We address the application and design of low-density parity-check (LDPC) codes to enhance the General Packet Radio Service (GPRS) system in order to support services such as the Multimedia Broadcast Multicast Service (MBMS). Advances in coding theory and further reduction in integrated circuit size have promoted LDPC codes to become one of the most attractive forward error correction (FEC) technologies in practice. The GPRS as well as enhanced GPRS (EGPRS) system currently uses the well-known convolutional code (CC) as an FEC mechanism, and the Viterbi algorithm for decoding. With the recent introduction of MBMS, new applications that require more bandwidth and reliability are foreseen. It is known that the current (E)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 large data block lengths, 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 minimised.
['Fakheredine Keyrouz', 'Wen Xu']
GPRS system enhancement by employing LDPC codes