Title :
Application of MMSE multi-user detection to CDMA unslotted ALOHA system
Author :
Okada, Hiraku ; Grant, Peter M. ; Band, Ian W. ; Ogawa, Akira
Author_Institution :
Center for Inf. Media Studies, Nagoya Univ., Japan
Abstract :
A CDMA unslotted ALOHA system using MMSE multi-user detection is proposed. In the CDMA unslotted ALOHA system, a user station can transmit a packet asynchronously, and so the number of simultaneously transmitted packets fluctuates moment by moment. This fluctuation affects the performance of the MMSE multi-user detection. At first, we employ the Wiener filter detector assuming perfect information as an upper bound of the performance of the proposed system. Then, we apply an adaptive filter to CDMA unslotted ALOHA to compensate for the birth/death of a packet
Keywords :
FIR filters; Wiener filters; access protocols; adaptive filters; adaptive signal detection; code division multiple access; filtering theory; least mean squares methods; multiuser channels; packet radio networks; CDMA unslotted ALOHA system; MMSE multi-user detection; Wiener filter detector; adaptive FIR filter; asynchronous packet transmission; packet birth/death compensation; packet communication system; perfect information; performance; upper bound; user station; wireless data communications; Adaptive filters; Binary phase shift keying; Finite impulse response filter; Fluctuations; Multiaccess communication; Multiple access interference; Multiuser detection; Throughput; Upper bound; Wiener filter;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2000. PIMRC 2000. The 11th IEEE International Symposium on
Conference_Location :
London
Print_ISBN :
0-7803-6463-5
DOI :
10.1109/PIMRC.2000.881480
