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Modular spectrum utilization for next-generation fixed transmission networks

University of British Columbia

Internet application and mobile service demands have continuously driven the need for increased data rates throughout global communication networks. One bottleneck of global network capacity is the backhaul network, which is responsible for connecting intermediate links throughout the core network. The backhaul network is commonly established either via high capacity optical fibre lines or low cost fixed microwave wireless antennas. Due to their low cost, microwave links are currently used for over 50% of the world's backhaul networks, as opposed to optical fibre connections. However, these links must follow strict regulation on the wireless bandwidths and pulse shapes they are allowed to occupy. The goal of this thesis is to improve the spectral efficiency within a transmission channel's regulated pulse shapes. The spectrum regions we intend to utilize are the sidebands outside the primary pulse, or spectrum "skirts''. While these skirts are commonly intended for adjacent channel usage, it has been shown that they typically go unused. We investigate two modular methods to take advantage of these unused sidebands, a superposition and multi-carrier approach. While the first method overlaps a primary and secondary pulse in the time domain, the other places the pulses adjacent to one another in the frequency domain. The superposition method must deal with the interference caused by overlapping pulse shapes. Simulations show that the primary stream cancellation is essential to this system's performance. The multi-carrier method requires custom pulse shapes that fit under the spectrum mask to match performance. Simulation results demonstrate that without phase noise impairments, the superposition scheme yields the highest performance. However when transmitting with phase noise, the multi-carrier scheme is predicted to transmit the most data under practical channel conditions.

Text

2020-08-12

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/75502

Electrical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/