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Wang J.,Fuzhou University | Wang J.,Fujian Integrated Circuit Design Center | Huang J.,Fujian Integrated Circuit Design Center | Huang J.,Fuzhou University | And 3 more authors.
Circuits, Systems, and Signal Processing | Year: 2014

This paper proposes a novel multicycle spectrum sensing method. The method first divides the received data samples into several segments, and then gets cyclic autocorrelation estimates from these segments, constructs a test statistic from these estimates, and finally makes an F-test to determine whether there is a primary signal or not. The method can use multiple cyclic frequencies simultaneously; hence, it is a multicycle detector. The method is also nonparametric, and thus it is robust to noise uncertainty. Compared with existing cyclic spectrum sensing methods, the proposed method can reduce computational complexity significantly at the cost of a little performance loss. Simulation results are given to show the validity and the superiority of the proposed method. © 2013 Springer Science+Business Media New York.

Jun W.,Fuzhou University | Jun W.,Fujian Integrated Circuit Design Center | Xiufeng J.,Nanjing Southeast University | Guangguo B.,Nanjing Southeast University | And 3 more authors.
IEEE Transactions on Communications | Year: 2012

In cognitive radios, energy detector is considered for spectrum sensing in the literature. However, its performance deteriorates rapidly if the noise power is not known exactly. Moreover, due to the presence of a colored channel interferer or some other reasons, the conventional white Gaussian noise may become colored. In order to solve these problems, this paper proposes several multicumulant based spectrum sensing methods: generalized likelihood ratio test (GLRT) based multicumulant (GLRTMC) based detection method and multiantenna-assisted multicumulant (MAMC) based detection method. GLRTMC detection method is derived from generalized likelihood ratio test and assumed to be near optimum in theory. MAMC detection method, on the other hand, by using multiple antennas, is a complexity-reduced detector and allows us to make a compromise between performance and complexity. It is well known that cumulants higher than second order are zero for Gaussian distributions. Thus, GLRTMC detection method and MAMC detection method can extract a non-Gaussian signal from Gaussian noise even when the noise is colored. In addition, the proposed methods are nonparametric in the sense that they do not require any exact prior knowledge about the signal or the noise, such as noise power or cyclic frequencies. Hence they are immune from noise uncertainty. Simulation experiments are provided to show the validity and the superiority over single-cumulant based detector of the proposed multicumulant based detectors. © 2012 IEEE.

Xu Y.S.,Fuzhou University | Xu Y.S.,Fujian Integrated Circuit Design Center | Hu W.,Fuzhou University | Hu W.,Fujian Integrated Circuit Design Center | And 6 more authors.
Advanced Materials Research | Year: 2013

The objective of this paper is to provide tutorial treatment of the steps for analyzing poles and zeros in multi-stage amplifiers and low dropout (LDO) regulators. The steps can be easily all done by hand simplification without lacking for accuracy, and divided into two methods depending on whether Miller effect exists or not. A two-stage Simple Miller Compensation (SMC) amplifier and an output capacitor-less regulator are analyzed in detail, and several multi-stage amplifiers reported in the literature are also included. To this end, Cadence Spectre simulations are performed to compare hand-computed pole/zero locations with AC analysis. © (2013) Trans Tech Publications, Switzerland.

Huang F.Y.,Fuzhou University | Huang F.Y.,Fujian Integrated Circuit Design Center | Wang J.,Fujian Integrated Circuit Design Center | Xu Y.S.,Fuzhou University | And 3 more authors.
Advanced Materials Research | Year: 2013

This paper proposes a new synchronized serial-parallel CRC(Cycle Redundancy Check) with PIE(Pulse Interval Encoding) decoding circuit for the UHF(Ultra-High Frequency) RFID(Radio Frequency Identification), which is based on the ISO/IEC 18000-6C standards protocol. The parallel algorithm of CRC circuit is derived, and the serial or parallel CRC circuit on RFID tag chip is evaluated in this paper. Finally, the designed circuit is simulated and analyzed on the FPGA platform. Simulation results show that the proposed circuit meets the communication requirement of the protocol and addresses the problem of low data processing rate of conventional serial CRC circuit, as well as implements 1 to 8 degree of parallelism of the parallel CRC circuit for UHF RFID. © (2013) Trans Tech Publications, Switzerland.

Xu Y.,Fuzhou University | Xu Y.,Fujian Integrated Circuit Design Center | Hu W.,Fuzhou University | Hu W.,Fujian Integrated Circuit Design Center | And 4 more authors.
Proceedings of International Conference on ASIC | Year: 2013

A new low-power voltage reference circuit was proposed using the SMIC 0.18um standard CMOS process technology. The resulting voltage is equal to the extrapolated threshold voltage of a MOSFET at 0K, which was about 620mV for this process. Cadence Spectre simulation results show that the temperature coefficient of the output voltage was 12.9ppm/° in a range from -20 to 80 °. The line sensitivity was 328ppm/V in a supply voltage range of 1.2-3V. Meanwhile - 68 dB @ 100Hz of the power supply rejection ratio (PSRR) is reached and it merely consumes 0.21 μ W of power. The proposed circuit is full composed of CMOS devices without any use of resistors, which enjoys the merits of low power consumption and small chip area. © 2013 IEEE.

Chi S.S.,Fuzhou University | Chi S.S.,Fujian Integrated Circuit Design Center | Hu W.,Fuzhou University | Hu W.,Fujian Integrated Circuit Design Center | And 6 more authors.
Applied Mechanics and Materials | Year: 2014

This paper presents a capacitor-less CMOS low dropout regulator (LDO) with a push-pull class AB amplifier, and a fast transient controller to achieve a better transient response. The undershoot/overshoot voltage and the settling time are effectively reduced. Through the theoretical analysis of the circuit, cadence simulation with SMIC 0.18μm process and under the condition of the input voltage range 1.4~4 V shows the output voltage is 1.2 V, with the fast controller the total quiescent current is 8.2 μA, the undershoot /overshoot voltage is 97 mV/47 mV and the settling time is 0.3 μs as load current suddenly changes from 1 to 100 mA, or vice versa. Compared with this paper without fast transient controller, the undershoot voltage, the overshoot voltage and the settling time are enhanced by 30%, 64% and 80%, respectively. © (2014) Trans Tech Publications, Switzerland.

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