We present the study of DC currents of an open dot generated from two time dependent electric fields in the absence of external bias. Two electrical setups were applied. In one configuration, two fast oscillating voltages were applied on two side gates; in the other, one of the oscillating biases was directly applied to the source lead. The DC current as a function of frequency, coupling strength, and magnetic field was investigated. The current is sinusoidally dependent with the phase shift and bilinearly dependent with the excitation voltage for both configurations. However, the current as a function of frequency, coupling strength, and magnetic fields behaves differently in these two setups. The results indicate that the currents generated in different setups originate from different mechanisms, and moreover, not from any classical circuitry effect.

TCP Vegas has the problem that it stops slow start too early, and it is more obvious in the large delay-bandwidth network. This phenomenon can cause a very long linear growth after entering congestion avoidance phase, and it will reduce the transmission efficiency. This paper analyzes that the reasons for this phenomenon is due to the exponential growth of slow start itself, then puts forward a dynamic growth algorithms of slow start, we call it Vegas-f. Improved algorithms can dynamically adjust the growth rate of slow start, so as to improve the transmission efficiency and competitiveness in mixing network. Simulation results show that the improved algorithm has completely solved the problem and the performance is improved significantly.

In this paper, based on the analysis of the existing encapsulation schemes, Generic Stream Encapsulation (GSE) is chosen to transmit IP-based services in the Terrestrial -Digital Multimedia Broadcasting (T-DMB) system. As a new emerging technology, no corresponding Forward Error Correction (FEC) function is considered for GSE. This motivates us to propose a GSE-FEC method for obtaining additional error protection, in the form of Reed Solomon (RS) outer error protection and virtual interleaving. To further improve the error correction capability of the proposed GSE-FEC, an Improved GSE Erasure (IGE) decoding scheme is presented. This IGE scheme allows us to obtain the erasure information and GSE-FEC frame reconstruction information by an Improved GSE (IGSE) encapsulation scheme.Simulation results demonstrate that the IGE scheme shows better characteristics than the Non-Erasure (NE) decoding scheme and the GSE Erasure (GE) decoding scheme which is based on the original GSE encapsulation. Moreover, compared with the GE scheme, the proposed scheme can reserve the correct bytes to the best of its ability for avoiding information wasting.

Multiple-input multiple-output (MIMO) interference broadcast channel (IBC) plays an important role in the modern wireless communications. The upper bound of degree of freedom (DoF) and corresponding achievable schemes have been investigated. However, all the achievable schemes require perfect channel state information at transmitters (CSIT). In the absence of CSIT, the DoF value is still unknown. This paper mainly focuses on theG-cellK-user MIMO IBC, where there areMantennas at each transmitter andNantennas at each receiver. The transmitters only know channel coherent time internals rather than the values of channel coefficients. The users in the same cell are assumed to be able to share the channel information. Based on a heterogeneous block fading model, a blind interference alignment (IA) scheme is proposed for this scenario. We show that when and , then a total of degrees of freedom (DoF) can be achieved. The inner bound is same with the decomposition DoF upper bound.

In this paper, we present a modified discrete Fourier transform (DFT)-based channel estimator for orthogonal frequency-division multiplexing (OFDM) systems with null carriers. Due to the channel leakage, the conventional DFT-based estimator has the problem of error floor. In order to suppress the leakage, we adopt the optimal leakage suppression method. Moreover, a novel denoising method based on dual-tree complex wavelet is proposed to further improve the performance. Simulation results show that the proposed channel estimator can effectively overcome the performance degradation caused by the leakage and additive-white gaussian noise (AWGN).