In this paper a new phase-frequency detector is proposed using transmission gates which can detect phase difference less than 500ps. In other word, the proposed Phase-frequency Detector (PFD) can work in frequencies higher than 1.7 GHz, whereas a conventional PFD operates at frequencies less than 1.1 GHz. This new architecture is designed in TSMC 0.13um CMOS Technology. Also, the proposed PFD a...

In high dynamic conditions, using vector tracking loops instead of scalar tracking loops in GPS receivers is proved as an efficient method to compensate the performance. The Minimum Mean Squared Error detector as a multiuser detector is applied in the vector tracking loop for more reliability and efficiency. The Kalman filter does the two tasks of tracking and extracting the navigation data aft...

In CDMA (Code - Division Multiple - Access) systems multi - user accessing of a channel is possible. Under the assumptions of Optimum multi - user and decorrelating detector in CDMA systems. By using signals with zero and / or identical cross correlations, a simple and expandable decorrelating detector with optimum efficiency which can be easily implemented are proposed. Constructing these sign...

In this paper, a new multiuser detector combining multicarrier and decorrelating detection schemes is proposed and analyzed in a frequency selective Rayleigh fading channel. The bit error probability is derived and compared with that of the conventional decorrelating detector. From the numerical results, it is shown that the proposed detector achieves better BER performance and lower computatio...

The purpose of this study was to determine the performance of low-dose computed tomography (CT) scanning with integrated circuit (IC) detector in defining fine structures of temporal bone in children by comparing with the conventional detector. The study was performed with the approval of our institutional review board and the patients' anonymity was maintained. A total of 86 children<3 years o...

In this paper, we propose to use a new nonparametric noncoherent detector for PN code acquisition in DS/CDMA systems. Because this detector is nonparametric, we can decide the threshold of the detector without "rst having to estimate the variance of time-varying interference. We compare the single-dwell scheme using the proposed detector with that using the conventional detector. From the simul...

Direct sequence code division multiple access (DS-CDMA) is a popular wireless technology. This paper presents comparative study between linear multiuser detectors, optimal multiuser detector, and conventional single user matched filter in DS-CDMA system. Analysis and simulations are conducted in synchronous AWGN channel, and Gold sequence is used as the spreading codes. The study shows that opt...

Equal-gain combining (EGC) is a conventional linear combining scheme used in non-coherent energy detection receiver for ultra-wideband (UWB) signals. However, due to the nonlinear nature of decision boundary, the EGC results in a suboptimal test statistic. In this paper, we propose a new design for a nonlinear combining energy detector based on Gaussian approximation, in which the energy detect...

By the using of MCML circuits, a 4 GB/s clock non-sequential phase detector circuit is designed in a 0.35μm CMOS technology. The power dissipation of proposed phase detector is much smaller than the conventional complementary pass transistor logic (CPL) phase detector. The implemented MCML phase detector consumes 0.7688nW when operating upto 4GHz clock frequency with 3.3V supply voltage. The co...

Chaos based communications have drawn increasing attention over the past years. Chaotic signals are derived from non-linear dynamic systems. They are aperiodic, broadband and deterministic signals that appear random in the time domain. Because of these properties, chaotic signals have been proposed to generate spreading sequences for wide-band secure communication recently. Like conventional DS...