An UNBALANCED QPSK (UQPSK) signal format is a QPSK signal where the two orthogonal components of the carrier have unequal power and are modulated with independent binary data streams of different rates.This transmission scheme is most useful when the data of two different sources with possibly varying rates have to be transmitted in the same frequency band.This signal design was used in the Tracking and Data Relay Satellite System (TDRSS) and the Navigation Satellite Timing and Ranging Global Positioning System (NAVSTAR GPS).To suit for the UQPSK-DS-SS adopted in S

-

Band forward link of TDRSS

this paper introduces a whole digital implementation of TDRSS IF carrier acquisition and tracking system.Finally we give its full implementation on FPGA and the performance

experimental and analytical results agree with each other very well.