Low Complexity GFDM Receiver Based on Sparse Frequency Domain Processing

Generalized frequency division multiplexing (GFDM) is a multi-carrier modulation scheme. In contrast to the traditional orthogonal frequency division multiplexing (OFDM), it can benefit from transmitting multiple symbols per sub-carrier. GFDM targets block based transmission which is enabled by circular pulse shaping of the individual sub- carriers. In this paper we propose a low complexity design for demodulating GFDM signals based on a sparse representation of the pulse-shaping filter in frequency domain. The proposed scheme is compared to receiver concepts from previous work and the performance is assessed in terms of bit error rates for AWGN and Rayleigh multipath fading channels. The results show, that for high-order QAM signaling, the error performance can be significantly improved with interference cancellation at reasonable computational cost.

I. Introduction

Current market trends and future projections indicate that one of the major challenges in next generation mobile communications systems will be to support massive wireless connectivity of machine-type communication (MTC) devices, also known as machine-to-machine or, in a wider sense, the Internet of Things devices. On the one hand, this vision can be implemented by designing an additional wireless communications standard, specifically tailored to MTC characteristics. On the other hand, this vision can be addressed more efficiently by designing a single flexible communications standard, supporting high rate traffic, intended for highly capable smart phones, down to sporadic traffic, intended for inexpensive and energy efficient sensors. Due the limited availability of licensed frequency bands, the opportunistic use of spectrum resources and the ability to aggregate non-contiguous frequency bands also needs to be supported by a flexible physical layer (PHY).