A Weak Signal Acquisition Method for Indoor Passive Location on Mobile Communications

Abstract

Under the indoor environment, since the attenuation of signal intensity of the mobile phone is caused by traversing multiple building walls, the signal strength that the receiver captured is pretty weak. Unfortunately, the existing indoor passive location receivers based on CDMA cannott capture that weak signal under such circumstances, hence it is urgent to propose a reasonable acquisition method to solve this problem. This paper starts from the existing signal capture methods based on CDMA communication system, by studying all the uplink channels in this system that are suitable for indoor passive location, preferentially chooses the RACH(Random Access Channel) signal after researching on the reverse channel of CDMA communication system. However, the existing signal acquisition method in CDMA system is not suitable for the weak RACH signal acquisition. This paper redesigns the local code generator and the acquisition process, and finally achieved the weak signal acquisition in CDMA system. Experimental results show that this method cannot only improve the signal to noise ratio of weak signal acquisition decision, but also has a great reference value for post disaster rescue and rescue detection station research based on CDMA mobile phone.

Foundation project: The National High Technology Research and Development Program (“863” Program) of China (No. 2015AA124101). The National Natural Science Foundation of China (No. 61401040). The National Science and Technology Support Program of China (No. 2014BAK12B00).