Method for determining station names of a list of radio stations

Abstract

A method for decoding the name of detected radio stations, the method being implemented by a receiving system including at least one radio receiver, each of the received radio signals including a digital datum corresponding, at least intermittently, to the name of the radio station, the method including the following steps: for each radio station belonging to a list of radio stations preselected from the detected radio stations, a first decoding of the digital datum at a first sampling frequency, in order to determine a probable name; for any detected radio station not belonging to the list of preselected radio stations, a second decoding of the digital datum at a second sampling frequency lower than the first, in order to determine a probable name; and measuring a quality of the radio signal and inhibiting the first and second decodings if the quality of the signal drops below a preset threshold.

Claims

1. A method for decoding the name of detected radio stations, said method being intended to be implemented by a receiving system comprising at least one radio receiver, said detected radio stations each corresponding to a multiplexed radio signal received by said at least one radio receiver, each of said received multiplexed radio signals comprising a digital datum corresponding, at least intermittently, to the name of the radio station, said method comprising the following steps: for each radio station belonging to a list of radio stations preselected from said detected radio stations, a first decoding (D1) of the digital datum at a first sampling frequency, comprising, at any given time, depending on the first sampling frequency, reading (R1) said digital datum to determine a possible name of the radio station, storing (S1) the successive possible names read and statistically processing the successive possible names read to determine (PROB1) a probable name of the radio station, for any detected radio station not belonging to the list of preselected radio stations, a second decoding (D2) of the digital datum at a second sampling frequency lower than the first sampling frequency, comprising, at any given time, depending on the second sampling frequency, reading (R2) the digital datum to determine a possible name of the radio station, storing (S2) the successive possible names read, and comparing said possible name of the radio station determined at the time in question to the possible name determined at the preceding time in order to determine (PROB2), if two successively determined possible names are identical, a probable name of the radio station, measuring (Q) a quality of the radio signal and inhibiting (I) the first and second decodings if the quality of the signal drops below a preset threshold.

2. The method as claimed in claim 1, wherein the radio signal is encoded according to the radio data system of the RDS standard and the digital datum corresponds to the field designated PS in said radio data system of the RDS standard.

3. The method as claimed in claim 2, wherein the comparing step of the second decoding comprises comparing said possible name of the radio station determined at the time in question to at least two successive possible names determined at successive preceding times, in order to determine (PROB2), if the at least three successively determined possible names are identical, a probable name of the radio station.

4. The method as claimed in claim 2, wherein the first sampling frequency is comprised between a first decoding (D1) every eight seconds and a first decoding (D1) every sixteen seconds.

5. The method as claimed in claim 2, wherein the second sampling frequency is comprised between a second decoding (D2) every four minutes and a second decoding (D2) every six minutes.

6. The method as claimed in claim 2, wherein the receiving system, which is located on-board a vehicle, also performs an informing function, corresponding to the reception of an information signal and to the transmission of information, contained in said information signal, to the driver of the vehicle, said method comprising inhibiting the first and second decodings (D1, D2) on reception of an information signal, until the end of the transmission of said information.

7. The method as claimed in claim 1, wherein the comparing step of the second decoding comprises comparing said possible name of the radio station determined at the time in question to at least two successive possible names determined at successive preceding times, in order to determine (PROB2), if the at least three successively determined possible names are identical, a probable name of the radio station.

8. The method as claimed in claim 7, wherein the first sampling frequency is comprised between a first decoding (D1) every eight seconds and a first decoding (D1) every sixteen seconds.

9. The method as claimed in claim 7, wherein the second sampling frequency is comprised between a second decoding (D2) every four minutes and a second decoding (D2) every six minutes.

10. The method as claimed in claim 7, wherein the receiving system, which is located on-board a vehicle, also performs an informing function, corresponding to the reception of an information signal and to the transmission of information, contained in said information signal, to the driver of the vehicle, said method comprising inhibiting the first and second decodings (D1, D2) on reception of an information signal, until the end of the transmission of said information.

11. The method as claimed in claim 1, wherein the first sampling frequency is comprised between a first decoding (D1) every eight seconds and a first decoding (D1) every sixteen seconds.

12. The method as claimed in claim 11, wherein the second sampling frequency is comprised between a second decoding (D2) every four minutes and a second decoding (D2) every six minutes.

13. The method as claimed in claim 11, wherein the receiving system, which is located on-board a vehicle, also performs an informing function, corresponding to the reception of an information signal and to the transmission of information, contained in said information signal, to the driver of the vehicle, said method comprising inhibiting the first and second decodings (D1, D2) on reception of an information signal, until the end of the transmission of said information.

14. The method as claimed in claim 1, wherein the second sampling frequency is comprised between a second decoding (D2) every four minutes and a second decoding (D2) every six minutes.

15. The method as claimed in claim 14, wherein the receiving system, which is located on-board a vehicle, also performs an informing function, corresponding to the reception of an information signal and to the transmission of information, contained in said information signal, to the driver of the vehicle, said method comprising inhibiting the first and second decodings (D1, D2) on reception of an information signal, until the end of the transmission of said information.

16. The method as claimed in claim 1, wherein the receiving system, which is located on-board a vehicle, also performs an informing function, corresponding to the reception of an information signal and to the transmission of information, contained in said information signal, to the driver of the vehicle, said method comprising inhibiting the first and second decodings (D1, D2) on reception of an information signal, until the end of the transmission of said information.

17. The method as claimed in claim 1, wherein, if the receiving system comprises a single radio receiver, said radio receiver receives and decodes the radio signal corresponding to the selected radio station, with a view to said signal being played, or implements the first decoding (D1) and the second decoding (D2), except in case of inhibition (I) of said first and second decodings (D1, D2).

18. The method as claimed in claim 1, wherein, if the receiving system comprises two radio receivers, a first radio receiver receives and decodes the radio signal corresponding to the selected radio station, with a view to said signal being played, and a second radio receiver implements the first decoding (D1) and the second decoding (D2), except in case of inhibition (I) of said first and second decodings (D1, D2).

19. A motor-vehicle radio receiving system, comprising a computer configured to control at least one radio receiver, in order to implement the method as claimed in claim 1.

20. A vehicle comprising a radio receiving system according to claim 19.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the invention will become apparent from the following description, which is given with reference to the appended figure.

(2) The figure shows the block diagram showing the steps of the method according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(3) The invention is envisioned mainly with a view to an implementation in a vehicle, especially a motor vehicle. However, the implementation of the invention in other contexts, in particular in any radio receiving system or in any multimedia system intended to display the names of a list of detected radio stations, is also targeted.

(4) To improve the determination of names of radio stations detected by a receiving system, the present invention proposes a method comprising two distinct decoding levels.

(5) It will be recalled that the context is that of a radio receiving system comprising at least one radio receiver and a screen able to display the name of the radio stations detected by said at least one radio receiver.

(6) A function performed by most receiving systems allows the user to preselect a certain number of radio stations to form a list of preselected stations corresponding to radio stations that the user desires to be able to rapidly find with a view to listening to them, on the face of it regularly. In general, the list of preselected stations is permanently accessible to the user and the names of the stations must therefore as a priority be reliably determined.

(7) Thus, with reference to the figure, for any radio station belonging to such a list of preselected stations, in practice corresponding to a list of stations permanently displayed or at least frequently displayed on the screen of the receiving system, a first decoding D1, at a high sampling frequency, is implemented. The objective of the first decoding D1 is to allow rapid decoding of the names of the stations belonging to the list of preselected stations, said names of said radio stations belonging to the list of preselected stations to be frequently displayed on the screen of the receiving system.

(8) Again with reference to the figure, for any detected radio station not belonging to said list of preselected stations, the method according to the invention makes provision to implement a second decoding D2, at a low sampling frequency.

(9) The objective of the second decoding D2 is to consolidate the probable names of all of the detected radio stations not belonging to the list of preselected stations.

(10) Moreover, with reference to the figure, provision is made, according to the invention to inhibit I the first decoding D1 and the second decoding D2 when the measured quality Q of the signal is insufficient, both because, in this case, the decoding of the PS field takes more time and in order to not monopolize for too much time the radio receiver, as this would risk degrading listening quality.

(11) In practice, the present invention is mainly intended to be implemented in a radio receiving system having one or two radio receivers. The method, except in case of inhibition because the received signal is of insufficient quality, then implements the first and second decodings in parallel. The first decoding D1 rapidly decodes the probable name of the radio stations belonging to the list of preselected stations. The second decoding D2 then decodes the probable name of the radio stations not belonging to the list of preselected stations more slowly in the “background”. Assuming that the radio receiving system has only one radio receiver, then the method according to the invention is implemented only if the radio receiver is not an active source playing a signal that is being listened to by the user. Assuming that the radio receiving system has two radio receivers, one receiver may be dedicated to the reception and decoding of the received radio signal corresponding to the radio station being listened to by the user, whereas the second radio receiver implements the method according to the invention.

(12) In both cases, i.e. when the radio receiving system has a single or two radio receivers, the quality of the signal is measured Q continuously, the first and second decodings D1, D2 being inhibited if said measured quality Q of the signal is insufficient. In practice, the measurement Q of the quality of the signal may correspond to a measurement of the power of the received radio signal, to a measurement of the signal-to-noise ratio of the received radio signal, or even to a measurement of RSSI, for Received Signal Strength Indication. The quality of the signal thus measured Q is then compared to a chosen threshold, which is for example chosen empirically by the manufacturer, in order to determine whether the quality is sufficient or not. If the quality is sufficient, the first decoding D1 and the second decoding D2 are implemented. If the quality is insufficient, the first and second decodings D1, D2 are inhibited.

(13) The first and second decodings D1, D2 are thus inhibited I when the quality of the signal is insufficient. In particular, when the radio receiving system comprises two radio receivers and is able to recombine the signals received by the respective antennas of said two radio receivers, for example using a so-called “phase-diversity” method, then said two radio receivers are monopolized, as a priority, to improve the quality of the received radio signal, and the first and second decodings D1, D2 are therefore inhibited. In other words, the determination of the names of the radio stations is a low-priority process; when high-priority processing is required, such as the search for an alternative that would allow the radio station being listened to continue to be received, the method makes provision to inhibit I the first and second decodings D1, D2.

(14) Furthermore, when a receiving system located on-board a motor vehicle also performs an informing function (such as one providing information relating to traffic or to the weather for example) corresponding to the reception of an information signal and to the transmission of said information to the driver of the vehicle, said method also makes provision to inhibit the first and second decodings D1, D2 on reception of an information signal, until the end of the transmission of said information.

(15) Moreover, the role of the first decoding D1, as indicated above, is to rapidly decode the probable name of the radio stations belonging to the list of preselected stations. Thus, the first sampling frequency, corresponding to the frequency at which the first decoding D1 decodes the PS field in each received radio signal corresponding to a radio station belonging to the list of preselected stations, is high. According to one embodiment, said first sampling frequency is comprised between 8 and 16 seconds, and for example equal to 12 seconds, allowing the fact that the PS field encoded in the multiplexed radio signal, according to the RDS standard, is potentially updated about every 5 seconds, to be taken into account.

(16) In parallel, the role of the second decoding D2 is to perform background decoding in order to determine the probable name of detected radio stations not belonging to the list of preselected radio stations. Thus, the second sampling frequency, corresponding to the frequency at which the second decoding D2 decodes the PS field in each detected radio signal corresponding to a radio station not belonging to the list of preselected stations, is low. According to one embodiment, said first sampling frequency is comprised between 4 and 6 minutes, and for example equal to 5 minutes, allowing the fact that a program, and in particular a song broadcast by a station, has an average length of 3-4 minutes, to be taken into account, so that, if the broadcaster of the radio station in question uses the PS field to broadcast the name of the song in the process of being listened to, said PS field will have changed between two successive iterations of the second decoding D2.

(17) With respect to the first decoding D1, with reference to the figure, provision is made, at any given time, depending on the first sampling frequency: to read R1 the PS field contained in the received multiplexed radio signal, in order to determine a possible name of the radio station, to store S1 the successive possible names read, and to statistically process PROB1 the successive possible names read in order to determine a probable name of the radio station.

(18) Such statistical processing may be carried out in various ways, at the choice of those skilled in the art. In particular, depending on the number of times an identical PS-field title appears and on the time for which said PS-field title does not change, a confidence index is attributed to said probable name. The more often and the longer the time for which said probable name appears, for example, the higher the confidence index and the more chance the probable name has of being the actual name of the station.

(19) According to one embodiment, above a preset threshold, the confidence index is sufficiently high to allow the probable name to be considered to certainly be the name of the radio station in question and the implementation of the first decoding D1 may be inhibited for said radio station.

(20) The second decoding D2 is implemented for any detected radio station not belonging to the list of preselected radio stations. Said second decoding D2 comprises, at any given time, depending on the second sampling frequency: reading R2 the PS field contained in the received multiplexed radio signal, in order to determine a possible name of the radio station, storing S2 the successive possible names read, and comparing PROB2 said possible name of the radio station determined at the time in question to the possible name determined at the preceding time in order to determine, if two successively determine possible names are identical, a probable name of the radio station.

(21) According to one embodiment, the possible name determined at a given time is compared to at least two successive possible names determined at two preceding successive times, in order to determine, if the at least three possible names are identical, the probable name of the radio station.

(22) Depending on the number of times a given PS field appears in the list of possible names, in the context of the implementation of the second decoding D2, a confidence index may also be attributed to the probable name, said confidence index increasing, for example, with the number of occurrences of said probable name. According to one embodiment, if a preset threshold is exceeded, the probable name may be considered to certainly be the name and the implementation of the second decoding D2 may be inhibited for said radio station.

(23) It is furthermore specified that the present invention is not limited to the examples described above, and is open to variants that will appear obvious to those skilled in the art.