In this paper, based on the principle of turbo processing, we propose two iterative receiver schemes for carrier frequency offset (CFO) compensation in orthogonal frequency division multiplexing (OFDM) systems. Our CFO compensation designs, one in time domain and the other in frequency domain, are based on joint estimation of time-varying channel and CFO. In our schemes, the random CFO problem,...

In this paper, the wavelength mismatch between the message and the chaotic carrier in the chaotic optical communication with chaos-masking has been experimentally investigated. The results show that the decryption performance of the receiver can be improved when the message wavelength is greater than that of the chaotic carrier. When the wavelength offset is set to 0.12 nm, high-speed secure op...

The goal of waveform shaping techniques in orthogonal frequency division multiplexing systems is reduction in out of band (OOB) transmit power as well as reduction in inter-carrier interference (ICI) generated by carrier frequency offset at the receiver. We propose waveform shaping using a linear combination of time-limited polynomial pulses having spectral decay rates of 1=f 4 and 1=f . The re...

This paper explains offset and develops a strategic approach for the implementation of offset-policy for a buyer country. Offset emerges when a country cannot afford to pay cash for non-essential imports, and cannot get cash for many of its products. Offset arrangements are most frequently found in the defense-related sector. However, recently, it refers to a range of industrial and commercial ...

We present a novel algorithm for estimating the Carrier Frequency Offset (CFO) in an OFDM receiver. The algorithm is based on locating the spectral minimas within null subcarriers embedded in the spectrum. This is done by using a scaled DFT algorithm to calculate the spectrum of the OFDM symbol around the null subcarrier, followed by averaging the absolute square of the amplitude. The method is...

Determination of optimal phase offset. Digital phase-shifting holography measures the relative phase of light at different pixels; the absolute phase values are unknown, and an unavoidable phase offset exists between the two measured fields. For example, a phase offset can be induced by a drift of the optical path length difference between the sample and reference arms due to environmental inst...

This paper presents a feasibility study of DC offset filtering for direct-conversion UTRA-FDD/WCDMA receivers. Spectral characteristics and properties of continuous transmission facilitate the use of simple high-pass filtering and this method is evaluated in the paper. Design equations for DC offset power to down-converted signal power ratio are presented and the impact on bit error rate of hig...

There is an increasing interest in monolithic integration for wireless transceivers. This integration can be made possible with the advantages of direct conversion techniques. However, DC offset and flicker noise become critical to the system. In this paper, we propose a wide tuning range and high gain AGC with an effective automatic DC offset cancellation. The proposed AGC and transceiver arch...

An autonomous surface vehicle, known as a wave glider, was used to record refracted and reflected signals from seismic source penetrating the shallow subsurface. integrated survey system consisting of gilder human-operated vessel deployed. These systems are acquire wide-offset data specific areas, such offshore structures. The gliders can collect refraction reflection data, which be estimate su...