Performance Comparison of QAM and ASK with Minimum Energy Coding in Phase Coded SSMA for Wireless Sensor Network

Source coding with spread spectrum technique for reducing multiple access interference (MAI) in phase coded SSMA for ASK and QAM in wireless sensor network has been presented in this paper. The source symbol is represented by modified minimum energy coding (MME) for both ASK and QAM. When each channel uses MME coding combined with phase coded SSMA the probability of error of multiple channels sending signals at the same time is lowered in QAM as compared to ASK, this implies that the MAI is reduced. It has been analysed that with the new low MAI with MME coding, signal to noise ratio significantly increases while error probability decreases in both ASK and QAM and no another differences is founded. Finally, a sensor network system is designed and simulated to verify the theoretical results and demonstrate the low MAI and low energy features of wireless sensor network.