Optimum processing of QPSK signals for site diversity
Abstract
For satellite communications systems which use frequencies above 10 GHz, rain and clouds attenuate signals severely, leading to an increase in bit error rate (BER) in digital links. This may be coped with by using two or more receivers on the ground, spaced far enough apart to avoid simultaneous rain outages. In this paper, a BER-minimizing descision processor is derived for two receivers and QPSK modulation. In particular, it is applied to a linear attenuating transmission channel adding independent white Gaussian noise. It is found that gains of nearly 3 dB compared to a switched system are possible in down-link limited cases.
- Publication:
-
International Journal of Satellite Communications
- Pub Date:
- April 1991
- Bibcode:
- 1991IJSC....9...93S
- Keywords:
-
- Atmospheric Attenuation;
- Bit Error Rate;
- Phase Shift Keying;
- Reception Diversity;
- Satellite Communication;
- Channels (Data Transmission);
- Interference Immunity;
- Pulse Communication;
- Signal To Noise Ratios;
- Communications and Radar