This paper proposes Coherent-HYBrid Direct-Sequence Fast-Frequency-Hopping (CHYB-DS-FFH) CDMA with Adaptive Interference Cancelling (AIC) for cellular mobile communications. The features of CHYB-DS-FFH are symbol-by-symbol frequency diversity and low chip-rate DS multiplexing; both of which are based on a coherent FFH modulation and demodulation scheme. The combination of coherent FFH, space diversity, and AIC is very effective for reducing the performance degradation due to interference. Computer simulations demonstrate BER performance of a 2 hop 500-kHz-interval frequency hopping system using (i) a linear canceller or (ii) a nonlinear canceller. Both systems employ the two branch space diversity reception of 10 kb/s QPSK with FFH over a 1 MHz system bandwidth. In quasi-static channels, the average BER performance is 10-2 with average Eb/No less than 8 dB. In dynamic fading channels under full interference conditions, CHYB-DS-FFH with the linear adaptive interference canceller realizes a BER of 10-2 at the average Eb/No of 15 dB with maximum Doppler frequency fD of 5 Hz, whereas CHYB-DS-FFH with the non-linear adaptive interference canceller achieves the same BER at the average Eb/No of 15 dB with fD equal to 30 Hz.
|Number of pages||9|
|Journal||IEICE Transactions on Communications|
|Publication status||Published - May 1 1994|
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering