부산대학교 도서관

Next generation networks (NGN) are required to fulfill a stringent set of requirements which include high data rate, spectral efficiency, low out-of-band (OOB) radiation and latency. Generalized frequency division multiplexing (GFDM) is one of the schemes proposed at physical layer for NGNs. GFDM is a block-based transceiver scheme consisting of non-orthogonal subcarriers which are individually filtered. The impulse response of this filter decides the characteristics of the signal. In GFDM, a block consists of a set of subcarriers and subsymbols, the block-based structure of GFDM is advantageous for low-latency applications. GFDM also increases spectral efficiency when compared with orthogonal frequency division multiplexing (OFDM) by reducing the overhead of cyclic prefix. Apart from these advantages of GFDM, individual filtering of subcarriers decides the overall performance of transmitter. In this paper, we study the characteristics of the transmitted GFDM signal such as peak-to-average power ratio and OOB radiation based on various filters. The proposed GFDM technique uses traditional Nyquist filters to perform subcarrier filtering, whereas we study the effect of improved Nyquist filters to do the same. We show that the use of improved Nyquist filtering improves the characteristics of the transmit signal.