Blind Multiuser Detection in Multirate CDMA Transmissions Using Fluctuations of Correlation Estimators

Abstract— This paper deals with the problem of blind multiuser detection in multirate direct-sequence code division multiple access (DS-CDMA). Direct-Sequence Spread Spectrum (DSSS) signals are well-known for their low probability of interception: their statistics are similar to those of a noise; furthermore, they are usually transmitted below the noise level. Here, the method based on the fluctuations of autocorrelation estimators, previously described in a single user context [1], is extended to multiusers. From the variable spreading length technique, we will evidence an increase of these periodical fluctuations and, on average, a relationship between their peak amplitudes and sequence lengths. A theoretical analysis will show that detection is possible, even with a very low signal-to-noise ratio (SNR) at the detector input. This approach will be illustrated with experimental results. The assessment of symbol periods allows one to start the synchronization process proposed recen...

• Type: Conference
• Year: 2006
• Where: GLOBECOM
• Authors: C. Nsiala Nzeza, R. Gautier, G. Burel
• Keywords: Blind Multiuser Detection, Direct-sequence Code Division Multiple Access, GLOBECOM 2006, Symbol Period, Telecommunications