Sample rate conversion for software radio

Abstract

Software radio terminals must be able to process different communications standards which are generally based on different master clock rates and thus employ different bit/chip-rates. A straightforward solution to cope with this diversity of master clock rates in one terminal is to employ dedicated master clocks for each standard of operation. Being too costly in most cases, this kind of solution moreover limits the applicability of a once realized and thus fixed terminal. The smart solution to this problem is to run the terminal on a fixed clock rate, and to perform digital sample rate conversion that can be controlled by software and thus, empowers the software radio concept.

Reconfigurable Multirate Systems in Cognitive Radios

“…The Farrow structure is efficient for interpolation whereas, for decimation, it is better to use the transposed Farrow structure, as discussed in Babic et al (2002); Hentschel & Fettweis (2000).…”

On the design and efficient implementation of the Farrow structure

“…The output of the FD-DF is given by (1) where is the input signal sampled at a period ; is the impulse response of the FD-DF with a system delay of , where is an integer constant, and is the fractional delay parameter between zero and one. is the length of .…”

“…The principle of the proposed random search algorithm is to generate random candidate SOPOT coefficients in the neighborhood of so as to search for the optimal discrete solution. More precisely, a new coefficient vector is generated by adding a random vector to the original coefficient vector as follows: (6) where is a scale factor that controls the size of neighborhood to be searched; is a vector with its elements being random numbers in the range [ 1,1]; and is the rounding operation that convert its argument to the nearest SOPOT coefficients with maximum number of terms in each coefficient being and dynamic range . The performance measures and of the new coefficients are then calculated.…”

“…It finds important applications in software radio [1], digital modems [2], arbitrary sampling rate conversion, time-delay estimation [3], etc. In general, the fractional-delay digital filters can be implemented either as finite-duration impulse response (FIR) or infinite-duration impulse response (IIR) digital filters [7].…”

Frequency-Based Optimization Design for Fractional Delay FIR Filters with Software-Defined Radio Applications

“…This flexibility is achieved by performing channel selection in the digital domain through sample rate conversion (SRC) with programmable digital filters. Fractional Delay (FD) filters are key components used to perform nonrational SRC [3][4][5].…”