scispace - formally typeset
Search or ask a question
Topic

Spread spectrum

About: Spread spectrum is a research topic. Over the lifetime, 16287 publications have been published within this topic receiving 282543 citations. The topic is also known as: spread-spectrum & spread-spectrum telecommunications.


Papers
More filters
Journal ArticleDOI
TL;DR: The characteristics of impulse radio using a modulation format that can be supported by currently available impulse signal technology are described and analytical estimates of its multiple- access capability under ideal multiple-access channel conditions are given.
Abstract: Impulse radio, a form of ultra-wide bandwidth (UWB) spread-spectrum signaling, has properties that make it a viable candidate for short-range communications in dense multipath environments. This paper describes the characteristics of impulse radio using a modulation format that can be supported by currently available impulse signal technology and gives analytical estimates of its multiple-access capability under ideal multiple-access channel conditions.

2,377 citations

Patent
21 Jun 1991
TL;DR: In this paper, a system and method for communicating information signals using spread spectrum communication techniques is presented, where PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance.
Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols. In the mobile-to-cell link, access and voice channels are defined. Information communicated on the mobile-to-cell link channels are, in general, encoded, interleaved, orthogonal signaling along with QPSK spreading.

1,891 citations

Journal ArticleDOI
TL;DR: An analysis of an asynchronous phase-coded spread-spectrum multiple-access communication system reveals which code parameters have the greatest impact on communication performance and provides analytical tools for use in preliminary system design.
Abstract: An analysis of an asynchronous phase-coded spread-spectrum multiple-access communication system is presented. The results of this analysis reveal which code parameters have the greatest impact on communication performance and provide analytical tools for use in preliminary system design. Emphasis is placed on average performance rather than worst-case performance and on code parameters which can be computed easily.

1,723 citations

Journal ArticleDOI
TL;DR: It is the intention of this paper to provide a tutorial treatment of the theory of spread-spectrum communications, including a discussion on the applications referred to, on the properties of common spreading sequences, and on techniques that can be used for acquisition and tracking.
Abstract: Spread-spectrum communications, with its inherent interference attenuation capability, has over the years become an increasingly popular technique for use in many different systems. Applications range from antijam systems, to code division multiple access systems, to systems designed to combat multipath. It is the intention of this paper to provide a tutorial treatment of the theory of spread-spectrum communications, including a discussion on the applications referred to above, on the properties of common spreading sequences, and on techniques that can be used for acquisition and tracking.

1,579 citations

Journal ArticleDOI
TL;DR: It is concluded that MMSE detectors can alleviate the need for stringent power control in CDMA systems, and may be a practical alternative to the matched filter receiver.
Abstract: We consider interference suppression for direct-sequence spread-spectrum code-division multiple-access (CDMA) systems using the minimum mean squared error (MMSE) performance criterion. The conventional matched filter receiver suffers from the near-far problem, and requires strict power control (typically involving feedback from receiver to transmitter) for acceptable performance. Multiuser detection schemes previously proposed mitigate the near-far problem, but are complex and require explicit knowledge or estimates of the interference parameters. In this paper, we present and analyze several new MMSE interference suppression schemes, which have the advantage of being near-far resistant (to varying degrees, depending on their complexity), and can be implemented adaptively when interference parameters are unknown and/or time-varying, Numerical results are provided that show that these schemes offer significant performance gains relative to the matched filter receiver. We conclude that MMSE detectors can alleviate the need for stringent power control. In CDMA systems, and may be a practical alternative to the matched filter receiver. >

1,494 citations


Network Information
Related Topics (5)
Fading
55.4K papers, 1M citations
94% related
Base station
85.8K papers, 1M citations
94% related
Wireless network
122.5K papers, 2.1M citations
93% related
Wireless
133.4K papers, 1.9M citations
92% related
Network packet
159.7K papers, 2.2M citations
91% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202339
202291
2021147
2020278
2019354
2018343