Further Specialization of Clustered VLIW Processors: A MAP Decoder for Software Defined Radio

Pablo Ituero Ituero, Marisa López-Vallejo López-Vallejo
2008 ETRI Journal  
Pablo Ituero et al. 113 Turbo codes are extensively used in current communications standards and have a promising outlook for future generations. The advantages of software defined radio, especially dynamic reconfiguration, make it very attractive in this multi-standard scenario. However, the complex and power consuming implementation of the maximum a posteriori (MAP) algorithm, employed by turbo decoders, sets hurdles to this goal. This work introduces an ASIP architecture for the MAP
more » ... , based on a dual-clustered VLIW processor. It displays the good performance of application specific designs along with the versatility of processors, which makes it compliant with leading edge standards. The machine deals with multi-operand instructions in an innovative way, the fetching and assertion of data is serialized and the addressing is automatized and transparent for the programmer. The performance-area trade-off of the proposed architecture achieves a throughput of 8 cycles per symbol with very low power dissipation. Keywords: Application specific instruction-set processor (ASIP), maximum a posteriori (MAP), soft-input softoutput (SISO) decoder, software defined radio (SDR), turbo code, very long instruction word (VLIW) architectures.
doi:10.4218/etrij.08.0107.0076 fatcat:yelt2yyya5f7tkuat5rg6jicem