A Reconfigurable LFSR for Tri-standard SDR Transceiver, Architecture and Complexity Analysis

In the Software Radio (SWR) Area, techniques of parameterization are an active research topic. These techniques factorize common functions or operators and in consequence lead to compact though open implementation. However, reconfigurability is often achieved at the cost of additional configuration logic and the benefit of factorization must be carefully analysed. This paper is dedicated to a Reconfigurable Linear Feedback Shift Register (R-LFSR), which can carry out several front rank operations of multi mode transceivers (Pseudo Random Sequence Generators, Scrambling, Convolutive Coding, Cyclic coding, Reed-Solomon Coding or Reed-Solomon decoding). This R-LFSR is then used in the context of a Tri-Standards Transceiver (IEEE 802.11g, IEEE 802.16-2005, 3GPP LTE). Several architectures based on this R-LFSR structure are analysed in terms of complexity in order to select the best implementation trade-off.