Results 211 to 220 of about 64,360 (256)

Trellis-coded direct-sequence spread-spectrum communications

IEEE Transactions on Communications, 1994
This paper considers the application of trellis coding techniques to direct-sequence spread-spectrum multiple-access (DS/SSMA) communication. The unique feature of the trellis codes considered is that they are constructed over the set of possible signature sequences rather than over some standard 2-D signal constellation.
Brian D. Woerner, Wayne E. Stark
openaire   +1 more source

Neural Direct Sequence Spread Spectrum Acquisition

2004
A neural network model is described which simulate the Parallel Matching Filtering (PMF) for Direct Sequence Spread Spectrum (DSSS) signal acquisition. This system is based on training the Counter Propagation Network (CPN) in all half chip phase shifts of the Pseudo Noise (PN) code.
Tarek Elhabian, Bo Zhang, Dingrong Shao
openaire   +1 more source

Soft synchronization of direct sequence spread-spectrum signals

IEEE Transactions on Communications, 1996
A new technique for soft synchronization of direct-sequence spread-spectrum (DSSS) signals is presented. The technique, referred to as the dominant mode despreading (DMDS) algorithm, exploits the eigenstructure of a frequency-channelized DSSS signal to estimate the spreading code and underlying message sequence of the signal.
Brian G. Agee, Roland J. Kleinman, Jeffrey H. Reed   +2 more
openaire   +1 more source

Direct sequence spread spectrum Walsh-QPSK modulation

IEEE Transactions on Communications, 1998
We present Walsh-quadrature phase-shift keying (Walsh-QPSK) pseudonoise (PN) modulation schemes for both coherent and noncoherent direct-sequence code-division multiple-access (DS-CDMA) systems, wherein the PN spreading sequences for in-phase and quadrature data in a conventional QPSK PN modulation scheme are coded by Walsh sequences indexed by a ...
Dongwook Lee, Hun Lee, Laurence B. Milstein   +2 more
openaire   +1 more source

Performance of direct-sequence spread-spectrum RAKE receivers with random spreading sequences

IEEE Transactions on Communications, 1997
In this paper, we derive error probability expressions for binary phase-shift keying (BPSK) and quaternary phase-shift keying (QPSK) spread direct-sequence spread-spectrum (DSSS) systems employing random spreading sequences with RAKE receivers. The derived expressions accurately take into account the effect of interpath interference which usually has ...
openaire   +2 more sources

A direct-sequence spread spectrum transceiver chip

Proceedings of IEEE Custom Integrated Circuits Conference - CICC '93, 2002
A single-chip spread-spectrum digital transceiver (CYCHIP) has been designed and fabricated in 0.7-micron LSI logic gate array technology. This chip includes a spread-spectrum transmitter, a spread-spectrum receiver, a time division duplex (TDD) control logic, a multiplexer, two FIFOs (first-in, first-out's) a 64-kbps voice codec (pulse code modulation)
D. Avidor, null Soei-Shin Hang, J. Omura
openaire   +1 more source

High-rate direct-sequence spread spectrum

IEEE Military Communications Conference, 2003. MILCOM 2003., 2004
Direct-sequence spread spectrum is popular for commercial wireless local-area networks, because license-free operation is permitted in certain frequency bands. The extensive development of equipment for such applications makes it attractive to investigate the use of the commercial technology for military communication networks.
M.B. Pursley, T.C. Royster, M.Y. Tan
openaire   +1 more source

A decision directed adaptive correlator for a direct sequence spread spectrum receiver

[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics, Speech, and Signal Processing, 1992
An adaptive correlator is presented as the data detector in a direct sequence spread spectrum communication system. The adaptive correlator has the same structure as an least-mean-square (LMS) adaptive filter, but the tapped delay line of the filter is shifted multiple times between each adaptation.
Charles N. Pateros, Gary J. Saulnier
openaire   +1 more source

Design of an all digital direct-sequence spread-spectrum receiver

5th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Wireless Networks - Catching the Mobile Future., 2002
The theory of a fully digital coherent direct-sequence spread-spectrum receiver for microprocessor implementation is described. The receiver samples the input signal at IF and uses a Costas loop for carrier tracking, a delay-lock loop for code tracking, and a serial search acquisition scheme to find the initial code phase.
openaire   +2 more sources

Blind spreading sequence set estimation of the M-ary direct sequence spread spectrum signals

2010 IEEE International Conference on Wireless Communications, Networking and Information Security, 2010
In the non-cooperative context, the M-ary direct sequence spread spectrum (DSSS) signals are much more difficult to be intercepted than the conventional DSSS signals. Few literatures can be found to provide the information of this kind of signal in such circumstances. In this paper, a blind spreading sequence set estimation algorithm for the M-ary DSSS
PengYu Qiu, Dan Xu, Zhi-Tao Huang, Wenli Jiang   +3 more
openaire   +1 more source