In the proposed algorithm,we got a threshold according to the cumulative distribution function.We contrasted the accumulated metric with the threshold when reaching a leaf node,and judge whether the maximum likelihood solution was found,the complexity could be reduced accordingly.The value of the threshold had a certain impact on the performance of the sphere detection algorithm.Thus we needed to make a tradeoff between the performance and the complexity in different SNR range at choosing the threshold.As shown in the simulation result,the expanded nodes converge to m in the high SNR range.

A design scheme for end system of the fingerprint IC validating is proposed in this paper.The principle of end system of fingerprint IC validating is described.And the program is designed on the fingerprint collection module.But in the programming design,the fingerprint algorithm was not included.The MCU chip ST89V564RD is used so that the system can be developed more expediently in future.