Abstract
In this paper, we present a method of reducing the effect of switching noise generated from the switching power supply using a GaN (gallium nitride) device for controlling industrial equipment communication signal. We point out the noise power with its peak at the resonance frequency determined by the parasitic impedance and circuit constants. We propose a contorted communication timing where the guard interval of the communication signal and the switching noise are overlapping. Then, we propose to select the dedicated LLR (log-likelihood ratio) calculation instantaneously when the switching noise overlaps the guard interval of the communication signal in the proposed timing. Using the proposed contorted communication timing, we have improved the SNR (signal-to-noise ratio) vs BER (bit error rate) from 1.0×10-1 to 2.5×10-2 at the SNR of 20[dB]. In addition using the proposed LLR calculation method, the SNR vs BER is improved by more than 5 [dB] while the SNR vs PER(packet error ratio) is improved by 10[dB] at the SNR of 20[dB].
