TITLE:
Performance Analysis of OFDM Synchronization Using Customized Floating Point for Low Complexity
AUTHORS:
V. Janakiraman, M. Kannan
KEYWORDS:
OFDM, Fast Fourier Transform, Floating Point Aithmetic, Synchronization, Customization
JOURNAL NAME:
Circuits and Systems,
Vol.7 No.10,
August
19,
2016
ABSTRACT: Orthogonal
frequency-division multiplexing (OFDM) is a multi carrier modulation scheme
mainly used for digital communications. The performance of OFDM system heavily
depends on the synchronization scheme used. In most cases, the accuracy level
of synchronization will be worsened by the error caused in fixed point
arithmetic involved. In this paper, we analyze the impact of the fixed point
arithmetic on the performance of the coarse timing and frequency
synchronization. Here with an analytical approach through numerical simulations
bit length of IEEE 754 standard single precision format is optimized according
to the required degree of accuracy for low complexity. Also, a complete
precision level requirement for FFT computations with all possible modulation
types is obtained. The proposed precision model is compared with IEEE standard single
precision model and its efficiency in OFDM synchronization process is proved
through MATLAB simulations. Finally, the complexity reduction of proposed
precision model in both addition and subtraction is proved against single
precision format using hardware synthesis. Here we proved that more than 50%
complexity reduction is achieved as compared to standard precision models
without compromising quality. The quality retention of proposed model is proved
in both timing and frequency synchronization process.