Preserving dynamic range in fixed-point representation in 5G

Abstract

This thesis proposes a method to preserve the dynamic range of frequency samples power in the physical layer of 5G base-station by using an exponent. Keeping the resource usage to its minimum while increasing performance and preserve a high Signal-to-Noise ratio SNR. Operations such as addition and subtraction on samples with different exponent is made possible by implementing a common exponent block that unifies exponent with varying powers. The scope also examines multiple rounding mechanisms to keep quantization as low as possible. Unlike Block Floating-Point technique which usually operates on the multiplication stages of fast Fourier transform, Dynamic scale gives more flexibility by separating block floating-point into two parts, the first part operates on a sample level extracting individual exponents, while the second extracts the maximum exponent to execute an operations involving more than one sample. A test case implementation is proposed to give a performance comparison against full precision floating point model in Matlab.