Doppler Localization using Golay Code by QPSK Transmission Technique

In this paper we transmit the complimentary golay code simultaneously using unique modulation technique which gives long length for the code. While reception the two complementary codes are separated by using reverse technique and the desired pulse compression is achieved by autocorrelation. Complementary Golay codes are transmitted by multiplying code c with cosine function and the complimentary code c which is code k with sine function and these codes are added up using an adder which are transmitted. The transmitted signal is reflected from a moving or static target, its complex demodulation is carried out at the receiver. A signal processing algorithm is designed for the detection, ranging and Doppler localization of a moving target using Golay code as the phase coding signal. This is followed by correlation of each component of demodulated signal with one member of the complementary Golay code pair separately. The correlation results of the two channels are added together, leading to effective side-lobe suppression. The developed technique exhibits excellent Doppler localization, target detection and range estimation performance by overcoming the side-lobe limitations of the conventional phase coding signals in ranging applications.