Based on the research of SDP location algorithm

an improved localization algorithm based on angle of arrival（AOA）information for node location in wireless sensor networks（WSNs）is proposed.All the sensor nodes’axis orientations are assumed to be unknown.All the AOA measurement data are employed to calculate the difference angle information of signal arrival.All the angle relationships are formulated as convex constraints and the location problems are then transformed as convex optimization ones.As all the angle measurements are accurate enough

the localization problem can be transformed as a linear programming（LP）problem.Otherwise

by introducing some auxiliary variables

it can be expressed as a quadratic programming（QP）problem.Simulation results demonstrate th

at the improved algorithm improve precision about 5 %

2

0 % better than SDP algorithm in location when AOA measurement error is less than 10°.