Efficient decoding of binary shortened cyclic fire code

Channel coding adds redundant bits to the original information bits in order to detect and correct possible errors occurring during transmission. In GSM (global system for mobile communications), we use both block coding and convolutional coding for error control. One of the channel coding schemes is CS-1 (see ETSI EN 300 909 v8.5.1, 1999), which employs shortened the cyclic fire code for burst error correction. We propose an efficient way of decoding the shortened binary cyclic fire code. The proposed scheme takes 224 clock cycles for syndrome computation and another 224 clock cycles for error trapping and correction. This decoding method is much less complex than conventional schemes and slightly less complex compared to the recently patented algorithm (Ramesh et al, "Shortened Fire code. Error-Trapping Decoding Method and Apparatus", US Patent 5,936,978). The proposed decoding scheme is applicable also to any binary shortened cyclic code.