This paper describes the first integrated circuit (IC) designed, fabricated, and tested to perform direct acquisition of the M code signal. This DirAc IC prototype provides direct acquisition capability for test receivers and also demonstrates the feasibility of performing direct acquisition over extended regions of time and frequency uncertainty. The IC is designed and fabricated using 180 nm ...

In this doctoral thesis, initial code synchronization (i.e., code acquisition) of a direct sequence spread spectrum (DS/SS) system is studied when a smart antenna is used in a receiver. Code synchronization means time synchronization of the used spreading code in the receiver. After an introduction to the topic, a literature review of code acquisition is presented. In addition, a review of the ...

Block processing Fast Fourier Transform (FFT) algorithms have been developed to do signal acquisition for the new CM and CL civilian codes that will appear on the L2 GPS frequency once the Block IIR-M satellites are launched. These algorithms have been developed to aid in the acquisition of weak GPS signals. FFT block processing can be used to significantly reduce the computational burden cause...

Accurate performance evaluation of direct-sequence pseudonoise code acquisition on Rayleigh fading channels is investigated in this paper. For fading channels the homogeneous Markov chain model, used to characterize the acquisition process over additive white Gaussian noise channels, is no longer valid due to the correlations between cell detections incurred by fading. Hence, the traditional di...