Analysis of Novel Low Complexity Direct-Sequence Spread Spectrum Receiver

This work presents design issues encountered in a DS-SS receiver that need to operate upon a wide Doppler band- width. The computational complexities of the conventional archi- tectures using either correlator or match filter are studied. The proposed architecture address the carrier acquisition complexity and we show that even with higher ppm crystal oscillators, the current design can efficiently acquire and track frequency errors. This solution exploits the line spectral property of DS-SS signal properly. The correlation property of the Gold codes are analyzed for fractional upsampling and used for reducing the computation complexity of the receiver, and gives more design margin in terms of selecting the sampling frequency. Intentional aliasing from the IF selection gives improved performance in terms of acquisition time with negligible degradation in performance. The BER and computation complexity of the proposed receiver presented along with the conventional design, to bring out the efficiency of this work.