Power Optimal Non-contiguous Spectrum Access in Multi Front End Radio Enabled Point-to-Point Link

TL;DR

This paper investigates power-efficient spectrum access in multi-front end radios using NC-OFDM, formulating an optimization problem to minimize total system power through power control and scheduling.

Contribution

It introduces a novel optimization framework for power minimization in multi-front end NC-OFDM systems, including a greedy algorithm for practical implementation.

Findings

The proposed algorithm effectively reduces system power consumption.

Optimal spectrum fragmentation balances circuit and transmit power.

The approach outperforms baseline methods in power efficiency.

Abstract

Non-contiguous spectrum chunks allow wireless links to flexibly access a wide amount of bandwidth. Multi- Channel Multi-Radio (MC-MR) and Non-Contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) are the two commercially viable strategies to access non-contiguous spectrum chunks. MC-MR accesses multiple non-contiguous chunks by activating multiple front ends which, in turn, increases the circuit power consumption of each of the activated front ends. NC-OFDM accesses non-contiguous spectrum chunks with a single front end by nulling remaining subchannels but increases spectrum span which, in turn, increases the power consumption of ADC and DAC. This work focuses on a point-to-point link where transmitter and receiver have multiple front ends and can employ NC-OFDM technology. We investigate optimal spectrum fragmentation in each front end from a system power (summation of transmit power and circuit power) perspective. We formulate a mixed integer non-linear program (MINLP) to perform power control and scheduling, and minimize system power by providing a greedy algorithm (O(M^3 I)) where M and I denote the number of channels and radio front ends respectively.