An Adaptive Hybrid FEC/ARQ Protocol Using Turbo Codes for Multi-Media Transmission of ATM over Wireless Networks
Abstract
This paper describes a type-II adaptive hybrid FEC/ARQ protocol using turbo codes for both voice and data services. Recently, a powerful family of error correcting codes using parallel concatenated convolutional codes is introduced. Near-Shannon-limit is achievable by such codes. For example, a bit error rate of 10(exp -5) can be achieved at E(sub 0)/N(sub 0) = 0.7 dB using a rate 1/2 code or at about 2.5 dB if fewer iterations are used in decoding. Given the promising performance of the codes, it is expected that the performance of an adaptive FEC/ARQ protocol employing turbo codes will be better than protocols using other error correcting codes. Rate compatible turbo codes are used in the protocol. Extra parity bits corresponding to a lower rate turbo code will be transmitted if the previous transmission leads to a decoding error. For real-time services, the number of retransmissions is limited to one so as to limit the delay. For data services, the number of retransmissions is unlimited to provide a reliable communication link. Results in terms of throughput are obtained for the adaptive FEC/ARQ protocol using compatible rate 1/2 and rate 1/4 turbo codes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADA442645
Entities
People
- Evaggelos A. Geraniotis
- Wai-chung Chan
Organizations
- University of Maryland