理论推导了等概率二元码判决时误码率和判决电平的关系,推导表明误码率随着判决门限偏离最佳值急剧升高,因而提出了一种新颖的自适应判决电路,可以使判决门限跟随被判决信号的变化自动调整到最佳值.电路采用SM IC 0.35μm CM O S工艺设计,并给出了芯片针对于27MH z无线FSK信号的接收判决这一具体应用的测试结果. The relationship between the bit error rate and the decision level in the judgment of equal probability binary codes is derived theoretically. The deduced result shows that the bit error rate increases sharply as the decision threshold deviates from the optimal value. Therefore, a novel adaptive decision circuit is proposed, So that the decision threshold is automatically adjusted to the optimal value following the change of the decision signal.The circuit is designed with SM IC 0.35μm CMOS process and the test result of the specific application of the chip to the receiving decision of the 27MHz FSK signal is given.