JPH04140911A - High speed search method for station substituting for rds receiver - Google Patents

Abstract

PURPOSE:To reduce the member of times of occurrence of noisy sound by searching AF stations being an object of one group and searching AF stations being an object of other group to decrease the number of times of a local oscillation signal of a sub side reception section crossing over a tuning frequency of a main reception section. CONSTITUTION:A controller 17 supplies a signal to a main/sub changeover circuit 15, which is switched to input an FM detection signal outputted from an intermediate frequency amplifier/FM detection circuit 5 to an RDS decoder 16. A PI code is extracted from an RDS data and registered in a memory as a PIM, an AF data is extracted and registered in an AF list memory by separating the frequency into a lower group 0 and an upper group 1 with a border of a reference frequency FR resulting from an IF frequency from a main reception frequency FM. The controller 17 sets '1' to (i) and inverts a flag A to '0', and judges whether or not an AF1 (0) exists in the AF list memory. Since an AFa exists, the controller 17 outputs a signal to a mute circuit 7 to stop an audio output at the main side, and outputs a sub side reception frequency control data FDTS to a sub PLL circuit 19 and searches a 1st AF station.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a high-speed alternative station search method for an RDS receiver,
In particular, based on the AF list extracted from the main side reception signal, the sub side reception section searches for AF stations in order to find an alternative station with better reception status than the main side reception station PL
The present invention relates to a high-speed alternative station search method for an L frequency synthesizer type RDS receiver.

<Prior art> In Europe, RDS (
radio data system) has been put into practical use. This RD
S is for superimposing various digital data on FM radio broadcasts, and the messages include (1) program identification code (PI code) (ii) broadcasting station name (PS) (ii) of the currently received FM broadcast. ) Frequency list of broadcasting stations currently broadcasting the same program (AF) (1v) Program content identification code (PTY) (v) Transmittal letter!
! Identification code (DI) (vl) Identification code for music or conversation (M, /S), (■) Identification code for traffic information broadcasting station (TP), (vi) Identification code for traffic information broadcasting (TA), etc. There is.

In this way, in the RDS, since many types of messages related to the FM broadcasts being received are multiplexed, the messages can be used to perform an unprecedented automatic channel selection operation.

As an example, an RD with two receiving sections, main and sub,
The S receiver is equipped with a high-speed alternative station search function that uses the AF list, and searches for alternative stations that are broadcasting the same program as the main side at high speed. When broadcasting, it is possible to quickly switch to another station with better reception that is broadcasting the same program without interrupting audio output.

FIG. 4 is a flowchart of automatic tracking reception control including such conventional alternative station high-speed search control.

P from the RDS data demodulated from the main side received signal
The I code is taken out and registered as a Pl in the memory (step 101), and the AF list is taken out and registered in the AF list memory (step 102). The AF list includes a maximum of 25 AF stations (alternative stations).

Set i indicating the storage number of the AF list memory to 1 (step 103), and store the first AF data A in the AF list memory.
Determine whether AF is present (step 104); if AF is present, perform channel selection control for the sub-side receiving unit and AF +
The station is searched (105), and the PI code is extracted from the RDS data demodulated from the sub-side received signal (step 106), and it is determined whether the sub-side PI code Pls matches Pl (step 107).

If they match, the received electric field strength 3 on the main side at that time
The received electric field strength S M s on the sub side is compared with the received electric field strength S M s on the sub side (step 108). If the main side is stronger, increment i and return to step 104 (step 10
9) Perform similar processing for AF.

Although AFz exists in the AF list memory, if the received field strength after the search is compared and the main side is stronger, i is set to 3 and the process returns to step 104.

From here on, search each AF station in the AF list in turn in the same way. Even if you search for the last station in the AF list, if the received field strength is stronger on the main side, go back to the beginning and AF, and then repeat the same process. Repeat the process.

After that, when the reception condition on the main side deteriorates and it is found that the received field strength is stronger on the sub side among the 8 AF stations, the tuning frequency of the main side receiver is changed to the AFi station (step 110), To switch to a station with better reception status using the same program without interrupting output.

<Is to be solved by the invention> By the way, normally, the AF data sent in the AP list has an irregular arrangement of frequencies. For example, as shown in FIG. 10.7M
When H2) is the reference frequency F, AF + is on the lower side, AF is on the upper side, AF is on the lower side, AF is on the upper side, etc.
Sometimes they are arranged like this...

In this case, the sub-side receiving section changes from the tuned state of AF to AF.
When shifting to the tuned state of z, the voltage controlled local oscillator circuit provided in the PI, L frequency synthesizer type sub-side receiving section cannot change the oscillation frequency discontinuously, and A F l+ 10.7 From AF.

It changes continuously up to +10.7 (MHz),
The sub-side reception frequency also changes continuously from AF to AFz (see path I in FIG. 5).

For this reason, there occurs a point in time when the local oscillation frequency on the sub side matches the receiving frequency on the main side (N+ in FIG. 5), and the local oscillation signal wraps around to the main side and causes interference, generating noise.

Similarly, AF 2 to AF3, AF, to AF
Noise is generated every time the tuning frequency changes to a.
There was a problem in that N2 in route ■ and N in route ■ in the diagram) made it difficult to listen to radio broadcasts.

In light of the above, an object of the present invention is to provide a high-speed alternative station search method for an RDS radio receiver that causes less interference to the main side even when searching for an AF station on the sub side.

<Means for Solving the Problems> In one aspect of the present invention, the above problem is solved by dividing the AF list into a group below and a group above the frequency obtained by subtracting the IF frequency from the main receiving frequency. This is achieved by a first search means that searches for an AF station as a target, and a second search means that searches for an AF station in the other group after the search for one group is completed.

In another aspect of the present invention, when the sub-side receiver (second part) shifts from the tuning state of the last AF station of one group to the tuning state of the first AF station of the other group, audio is temporarily output. This is achieved by muting means.

According to one aspect of the present invention, when searching the AF list, first,
Search for the lower (upper) group than the frequency obtained by subtracting the IF frequency from the main reception frequency, and then
A search is performed for groups above (below) the frequency obtained by subtracting the IF frequency from the main reception frequency. As a result, it is possible to reduce the number of times that the local oscillation signal of the sub-side receiving section interferes with the main-side receiving section during the search of the AF list, thereby reducing the number of times noise sounds occur.

According to another aspect of the present invention, the sub-side receiving section is connected to one of the AFs.
When moving from the tuning state of the last AF station in a group to the tuning state of the first AF station in the other AF group, the audio output is temporarily muted.

As a result, when the local frequency of the sub-side receiving section crosses the receiving frequency of the main side, no noise is generated and there is no discomfort.

<Embodiment> FIG. 1 is a block diagram of a main part of an RDS receiver that implements a high-speed alternative station search method according to the present invention.

1 is an antenna, and 2 is a matching box, which distributes the antenna reception signal to the main side and the sub side while performing matching.

3 is a main side receiving section, 4 is a main side front end, and 5 is an intermediate frequency amplification/FM detection circuit (IF/DET).
Consists of.

The main side front end 4 is a main side PLL which will be described later.
Based on the voltage signal input from the circuit 18, a 10.7 MH2 intermediate frequency signal is generated in tune with a predetermined broadcasting station.

The intermediate frequency amplification/FM detection circuit 5 amplifies the intermediate frequency signal converted by the main side front end 4 and performs FM detection.

6 is a stereo demodulation circuit (MPX), which demodulates the FM detection signal inputted from the intermediate frequency amplification/FM detection circuit 5 into a stereo signal. 7 is a mute circuit, 8 is an amplifier (A
MP), 9 is a speaker, which is driven by an amplifier 8 and outputs audio.

IO is a main side electric field strength detection circuit, which detects the reception level (received electric field strength) of the main side receiving station by monitoring the signal strength of the intermediate frequency signal output from the intermediate frequency amplification/FM detection circuit 5. .

Reference numeral 11 denotes a sub-side receiving section, which includes a sub-side front end of I2 and an intermediate frequency amplification/FM detection circuit (IF/DE) of 13.
T).

The sub-side front end device 2 generates an intermediate frequency signal in tune with a predetermined broadcasting station based on a voltage signal input manually from a sub-side PLL circuit 19, which will be described later.

The intermediate frequency amplification/FM detection circuit 13 amplifies the intermediate frequency signal converted by the sub-side front end 12 and performs FM detection.

I4 is a sub-side electric field strength detection circuit, which monitors the signal strength of the intermediate frequency signal output from the intermediate frequency amplification/FM detection circuit I3 to determine the reception level (
(received electric field strength).

15 is a main/sub switching circuit which switches between the FM detection signal output from the main side intermediate frequency amplification/FM detection circuit 5 and the FM detection signal output from the sub side intermediate frequency amplification/FM detection circuit 13. Output. 16 is RDS
:j'2l-da, main//゛ No. bukiriso circuit 1
The digital data superimposed on the FM detection signal output from 5 is demodulated.

17 is RDS data and received field strength signal SM.

and SM! Based on i, automatic tracking reception processing including alternative station high speed processing is performed
Vn 10-A, 18 is the main side receiver manually operated from the Vn 10-A, 18 is the power I + signal in response to the main side receiver A5 frequency control data I). 11: The main side manually tunes radio station 4 to the specified broadcasting station.
, 12 circuits.

19 manually inputs the voltage A, -1 according to the frequency control data FD I"S to the rib side receiver input from 17) to the sub side solenoid 11 and 12, and then adjusts it to the specified value with 1. sub-detective who tunes in to the broadcasting station] i' 1. t, J.
).

Main example song 1 nt 4 todubukureno 11! ''
At 12, there are names, main, inner side 1-' L, 1. −
Circuit 182 sub side P l=1. Circuit 1 (Electric power input from 1, i; Si to the 8th code, addressed to the station of the frequency -j-
A local optical oscillator circuit is installed to control the electromagnetic interference (IL) for non-emissions.

The oscillation frequency of the local oscillator A; the oscillation frequency of the - number is 11, the main side receiving 4QL frequency, L is 1O67M i (higher by z, and the oscillation frequency of the local oscillator I on the sag side is also 10 times higher than the receiving frequency on the side). .1'AHz higher.

Below, the flowchart in FIG. 2 and the explanatory diagram in FIG. 3 are shown (d.

The automatic tracking reception process of the RDS radio receiver shown in FIG. 1 will now be explained.

In addition, initially the main side 91, 1 part 3 consists of R1. ) S
Tuning to the frequency associated with the station 1. The I8; 1? part 10 on the receiving side consists of the I8;1? :j number FS
(>FM) Assume that you are in tune with it,”: T, A F
It is assumed that the flag 8 indicating which of groups 0 and 1 of the target M AF station is to be determined is set to 1 in the list L.

First, 2λn 1st]-F 17 is the switching control engine 2 main 2. '±B switching circuit 15..., output 1. Then, switch to the main ←] and manually output the FM detection signal far from the FM detection circuit 5 which has been output from the intermediate frequency amplification circuit 5 (step 201).

Next, demodulation 1. from the main side reception signal 46. TA RDS
PI v~ from data 4 Extract 1, memory k
"1'1. Register with binding, (su'l-)g202),
Next, take out the A F day 7 related to C3AF squirrels 1 to 1, and calculate the main side color reception frequency at the time of A (C), then I!” frequency (10.7 MHz) i minus the reference frequency, and the frequency F.
Pa, through I J15, -ζ ■Glue nib on the Pa side ()h Croop I on the F side
, m A F IJ St□ J T:1. IM Register 1 (S-3-7 20ζ)).

For example, AF, AFb-AP. ,AP,
, ΔF, , AF, I+1 (i7) r7) AF data -
・Suppose that you received 2 and received 3, and between 6 AI = ゛ data and F x 2x, A do, AF, , as shown in Fig.
AI',-",l?6,ΔF,,,AF,,A
Is it related to the frequency h゛,>do? , as shown in Figure 3, group O has l + old API (0) ・
Eight [Pa. , AFa (41) -AFc, AI”!I (
0)-AF# is registered, and 11-AF# is registered in group 1.
F, (1)=AFt, ,AF2 (1-8F,
, AF, (1) ・-At”r is registered.

Next, jntl' e17 sets 1 to L and sets the flag 8 to 0 to set it to 0.
204), AF squirrel (・Me71), glue '7' 0
/Is there an API (0) related to flies?
+ Worth praying for (Sujitsubu 205).

Since A'1 exists, the '1 controller 17 outputs the Miff~=-1 control signal υ to the M,z-) circuit 7-5, and the main -(a station's PJ output) -・time -
Stop [Shuta]' (Slap 20 fi), 'Knob side P Li,..., circuit 19..., sub side reception related to AF; 1 same wave number control gator F i) T, output L
7. The reach of the first head station of Groove 0 is JI->(
Sujitsubu 207) After the 6th day, the control U---
717 is Mi, 1~1 release system wholesale Jingo is missed - 1 circuit 7.
'・Output 2 and restart the sound output (step 2)
0B).

On the way to confirm the transposition 1 of the key state r', the -1 part lO changes from the frequency Fs to Al',
・The local oscillator frequency of Yundo 12 crosses the tuning frequency of the main side and gives a disturbance, but Mu-F is applied to the audio output,
.

ζ Because of the noise, there is a feeling of discomfort.
(See route 1, P, in Figure 3).

After Slafugu 20B, the -/1/L circuit 17 temporarily switches the main /' switch circuit 1 to the double side, intermediate frequency amplification, and output from the /FM detection circuit 1: ( In step 209), the sub side FM detection signal is input to the RDS decoder 16 and the PI code is extracted from the RDS data demodulated from the sub side received signal. (step 210).

If they match, then the controller 17 inputs and compares the main side received field strength signal SMm and the sub side received field strength signal SM from the field strength detection circuits 10 and 14, and determines whether the sub side is stronger than the main side. (Step 211).

When the received field strength on the main side is stronger, it is determined as i-2 (Step 212), and it is determined whether there is an AF (0) related to the second group O in the AF list memory (
Step 213) Since AFc exists, the sub-side receiver 11 searches for AF and stations without performing mute control (step 214). After the search is completed, the sub-side P
If the I coat matches the main side, the received electric field strengths are compared (steps 209 to 211).

Regarding the AFc station, when the received field strength is stronger on the main side, the controller 17 searches for the third AF day AP in group 0 without muting, and then compares the PI code and the received field strength. conduct.

In this way, when transitioning from the AF tuning state to the AFc tuning state, and from the AFc tuning state to the AF tuning state.

When transitioning to a state of attunement to
Since the local frequency of the sub receiving section 11 does not cross the main receiving frequency, there is no need to mute the audio output.

Regarding AF and stations, when the received field strength is stronger on the main side, the controller 16 is set to j-4, but group 0
Since there is no fourth AP data in step 20
Return to step 4 and change i=1, A=1, and enter the AF+ related to the first group of group l in the registered data of the AF list memory.
It is determined whether (1) exists (step 205). AF exists, the controller I7 mutes the audio output (step 206), and the sub-side receiving unit 11 searches for the first AF station (=AF) in group 1 (step 207).

After the search ends, the controller 17 cancels muting (step 20B).

Until then, the sub-side receiving section 11 had been tuned to a lower frequency than F, and on the way to the tuning state to AF, the sub-side local frequency crosses the main-side receiving frequency and causes interference. (See route ■ and P in Figure 3), the audio output is muted, so no noise is generated and no discomfort occurs.

After step 208, the controller 17 compares the P code and the received electric field strength (steps 209 to 211).
.

When the received field strength on the main side is stronger, it is necessary to judge whether there is AF't(1) related to the second group I (step 213), since there is an AP, this time the sub In step 214), the side receiving section 1 searches for an AF station.

If the PI code received from the station is the same as that on the main side, the received electric field strengths are compared (steps 209 to 211).
.

Regarding the AF□ station, when the received field strength is stronger on the main side, the controller 17 determines whether the third data of group 1 is present, and since there is AF, it is muted as in the case of AFz (1). sub-side receiving section 11 without multiplying
Search for AF and stations, and compare the PI code and received field strength.

In this way, when transitioning from the tuned state of AF to the tuned state of AF, and from the tuned state of AF to the tuned state of AF, (paths ■ and ■ in Figure 3), the sub Since the local frequency of the side receiver 11 does not cross the main side receiving frequency, there is no need to mute the audio output.

Regarding AF and stations, when the received field strength is stronger on the main side, the controller 17 sets j=4 (step 2).
12) Since the fourth AF date does not exist in group 1, the process returns to step 204, changes i=1 and A=O, and repeats the subsequent processing for group 0.

Last AF of group 1, station to first A of group 0
F. Even when shifting to the station (route ■ in Figure 13), the local oscillation frequency on the love side is cut off by the main side receiving 46 frequencies, but noise is generated as the signal is muted in the same way as described above. do not.

In this way, when performing a high-speed search for an alternative station based on the AF list (,,,:, when the reception condition on the main side 1 deteriorates L2, for example, when searching for the head 1 station on the sub side) When the force on the sub side is stronger than the main side, the electric field strength of the receiver 3 is stronger (YES in Sub 211): 17
After the troller 17 multiplies the five-tone output ζ2me1-t (
Step 215), AFc on the main side ■) LL circuit 18
Outputs the main side reception frequency control door data FDT related to L
7. Tuning the main receiver 3 to AF (step 2)
1 fi ), cancel the meet (step 21
'7).

Then, proceeding to the first step 201, the PI data received from the AFc station is registered, the AF list is classified and registered, and the subsequent high-speed search for alternative stations is carried out.

<Effect of the invention> According to one aspect of the present invention, the AF list can be adjusted.

At the time of Q, first subtract the target U, l-'' station from the 1, - horn group, which is divided into the G side group and the upper group based on the IEJ wave number obtained by subtracting the lF frequency from the main side reception frequency, and then, AF station σ door 1- for the other group
Since the configuration is configured to perform the tuning frequency, the local oscillation of the sub side receiver 45 (no. According to another aspect of the invention, the sub-side receiver changes from the tuning state of the last AF station in one AF group to the tuning state of the first AF station in the other AF group. When moving to 4, the audio output is temporarily multiplied by mute 4, and as a result of the 7 steps, the sub-side receiving section's station interrogation number crosses the main receiving frequency 4 during the step, and noise is generated. The table does not occur and the sense of discomfort disappears.

[Brief explanation of the drawing]

The first is the R[')S receiver's alternative station high-speed processing according to the present invention.
2 is a flowchart of automatic tracking reception processing including alternative station high distance search processing according to the present invention, FIG. - Flowchart of automatic tracking reception processing including check 1. FIG. 5 is an explanatory diagram illustrating the operation of the conventional example. 3. Main side receiving section 11 - Sub side receiving section 16... RDS decoder 17... Controller Patent applicant Alvine Co., Ltd. Agent Patent attorney Chiki Saito Figure 3 Figure 4

Claims (2)

[Claims] (1) Based on the AF list extracted from the received signal of the main receiving station, the RDS receiver searches for AF stations in order at the sub receiving station in order to find an alternative station with better reception than the main receiving station. In the alternative station high-speed search method, the AF list is divided into groups below and above the frequency obtained by subtracting the IF frequency from the main receiving frequency.
A high-speed alternative station search method for an RDS receiver, characterized by: searching for an AF station in one group, and then searching for an AF station in the other group. (2) When the sub-side receiving unit shifts from the tuning state of the last AF station in one group to the tuning state of the first AF station in the other group, the audio output is temporarily muted; 2. A high-speed alternative station search method for an RDS receiver according to claim 1.