Analytical and comparative investigation of 60 GHz wireless channels

This work analytically investigates the wireless channel characteristics at 60 GHz in five aspects: path loss on the range of a wireless communication system, multi-path fading, spatial diversity, high peak-to-average power ratio of orthogonal frequency division multiplexing (OFDM), and detection time of clear channel assessment. The analysis is conducted in comparison to the 2.4 GHz system. The observations are summarized as follows: the 60 GHz system experiences large path losses and can support only short range communications, approximately half of that at 2.4 GHz. However, it suffers lightly from multi-path fading due to its small average fade duration. Because of the short wave length, the 60 GHz communication can support packing a large number of antennas at a transceiver to exploit spatial diversity that can significantly boost the transmit or receive gains. One problem of 60 GHz in using OFDM to avoid frequency selective fading on its wide bandwidth is high peak-to-average power ratio that increases the cost and complexity in implementing transceivers. Due to its wide bandwidth that hints to high symbol rate, the 60 GHz system can achieve a fast detection of signals in carrier sense.