Title :
Doppler diversity and turbo coded CDMA
Author :
Rimbert, Michael F. ; Hombs, Brandon P. ; Nagaraj, Santosh V.
Author_Institution :
Sch. of Electr. & Comput. Eng., Purdue Univ., West Lafayette, IN, USA
Abstract :
In this paper, we track the performance of the turbo decoder as a function of the diversity order achieved by the 2D RAKE receiver and the number of MAP iterations performed by the turbo decoder. In particular, we show the benefits of utilizing Doppler diversity in addition to multipath diversity in CDMA systems. Simulations around the waterfall region of the turbo code show gains ranging from 1 dB to about 3.5 dB under different realistic channel conditions when Doppler diversity is exploited. Similarly, for a given BER, utilizing Doppler diversity is shown to reduce the number of MAP iterations required by a factor of approximately 2.
Keywords :
Doppler effect; code division multiple access; diversity reception; error correction codes; fading channels; maximum likelihood decoding; mobile radio; multipath channels; radio receivers; turbo codes; 1 to 3.5 dB; 2D RAKE receiver; BER; Doppler diversity; MAP iteration number; diversity order; error control codes; fast fading channels; mobile user; multipath diversity; turbo code waterfall region; turbo coded CDMA; turbo decoder; Delay; Diversity reception; Error correction; Fading; Frequency diversity; Multiaccess communication; Multipath channels; RAKE receivers; Signal resolution; Turbo codes;
Conference_Titel :
Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th
Print_ISBN :
0-7803-8521-7
DOI :
10.1109/VETECF.2004.1400341
