PROGRAMMABLE SIGNAL PROCESSING CIRCUIT AND METHOD OF DEMODULATING

摘要

A programmable signal processing circuit has an instruction processing circuit (23, 24. 26), which has an instruction set that comprises a demapping instruction. The instruction processing circuit (23, 24, 26) has an operand input (30a) for receiving a complex number operand of the demapping instruction from a register file (22) and a result output (34) for writing a demapping result of the demapping instruction to the register file (22). The instruction processing circuit (23, 24, 26) determines at least four bit metrics in response to the demapping instruction, each indicating a relative position of the complex number relative to respective border line in a complex plane. The instruction processing circuit (23, 24, 26) writes a combination of the at least four bit metrics together to the result output (34) in the demapping result.