Hardware Complexity Reduction in Universal Filtered Multicarrier Transmitter Implementation

Abstract

The inclusion of machine-type communication in the 5G technology has motivated the research community to explore new derivative waveforms of orthogonal frequency division multiplexing. Filter bank multicarrier, universal filtered multicarrier (UFMC), and generalized frequency division multiplexing techniques are under evaluation with respect to their suitability to 5G requirements. In addition to acceptable spectral performance, investigation on computational complexity reduction while addressing flexibility can help in the selection of suitable waveform among multiple options available for 5G. In this regard, based on analysis of computation involved in UFMC waveform construction, few reduced complexity solution for UFMC transmitter implementations are recently proposed. However, hardware-implementation-related issues have not been discussed in detail. In this paper, we have proposed reduced complexity hardware solutions for all three constituent blocks, i.e., inverse discrete Fourier transform (IDFT), finite impulse response (FIR) filter, and spectrum shifting blocks of a UFMC transmitter. For IDFT part, a reduced complexity IFFT solution using Radix-2 decimation in a time technique is presented, where more than 42% computations can be avoided. It is also shown that how five times less number of multipliers can be used in an FIR filter to simplify filter architecture. Finally, a highly efficient method is presented to compute spectrum shifting coefficients through small sized lookup table.