Coherent accumulation by using sequence shifting and genetic algorithm

We propose to eliminate the random phases in the coherent accumulation by shifting the sampling sequences of the accumulation pulses. Because there is a certain phase difference between the adjacent two samples of analog-to-digital converter (ADC) for a heterodyne signal, the random phases may be eliminated in the sum of these sequences shifted with different steps. Genetic Algorithm (GA) is used to determine the appropriate shifting steps of each sequence. Numerical calculations confirm that the combination of GA and our method is effective to increase the coherence of the accumulation pulses. Thereby, the signal-to-noise ratio (SNR) can be increased notably. These random phases both in transmitter and reception can be eliminated by our approach, which make it has great advantage compared with the existing technologies. Our approach can be realized in a conventional microcontroller unit (MCU). Without the need of reserving the random phase by sampling the transmitter pulse, our approach is easier to realize in practice.