Title :
Optimum and suboptimum multiuser detection for diversity combining in DS/CDMA systems
Author :
Damnjanovic, Jelena ; Vojcic, Branimir
Author_Institution :
Dept. of Electr. & Comput. Eng., George Washington Univ., DC, USA
Abstract :
In this paper we propose joint multiuser detection and packet combining in conjunction with an error control retransmission protocol to improve throughput in multiuser communications. Multiuser detection utilizes advanced signal processing techniques to demodulate the user´s data by exploiting the structure of multiuser interference. Packet combining is an enhancement of the standard automatic repeat request protocol, whereby the erroneous packets are not discarded but preserved and combined with retransmitted ones to improve new decisions. Three schemes - optimum detection of combined packets and two suboptimum multiuser detection schemes - are suggested. Using the Markov chain theory we present a method for throughput calculation. It is shown that the obtained theoretical values closely agree with the simulation results. The proposed packet combining with multiuser detection is an adaptive scheme with considerably improved robustness and capacity.
Keywords :
Markov processes; adaptive signal detection; automatic repeat request; channel capacity; code division multiple access; data communication; demodulation; diversity reception; error correction codes; military communication; mobile radio; multiuser channels; optimisation; packet switching; protocols; spread spectrum communication; DS/CDMA systems; Markov chain theory; adaptive scheme; advanced signal processing; automatic repeat request protocol; capacity; diversity combining; error control retransmission protocol; joint multiuser detection; military communication; multiuser interference; optimum multiuser detection; packet combining; robustness; suboptimum schemes; throughput calculation; user data demodulation; Automatic repeat request; Diversity reception; Error correction; Interference; Multiaccess communication; Multiuser detection; Protocols; Robustness; Signal processing; Throughput;
Conference_Titel :
Military Communications Conference, 2001. MILCOM 2001. Communications for Network-Centric Operations: Creating the Information Force. IEEE
Print_ISBN :
0-7803-7225-5
DOI :
10.1109/MILCOM.2001.986014
