A frequency offset compensation method for ultra narrowband digital wireless modems
Young‐Jun Chong, Sungjin You, Min-Soo Kang, Myung-Sun Song, Seung‐Hyeub Oh · 2005
We evaluate the performance of the digital modulation schemes described in the APCO Project 25 FDMA specifications which can be used for applying the ultra-narrowband technology to the simple two-way radio systems, and discuss difficulties in the DSP implementation of the systems. We analyze the effect on the systems' BER performance of the frequency-offset between the transmitter and receiver oscillators. And we present a frequency offset compensation method for improving the system performance. With the frequency offset compensation method implemented in the systems using DSP, the Eb/No performance degradation of about 1.0 dB was occurred at the BER of 10/sup -3 /for 10 % of frequency offset.