An FFT-based acquisition scheme for DS-CDM a systems

This paper introduces an efficient acquisition/correlation technique for DS-CDMA systems using a frequency-domain approach employing TCH-based training blocks (Tomlison, Cercas and Hughes). The classical time-domain active acquisition technique is compared with the proposed passive matched-filter type frequency domain technique. Moreover using the fact that an N-point discrete Fourier transform (DFT) can be partitioned into M smaller DFTs, we present a procedure for simultaneous decoding/despreading and synchronization that switch between 16 bit-length and 256 bit-length cyclic codes thus providing code rate variability.