Design of early stopping unit in parallel turbo decoder based on galois field operation

The early stopping of turbo decoder is widely used in LTE/LTE-Advanced systems to avoid unnecessary iterations. To achieve high throughput requirements in next generation mobile communication systems, parallel turbo decoding where multiple SISO (Soft-Input Soft-Output) decoders work is commonly employed. Although CRC (Cyclic Redundancy Check)-based stopping criterion is well known by its superior performance, conventional CRC implementation is hard to be applied to parallel turbo decoding due to the timing overhead incurred by the intrinsic feature where the input data should be serialized. In this paper, to reduce the timing overhead, we present the parallel CRC architecture based on GF (Galois field) operations with negligible hardware overhead.