Enhanced Receivers for Interference Cancellation in 3G Systems

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 and their properties are verified via simulations. The results imply that some of these algorithms are able to overcome the performance of the conventional receivers

A closed core microfluxgate sensor with cascaded planar FeNi rings

In this paper, we present a new microfabricated fluxgate sensor structure using cascaded planar rings as the ferromagnetic core. The planar ring structures provide closed magnetic excitation loops enabling uniform core saturation with relatively small excitation magnetic field. The magnetic excitation is provided with a rod passing through the ring cores. Planar coils placed under the edges of the core are used as sensing elements. By using this structure, fluxgate sensors having a closed core configuration are realized with a developed microfabrication process in a very small area (<0.1 mm(2)) with reduced number of via connections. The ferromagnetic rings are realized with a standard FeNi (iron nickel) electroplating process. The main advantage of this structure is the possibility to arrange the linear operation range of the sensor by only changing the number of ring cores, without affecting the excitation mechanism. This is demonstrated by simulations and microfabricated prototypes having 18 and 12 ring cores with +/- 300 mu T and +/- 550 mu T linear operation ranges, respectively. A maximum linear operation range of +/- 2 mT is achieved with a larger size, 4-ring core. This is the widest linear operation range achieved with the microfabricated fluxgate type sensors, without using a feedback loop, to the best of our knowledge. (C) 2010 Elsevier B.V. All rights reserved

Submicrometer Hall devices fabricated by focused electron-beam-induced deposition

Hall devices having an active area of about (500 nm)(2) are fabricated by focused electron-beam-induced deposition. The deposited material consists of cobalt nanoparticles in a carbonaceous matrix. The realized devices have, at room temperature, a current sensitivity of about 1 V/AT, a resistance of a few kilo-ohms, and can be biased with a maximum current of about 1 mA. The room-temperature magnetic field resolution is about 10 muT/Hz(1/2) at frequencies above 1 kHz

Admission Control Techniques for UMTS System

Universal mobile telecommunications system (UMTS) is one of the 3rd generation (3G) cell phone technologies. The capacity of UMTS is interference limited. Radio resources management (RRM) functions are therefore used. They are responsible for supplying optimum coverage, ensuring efficient use of physical resources, and providing the maximum planned capacity. This paper deals with admission control techniques for UMTS. An own UMTS simulation program and several versions of proposed admission control algorithms are presented in this paper. These algorithms are based on fuzzy logic and genetic algorithms. The performance of algorithms is verified via simulations

Comparison of Pilot Symbol Embedded Channel Estimation Algorithms

In the paper, algorithms of the pilot symbol embedded channel estimation are compared. Attention is turned to the Least Square (LS) channel estimation and the Sliding Correlator (SC) algorithm. Both algorithms are implemented in Matlab to estimate the Channel Impulse Response (CIR) of a channel exhibiting multi-path propagation. Algorithms are compared from the viewpoint of computational demands, influence of the Additive White Gaussian Noise (AWGN), an embedded pilot symbol and a computed CIR over the estimation error

Micro fluxgate sensor with cascaded planar ring cores

In this paper, we present a new microfabricated fluxgate sensor structure having cascaded planar rings as the ferromagnetic core. A circular magnetic excitation is provided with a rod passing through the FeNi rings as a sewing thread. Planar coils placed under the edges of the core are used as sensing elements. The sensing coils and the excitation rod are made of AlSi, and the planar FeNi ferromagnetic core is electroplated in between the excitation rod metallization. The sensor with 18 cascaded cores has 623 mu V/mT sensitivity and +/- 300 mu T linear operation range for a sinusoidal current excitation at 1 MHz with 170 mA peak

Advanced Fuzzy Logic Based Admission Control for UMTS System

The capacity of CDMA (Code Division Multiple Access) systems is interference limited. Therefore radio resources management (RRM) functions are used. They are responsible for supplying optimum coverage, ensuring efficient use of physical resources, and providing the maximum planned capacity. This paper deals with admission control techniques for UMTS (Universal Mobile Telecommunication System). A UMTS system model and four fuzzy logic based admission control algorithms are presented in this paper. Two new versions of fuzzy logic based admission control algorithms are presented there. All algorithms are mutually compared via simulations. Simulations show that the novel advanced fuzzy algorithm outperforms the other simulated algorithms (in terms of blocking probability, dropping probability and the number of active UEs in cell)