In channel coding redundancy is inserted in the transmitted information bit-stream. This redundant information is used in the decoder to eliminate the channel noise. The error correction capability of a FEC system strongly depends on the amount of redundancy as well as on the coding algorithm itself. TPCs perform well in the moderate to high SNRs because the effect of error floor is less. As TPCs have more advantage when a high rate code is used, they are suitable for commercial applications in wireless and satellite communications. The ntTPC Turbo Product Codec IP core is consisted of the Turbo Product Encoder (ntTPCe) and the Turbo Product Decoder (ntTPCd) blocks. The product code C is derived from two/three constituent codes, namely C1, C2 and optionally C3. The information data is encoded in two/three dimensions. Every row of C is a code of C2 and every column of C is a code of C1. When the third coding dimension is enabled, then there are C3 C1*C2 data planes. The ntTPC core supports both e-Hamming and Single Parity Codes as the constituent codes. The core also supports shortening of rows or columns of the product table, as well as turbo shortening. Shortening is a way of providing more powerful codes by removing information bits from the code. The ntTPCe core receives the information bits row by row from left to right and transmits the encoded bits in the same order. It consists of a row, column and 3D encoder. The ntTPCd decoder receives soft information from the channel in the 2’s complement number system and the input samples are received row by row from left to right. The implemented decoding algorithm computes the extrinsic information for every dimension C1, C2, C3 by iteratively decoding words that are near the soft-input word. An advanced scalable and parametric design approach produces custom design versions tailored to end customer applications design tradeoffs.
