OFDM is a broadband wireless technology which supports data rates in excess of 100 Mbps. In addition to this, OFDM has some limitations as it requires strict frequency synchronization and low peak to average power ratio. So considering DFT-OFDMA, which performance in terms of PAPR, is equivalent to SC-FDMA. This paper represents the suitability of using OFDMA in the up-link for high-data-rate s...

1 Frequency response of the DDC. . . . . . . . . . . . . . . . . . . . . . 3 2 Top: DCR input terminated. Bottom: Single tone at 1420.8 MHz applied to the input of the DCR. Both panels: Integration over 100 sweeps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 GPS L1 observation, 1000 sweeps. Top: Sky. Bottom Left: Sky (zooming in). Bottom Right: Absorber. . . . . . ...

Hydrophobic surfaces with microscale roughness can be rendered ultrahydrophobic by the addition of sub-micron-scale roughness. A simple yet highly effective concept of fabricating hierarchical structured surfaces using a single-step deep reactive ion etch process is proposed. Using this method the complexities generally associated with the fabrication of two-tier roughness structures are elimin...

A novel design method for compact planar lowpass filter (LPF) with prominent roll-off rate and wide stopband suppression is proposed by using fragment-type structures (FTS) multi-bit scheme. The FTS has the potential to achieve higher LPF performance at optimization efficiency, without any prerequisite knowledge about pivotal needed in conventional designs. definition of implementation scheme a...

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The performance of multi-user Orthogonal Frequency Division Multiplexing (OFDM) with raised cosine time domain pulse shaping is studied on the Satellite Mobile channel (SMC) and the two-path Rayleigh Fading channel. A multi-user time and carrier frequency synchronization scheme is discussed. The relationship between the synchronization requirement and the roll-off rate (B) of the pulse shaping ...

A new characteristic waveform decomposition method based on wavelets is proposed for the Waveform Interpolation (WI) paradigm. In WI, pitch-cycle waveforms are filtered in the evolution domain to decompose the signal into two waveform surfaces, one characterising voiced speech and a second representing unvoiced speech. The slow roll-off of FIR filters leads, however, to a significant inter-rela...

A stable autonomous underwater vehicle (AUV) is essential for underwater survey activities. Previous studies have associated poor results in bathymetry survey and side-scan imaging with the vehicle’s unwanted roll motion. The problem is becoming more prominent as AUVs are smaller nowadays. This causes reduction in the metacentric height of the AUVs which affects the inherent self-stabilization ...

In this paper, a compact and high isolation microstrip diplexer is designed for broadband and wireless local area network (WLAN) application, simultaneously. The bandpass filter (BPF) for broadband channel is formed by three-coupled-line structure and two short stubs with different size loaded in 50 Ω feed lines, and the BPF for WLAN channel consists of two coupling quarter-wavelength resonator...