scholarly journals An Improved Cross Talk Cancelling Digital Predistortion for MIMO Transmitters

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zhiliang Zhang ◽  
Ying Shen ◽  
Shihai Shao ◽  
Wensheng Pan ◽  
Youxi Tang

An improved cross talk cancelling digital predistortion (ICTC-DPD) with novel estimating technique and decoupling technique is proposed, which can be used to compensate the cross talk with possible delay and compensate the nonlinearity with memory effect in MIMO transmitting channels. The cross talk cancellation ability, which is defined as the cross talk power ratio before cancellation to after cancellation in decibel, is analyzed and its closed-form expression is derived. Simulation results prove that the ICTC-DPD can achieve higher cross talk estimation accuracy and higher cross talk cancellation ability than the original CTC-DPD. Experimental results show that the ICTC-DPD can achieve 20 dB cross talk cancellation for two channels transmitting 20 MHz LTE signals.

2012 ◽  
Vol 503 ◽  
pp. 163-168
Author(s):  
Shi Tao Wang ◽  
Yu Bin Jia ◽  
Bin Zhen Zhang ◽  
Xue Song Liu ◽  
Qin Wen Huang ◽  
...  

In this paper, an integrated 3-axis MEMS accelerometer was analyzed. Because of asymmetrical structure, z-axis sensing element, which was imbedded in the proof mass of lateral accelerometers, had large mechanical coupling. Simulation result showed that the cross talk in z-axis was as high as 64.3%. To solve the problem, a fully symmetrical structure with vertical springs was adopted in z-axis sensing element. The movement of z-axis was linear vertical displacement instead of torsional displacement. Simulation results showed there was no obvious cross talk in z-axis sensing element.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hongyuan Gao ◽  
Yangyang Hou ◽  
Shibo Zhang ◽  
Ming Diao

With the further research in communication systems, especially in wireless communication systems, a statistical model called Nakagami-mdistribution appears to have better performance than other distributions, including Rice and Rayleigh, in explaining received faded envelopes. Therefore, the Nakagami-mquantile function plays an important role in numerical calculations and theoretical analyses for wireless communication systems. However, it is quite difficult to operate numerical calculations and theoretical analyses because Nakagami-mquantile function has no exact closed-form expression. In order to obtain the closed-form expression that is able to fit the curve of Nakagami-mquantile function as well as possible, we adopt the method of curve fitting in this paper. An efficient expression for approximating the Nakagami-mquantile function is proposed first and then a novel heuristic optimization algorithm—generalized opposition-based quantum salp swarm algorithm (GO-QSSA)—which contains quantum computation, intelligence inspired by salp swarm and generalized opposition-based learning strategy in quantum space, to compute the coefficients of the proposed expression. Meanwhile, we compare GO-QSSA with three swarm intelligence algorithms: artificial bee colony algorithm (ABC), particle swarm optimization algorithm (PSO), and salp swarm algorithm (SSA). The comparing simulation results reveal that GO-QSSA owns faster convergence speed than PSO, ABC, and SSA. Moreover, GO-QSSA is capable of computing more accurately than traditional algorithms. In addition, the simulation results show that compared with existing curve-fitting-based methods, the proposed expression decreases the fitting error by roughly one order of magnitude in most cases and even higher in some cases. Our approximation is proved to be simple and efficient.


2005 ◽  
Vol 72 (1) ◽  
pp. 147-148 ◽  
Author(s):  
Jen-San Chen ◽  
Jian-San Lin

In this note we show that for a pinned half-sine arch under end couples snap-through buckling will occur unsymmetrically if the initial height of the shallow arch is greater than 6.5466r, where r is the radius of gyration of the cross section. The closed-form expression for the critical couple can be obtained analytically.


2018 ◽  
Vol 18 (18) ◽  
pp. 1567-1571
Author(s):  
Anna Lucia Tornesello ◽  
Luigi Buonaguro ◽  
Maria Lina Tornesello ◽  
Franco M. Buonaguro

2013 ◽  
Vol 313-314 ◽  
pp. 1115-1119
Author(s):  
Yong Qi Wang ◽  
Feng Yang ◽  
Yan Liang ◽  
Quan Pan

In this paper, a novel method based on cubature Kalman filter (CKF) and strong tracking filter (STF) has been proposed for nonlinear state estimation problem. The proposed method is named as strong tracking cubature Kalman filter (STCKF). In the STCKF, a scaling factor derived from STF is added and it can be tuned online to adjust the filtering gain accordingly. Simulation results indicate STCKF outperforms over EKF and CKF in state estimation accuracy.


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