Sidelobe Suppression in Ofdm Systems

In this contribution, we develop a method for reducing out-of-band emission caused by high sidelobes in OFDM systems. The method is termed multiple-choice sequences (MCS) and operates in the frequency domain of an OFDM system. The principle of MCS is to map the original transmission sequence onto a set of sequences and to choose, from this set, a sequence with the lowest power in sidelobes for the actual transmission. To enable successful signal detection, de-mapping of the received sequence onto the original sequence is required at the receiver. Hence, an index which uniquely identifies the selected sequence is signalled from the transmitter to receiver. From this generalized framework we derive several practical MCS algorithms. Simulation results show that the MCS method achieves a considerable sidelobe suppression which justifies the introduced signalling overhead.