Method and device for synchronizing a mobile radio receiver with a time slot structure of a received radio signal

1. A method for synchronizing a mobile radio receiver with a time slot structure of a radio signal obtained from a base station, the method which comprises:

in each of a plurality of time slots, using the base station to send out a time slot synchronization code sequence that is known in the mobile radio receiver, the time slot synchronization code sequence including a predetermined sequence of data elements; and

in the mobile radio receiver:

dividing the period corresponding to the one time slot synchronization code sequence into two or more time intervals, each time interval containing a portion of the time slot synchronization code sequence;

during a first time slot period, detecting a first portion of the time slot synchronization code sequence,

obtaining a first result by correlating the first portion of the time slot synchronization code sequence that is detected with a known time slot synchronization code sequence,

during a second time slot period, detecting a second portion of the time slot synchronization code sequence,

obtaining a second result by correlating the second portion of the time slot synchronization code sequence that is detected with the known time slot synchronization code sequence, and determining a time slot position in time from the first result and the second result.

2. The method according to claim 1 , which comprises:

during the first time slot period and during the second time slot period, detecting a plurality of portions of the time slot synchronization code sequence, respectively, and correlating the plurality of the portions of the time slot synchronization code sequence with the known time slot synchronization code sequence.

3. The method according to claim 1 , which comprises:

overwriting a memory content of a given data memory to store the portion of the time slot synchronization code sequence of the second time slot period.

4. The method according to claim 1 , which comprises:

defining the time slot synchronization code sequence as a first time slot synchronization code sequence;

after each one of a plurality of recursion periods of K time slot periods:

detecting a first portion of a second time slot synchronization code sequence that is sent out by the base station, the second time slot synchronization code sequence being identical to the first time slot synchronization code sequence,

obtaining a first additional result by correlating the first portion of the second time slot synchronization code sequence with the known time slot synchronization code sequence,

detecting a second portion of the second time slot synchronization code sequence, and

obtaining a second additional result by correlating the second portion of the second time slot synchronization code sequence with the known time slot synchronization code sequence;

obtaining a first integration result by integrating each first additional result obtained over the plurality of the recursion periods;

obtaining a second integration result by integrating each second additional result obtained over the plurality of the recursion periods; and

using the first integration result and the second integration result to perform the step of determining the time slot position in time.

5. The method according to claim 1 , which comprises:

compressing the first result and the second result to obtain a compressed first result and a compressed second result; and

performing the step of determining the time slot position in time by using the compressed first result and the compressed second result.

6. A device for synchronizing a mobile radio receiver with a base station sending out a time slot synchronization code sequence in each one of a plurality of time slots of a radio signal, the time slot synchronization code sequence including a predetermined sequence of data elements, the time slot synchronization code sequence defining a known time slot synchronization code sequence that is known in the mobile radio receiver, the device being configured in the mobile radio receiver and comprising:

a data memory for storing one or multiple detected portions of the time slot synchronization code sequence;

a correlator for obtaining correlation results by correlating individual ones of the detected portions of the time slot synchronization code sequence, which are stored in said data memory, with the known time slot synchronization code sequence; and

a time slot position determining device for using the correlation results to determine a position of a time slot structure in time of the radio signal obtained from the base station.

7. The device according to claim 6 , wherein said data memory has a memory size that essentially corresponds to a data volume contained in one of the detected portions of the time slot synchronization code sequence.