US Patent 7519896 Turbo encoder and related methods

A turbo encoder includes multiple interleaved parallel concatenated recursive systematic convolutional encoders wherein each recursive systematic convolutional encoder is provided with an LUT that simultaneously provides the output bit pattern as well as the next state value corresponding to a defined set of multiple input bits and present state for operating the recursive systematic convolutional encoder. Thus, the approach works with LUTs, which do the job of both puncturing and multiplexing for four input bits at a time. The proposed approach may operate almost four times faster than the conventional approach, which can handle only one input bit at a time.