Methods and devices for transmission of signals in a telecommunication system

Abstract

Methods and devices for generating and receiving a training sequence in a radio communication network for a user sharing the same transmission slot with other users is provided where multiple users are multiplexed in the same time slot. A first, original, bit sequence, is repeated and a cyclic prefix and a cyclic postfix is added to the repeated bit sequence thereby forming the training sequence for the user.

The invention claimed is:  
     
       1. A method of generating a training sequence in a radio communication network for a user sharing a transmission slot with other users, where multiple users are multiplexed in the time slot, the method comprising, in a transmitter device:
 repeating one or more times a first, original, bit sequence; and 
 adding a cyclic prefix and a cyclic postfix to the repeated bit sequence, thereby forming the training sequence for the user, wherein the bits in some sub-blocks of the repeated bit sequence are bit flipped, wherein the flipped bits are user specific. 
 
     
     
       2. The method of  claim 1 , wherein the repeated bit sequence is repeated a number of times corresponding to a number of users in the time slot. 
     
     
       3. The method of  claim 1 , wherein the sub-blocks correspond to the original bit sequence. 
     
     
       4. The method of  claim 1 , further comprising formatting a burst to be transmitted by adding other bits in a predetermined order to the training sequence for the user. 
     
     
       5. The method of  claim 4 , wherein said other bits comprise one or many of tail bits, guard bits, and user specific payload bits. 
     
     
       6. The method of  claim 5 , wherein the burst is formatted by adding GSM (Global System for Mobile Communication) guard bits at the beginning, followed by tail bits, followed by a first half of the payload, then training sequence bits for the user are added, followed by a second half of the payload bits followed by more tail bits and guard bits. 
     
     
       7. The method of  claim 4 , further comprising feeding the burst to a modulator. 
     
     
       8. The method of  claim 7 , wherein the modulator is a Continuous Phase Modulator (CPM) modulator. 
     
     
       9. The method of  claim 8 , wherein the modulator is a GMSK modulator. 
     
     
       10. The method of  claim 7 , further comprising rotating an output signal from the modulator with a user specific rotation angle. 
     
     
       11. A method of blind detection of a received GSM radio signal, the method comprising:
 determining whether the received GSM radio signal includes a training sequence for user sharing a transmission slot with other users, wherein a positive result for the determination occurs only when the controller circuitry detects a cyclic prefix and a cyclic postfix of a repeated bit sequence within the received GSM radio signal, wherein in the repeated bit sequence bits in some sub-blocks of the repeated bit sequence are bit flipped, wherein the flipped bits are user specific; and 
 detecting the received GSM radio signal as a single layer EGPRS/EGPRS2 when the determination does not yield the positive result and to detect the received GSM radio signal as a multilayer (MIMO/MU-MIMO) signal when the determination yields the positive result. 
 
     
     
       12. A device for generating a training sequence in a radio communication network for a user sharing a transmission slot with other users, where multiple users are multiplexed in the time slot, the device comprising controller circuitry configured to:
 repeat one or more times a first, original, bit sequence, and 
 a cyclic prefix and a cyclic postfix to the repeated bit sequence, thereby forming the training sequence for the user, wherein the controller circuitry is adapted to bit flip the bits in some sub-blocks of the repeated bit sequence, wherein the flipped bits are user specific. 
 
     
     
       13. The device of  claim 12 , wherein the controller circuitry is adapted to repeat the repeated bit sequence a number of times corresponding to a number of users in the time slot. 
     
     
       14. The device of  claim 12 , wherein the sub-blocks correspond to the original bit sequence. 
     
     
       15. The device of  claim 12 , wherein the controller circuitry is adapted to format a burst to be transmitted by adding other bits in a predetermined order to the training sequence for the user. 
     
     
       16. The device of  claim 15 , wherein said other bits comprise one or many of tail bits, guard bits, and user specific payload bits. 
     
     
       17. The device of  claim 16 , wherein the controller circuitry is adapted to format the burst by adding GSM (Global System for Mobile Communication) guard bits at the beginning, followed by tail bits, followed by a first half of the payload, then training sequence bits for the user are added, followed by a second half of the payload bits followed by more tail bits and guard bits. 
     
     
       18. The device of  claim 15 , further comprising a modulator adapted to receive the formatted burst. 
     
     
       19. The device of  claim 18 , wherein the modulator is a Continuous Phase Modulator (CPM) modulator. 
     
     
       20. The device of  claim 19 , wherein the modulator is a GMSK modulator. 
     
     
       21. The device of  claim 18 , further comprising a rotator for rotating an output signal from the modulator with a user specific rotation angle. 
     
     
       22. A device for blind detection of a received GSM radio signal, the device comprising:
 controller circuitry adapted to determine whether the received GSM radio signal includes a training sequence for user sharing a transmission slot with other users, wherein a positive result for the determination occurs only when the controller circuitry detects a cyclic prefix and a cyclic postfix of a repeated bit sequence within the received GSM radio signal, wherein in the repeated bit sequence bits in some sub-blocks of the repeated bit sequence are bit flipped, wherein the flipped bits are user specific; and 
 controller circuitry adapted to detect the received GSM radio signal as a single layer EGPRS/EGPRS2 when the determination does not yield the positive result and to detect the received GSM radio signal as a multilayer (MIMO/MU-MIMO) signal when the determination yields the positive result.