Practical out-of-band interference reduction for OFDM systems

Orthogonal frequency-division multiplexing (OFDM) systems suffers from large out-of-band (OOB) emissions caused by high sidelobes of the modulated subcarriers. In the literature, performing considerable OOB emissions reduction at all frequencies in the OOB regions can be done at the expense of wasting the available resources drastically. In this paper, we introduce the idea of combining two efficient OOB emissions reduction techniques (the shaping and the advanced cancellation carriers (ACC)). These two techniques are chosen to enable considerable reduction at all frequencies in the OOB regions while at the same time to utilize the available resources. Also, these techniques do not require performing complex optimizations (which is essential for practical implementations). The proposed combination is implemented in a software defined radio and tested for over-the-air transmissions.