In this paper maximum likelihood (ML) estimator is proposed for the joint estimation of the direction of arrival (DOA) and range parameters of moving sources in the near-field of the antenna array. ML estimation algorithm is presented for deterministic signal model. Recursive form of the expectation maximization (REM) algoritm is suggested for the estimation of the near-field parameters because there is not closed form solutions for the maximum likelihood functions. Moreover simulation results of ...

In this paper various post-operative recurrence estimation models called nomograms for the kidney cancer patients without any metastates are introduced and novel systems based on a Multilayer Perceptron Neural Network are designed to simplify and integrate the mentioned techniques which is believed to ease the physician's post-operative follow up procedures. The parameters effecting the recurrence are the TNM stage tumor size and nuclear (Fuhrman) grade the existance of necrosis and vascular ...

Cooperative underwater acoustic communication systems come into prominence in recent years. Since underwater channels are sparse and additive noise entering the system is colored Gaussian noise it is very difficult to estimate the underwater channels and theoretically makes it interesting. in the first part of the thesis the transmission from source to the target recipient is realized by means of a relay system. Orthogonal frequency division multiplexing (OFDM)-based channel estimation problem is ...

As a result of increasing demand for new technologies unlicensed usage of available spectrum has become very essential to provide an efficient usage of spectrum. For that reason sensor networks may be a reliable option to decide on the absence/presence of licensed users and to communicate without causing much interference as a secondary user network. These networks consist of two communication links for primary user detection. One link is between the primary user and the sensors and the other link ...

This paper is concerned with the challenging and timely problem of joint channel estimation and equalization for orthogonal frequency division multiplexing (OFDM) systems in the presence of frequency selective and very rapidly time varying channels. The resulting algorithm is based on the space alternating generalized expectation maximization-maximum a posteriori probability (SAGE-MAP) technique which is particularly well suited to multicarrier signal formats. The algorithm is implemented in the ...

The performance of multiple input single output (MISO) and multiple input multiple output (MIMO) systems is limited by spatial channel correlation. This limitation becomes particularly severe in light lidelity (LiFi) systems, which use intensity modulation/direct detection (IM/DD) for data transmission, because light emitting diodes (LEDs) can only emit incoherent light. This paper proposes a novel transmitter structure that provides spatially separated channels and enables optical MISO/MIMO spatial ...

In this paper the performance of coded OFDM transmission over multiple antennas is explored when joint transmit and receive antenna selection is employed. The channel is assumed as Rayleigh frequency selective fading channel and only receiver is assumed to have perfect channel state information (CSI). The performance of MIMO OFDM system using pragmatic coding techniques such as convolutional coding (CC) and space-time block coding (STBC) with antenna selection based on subcarrier groups and other ...

Visible Light Communication(VLC) has been considered as a potential access option for 5G wireless systems to solve performance limitation due to bandwidth shortage at radio frequency (RF) band. In (VLC) system illumination infrastructure has dual usage at the same time namely illumination and wireless data transmission. DC Biased optical (DCO)-OFDM has been proposed for VLC systems to provide optically power efficient solution and easy implementation. Wireless communication systems generally require ...

In this paper we propose optical orthogonal frequency division multiplexing with index modulation (O-OFDM-IM) for visible light communications (VLC) systems employing light emitting diodes (LEDs) and photodetectors (PDs). The proposed scheme uses the indices of the active subcarriers of an optical OFDM system to transmit additional information bits. In the proposed scheme the bipolar signals are asymmetrically clipped or DC biased and a log-likelihood ratio (LLR) calculation based detector is used ...

In this paper a new optical orthogonal frequency division multiplexing (OFDM) method is proposed for multiple-input multiple-output (MIMO) visible light communications (VLC) systems. In the new scheme non-DC biased optical OFDM (NDC-OFDM) and optical spatial modulation (OSM) methods are combined to obtain a novel optical OFDM scheme which has a better error performance. The new scheme is named as non-DC biased optical spatial modulation OFDM (NDC-OSM-OFDM). It is shown via computer simulations ...