60 GHz OFDM experimental system employing decision-directed phase noise compensation

This paper presents decision-directed phase noise compensation (DD-PNC) by digital signal processing for millimeter-wave 60 GHz OFDM systems, and verifies the effectiveness of DD-PNC by using a 60 GHz OFDM experimental system. 60 GHz frequency synthesizer implemented in single-chip RF-CMOS IC suffers from relatively large phase noise, which severely degrades performances of the OFDM transmission with multi-level QAM. In order to alleviate this impairment, this paper applies DD-PNC to the baseband (BB) demodulation processing which recursively estimates the phase noise and removes the estimate from the received signal. This paper also introduces the 60-GHz OFDM experimental system which consists of both a BB signal processing circuit including ADC and DAC and a commercial 60 GHz transceiver. Experimental results demonstrate that DD-PNC can drastically alleviate severe performance degradation of 2.96 Gbps OFDM/64QAM due to the phase noise of -80 dBc/Hz at 1 MHz offset.