N-continuous orthogonal frequency division multiplexing (OFDM) is a promising solution to the outof- band (OOB) emission issue in OFDM systems where the Nth-order continuity between OFDM symbols leads to lower OOB emission than the plain OFDM, however, high self-interference in such systems is an obstacle. In this paper we propose a new class of quasi-cyclic symbol extensions which makes the OFDM system N- continuous. The new extension leads to low OOB emission while the additive interference is less than other N-continuous OFDM systems. Moreover, we propose a general analysis of the spectrum and interference that occurs in a linear precoded OFDM system. The framework is applicable to many N-continuous OFDM systems including our proposed method.
Validerad;2018;Nivå 2;2018-10-10 (inah)