Background: Carrier generation based on optical heterodyning techniques where a beat signal is generated from the mixing of two light sources can be interesting solution due to ease on tunability. The free running heterodyning scheme benefits with a very wide tuning capability and the generated carrier can be freely adjusted. However, the drawbacks come in the form of frequency stability. Heter...

In this paper, we propose the residual carrier frequency offset tracking and sampling clock offset tracking algorithm that can be used in IEEE 802.11a and HIPERLAN Type 2 systems. Above Wireless LAN systems has short and long preambles, the carrier frequency offset is estimated and compensated. In case that the frame length is long, however, residual carrier frequency offset induces the severe ...

In the context of this example, the alphabet has only two symbols 0 and 1. When the alphabet consists of just two symbols, the symbols are called bits. The modulation method is a variant of frequency modulation (FM) of some carrier frequency ωc. Frequency shift keying (FSK) conveys information by decreasing the carrier frequency for the duration of a 0 symbol and increasing the frequency for th...

PURPOSE CYP1B1 mutations cause autosomal recessive congenital glaucoma. Disease risk assessment for families with CYP1B1 mutations requires knowledge of the population mutation carrier frequency. The purpose of this study is to determine the CYP1B1 mutation carrier frequency in clinically normal individuals residing in the United States. Because CYP1B1 mutations can exhibit variable expressivit...

Timing and frequency synchronizationsare the important tasks in receiver. In this paper, an efficient timing and carrier frequency offset (CFO) estimation algorithm for orthogonal frequency division multiple access/ time division duplexing (OFDMA/TDD) mode in IEEE 802.16-2004 standard (WiMAX) is represented. This method has high performance and jointly estimates timing error and CFO. The perfor...

Recognition of consonants, vowels, and sentences was measured in conditions of reduced spectral resolution and distorted spectral distribution of temporal envelope cues. Speech materials were processed through four bandpass filters (analysis bands), half-wave rectified, and low-pass filtered to extract the temporal envelope from each band. The envelope from each speech band modulated a band-lim...

Two types of radio-frequency front-end imperfections, that is, carrier frequency offset and the inphase/quadrature (I/Q) imbalance are considered for orthogonal frequency division multiplexing (OFDM) communication systems. A preamble-assisted carrier frequency estimator is proposed along with an I/Q imbalance compensation scheme. The new frequency estimator reveals the relationship between the ...

In wireless communications systems, Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) are used to improve spectral efficiency and spatial diversity. Beamforming is used to improve bandwidth utilization. It increases the network range in wireless systems. The main challenge of OFDM system is Carrier frequency offset (CFO). The project focuses on CFO esti...

In this paper, we propose a robust method to estimate carrier frequency offset (CFO) for orthogonal frequency division multiplexing (OFDM) systems. A training symbol with two identical halves is employed to measure the fractional part of the CFO. While the integral part is estimated by using a novel noise subspace based metric. Simulation results demonstrate that the proposed method can achieve...

Orthogonal frequency division multiplexing (OFDM) has developed into a popular scheme for wideband digital communications used in consumer applications such as digital broadcasting, wireless networking and broadband internet access. In the OFDM system, carrier frequency offset (CFO) causes intercarrier interference (ICI) which significantly degrades the system error performance. In this paper w...