On the use of double-LSB and signed-LSB encodings for RNS

Double-LSB and signed-LSB have been recently proposed as efficient encodings for addition and multiplication in the modulo 2ⁿ+1 and 2ⁿ±1 channels respectively of a Residue Number System (RNS). In this paper we introduce reverse converters for two 4-moduli sets that adopt these encodings and analyze their efficiency. The theoretical and experimental results that are derived indicate that the area and delay costs of the reverse conversion in such RNSs are comparable to those that use the ordinary binary encoding and hence both the double-LSB and the signed-LSB encodings are well suited to RNSs.