Angle of arrival estimation in the presence of multiple access interference for CDMA cellular phone systems

In code division multiple access (CDMA) cellular phone systems, such as those using the IS-95 standard, multiple users produce cochannel multiple access interference (MAI). In this paper adaptive time-domain interference mitigation techniques are developed and applied to the angle of arrival (AOA) estimation problem. This interference mitigation approach is motivated by a maximum likelihood formulation of multiuser space-time channel estimation. This approach is exercised using experimental data approximating that which might be experienced by an emergency response vehicle attempting to locate the source of an emergency 911 call using a vehicle-mounted antenna array. In this multiuser environment the users span a large range of received powers