In this paper, we investigate the issue of pseudo noise (PN) code acquisition in single-carrier and multicarrier (MC) direct-sequence code-division multiple-access (DS-CDMA) systems, when the channel is modeled by frequency-selective Nakagamifading. The PN code acquisition performance of single-carrier and MC DS-CDMA systems is analyzed and compared when communicating over Nakagamifading channe...

We propose a scheme for rapid acquisition of PN signals for direct-sequence spread spectrum (DS/SS) CDMA systems by estimating the phase of the incoming PN signal with the use of an auxiliary signal. The phase of the incoming P N signal is estimated using the cross-correlation properties between the PN signal and the auxiliary signal. The estimated phase is used to initialize the phase of the l...

An adaptive serial search pseudonoise (PN) code acquisition scheme is proposed, in which the detection threshold is scaled by the instantaneous received power measured prior to PN code correlation. We observe that the proposed scheme achieves significantly improved mean acquisition times compared to the conventional nonadaptive schemes under Rayleigh fading and pulsed Gaussian noise jamming. Fu...

In this paper, a new pseudo noise (PN) code acquisition scheme for direct sequence spread spectrum (DS/SS) signals is proposed based on a joint decision rule of two correct cells ( cells) at which the code phase offset between the locally generated and received PN codes is within a desired small value. To derive the joint decision rule, the acquisition problem is modeled as a hypothesis testing...

In this paper, a new pseudo noise (PN) code acquisition scheme for direct sequence spread spectrum (DS/SS) signals is proposed based on a joint decision rule of two correct cells ( cells) at which the code phase offset between the locally generated and received PN codes is within a desired small value. To derive the joint decision rule, the acquisition problem is modeled as a hypothesis testing...

Direct sequence spread spectrum systems require a local replica of the pseudonoise (PN) sequence to be synchronized with the received signal’s spreading code. A method is proposed to improve the PN sequence acquisition time and decrease the acquisition time variability. The proposed method is based on a binary search algorithm. At each stage of the algorithm, an auxiliary signal is used to form...

In this paper, an acquisition algorithm is discussed in parallel combinatory spread spectrum (PCSS) system. The algorithm model is first built. Then, an improved algorithm utilizing multiple correlation peak accumulation under low SNR is proposed. The simulation results show that Doppler offset and PN code-phase delay can be obtained by using the proposed acquisition algorithms. The simulation ...