suppressed. For the remaining receiving means that are not used, the power supply may be temporarily interrupted.

  In the digital broadcast receiving apparatus of the present invention, the diversity processing means includes C / N ratio detection means for detecting a carrier-to-noise ratio relating to a received signal detected by each of the plurality of reception means, and the C / N ratio detection A combined result obtained by multiplying each received signal by a weighting coefficient corresponding to the carrier-to-noise ratio of each received signal detected by the means and weighting and adding the result is output as a received signal subjected to maximum ratio combining diversity processing. , Including things.

  With this configuration, weighting is performed according to the carrier-to-noise ratio (C / N ratio) detected for each of the plurality of receiving means, and then the reception signals output from the plurality of receiving means are added. Therefore, it is possible to synthesize a good received signal with high quality as compared with the case where the addition is simply performed. Therefore, effective diversity reception is realized.

  The reception control method of the present invention includes: a reception step for receiving and processing digital broadcast signals received by a plurality of antennas; a diversity combining step for combining reception signals processed in the reception step; and a digital broadcast receiving apparatus And a control step of executing a combining process in the diversity combining step when it is detected that there is a connection between the digital broadcasting receiving device and an external power source. It is characterized by.

  The reception control method of the present invention includes: a reception step for receiving and processing digital broadcast signals received by a plurality of antennas; a diversity combining step for combining the reception signals received and processed in the reception step; A control step of performing a combining process in the diversity combining step when it is detected that there is power supply to the broadcast receiving device or power supply from an external power source to the digital broadcast receiving device. And

  With this configuration, it is possible to automatically switch whether to perform diversity reception according to whether charging is in progress. Accordingly, when it is necessary to suppress battery consumption, such as when charging is not being performed, diversity reception can be prohibited to suppress an increase in power consumption, and when power consumption is not required to be suppressed as during charging, diversity is not allowed. The reception state can be improved by performing reception.

  In addition, the reception control method of the present invention includes a demodulation step for demodulating the signal combined in the diversity combining step, and there is no connection to the predetermined charging device or the external power source in the control step. Or the diversity based on the bit error rate value of the received signal demodulated in the demodulation step when it is detected that there is no power supply from the predetermined charging device or the external power source. Includes one that controls the execution of the synthesis process in the synthesis step.

  With this configuration, even when the charging device and the external power supply are not connected, or even when power is not supplied from the charging device and the external power supply, reception is performed by performing diversity reception in an environment where the reception state has deteriorated. The condition can be improved. Also, in an environment where the reception state has not deteriorated, that is, when digital broadcasting can be received in a good state without performing diversity reception, the diversity reception is stopped and one of a plurality of reception means is received. Therefore, increase in power consumption can be suppressed. For the remaining receiving means that are not used, the power supply may be temporarily interrupted.

  In addition, the reception control method of the present invention includes a C / N ratio detection step for detecting a carrier-to-noise ratio related to the reception signal received and processed in the reception step, and the C / N ratio is detected in the diversity combining step. The combined result obtained by multiplying each received signal by the weighting coefficient corresponding to the carrier-to-noise ratio of each received signal detected in the detection step and adding the weighted result is the received signal subjected to the maximum ratio combining diversity processing. Includes things to output.

  With this configuration, weighting is performed according to the carrier-to-noise ratio (C / N ratio) detected for each of the plurality of receiving means, and then the reception signals output from the plurality of receiving means are added. Therefore, it is possible to synthesize a good received signal with high quality as compared with the case where the addition is simply performed. Therefore, effective diversity reception is realized.

  According to the present invention, in an environment in which the reception state deteriorates, diversity reception can be performed to improve the reception state. Also, in an environment where the reception state has not deteriorated, that is, when digital broadcasting can be received in a good state without performing diversity reception, the diversity reception is stopped and one of a plurality of reception means is received. Therefore, increase in power consumption can be suppressed.

  One embodiment of the digital broadcast receiving apparatus and reception control method of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram illustrating a configuration example of a digital broadcast receiving apparatus according to an embodiment. FIG. 2 is a flowchart showing a main operation example of the digital broadcast receiving apparatus shown in FIG.

  The digital broadcast receiving apparatus shown in FIG. 1 includes a mobile phone terminal 18 that is a main body of the apparatus and a charger 19 attached thereto. Although the mobile phone terminal 18 and the charger 19 are independent from each other, the connector 14 provided on the mobile phone terminal 18 side and the connector 15 provided on the charger 19 side are physically connected to connect both. Can be electrically connected.

  The mobile phone terminal 18 is a device equivalent to a general mobile phone, but is also equipped with a function for receiving and viewing a signal for a portable device of terrestrial digital television broadcasting, that is, a “one-segment” broadcast. ing. The notation of components for realizing the function of a general mobile phone is omitted in FIG.

  Of course, the present invention can also be applied to a receiving device other than a mobile phone terminal, and the digital broadcast to be received may be a broadcast other than the “one-segment” broadcast.

  As shown in FIG. 1, a mobile phone terminal 18 includes two antennas 1 and 3, two RF (Radio Frequency) receiving units 2 and 4, a combining unit 5, a demodulating unit 6, and a TD (transport decoder). ) Unit 7, AV (audio / video) decoding unit 8, display unit 9, speaker 10, memory 11, microprocessor (CPU) 12, battery 13, and connector 14.

  The two antennas 1 and 3 are both used to receive radio waves of “One Seg” broadcasting of digital terrestrial television broadcasting. One antenna 1 is connected to the antenna input of one RF receiver 2, and the other antenna 3 is connected to the antenna input of the RF receiver 4.

  Therefore, the high frequency signal of “One Seg” broadcast received by the antenna 1 is input to the RF receiver 2, and the high frequency signal of “One Seg” broadcast received by the antenna 3 is input to the RF receiver 4.

  The RF receiving unit 2 converts a “one-segment” broadcast radio frequency (RF) signal input from the antenna 1 into a received signal SG1 having an intermediate frequency (IF) and outputs the received signal SG1 to the combining unit 5. The RF receiver 4 converts the high frequency signal of “One Seg” broadcast input from the antenna 3 into an intermediate frequency received signal SG <b> 2 and outputs it to the synthesizer 5.

  The synthesizer 5 has a signal synthesizer function for synthesizing two systems of received signals SG1 and SG2 input from a plurality of independent antennas and receivers in order to realize diversity reception. Further, in order to synthesize the two systems of received signals SG1 and SG2 under optimum conditions, the synthesizer 5 includes a C / N (carrier power to noise power) ratio detection circuit. The C / N ratio detection circuit processes the respective reception signals SG1 and SG2 output from the RF reception unit 2 and the RF reception unit 4 to detect the C / N ratio related to each reception signal.

  Then, the synthesizer 5 sets an optimum weighting factor based on the C / N ratio of the received signal SG1 output from the RF receiver 2 and the C / N ratio of the received signal SG2 output from the RF receiver 4. The received signal is calculated. Further, the weighted reception signal SG1 and the received signal SG1 are multiplied (weighted), the other weighting coefficient and the received signal SG2 are multiplied (weighted), and the weighted received signal SG1 and the weighted received signal are multiplied. The result of adding SG2 is output from the synthesizer 5 as an intermediate frequency received signal SG3. Thus, processing is performed so that the C / N ratio of the received signal SG3, which is the result of the weighted addition, is maximized. That is, the synthesizer 5 receives two systems of received signals SG1 and SG2 and performs maximum ratio combining diversity processing.

  Received signal SG3 output from combining section 5 is input to demodulation section 6. The demodulation unit 6 performs demodulation and error correction processing on the received signal SG3 that is an OFDM (Orthogonal Frequency Division Multiplexing) signal, and extracts and outputs a TS (Transport Stream) included in the received signal SG3. The demodulator 6 also has a function of measuring a bit error rate (BER) after Viterbi decoding in error correction processing.

  The TD unit 7 distinguishes the type of TS output from the demodulating unit 6 and outputs it by separating it into video, audio, data broadcast, and other data.

  The AV decoding unit 8 decodes video and audio data among the signals output from the TD unit 7. Then, the decoded video signal is output to the display unit 9, and the decoded audio signal is output to the speaker 10. Accordingly, the broadcast video received by the display unit 9 can be displayed, and the broadcast audio can be reproduced by the speaker 10.

  The connector 14 is a contact portion for connecting the mobile phone terminal 18 and the charger 19, and has a structure that can be electrically and physically connected to the connector 15 of the charger 19.

  The battery 13 is used as a power source for supplying power to each circuit of the mobile phone terminal 18. Further, when the charger 19 is connected to the connector 14, it is possible to charge with the power supplied from the charger 19. In this example, a signal indicating whether or not the battery 13 is being charged is output from the battery 13 and supplied to the microprocessor 12.

  The memory 11 is a storage device from which data can be read and written by the microprocessor 12.

  The microprocessor 12 operates according to a program prepared in advance and controls the entire mobile phone terminal 18. The processing executed by the microprocessor 12 includes an operation as shown in FIG.

  On the other hand, the charger 19 includes a connector 15, a charging circuit 16, and a charging control unit 17. The charging circuit 16 generates DC power necessary for charging the battery 13 on the mobile phone terminal 18 side, and supplies this DC power to the mobile phone terminal 18 via the connector 15. The charging control unit 17 monitors the voltage and current states in the connector 15 and controls the charging circuit 16 according to the result.

  FIG. 2 shows a specific example of control related to diversity reception when the mobile phone terminal 18 shown in FIG. 1 receives “One Seg” broadcast. This control is realized by a process whose operation is mainly performed by the microprocessor 12. The contents shown in FIG. 2 will be described below.

  In step S1, the microprocessor 12 identifies whether or not a power switch (not shown) of the mobile phone terminal 18 is on. If the power is on, the process proceeds to the next step S2.

  In step S2, the operation state of each unit on the mobile phone terminal 18 is grasped, and the microprocessor 12 identifies whether or not the “One Seg” broadcast TV program is being viewed. If the viewer is viewing, the process proceeds to the next step S3. .

  In step S3, the microprocessor 12 identifies whether or not the battery 13 is being charged by examining a signal output from the battery 13. If charging is in progress, the process proceeds to step S4. If not charging, the process proceeds to step S5.

  In step S4, the microprocessor 12 gives an instruction for performing diversity reception to the synthesizer 5. In response to this command, the synthesizer 5 generates a received signal SG3 by synthesizing them using the received signals SG1 and SG2 output from the two RF receivers 2 and 4. That is, diversity reception is performed using two received signals.

  In step S5, the microprocessor 12 compares the bit error occurrence rate BER after the latest Viterbi decoding detected in the demodulator 6 with a threshold prepared in advance to determine whether or not the reception state has deteriorated. Identify. If the reception state has deteriorated, the process proceeds to step S4. If the reception state has not deteriorated, the process proceeds to step S6.

In the demodulator 6, the bit error occurrence rate BER after Viterbi decoding is repeatedly detected at a predetermined constant period (for example, 100 ms). About the said threshold value, it is possible to use the value of about 2.0 * 10 <^-4> as a specific example.

  In step S <b> 6, the microprocessor 12 gives an instruction for performing “single reception” to the synthesis unit 5. “Single reception” means an operation mode in which no diversity reception is performed and reception processing is performed using only one system of received signals. Therefore, when the synthesizer 5 receives an instruction for performing “single reception” from the microprocessor 12, it stops the diversity processing and outputs the received signal SG 1 output from the RF receiver 2 and the RF receiver 4. The received signal SG3 is generated using only one of the received signal SG2 and the received signal SG2. Further, when “single reception” is performed, the synthesis unit 5 or the microprocessor 12 stops the operation of the circuit that is not used among the two RF reception units 2 and 4. In addition, supply of power supply power may be temporarily stopped with respect to the circuit which stopped operation | movement among the two RF receiving parts 2 and 4. FIG.

  By performing “single reception”, the power consumed in the RF receiving unit 2 or the RF receiving unit 4 and the combining unit 5 is reduced. Therefore, the power consumption of the mobile phone terminal 18 is compared with the case of performing diversity reception. Can be reduced.

  In step S7, the microprocessor 12 identifies whether or not the TV program of “One Seg” broadcasting is being viewed by grasping the operating state of each unit on the mobile phone terminal 18, and if the viewing is not finished, step S3 is performed. The subsequent processing is repeated, and when the viewing ends, this processing ends.

  That is, by performing the control shown in FIG. 2, the microprocessor 12 can automatically switch between the operation mode in which diversity reception is performed and the operation mode in which “single reception” is performed according to the situation. That is, if the battery 13 of the mobile phone terminal 18 is being charged, an increase in power consumption does not become a problem, so the reception state is improved by performing diversity reception. In addition, when the battery 13 of the mobile phone terminal 18 is not being charged, the presence / absence of deterioration of the reception state is identified based on the detected bit error occurrence rate BER after Viterbi decoding, and the reception state exceeds a predetermined level. Diversity reception is performed only when the situation has deteriorated. Accordingly, it is possible to suppress the deterioration of the program viewing quality accompanying the deterioration of the reception state. If the reception state has not deteriorated, the mode is switched to “single reception”, so that power consumption of the RF reception unit 2 or the RF reception unit 4 and the synthesis unit 5 can be suppressed and consumption of the battery 13 can be delayed. Even when the terminal 18 is not connected to the charger 19, the television program can be viewed for a longer time.

  In addition, about a structure and operation | movement of the above-mentioned apparatus shown as a specific example, various deformation | transformation can be considered as shown below, for example.

  (1) Although the microprocessor 12 identifies whether or not the battery 13 is being charged in step S3 in FIG. 2, the connector 15 of the charger 19 and the connector 14 of the mobile phone terminal 18 are physically or electrically connected. It is also possible to change the detection result to be identified in step S3 as a determination element equivalent to “whether or not charging”.

  (2) The connection form between the mobile phone 18 and the charger 19 is not limited to a wired connection, but is changed to supply power from the charger 19 to the mobile phone terminal 18 in a non-contact manner using, for example, electromagnetic induction. Also good.

  (3) In the configuration shown in FIG. 1, it is assumed that the charger 19 is mounted with the charging control unit 17 that performs charging control, but the simple configuration that does not include the charging control unit 17 instead of the charger 19. When a device such as an external power source is used, the microprocessor 12 on the mobile phone terminal 18 side may be changed so as to perform charging control.

  (4) For example, the remaining power amount of the battery 13 may be detected when the battery 13 is not being charged, and the magnitude relationship of the remaining power amount may be added as a determination factor in the determination in step S5. Furthermore, three or more reception states may be identified using a plurality of threshold values in the determination in step S5.

  As described above, for example, when a digital broadcast such as a one-segment broadcasting is received using a mobile device such as a mobile phone terminal or a portable information terminal, the present invention is applied to make the mobile device like a charging device. Even in a state disconnected from an external device, it is possible to improve the reception state by performing diversity processing, and to suppress an increase in power consumption.

It is a block diagram which shows the structural example of the digital broadcast receiver in embodiment. 3 is a flowchart showing a main operation example of the digital broadcast receiving apparatus shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 3 Antenna 2, 4 RF receiving part 5 Synthesis | combination part 6 Demodulation part 7 TD part 8 AV decoding part 9 Display part 10 Speaker 11 Memory 12 Microprocessor 13 Battery 14, 15 Connector 16 Charging circuit 17 Charging control part 18 Cellular telephone terminal 19 Charger

Claims (8)

Multiple antennas,
A plurality of receiving means for receiving and processing digital broadcast signals received by the plurality of antennas;
Diversity processing means for synthesizing received signals output from the plurality of receiving means;
A digital broadcast receiving apparatus comprising:
An external power source detecting means for detecting the connection between the digital broadcast receiving device and a predetermined charging device or the connection between the digital broadcast receiving device and an external power source;
A reception control means for executing a combining process in the diversity processing means when the external power supply detection means detects that the predetermined charging device or the external power supply is connected;
A digital broadcast receiving apparatus comprising: Multiple antennas,
A plurality of receiving means for receiving and processing digital broadcast signals received by the plurality of antennas;
Diversity processing means for synthesizing received signals output from the plurality of receiving means;
A digital broadcast receiving apparatus comprising:
An external power source detecting means for detecting whether or not power is supplied from a predetermined charging device to the digital broadcast receiving device or from the external power source to the digital broadcast receiving device;
A reception control unit that executes a combining process in the diversity processing unit when the external power source detection unit detects that the predetermined charging device or the external power source is supplied with power;
A digital broadcast receiver characterized by that. A demodulating means for demodulating the signal output from the diversity processing means;
When the external power source detection unit detects that the reception control unit is not connected to the predetermined charging device or the external power source, or that no power is supplied from the predetermined charging device or the external power source. In addition, based on the magnitude of the value of the bit error rate of the received signal demodulated by the demodulating means, the execution of the combining process in the diversity processing means is controlled.
3. The digital broadcast receiver according to claim 1, wherein the digital broadcast receiver is a digital broadcast receiver. The diversity processing means includes C / N ratio detection means for detecting a carrier-to-noise ratio relating to the reception signal detected by each of the plurality of reception means, and the carrier wave of each reception signal detected by the C / N ratio detection means A combined result obtained by multiplying each received signal by a weighting coefficient corresponding to a noise-to-noise ratio and performing weighted addition is output as a received signal subjected to maximum ratio combining diversity processing.
The digital broadcast receiver according to claim 1, wherein the digital broadcast receiver is a digital broadcast receiver. A receiving step for receiving and processing digital broadcast signals received by a plurality of antennas;
A diversity combining step of combining the received signal received and processed in the receiving step;
A control step of performing a combining process in the diversity combining step when it is detected that there is a connection between the digital broadcast receiving device and a predetermined charging device or a connection between the digital broadcast receiving device and an external power source;
A reception control method comprising: A receiving step for receiving and processing digital broadcast signals received by a plurality of antennas;
A diversity combining step of combining the received signal received and processed in the receiving step;
When it is detected that there is power supply from the charging device to the digital broadcast receiving device, or power supply from the external power source to the digital broadcast receiving device, a control step for executing a combining process in the diversity combining step;
A reception control method comprising: A demodulation step of demodulating the signal combined in the diversity combining step;
When the control step detects that there is no connection to the predetermined charging device or the external power source, or that there is no power supply from the predetermined charging device or the external power source, the demodulation step Based on the magnitude of the value of the bit error rate of the received signal demodulated in step 1, the execution of the combining process is controlled in the diversity combining step.
The reception control method according to claim 6 or 7, wherein A C / N ratio detection step of detecting a carrier-to-noise ratio related to the reception signal received and processed in the reception step;
The diversity combining step multiplies each received signal by a weighting coefficient corresponding to the carrier-to-noise ratio of each received signal detected in the C / N ratio detecting step and weights and adds the combined result obtained. , And output as a maximum ratio combining diversity processed received signal,
The reception control method according to any one of claims 5 to 7.

Images