The impact of synthesizer transient response on OFDM radio receivers

Switching a wireless transceiver from a transmit to a receive mode or vice versa causes an initial jump in the frequency of local oscillator. The settling profile of the synthesizer loop would then impact the system performance by affecting the results of the acquisition algorithms performed at the beginning of each packet. Specifically, the frequency offset estimation algorithm may yield values which are highly biased. In this paper, we will investigate the transient behavior of the synthesizer on an OFDM communication system and obtain simulation results for different loop dynamic responses for a physical layer design based on IEEE 802.11 a standard for wireless local area network.