In order to achieve frame synchronization in packetbased communication systems, a known sequence (preamble) is sent at the beginning of each packet. This paper presents a low power scheme for preamble detection using dynamic precision configuration. The proposed scheme is based on the observation that signal processing algorithms at the front end (including mixer, Square root raised cosine (SRR...

Pseudonoise code acquisition is investigated for constant hopping rate fast frequency-hopped (FFH)/M -ary frequency-shift keying systems under the effects of white Gaussian noise and band multitone jamming. In particular, serial search acquisition systems based on the traditional multiple-dwell test (up to three dwells) and three novel sequential tests are analyzed and compared. Analytical resu...

The authors consider a low-complexity technique for direct-sequence spread spectrum code acquisition. They present performance analysis in Rayleigh fading channels, and with carrier frequency offset in the receiver. They derive analytical expressions for acquisition probabilities, and use them to determine the mean and variance of the acquisition time. It is shown that acceptable performance ca...

The advent of the new European satellite navigation system Galileo and the current study of a new generation of GPS satellites are increasing the interest towards navigation related systems, services and applications. Both the systems foresee improved performances with respect to the present GPS C/A code, mainly achieved by using novel modulation schemes for the signalsIn-Space. The Binary Offs...

In this paper, we propose a novel approach for code acquisition in the code-division multiple access (CDMA) communication system. The essential assumption is that the pilot signal of the desired user is available. If the codes are exactly orthogonal, the method can be derived from an optimization criterion. Using the pilot signal, the performance can be greatly improved without increasing compu...

An overview of the hardware and software used to study the transverse emittance on the ISIS Pulsed Spallation Neutron Source at RAL is given. Vertical and horizontal slit-slit emittance scanners are used for high resolution measurements. Data acquisition and analysis is performed using in-house written C# code. Alternatively, a pepperpot head can be used to record both the emittance and beam pr...

The acquisition of volatile memory from a compromised computer is difficult to perform reliably because the acquisition procedure should not rely on untrusted code, such as the operating system or applications executing on top of it. In this paper, we present a procedure for acquiring volatile memory using a hardware expansion card that can copy memory to an external storage device. The card is...

AbstTactIn this paper, performance of PN code acquisition is analyzed for a DS/CDMA overlay system with imperfect power control. Acquisition performance is evaluated in terms of mean acquisition time using state transition diagram for acquisition process. To apply for a DS/CDMA cellular environments, the MA1 and imperfection of power control are taken into account in the analysis of acquisition...

This work was supported by the Brain Korea 21 Project. Abstract~A code acquisition scheme is proposed for DS/ CDMA systems with multiple antennas. The proposed scheme employs a new search scheme, referred to as sparse search, to utilize multipath signals in reducing mean acquisition time over frequency-selective fading channels. The mean acquisition time performance of the proposed scheme is an...

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...