Although numerous channel estimation and multiuser detection approaches have appeared for long-code uplink CDMA systems, joint performance study of channel estimators and symbol detectors remains largely open. In this paper, we construct three typical symbol-level linear receivers upon existing channel estimationmethod, known as zero-forcing (ZF), minimummean-square-error (MMSE), and RAKE recei...

We extend the direct sampling method proposed in [13] to image a wavepenetrable inhomogeneous medium in a 3D waveguide. Incidences and receivers are available only on part of the surface of a cylinder. The proposed method is basically direct and does not involve any matrix inversions or optimizations, thus computationally very cheap and efficient. Numerical simulations are presented to show the...

The structure of the optimum direct detection array receiver is obtained for a system consisting of an amplitude-stabilized optical source, a lognormal channel, and a bank of photocounting detectors. Additive independent background radiation and detector dark current are taken into account. Both orthogonal and nonorthogonal M-ary signaling formats are considered. Attention is given to detection...

This paper presents a study of LO selfmixing and RF gain control issues in direct conversion receivers. In cellular systems, that use continuous time frequency duplexing, these can constitute serious problems. The presented topic is of special importance when digitally programmable gain is implemented at the RF frequencies before the downconversion mixers, practically in the LNA. Furthermore, t...

First receiver I was ever built for HF was tube receiver without RF amplification called OV2 .It was working good and enable me to listen short waves and HAM bands. After that I build super heterodyne receivers but when I built DC transceiver by W7EL at the beginning of 80’s ZL2BKW version I was surprised how good DC receiver can be. With simple dipole antenna for 7MHz I worked 102 DXCC in 1985...

primary assumption in most problems of elasticity theory in petroleum geophysics is that the elastic media is isotropic. laboratory experiments confirmed that most rocks are anisotropic. if in one medium, properties vary with directions, it is named as anisotropic. knowledge about anisotropy reduces risk and cost of hydrocarbon production. in the present study, anisotropy of a carbonate reservo...

In this paper, we analyze the performance of a particular class of Transmitted–Reference (TR) receivers for Impulse Radio (IR–) Ultra Wide Band (UWB) communication systems, which is called Chip–Time Differential Transmitted– Reference (Tc–DTR). The analysis aims at investigating the robustness of this receiver to single– and multi–tone Narrow–Band Interference (NBI), and at comparing its perfor...

Ambient backscatter communication (AmBC) is an emerging technology enabling green Internet of Things deployments. The widespread acceptance this paradigm limited by the low signal-to-interference-plus-noise ratio (SINR) signal impinging on receiver antenna due to strong direct path interference and unknown ambient signal. adverse impact these two factors can be mitigated using noncoherent multi...

In this paper, noncoherent receivers for differential space–time modulation (DSTM) are investigated. It is shown that the performance of the previously proposed conventional differential detection (DD) receiver is satisfactory only for very slow flat fading channels. However, conventional DD suffers from a considerable loss in performance even for moderately fast fading. In order to overcome th...

Interference cancellation and multiuser detection in CDMA systems are still actual research topics. These techniques enable us to deal with interference and to increase system capacity. In this paper, a so-called Generalized RAKE receiver, an Uplink generalized multiuser detection and a Blind adaptive multiuser detection are described. These algorithms are compared with conventional receivers a...