Use of a Variable Wordlength Technique in an OFDM Receiver to Reduce Energy Dissipation
Shingo Yoshizawa, Yoshikazu Miyanaga · IEEE Transactions on Circuits and Systems I Regular Papers · 2008
Wordlength determination is an indispensable task in digital hardware implementations of signal processing algorithms because the wordlength affects power consumption and system performance. There is a tradeoff between power consumption and system performance when searching for the optimum wordlength. We have developed a technique of dynamically controlling the wordlength used in the signal processing algorithms of wireless orthogonal frequency-division multiplexing (OFDM) receivers. The receiver dynamically changes the wordlength on the basis of the conditions in the propagation environment while satisfying the user-required communication quality. That is, the system optimizes the wordlength while operating by sensing its own performance and gradually adjusting this wordlength to improve performance. Testing revealed that, for a packet error rate (PER) of 10-2, the application of this technique to an OFDM receiver reduces energy dissipation by 18.1%-30.2%.