Title :
A diversity combining DS/CDMA system with convolutional encoding and Viterbi decoding
Author :
Souissi, Slim ; Wicker, Stephen B.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
fDate :
5/1/1995 12:00:00 AM
Abstract :
Averaged diversity combining is applied to an asynchronous DS/CDMA system using convolutional encoding and Viterbi decoding. A cyclic redundancy check (CRC) code is included in the scheme to trigger retransmission requests. Multiple received packets are combined on a bit by bit basis to form a single, more reliable packet. The error correcting decoder operates on the combined packet, as opposed to the most recently received individual packet (e.g., as in a type-I hybrid ARQ protocol), substantially increasing the probability of acceptance with each additional transmission. We show that the proposed technique allows a significant increase in the CDMA system capacity, throughput, and reliability
Keywords :
Gaussian channels; Viterbi decoding; automatic repeat request; code division multiple access; convolutional codes; cyclic codes; diversity reception; error correction codes; error statistics; fading; land mobile radio; packet radio networks; probability; pseudonoise codes; spread spectrum communication; telecommunication network reliability; AWGN channel; CDMA system capacity; CRC code; Viterbi decoding; acceptance probability; adaptive ARQ protocol; asynchronous DS/CDMA system; averaged diversity combining; bit error probability; convolutional encoding; cyclic redundancy check; error correcting decoder; fading channels; mobile radio; packet radio network; reliability; retransmission requests; system performance; throughput; Automatic repeat request; Convolutional codes; Cyclic redundancy check; Cyclic redundancy check codes; Decoding; Diversity reception; Encoding; Error correction; Multiaccess communication; Viterbi algorithm;
Journal_Title :
Vehicular Technology, IEEE Transactions on
