Spread Spectrum Communication Research Papers (original) (raw)
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Recent papers in Spread Spectrum Communication
A digital watermark is an invisible mark embedded in a digital image which may be used for Copyright Protection. This paper proposes that Fourier-Mellin transform-based invariants can be used for digital image watermarking. The embedded... more
A digital watermark is an invisible mark embedded in a digital image which may be used for Copyright Protection. This paper proposes that Fourier-Mellin transform-based invariants can be used for digital image watermarking. The embedded marks may be designed to be una ected by any combination of rotation, scale and translation transformations. The original image is not required for extracting the embedded
When the mechanisms of fading channels were first modeled in the 1950s and 1960s, the ideas were primarily applied to over-the-horizon communications covering a wide range of frequency bands. The 3-30 MHz high-frequency (HF) band is used... more
When the mechanisms of fading channels were first modeled in the 1950s and 1960s, the ideas were primarily applied to over-the-horizon communications covering a wide range of frequency bands. The 3-30 MHz high-frequency (HF) band is used for ionospheric communications, and the 300 MHz-3 GHz ultra-high-frequency (UHF) and 3-30 GHz super-high-frequency (SHF) bands are used for tropospheric scatter. Although the fading effects in a mobile radio system are somewhat different than those in ionospheric and tropospheric channels, the early models are still quite useful to help characterize fading effects in mobile digital communication systems. This tutorial addresses Rayleigh fading primarily in the UHF band. That affects mobile systems such as cellular and personal communication systems (PCS). Part I of the tutorial itemizes the fundamental fading manifestations and types of degradation
- by Nouha Baccour and +1
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- Engineering, Information Security, Metrics, Wireless Sensor Networks
This paper is focused on the design of a set of orthogonal linear periodic time varying (LPTV) filters and proposes to apply this result to spread spectrum multiuser transmissions. The construction method of such an orthogonal set is... more
This paper is focused on the design of a set of orthogonal linear periodic time varying (LPTV) filters and proposes to apply this result to spread spectrum multiuser transmissions. The construction method of such an orthogonal set is presented, emphasizing that only an invertible LPTV filter is required, since the full set is then deduced from this kernel element. Based on this theoretical result, a spread spectrum multiuser transmission is proposed. In order to appreciate the performance of the proposed system, simulations are performed and results are compared to a classical DS-CDMA system.