Experimental evaluation of coherent RAKE receiver for broadband DS-CDMA mobile radio
Takehiro Ikeda, K. Okawa, Mamoru Sawahashi, Fumiyuki Adachi · 2002
This paper experimentally evaluates the bit error rate (BER) performance of single-carrier broadband DS-CDMA (B-CDMA) access scheme using a 100 MHz bandwidth in multipath fading channels. The achievable information bit rate is 20.36 (2.5) Mbps when the spreading factor (SF) is SF=4 (32). In order to achieve a high data-rate transmission with high quality (i.e., average BER is below 10/sup -6/), we apply pilot symbol-assisted coherent RAKE receiving with a large number of RAKE fingers (maximum number of RAKE fingers is SF/spl times/2), 2-branch antenna diversity reception, convolutional coding, and signal-to-interference power ratio (SIR) measurement-based fast closed-loop transmit power control (TPC). Experimental results show that the average BER of 10/sup -6/ of 20.36 (2.5) Mbps transmission is achieved at the required average transmit E/sub B//N/sub 0/ of approximately 6.7 (5.0) dB when the number of multipaths is L=2 and the maximum fading Doppler frequency is f/sub D/=20 Hz. We also show that the RAKE path diversity effectively works in a broadband propagation channel where many resolvable paths (such as 12 paths) are observed.