JP3529976B2 - Radio receiver - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital audio broadcasting and analog audio broadcasting, for example, DAB.
(Digital Audio Broadcasti
ng: digital audio broadcast) and RDS (Radi
The present invention relates to a radio receiver that can select and listen to any one of O Data System, and more particularly, to a radio receiver that can appropriately cope with processing of interrupt information. 2. Description of the Related Art DAB has attracted attention as a radio broadcast format capable of coping with deterioration of sound quality due to interference due to multi-localization of FM broadcasts and difficulty in receiving high-quality signals at mobile units. DA
B is being developed by EUREKA (European Advanced Technology Development Plan), and its specifications have already been defined. As a modulation method, π / 4 shift DQPSK-OFDM is used.
(Differential Quadrature
Phase Shift Keying-Orthog
onal Frequency DivisionMu
ltiplex (orthogonal frequency division multiplexing), which is characterized by being less susceptible to fading and multipath.
Using PEG layer II, a large number of stereo broadcasts and data broadcasts are enabled with a transmission bandwidth of 1.5 MHz. [0003] Both DAB and RDS include an interrupt service such as an alarm (warning) and road traffic information. However, DAB / RDS can be used to select and listen to either DAB or RDS. In the radio receiver, for example, during the listening of DAB, since the interrupt service of RDS was received earlier than the interrupt service of DAB, it is immediately switched from DAB to RDS, and the interrupt service of RDS flows. After a short wait,
Without being switched to the RDS, the DAB interrupt service can be accepted and the DAB interrupt service can be heard but cannot be performed. [0004] It is an object of the present invention to provide a radio receiver capable of effectively coping with an interruption service provided at about the same time from both digital audio broadcasting and analog audio broadcasting. [0005] A radio receiver according to the present invention.
According to (40), it is possible to select and listen to either digital audio broadcast or analog audio broadcast including both interrupt services, and when an analog audio broadcast interrupt service is received during selective listening of digital audio broadcasts. Suspends the audio output of the analog audio broadcast interrupt service for a predetermined time, and outputs the digital audio broadcast interrupt service when the digital audio broadcast interrupt service is received within the hold time. Cancel switching to broadcast. The radio receiver (40) of the present invention has the following (a)
To (c). (A) audio output means (54) for selecting and outputting either digital audio broadcast or analog audio broadcast, both of which include an interrupt service; (b) providing an interrupt service for analog audio broadcast during the selective output of digital audio broadcast; When received, the analog audio broadcasting interrupt service audio output is held for a predetermined time by the analog interrupt service holding means (c). The digital audio broadcast is held within the analog audio broadcasting interrupt service audio output holding time by the analog interrupt service holding means. When an interrupt service is accepted, the digital interrupt service is output as audio and the switching from digital audio broadcast to analog audio broadcast is stopped. According to this, when the interrupt service from the digital audio broadcast arrives without much difference in time from the interrupt service from the analog audio broadcast, the radio receiver (40) switches from the digital audio broadcast to the analog audio broadcast. Without being switched, interrupt services from digital audio broadcasts of excellent quality can be given priority and flow. An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a system configuration diagram of the DAB tuner 10. The DAB tuner 10 includes a main body 12, a DAB control microcomputer 26 separate from the main body 12, and the like. In the main body 12, the DAB system microcomputer 14
Has a memory 16 and includes a plurality of ensembles (each ensemble is transmitted by radio broadcast waves modulated by DQPSK-OFDM, and one ensemble has a bandwidth of about 1.5 MHz and usually has six ensembles. Broadcast programs are included.), And one ensemble is designated, and the designated information is sent to the RF block 18. RF block 18 is DAB
Ensemble R specified by system microcomputer 14
F (Radio Frequency) is extracted and sent to the demodulation block 20. In demodulation block 20, RF block
The RF signal from 18 is demodulated, and the channel decoding block 22 decodes the demodulated signal from the demodulation block 20. In this way, an all-digital signal of one ensemble designated by the DAB system microcomputer 14 to the RF block 18 is obtained in the channel decoding block 22. Channel decoding block
Among the digital signals decoded at 22, the audio data is sent from the channel decoding block 22 to the audio decoding block 24, and FIG data such as program types other than audio data (FIG. It is sent to the microcomputer 14. The audio decoding block 24 outputs the DAB of the audio data input from the channel decoding block 22.
The sub-channel audio data specified by the system microcomputer 14 is decoded and sent to the left and right speakers 54 (FIG. 3). The DAB control microcomputer 26 includes a memory 28, and exchanges data with the DAB system microcomputer 14 of the main body 12. The DAB control microcomputer 26 receives instructions from the user via the key 30 and outputs predetermined data to the display 32 to display information and inform the user. FIG. 3 shows a DAB / RDS shared radio receiver 40.
FIG. CD player 42, RDS tuner
The outputs of 44 and DAB tuner 10 are sent to switch 48. The microcomputer 46 includes the DAB system microcomputer 14 and the DAB control microcomputer 26 shown in FIG. 2, and a volume 50, a CD player 42, and an RDS tuner via a switch 48.
44 and the connection with the DAB tuner 10, and sends the selected one of the outputs of the CD player 42, the RDS tuner 44 and the DAB tuner 10 to the volume 50. The volume 50 adjusts the volume of the sound output from the speaker 54, and the output of the volume 50 is amplified by the amplifier 52 and then output from the speaker 54. The user operates the key 30 to make a predetermined input to the microcomputer 46, and the microcomputer 46 displays the data on the display 32. In FIGS. 4 to 9, communication protocols of various elements of DAB such as a transmission frame will be described as appropriate. For details, see the European Telecommunications Standards Association (European Telecommunications)
ications Standards Instiu
te) Published by the European Telecommunications Standard
ionics Standard). FIG. 4 shows the structure of a DAB transmission frame. Transmission frame (Transmission fra
me) are the synchronization channel and FIC (Fast)
Information Channel) and M
It has SC (Main Service Channel). The FIC further includes a plurality of FIBs (Fast
Information Block), MS
C is a plurality of CIFs (Common Inter)
(Leaved Frame). The specifications of DAB are determined from mode 1 to mode 3, and the transmission frame time (duration) and the number of FIBs and CIFs in one transmission frame are different for each mode. For example, in mode 1, the time of one transmission frame is 9
The number of FIBs and CIFs in 6 ms and one transmission frame is 12 and 4, respectively. FIG. 5 is a view showing an example of the DAB service structure. Ensemble label is DAB Ensemble 1 (DA
B ENSEMBLE ONE) is an ensemble (Ensemble) whose service label is alpha1.
Radio (ALPHA1 RADIO), Beta Radio (BETA RADIO), Alpha 2 Radio (ALP)
HA2 RADIO) and other services (Servi
ce). The user hears the selected service from the DAB radio 10. The alpha 1 radio has one main service component (Service components) and two sub service components. The primary service component is audio, and the secondary service component is a traffic message channel: TMC (Traf).
fic Message Channel and service information: SI (Service Information)
It is. The audio component and the SI are transmitted on separate sub-channels (SubCh) in the MSC, and the TMC is transmitted in the FIDC (Fast Information Da) in the FIC.
ta Channel). Beta radio has two service components.
Audio and secondary audio (secondary a
audio component), both of which are MS
On the C subchannel. The alpha 2 radio has the same TMC and SI as the alpha 1 radio, and the audio may be the same as the alpha 1 radio depending on the switch. FIG. 6 is a structural diagram of the FIB. FIB,
FIB of the leading 30 bytes consisting of 256 bits in total
B data area (FIB data field) and rear 16-bit CRC (Cyclic Redunda)
ncy Check word). The FIB data area further includes a plurality of FIG (Fas
t Information Group), one end marker (Endmarker), and one padding (filling the remaining bits with 0s to fit the FIB data area to bytes). The FIG part is a useful data area (useful data view).
ld). Each FIG is, in order from the beginning, a FIG type, a Length (length: represents a bit length of a subsequent FIG data area), and a FIG data area (FIG.
data field). Fig type and Le
ngth forms a FIG header. FIG. 7 is a structural diagram of the FIG data area of FIG. 6 in which the FIG type is 0 (000 in 3-bit binary notation). The FIG data area further stores C / N
(Current / Next), OE (Other E)
nsemble), P / D (Programme / Da)
ta), Extension, Type 0 area (Type
0 field). Extension is 1 to 4
And 7, when C / N = 0, it means the current multiplex structure, and when C / N = 1, it means the next multiplex structure. Also, C / N =
When it is 1, it means that the type 0 area is related to the following arrangement. Extension is 6, 9, 11, 1
In the case of 8, 21, 22, 23, 24, 25, 27, and 30, C / N indicates the version number of the type 0 area.
OE is Extension = 12, 16, 17, 21,
24, 30 are used, and OE = 0 indicates this type 0
The information of the area means that it is related to this ensemble, and OE = 1 means that it is related to another ensemble. P / D = 1 is the SId of the type 0 area
Is the 16-bit SId used for program services
And P / D = 0 indicates that S in the type 0 area
Id is the 32 bit S indicator used for data services
Id. This P / D is Extnsi
Used when on is 2, 9, 23, 24, and when not used, SId is in 16-bit format. FIG. 8 shows the extension of the FIG.
on is 18 (hereinafter, each FIG is referred to as the FIG type and Exte
and nsion as shown in FIG. FIG. 2 is a structural diagram of a type 0 area. The type 0 area further:
Multiple announcement support (Announce)
ment support. Announcement = interrupt. ) Area. Each announcement support is SId
(Service Identifier), Asu_
flags (Asu = Announcement su
report), and Cluster_Id data. SId indicates which service it is. A
Each bit of su_flags corresponds to the type of interrupt information (for example, an alarm corresponds to bit 0 in interrupt information), and Cluster_Id indicates a cluster to which this SId belongs. SIds having the same Cluster_Id share interrupt information. FIG. 9 is a diagram of the FIG.
FIG. 10 is a structural diagram of a type 0 area where on is 19 (FIG0 / 19). The type 0 area further includes a plurality of announcement switching (Announcement sw).
). Each announcement switching is performed by Asw (Announcement switch).
tching) _flags, Cluster_Id,
And SubChId and the like. Each bit of Asw_flags has the same meaning as each bit of Asu_flags of FIG0 / 18, and corresponds to the type of interrupt information. Cluster_Id indicates a cluster, and SubC
hId indicates the subchannel carrying the interrupt information for this cluster. The reception of FIg0 / 19 means that an announcement (= interrupt) has occurred. From FIG0 / 18 and FIG0 / 19, DA
At B, an interrupt occurs, and it is possible to detect which sub-channel the content of the interrupt information is in. On the other hand, the occurrence of the interrupt service in the RDS is based on the TA of the Group Type 0A, 0B, and 14B.
It can be detected from A flag. FIG. 1 shows a DAB / RDS shared radio receiver 40.
7 is a flowchart of an interrupt service process in FIG.
In S60, it is determined whether or not the user is selecting (listening) the DAB. If NO, the interrupt service process ends, and if YES, the process proceeds to S62. In S62, DA
Determine whether an interrupt service from B has been accepted,
If YES, proceed to S64, if NO, S66
Proceed to. In S64, the interrupt service of the accepted DAB is output from the speaker 54. In S66, it is determined whether or not an interrupt service from the RDS has been received. If NO, the interrupt service process ends, and if YES, the process proceeds to S68. In S68, it is determined whether or not the (interrupt service) hold timer is operating. If the hold timer is already operating, the process skips S70 and proceeds to S72. If not, the process proceeds to S70. Then, the operation of the hold timer is started. The hold timer is set to a predetermined time, for example, 10 seconds. In S72, it is determined whether or not the operation of the hold timer has ended, that is, whether or not 10 seconds have elapsed since the interruption service was received from the RDS. If YES, the process proceeds to S74 and the hold is performed. R
The interrupt service from the DS is output from the speaker 54, and N
If O, the process returns to S62. According to the interrupt service processing shown in FIG. 1, during the period when the user or the DAB / RDS shared radio receiver 40 selects and listens to the DAB, the interrupt service from the RDS is earlier than the interrupt service from the DAB. Even if the speaker output of the interrupt service from the RDS is 1
If the interrupt service from the DAB is received during the hold time for 0 second and the interrupt service from the DAB is received within the hold time, the speaker outputs the interrupt service from the DAB (S64). After the elapse of the hold time, the speaker output of the interrupt service from the RDS is performed. In order to output the interrupt service from the RDS to the speaker after the hold time, a memory for storing the interrupt service from the RDS during the hold time may be provided, and the interrupt service from the DAB and the RDS may be usually provided.
Since it is repeated several times, the interrupt service first received from the RDS after the hold time may be output to the speaker.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart of an interrupt service process in a DAB / RDS shared radio receiver 40. FIG. 2 is a system configuration diagram of a DAB tuner 10; FIG. 3 is a block diagram of a DAB / RDS shared radio receiver 40; FIG. 4 is a diagram showing the structure of a DAB transmission frame. FIG. 5 is an exemplary diagram of a DAB service structure; FIG. 6 is a structural diagram of an FIB. FIG. 7 is a structural diagram of an FIG data area in which the FIG type in FIG. 6 is 0 (000 in 3-bit binary notation). FIG. 8 shows an extension of 18 in FIG.
FIG. 4 is a structural diagram of a type 0 region of FIG. FIG. 9 shows an extension of 19 in FIG.
FIG. 4 is a structural diagram of a type 0 region of FIG. [Description of Signs] 40 DAB / RDS shared radio receiver (radio receiver) 54 speaker (audio output means)

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-10-224244 (JP, A) JP-A-10-209985 (JP, A) JP-A-10-150345 (JP, A) JP-A-10-1998 126293 (JP, A) JP-A-10-4365 (JP, A) JP-A-9-219654 (JP, A) JP-A-64-81531 (JP, A) JP-A-57-97732 (JP, A) Special table Hei 7-500710 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04H 1/00-3/00 H04B 1/06 H04B 1/16

Claims (1)

(57) [Claim 1] (a) Audio output means for selecting either digital audio broadcast or analog audio broadcast including interrupt service and outputting audio
(54), (b) an analog interrupt service holding means for holding the audio output of the analog audio broadcast interrupt service for a predetermined time when an interrupt service of the analog audio broadcast is received during the selective output of the digital audio broadcast; and c) If the interrupt service of the digital audio broadcast is received within the hold time of the audio output of the interrupt service of the analog audio broadcast by the analog interrupt service holding means, the interrupt service of the digital audio broadcast is output as an audio signal and the digital audio broadcast is converted into an analog signal. A radio receiver, comprising: digital interrupt service priority means for stopping switching of audio broadcasting.