Maximum Likelihood (ML) algorithms, for the joint estimation of synchronization impairments and channel in Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system, are investigated in this work. A system model that takes into account the effects of carrier frequency offset, sampling frequency offset, symbol timing error, and channel impulse response is formu...

Similar to the single-carrier transmission [1], the bit error rate (BER) performance of DS-CDMA in a frequency-selective fading channel can be significantly improved with coherent frequency-domain equalization (FDE) instead of using Rake combining [2][3]. However, coherent FDE requires accurate channel estimation and the imperfect channel estimation results in the performance degradation. For p...

The purpose of this paper is to compare the turbocoded orthogonal frequency division multiplexing (OFDM) and turbo-coded single carrier frequency domain equalization (SCFDE) systems under the effects of carrier frequency offset (CFO), symbol timing offset (STO) and phase noise in wideband VoglerHoffmeyer HF channel model. The BER performance versus CFO, STO and phase noise obtained through Mont...

We consider blind estimation of the carrier frequency o set of a linearly modulated non-circular transmission through an unknown frequency selective channel. A frequency estimator is developed based on the unique conjugate cyclic frequency of the received signal that equals twice the frequency o set. We establish consistency and asymptotic normality of the frequency estimator, and calculate its...

This paper analyzes the channel model under mobile reception state firstly, then study the self-correlation characteristic of ATSC-Mobile DTV training sequence. According with the mobile channel characteristic and selfcorrelation of training sequence, proposed a parallel channel estimation algorithm with multi-channel to reduce the channel estimation time and to improve the estimation efficienc...

The fundamental limit that is imposed on any wireless system is due to the radio channel. Propagation and channel models are essential for the analysis and simulation of wireless systems. Knowledge of the radio channel is essential to the development and deployment of a wireless system. Radio channel models are used to support research into methods for mitigating channel impairments, such as th...

A carrier frequency synchronization scheme is proposed for orthogonal frequency-division multiplexing (OFDM) systems in the presence of phase noise (PHN). In the proposed scheme, carrier frequency synchronization is performed based on the maximum-likelihood (ML) algorithm using an OFDM preamble symbol. The proposed scheme is compared with conventional methods. Simulation results are presented t...

This paper proposes novel application of the Bees algorithm to multi objective optimization problems for the uplink of a multi carrier code division multiple access (MCCDMA) system based on orthogonal frequency division multiplexing (OFDM). The multiple input multiple output (MIMO) channel from users, which moves at vehicular speed, to the base-station (BS) is time variant. For time varying cha...

We propose and experimentally demonstrate a wavelength-division multiplexed (WDM) optical stealth transmission system carried by amplified spontaneous emission (ASE) noise. The stealth signal is hidden in both time and frequency domains by using ASE noise as the signal carrier. Each WDM channel uses part of the ASE spectrum, which provides more flexibility to apply stealth transmission in a pub...

We introduce a multi-channel soft input/soft output receiver for underwater communication that performs joint iterative channel estimation, linear equalization, and decoding. The transmitted symbols were encoded using a turbo coded bit-sequence. Our method exploits the gain present in the turbo code through a feed-back of soft information from the decoder to the channel estimator and to the equ...