Method for the transmission of digital signals in a mobile radio system.

The invention relates to be transferred to a method for transmitting digital signals in mobile radio systems with fixed and mobile stations, with a time slot raster, in the message telegrams on staggered in multiplexer array signal channels (burst), and wherein said according to the main patent P 36 07 890.5 of base station for each mobile station, information for controlling the burst phase is also transferred, which contains for each burst of the mobile station, the required phase position with respect to the frames transmitted from the base station in encoded form.

The TDMA technology (Time-Devison Multiple Access) has been developed especially for satellite radio. In her a plurality of transmission channels not like the FDMA technology by allocating broadcast frequencies, but through the allocation of time slots are formed. Doing, the many ground stations all have different de-distances from the satellite, its signal bursts so submit that they meet at the satellite transponder in the allotted time gaps. Since light moves the satellite into its geostationary orbit on a daily basis, a constant readjustment of the burst phase is also necessary after the initial access. This is easy to do with the satellite radio because the transponder of the satellite converts the entire frame of the bursts transmitted by the various ground stations only in a different frequency range and then sends back to Earth. Each ground station can thus receive not only intended for them bursts of the other ground stations, but also their own burst and thereby also regulate in the correct position.

In mobile communications, this is not possible, because the fixed station is not operating as a transponder, but sends the sent from each mobile station signals over the telephone network to the other party. So there is not for the mobile station as the satellite radio, the way to determine the caused by the movement of the vehicle deviation correct burst location. The skew can, depending on the distance of the mobile stations from the base station, assume considerable values.

The problem described above is solved according to the main patent in such a way that an information for controlling the burst phase is also transmitted from the base station for each mobile station for each burst of the mobile station, the required phase position with respect to the transmitted by the beacon frame in coded form contains.

Having a burst phase control is achieved such that the guard time between each burst of a frame can be substantially reduced, which leads to a significantly better utilization of the transmission capacity. According to this process with each burst toward mobile station information for controlling the burst phase also transferred, so that despite varying radio propagation time of the burst of the mobile station meets in the intended gap of the receiving frame of the base station. This is shown in a graph in FIG. 1 Here (top row) and mobile station (bottom row) is in the upper diagram a the interaction of base station reproduced for maximum signal propagation time, the lower diagram b of a minimum signal duration. However, since the radio propagation time can change very quickly by its passage through the dead spot -the signal then passes over distant Reflexionen-, must still an, albeit small guard time may be provided, because the control variable for the burst phase of the mobile station Always next to the burst, ie can be communicated to a frame length and has now changed the term of the radio signal. This guard time is added to the representation of FIG. 1

The invention is based is to improve the subject of the main patent to the effect that a further reduction in the protection time is achieved on the object.

This object is achieved according to the invention in such a way that the controlled variable obtained from the co-transmitted from the base station to the mobile station information as compared with the stored control quantity of or the previous burst and from the rate of change of the term is calculated, each having a predictive correction variable for the next rule information provides.

In an advantageous embodiment of the subject invention provides that the prediction is carried out from two successive measured values, only the slope of the delay variation is used for the prediction.

An improved calculation is achieved in that the predictive correction variable is calculated with three successive measurement values, whereby the curvature of the run-time fluctuation curve enters the prediction.

Further illustrate the subject invention is a graphical representation of Figure 2, in which the signal propagation time is plotted against the time t. The curve shows a slightly curved profile. The distances on the time axis represent the burst intervals or the frame length. In the figure, the case is indicated in which no prediction is taking place (the horizontal distance from the time t2 to t3), and the case with a linear prediction (intersection of the tangent to the signal transit time curve) at the time t2 with a time line at time t3, which therefore the slope of the delay variation is used for prediction.