Implementation of near Shannon limit error-correcting codes using reconfigurable hardware

Error correcting codes (ECCs) are widely used in digital communications. New types of ECCs have been proposed which permit error-free data transmission over noisy channels at rates which approach the Shannon capacity. For wireless communication, these new codes allow more data to be carried in the same spectrum, lower transmission power, and higher data security and compression. One new type of ECC, referred to as Turbo Codes, has received a lot of attention, but is computationally expensive to decode and difficult to realize in hardware. Low density parity check codes (LDPCs), another ECC, also provide near Shannon limit error correction ability. However, LDPCs use a decoding scheme which is much more amenable to hardware implementation. This paper first presents an overview of these coding schemes, then discusses the issues involved in building an LDPC decoder using reconfigurable hardware. It presents a hypothetical LDPC implementation using a commercial FPGA, which will give an idea of future research issues and performance gains.