Complex Number RS Coded OFDM With Systematic Noise in the Guard Interval
Recently, the authors presented a novel OFDM (Orthogonal Frequency Division Multiplexing) signaling concept, where the Cyclic Prefixes (CPs) are replaced by deterministic sequences which they call Unique Words (UWs). The UWs are generated by appropriately loading so-called redundant subcarriers. By that a complex number Reed Solomon (RS) code construction is introduced which can advantageously be exploited in an LMMSE (Linear Minimum Mean Square Error) receiver. The overall concept clearly outperforms CP-OFDM in frequency selective channels. In this paper, they introduce a method that significantly reduces the energy of the redundant subcarrier symbols by allowing some systematic noise in the UWs.