Applying LDPC Codes to the GPRS

Inhalt:
For GPRS the well-known convolutional code is currently used as a Forward Error Correction (FEC) mechanism, and the Viterbi algorithm for decoding. With the recent introduction of Multimedia Broadcast Multicast Services (MBMS), new applications that require more bandwidth and reliability are foreseen. It is known that the current GPRS system does not perform well enough without further modifications, therefore, more efficient information distribution schemes need to be considered. To meet these increased requirements, especially for MBMS, we study the introduction of carefully designed LDPC codes at the physical layer. To exploit the full benefit of the superior performance of LDPC codes for longer streams in MBMS, a modification in the GPRS protocol stack is proposed where larger RLC/MAC blocks are allowed, and its impact on the existing GPRS protocol stack is minimized.