All-Lag Spread-Spectrum Correlators With Rotating References
An All-Lag Rotating-Reference Correlator Correlates A Received Spread-Spectrum Signal With A Rotating Reference Code, And Produces In Each Sampling Instance N Correlation Lags Corresponding To The Correlation Of The Received Signal With 0, 1, . . . , N-1 Lags (Or Delays) Of The Rotating Reference Code, Wherein N Is The Length Of The Rotating Reference Code. The Rotating Reference Code Is Time-Variant And Is Generated By A Rotation Of A Basic Reference Code. The Received Signal, Possibly Embedded In Noise And Interference, Consists Of Periodic Replicas Of The Basic Reference Code With Or Without Data Modulation. The First Embodiment Of The Present Invention Describes A Method And Apparatus Of An All-Lag Rotating-Reference Correlator Which Is Applicable To Situations Where Data Modulation Is Not Present In The Received Signal. The Second Embodiment Of The Present Invention Describes A Method And Apparatus Of An All-Lag Rotating-Reference Correlator Which Is Applicable For Situations Where Data Modulation Is Present In The Received Signal. Corresponding Methods And Apparatus Are Also Described When Only A Number Of Selected Correlation Lags Are Required To Be Generated. Each Apparatus Comprises Storage Means For Storing Spread-Spectrum Signal Samples, Subtraction Means, A Plurality Of Multiplication Means Each Of Which Computes The Multiplication Result For The Output Of Subtraction Means And An Element Of Rotating Reference Code, Storage Means For Storing Correlation Lags, And A Plurality Of Addition Means.
Patent Number: US6868115B1
Application Number: US2000607649A
Inventor: Cheng, Chin Long | Ng, Tung Sang | Yip, Kun Wah
Priority Date: 30 Jun 1999
Priority Number: US6868115B1
Application Date: 30 Jun 2000
Publication Date: 15 Mar 2005
IPC Current: H04B000169
US Class: 375150 | 375142 | 375147
Assignee Applicant: The University of Hong Kong
Title: All-lag spread-spectrum correlator
Usefulness: All-lag spread-spectrum correlator
Summary: Used in a spread-spectrum system for correlating a spread-spectrum signal sample with a reference code for secure communication, multiple-access communication, channel sounding, ranging and target identification using a radar and a sonar, and navigation using global positioning system (GPS) or GLONASS.
Novelty: All-lag even-correlation generator for use in spread-spectrum system, has adders for generating correlation lag for present sampling instance based on correlation lag at previous sampling instance
信息和通信技術/電信
電信
香港
