In this paper, we study the channel estimation in the presence of the receiver in-phase and quadrature-phase (I/Q) imbalance and carrier frequency offset (CFO) for orthogonal frequency division multiplexing (OFDM) systems using pilot symbols. The concept of channel residual energy (CRE) [9] is used to solve the joint estimation problem. By minimizing the CRE, we can jointly estimate the receive...

Multiple input multiple output (MIMO) communications has become a stalwart in high speed communication systems. By using multiple antennas along with space-time coding, one can leverage spatial diversity gain, or multiple propagation paths, for transmitted signals. This in turn can improve reliability in communication systems. Channel shortening is necessary when the channel impulse response is...

Recent results have shown that blind channel estimators, which are resilient to the location of channel zeros, color of additive stationary noise, and channel order overestimation errors, can be developed for communication systems equipped with transmitter-induced cyclostationarity precoders. The present paper extends these blind estimation approaches to the more general problem of estimating t...

~~~. ~~~~~~ ~ . . ~ ~ ~ ~ ~ ~ ~ . ~ ~ ~ ~ ~ ~ . . near the Cram&-Rao bound in the variance of estimation errors: Simulations of several estimation algorithms in a estimation. Also the complex data of the pilot subcarriers, instead of their phases, are averaged. However, these multipath fading channel show'that this algorithm provides the most accurate estimation in both the carrier frequency of...

Effectiveness of the application telecommunications systems is directly influenced by effectiveness functioning each component and device its design. The article examines issue improving carrier frequency estimation methodology for data transmission in telecommunication management distance learning systems. essence solution lies proposals efficiency at input signal synchronization stage, which ...

For wireless transmission, the channel estimation is necessary to improve the performance of receiver. In the ultra-wideband (UWB) wireless systems, there are two practicable modulation schemes: orthogonal frequency-division multiplexing (OFDM) and single-carrier direct-sequence UWB (DS-UWB). The OFDM based scheme is an attractive mode because it can capture the multipath energy more efficientl...

We consider the problem of digital communication in a fading environment using the Multi-Carrier CDMA technology. By incorporating the effect of the pulseshaping filter in the channel estimation and signal detection modules, we develop new estimator and detector structures which significantly outperform the commonly used timedomain equalizers and matched filter detector. Our simulation results ...

Abstract—A low-complexity, high-accurate frequency offset estimation for multi-band orthogonal frequency division multiplexing (MB-OFDM) based ultra-wide band systems is presented regarding different carrier frequency offsets, different channel frequency responses, different preamble patterns in different bands. Utilizing a half-cycle Constant Amplitude Zero Auto Correlation (CAZAC) sequence as...

Channel knowledge is the important information required for good UWB communications. So many methods are available for UWB channel estimation. However, it is critical to find the multi-path clustered model of UWB transmission. In this paper, we present a new Innovative method with very simple and less complex channel estimation technique. We derived channel estimation equation for the Time Hopp...

Abstract— Spatial multiplexing and diversity are in a tradeoff relationship. Multiple-input multiple-output (MIMO) can increase the maximum throughput in a good propagation environment by selecting high multiplexing order, but the achievable throughput degrades in a poor propagation environment. By adaptively selecting the multiplexing order according to the changing propagation environment, th...