Introduction

The millimeter wave spectrum has been identified as a candidate of choice to support multi-gigabit/s data transmissions. The increasing interest of recent years has pushed the regulatory agencies to provide new opportunities for unlicensed spectrum usage with fewer restrictions on radio parameters. In order to provide more flexibility in spectrum sharing, the FCC introduced an opening of 7 GHz unlicensed spectrum at millimeter wave frequencies around 60 GHz, from 57 to 64 GHz.

As known, in the case of comparable bandwidths and data-rates, an important advantage of using millimeter wave frequencies instead of microwave ones is the reduced ratio between the bandwidth and the central frequency, leading the way to transceiver simplicity. In addition, compared to microwave frequencies, the strong signal attenuation at 60 GHz allows an efficient reuse. This helps to create small indoor cells for hot spot secure wireless communications. This spectrum is suitable for multi-gigabit/s wireless communication systems, which could be home or office high-speed wireless networking and entertainment, such as extremely fast downloading of files via wireless Gigabit Ethernet, and wireless High Definition Multimedia Interface (HDMI).