Extrinsic data compression method for double-binary turbo codes

This paper presents an extrinsic data compression method for double-binary turbo codes. Frame and extrinsic data memory occupy more area in turbo decoder implementations with the frame size increasing. Besides, non-binary turbo codes have much more extrinsic memory usage than single-binary turbo codes. This proposed compression method utilizes an operation in radix-4 single-binary turbo decoder and also can simplify the integration of single and double-binary turbo decoders in hardware implementations. It can reduce one-third of extrinsic memory size, about 15% of total memory usage. Simulation results show that this method only causes 0.2dB performance loss when bit error rate is equal to 10⁻⁵ with slight hardware increment.