Patent ID: 7308017

Claim:
A direct spread spectrum/CDMA integration spreading spectrum coherent receiver comprising: a state control means for receiving control information from a CPU (center processor unit), generating PN code state control signals to be inputted into a PN code generating and sliding control unit, integrating period control signals to be inputted into a correlator bank, acquisition state control word to be inputted into a post correlation data processing unit, and state control word to be inputted into a post combing unit; a timing generating unit for receiving a external clock, generating CPU interruption signals required for entire system, timing clock and time sequence by dividing frequency and counting, and for adjusting the timing based on a PN code tracking unit; the correlator bank for receiving input signals from a data delay line unit, PN code signals from the PN code generating and sliding control unit, Walsh code signals from a Walsh function generating unit in order to perform the complex correlation integration between the input signal and the PN code signal multiplied by the Walsh coding signal, integrating period control signals form the timing generating unit respectively, and for periodically performing effective correlating integration by time division multiplexing one complex correlator to form equivalent correlators; the post correlation data processing unit for receiving the output from one of the correlators in the correlator bank, processing the data included in the output from the correlator, performing initial acquisition, adjacent cell search, selection of effective multipath based on the energy window according to the control signals from the state control unit; the PN code tracking unit for receiving a channel evaluation relating to effective multipath of pilot channel from the post correlation data processing unit, calculating the barycenter of a energy window and a loop filter to obtain a mode value for a variable mode counter, and sending the mode value to the timing generating unit to finely adjust the PN code generating clock, thereby adjusting local PN code phase; and an automatic frequency correction (AFC) loop calculating unit for performing frequency error evaluation and loop filter calculation based on the information associated with effective multipath of the pilot channel from the post correlation data processing unit, and sending the obtained result to a controllable frequency reference unit.