A wide-range frequency offset tolerant OFDM for in-vehicle PLC system

摘要

In this paper, a wide-range frequency offset tolerant OFDM for in-vehicle PLC system is presented. The carrier frequency and a new short frame OFDM suitable for low latency sensor network are discussed by analyzing the noise immunity, electrical emission characteristics and the channel property. We propose a new lookup table based estimation method of carrier frequency offset (CFO) and sampling frequency offset (SFO). The estimator adaptively controls time delay of autocorrelation, loop filter and gain depending on an estimated CFO in order to realize wide-range cancellation and fast-tracking of CFO and SFO. The simulation results show BER ≤ 10-8 with carrier to noise ratio (CNR) ≥ 12 dB with a data rate of 12 Mbps and a coding rate of 1/2. CFO/SFO with ±1000ppm reference frequency offset are cancelled within 30 ms.