Method for selecting a broadcast programme.

p0001The invention relates to a method for calling a broadcast program in the mobile radio receivers, the information received and processed by the Radio Data System can and storage facility for storing data relating to the receiving frequency and RDS data feature.

p0002The Radio Data System (RDS) data is transmitted in the FM broadcast, which also convey to the listener the broadcast radio program information. This additional information should serve the listener to facilitate the tuning process. To this end, data is transmitted, indicating the program name, so that the receiver will not only have to listen for a certain time or must look in a frequency table, in order to know what program he has set. Great benefits for the reception in car radio has the vibe of an AF list. This list of broadcasting frequencies on which the same program is broadcast, as on the tuned frequency.

p0003In addition to the AF-list will each have a PI code which is a code for identifying the program broadcast. Each program is assigned a PI code, so that it is possible by reviewing this code to determine whether a change in the tuning the same program is received again.

p0004In the German Offenlegungsschrift DE-OS 37 25 487 describes a process is described, which relates to the evaluation of the transmitted to the Radio Data System information.

p0005After this process, the AF-code and / or the PI code to be evaluated, so that it is determined to which alternative transmission frequencies, the program signal of the current receiving frequency to be received yet.

p0006Furthermore, the alternative transmission frequencies are determined by evaluating the AF codes and the PI code, which is then matched briefly and checked on reception quality. Thereafter, the frequency is set with the best reception quality. Furthermore a method is described, which indicates the extraction of criteria for determining the reception quality. The receiver tuning is then performed in accordance with the reception quality.

p0007In the German Offenlegungsschrift DE-OS 38 32 455 describes a process, with which the change is to be performed by a frequency of a program to a better receivable frequency of the same program when the receiving quality is no longer sufficient at the first frequency to the to process RDS data. The change takes place here in the state of waiting for an interrupt which is signaled by a traffic announcement announcement code.

p0008In the patent application with the file reference P 3928828.5 the applicant an RDS radio receiver is described that takes into account when checking the alternative frequencies that are stored in a memory or included in the received RDS data, including those for which regional identifier, ie second place the PI code, is different from the currently received if no station is receivable with the same PI code. In this manner is switched in case of loss of a regional program chain to another program a national program chain, if you go from a regional area to another.

p0009In the known prior art, alternative frequencies during reception or polling program checks whose PI code is the same or only in the second place, that the region code is different. If such an alternative frequency is found, the receiver is tuned on, otherwise start a search.

p0010When stored individual stations without alternative frequencies or in a poor reception area, ie, when no or few alternative frequencies exist, it can occur in mobile operation, however, that when a subroutine call, the received signal due to the current unfavorable location of the receiver is not RDS-capable. Since no alternative frequencies are available, a search would be started and tuned to a frequency that is may be undesirable for the user by the known methods.

p0011It is therefore an object of the invention to provide a strategy for a program call, wherein the fetched receiving frequency is set for a specific time and then remains, if due to the currently poor reception location after a previously unknown prior art, a channel search will start.

p0012This object is achieved by a rank is assigned to the program call when checking the alternative frequencies that are included in the station memory, each frequency, which is dependent on the identity of the PI code and the reception quality. When the reception quality, the RDS quality (error-free code detection) and the RF reception quality such as multipath, received signal strength and the transmitter center, checked. If no frequency is of sufficient RDS quality found, that is, when the error rate in decoding the RDS data exceeds an allowable limit, the frequency is set with the highest field strength, provided that is closed from the RF reception quality is adequate audio quality. The so-set frequency is set for a predeterminable time. Only when at this time no RDS identification is made, a search is started by the same program chain.

p0013In the present process the belonging to the program data is loaded into a memory in a program call. In memory then are the PI code, the alternative frequencies and the station name. When program call all stored frequencies are measured, evaluated by RF reception quality and possible RDS decoding is done. Ranked by coordinated briefly on each frequency. It is the PI code and the RF quality, in particular, examine the received signal strength, and the alternative frequency is stored with the review of the rank in the memory. The checking of the next frequency is carried out in the same manner, whereby the evaluation of the rank with the last or the previous best frequency is compared. The best frequency obtained contain a code that is required for subsequent tuning, and is stored into memory.

p0014The main memory is divided into several areas in order of precedence when placing the checked frequencies. Within each of the frequencies stored there by RF reception quality are rated.

p0015The ranks are ordered such that the conformity of the PI code of the retrieved program and the verified frequency of highest rank is assigned. The next step involves the frequency whose PI code is different in the second location. The field strongest frequency of this rank is set when all alternative frequencies that are stored in memory and all of which were checked, no frequency has been with the same PI code found.

p0016All frequencies at which no PI code identification was possible, get the third rank. If not checked the two frequency higher ranks could be assigned, the setting is a frequency from the last rank, provided at one of these frequencies sufficient audio quality, ie sufficiently good RF reception quality were measured. If this is the case at multiple frequencies, the best is selected.

p0017When selecting the best frequency without identification of the PI code can advantageously still a distinction between broadcasters be made which recognizable broadcast RDS data and stations, where no RDS data can be viewed with a transmitter and RDS station accepted is when two RDS data blocks are detected in sequence. In error-free identification of the PI code is omitted in this case.

p0018If a frequency of the last rank has been set, it remains for a predetermined time, eg 20 sec, is set. At this time an attempt is made to identify the PI code. If this fails, a search is started.

p0019With this type of Rangstufung in a program call a longer period is specified for the identification of individual saved stations. Thus, if done the program call just one place, available to the poor reception conditions, a search is started is not equal. If you continue a bit with the car, the reception situation can already be good and the set frequency are identified. It is done in this case no undesired tuning within the same program chain.

p0020As is shown in a program call in an RDS receiver, the station name on the display, is displayed in an advantageous embodiment of the invention, when adjusting a frequency without PI-code identification after a predetermined time instead of the station name, the set frequency because another might program can be set as the assigned the Pogrammspeicherplatz.