Code and frequency acquisition are important stages of today’s satellite systems, such as the European system Galileo. Newly proposed modulation types, such as Binary Offset Carrier (BOC) modulation, have triggered new challenges in the acquisition process. The features and properties of BOC-modulated code sequences are still not wellunderstood in the context of fast acquisition algorithms. Mor...

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...

This paper proposes a fast code acquisition scheme for optical code division multiple access (O-CDMA) systems. Unlike the conventional scheme, the proposed scheme employs multiple thresholds providing a shorter mean acquisition time (MAT) performance. The simulation results show that the MAT of the proposed scheme is shorter than that of the conventional scheme. Keywords—Optical CDMA, acquisiti...

The present dissertation deals with initial synchronization in Code Division Multiple Access (CDMA) networks. In the first part of this thesis an extensive and up-to-date review of the literature is presented.The basic theory of code acquisition as well as different techniques and structures used to achieve the initial synchronization are discussed. A survey of the most common theoretical appro...

In direct-sequence wideband (DS-WB) systems, long spreading sequences are used to span multiple symbol intervals in order to remove spectral lines and to mitigate multiple access interference. The usage of long spreading sequences will result in a large search space during acquisition stage. As a result, the DS-WB systems will need a lot of time to achieve acquisition state. This paper proposes...

In this paper, we first investigate the effect of residual code phase offset on the direct-sequence code-division multiple-access code acquisition scheme using a noncoherent matched filter receiver. We then propose a new code acquisition scheme that is robust to the variation of the residual code phase offset and outperforms the conventional scheme. When the code phase offset normalized to the ...

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...

A code acquisition technique based on active optical correlation detection is introduced for coherent optical pulse code-division multiple-access (CDMA) systems implemented through coherent correlation demodulation. Passive matched filter acquisition, commonplace in most radio CDMA systems, does not translate directly into the optical domain since synchronization between the incoming optical si...

The new GPS/Galileo/Compass signals use much longer code lengths and higher code frequencies than the GPS L1 C/A signal. As a result, they can provide improved ranging and anti-jamming performances. Unfortunately, their acquisition complexity is significantly higher, especially in the high sensitivity or weak signal acquisition context. Acquisition of very weak signals requires long integration...

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...