Cooperative Power Optimization for Power-Limited Wireless Networks

Abstract

Due to the increasing demand for reliable networks with high data rates and communication services, energy optimization and lifetime maximization techniques are gaining a huge attention in order to contribute in establishing energy efficient communication networks. In this thesis we present a novel metric to compare the computational complexity and their associate power consumption of various digital signal processing (DSP) algorithms used in wireless communications systems. The proposed metric makes the comparison and trade-offs between different algorithms implementation becomes feasible and more informative. The operations considered in this work are addition, subtraction, multiplication and division, all implemented for different number of operations and operating frequencies. The obtained results show that the power consumption of such operations is approximately linear as a function of the number of operations and operating frequencies. Moreover, the relative power of the subtraction, multiplication and division with respect to the addition is equal to 1.09, 3.92 and 222.79, respectively in the FPGA technology, while the relative power for multiplication and division in ASIC technology were found to be 3.1 and 10.9 respectively. The obtained results are used to evaluate the computational power of several signal processing algorithms in wireless receivers. On the other hand, a novel lifetime maximization algorithm for certain wireless networks that perform hybrid Automatic Repeat Request with Chase Combining (ARQ-CC) is proposed. This technique is based on maximizing the network lifetime by considering the energy difference between two communicating nodes and optimizing the number of retransmissions . The system was simulated for different maximum retransmission values ranging from 3 to 5 and for different processing energy per bit values; 10−4, 10−5 and 10−6J. The obtained results show that the proposed system improves the lifetime when the energy ratio between the two nodes is greater than 2 Et Ep , where Et is the transmit energy per bit and Ep is the processing energy per bit, while for smaller ratios, it gives the same lifetime value compared to the system where retransmissions occur based on erroneous packets only.

Date of Award	Oct 2017
Original language	American English
Supervisor	Arafat Aldweik (Supervisor)