Low-cost IP-blocks for UMTS turbo decoders

After several years from their introduction in 1993, turbo codes are now universally known as one of the most effective techniques for achieving performance very close to the Shannon theoretical limits in many transmission systems; they are also proposed as coding standard for several applications, including the Universal Mobile Telecommunications System (UMTS). This paper presents new, low-cost IP blocks for the implementation of UMTS standard compliant turbo decoders. The proposed architectures achieve an important complexity reduction with respect to the previously reported solutions: this achievement, resulting from an accurate architecture optimization, is mainly related to the elimination of some large memories, that are allocated in the usual decoder structure.