Energy-scalable OFDM transmitter design and control

Orthogonal frequency division multiplexing (OFDM) is the modulation of choice for broadband wireless communications. Unfortunately, it comes at the cost of a very low energy efficiency of the analog transmitter. Numerous circuit-level and signal processing techniques have been proposed to improve that energy efficiency. However more disruptive improvement can be achieved at system-level, capitalizing on energy-scalable design and circuit reconfiguration to match the user requirements and operation environment. We describe the design of such an energy-scalable reconfigurable transmitter as well as its control strategy. Based on measurement carried out on the physical realization of this transmitter, the benefit of system-level energy management is shown. Energy-efficiency scalability ranges over 30%, which translates in an average system-level energy improvement of up to 40% compared to a non-scalable system.