Wireless technologies are an essential communication means that transform a branched localized fixed meshwork into a ubiquitous disconnected network. A clear trend shows that cells are becoming smaller, homogeneously distributed, operating at higher carrier frequencies, and more energy conscious. This points toward wireless picocell systems that implement millimeter-wave (mm-wave) modulation. In this work various techniques are proposed, which are oriented to specific traits of the 60-GHz mm-wave band. Two techniques oriented to solve physical and data-link layer issues are proposed. Single carrier frequency division multiple access (SC-FDMA) is proposed as the technology to be implemented at the physical layer, and a variable slot time multiplexing access technique, called variable slot time-time division multiple access (VST-TDMA), with a conscious energy-conservation protocol, is proposed for the data-link (MAC) layer. SC-FDMA with pulse shaping is implemented to minimize the peak-to-average power ratio of the system, which reduces energy consumption. The multiplexing access technique takes advantage of the reduced cell size by multiplexing data in the time domain, this allows the reduced number of users to utilize the entire available bandwidth. Incorporated into the access protocol is the option of energy pacing or even self-sustainability if an energy harvesting device is present. Self-sustainability can be achieved at the cost off throughput, some techniques are discussed to relieve this trade-off condition. Also, a thorough discussion is included on battery energy depletion, even with an energy harvesting device present, to further increase the throughput performance. Since using SC-FDMA reduces the energy consumption, it enables VST-TDMA to operate at higher speeds under self-sustainability mode. Overall the proposed set of solutions showed independently significant improvements to the system. It is also discussed how these techniques coalesce conveniently by working in unison, improving the energy efficiency and throughput capabilities of 60-GHz systems.
['Claudio Estevez', 'Cesar Azurdia']
Bottom-layer solutions for 60 GHz millimeter-wave wireless networks: modulation and multiplexing access techniques