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...

An alternative method for communicating over frequency-selective channels is multi-carrier modulation. In a multi-carrier system, the available bandwidth is divided into many narrow subbands, such that the channel distortion appears as flat (frequency-nonselective) within each subband. Thus, no equalization is needed per subband. Instead, modulation and demodulation have to be performed over mu...

In the near future, the need for portable multi-antenna wireless devices supporting high data-rates in a harsh mobile environment is anticipated. Typically, in this scenario, the underlying wireless channels are timeand frequency selective, hence doubly selective (DS). Multicarrier modulation (MCM) schemes, wherein data is split into sub-streams and transmitted on a set of subcarriers in parall...

Underwater acoustic communication has the characteristics of multipath effect and frequency selectively attenuation. Aiming at these characteristics, this paper proposes a Multi-Rate model based on channel feature based on OFDM (Orthogonal Frequency Division Multiplexing) technology. With the frequency selectivity of underwater acoustic channel and the link distance, the optimal carrier frequen...

In this paper, we study the performance of block diagonalization (BD) scheme for a downlink multiuser multi-input multi-output (MIMO) system with imperfect channel state information (CSI). At each mobile user, information about the channel is obtained by applying the minimum mean-square-error (MMSE) channel estimation method. The channel state information is fed back to the base station through...

We consider the problem of joint carrier frequency offset and channel estimation between transmitter and receiver in a frequency-selective channel MIMO-OFDM system. Recently two high performance estimators based on the expectation-maximization (EM) algorithm have been proposed. The main drawback of the maximum likelihood base algorithms, like EM algorithm, is the high computational complexity. ...

In this paper, we investigate the system performance of a multi-cell multi-user (MU) hybrid millimeter wave (mmWave) multiple-input multiple-output (MIMO) network adopting the channel estimation algorithm proposed in [1] for channel estimation. Due to the reuse of orthogonal pilot symbols among different cells, the channel estimation is expected to be affected by pilot contamination, which is c...

A method for the single trial estimation of the evoked potentials is presented. The method is based on the regularized least squares scheme. An approach to single trial estimation of multi channel evoked potentials is derived by applying additional information of the spatial correlation of the channels to the estimation. Amplitude estimates obtained with these methods are compared. The performa...

Multi-carrier (MC) signal has a large peak to mean envelope power ratio, so that the MC signal suffers from a high level of inter-modulation distortion due to the nonlinearity of the power amplifier stage. For portable terminals, it is undesirable to use linear amplifiers because high power efficiency is needed. To solve this problem, we propose a time division duplex (TDD)–code division multip...