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Automatic test paper generation system is to automatically generate papers by computer from test database with many constraint conditions according to requirements of teachers and teaching. It could greatly reduce teachers' work, and make the difficulty coefficient of test paper reasonable. The system plays an important role in reform of examination system. Traditional genetic algorithm uses binary...
This paper proposes a novel interference-resistant receiver for wideband long-term evolution (LTE) system which employs orthogonal frequency division multiple access (OFDMA) for the downlink. In case the received spectrum is underutilized, compressed sensing (CS) enables us to operate at a sub-Nyquist sampling rate for lower device cost, higher data transmission rate and faster spectrum sensing speed...
Heterogeneous network (HetNet) uses two-tier network architecture in which an unplanned femtocell layer is randomly deployed with no coordination between the coexisting macrocell layer. Both layers share the same spectrum so that spontaneous intercell interference is unavoidable and needs to be identified and canceled afterwards. In order to address the subsequent interference management, this paper...
This paper proposes a randomly jittered temporal sampling scheme with a successive approximation register (SAR) ADC. The sampling time points are jittered around a uniform sampling clock. A control logic is implemented on a traditional SAR ADC to force it to terminate the sample conversion before reaching the full precision at the jittered time points. As a result, variable word length data samples...
Cognitive radio (CR) systems offer higher spectrum utilization by opportunistically allocating the unused spectrum from primary users to secondary users. For CR it is vital to perform fast and accurate spectrum sensing in a wideband and noisy channel. Cyclic feature detection performs well in signal detection and is also highly robust to noise uncertainty. However, it requires a high sampling rate...
This paper presents a novel digital blind calibration method for time interleaved analog to digital converters (TIADCs). A simple cost function based on the cross-correlation of channel statistics is used to derive a steepest descent algorithm for the compensation of timing mismatch errors. Instead of calibrating the timing mismatches independently for each channel, only one adaptation channel needs...
This paper proposes a general structure for FIR filters with adjustable magnitude and phase responses controlled by a few parameters. The Farrow structure which uses one parameter to control the fractional delay of an FIR filter can be viewed as special case. A filter bank structure consisting of different types of linear phase differentiators forms the basis of the structure. The filter bank outputs...
Multicast is emerging as an important means of transmitting the same content to multiple receivers so as to efficiently utilize the overall network resource. We propose an opportunistic multicast scheduling algorithm that exploits time-varying channel conditions in time division multiplexing (TDM) cellular networks and maximizes the overall network throughput under certain resource fairness constraints...
The contourlet transform provides a flexible directional image decomposition by employing Laplacian pyramid and uniform directional filter banks. Although it is able to efficiently capture the 2-D piecewise smooth functions with line or curve discontinuities, its major drawbacks of 4/3 redundancy and non-ideal filter banks in Laplacian pyramid are the main obstacles for high performance image/video...
Although wavelet-based scalable video coding becomes the state-of-the-art video compression engine for its adaptability to heterogeneous networks and clients, a large number of attempts have been made to integrate local directionality onto discrete wavelet transform to explore the intrinsic geometrical structures. Taking into consideration that the contours and textures scattered in different scales...
Regarding orientation resolution as an isolated variable from scale, this paper proposes a dual (scale and orientation) multiresolution transform into scalable video coding (SVC) framework. By projecting 2D signals (textures and edges) onto nonuniformly divided orientation subspaces, the dual multiresolution SVC (DMSVC) can capture 2-D curve smoothness with less coefficients, and provide more flexible...
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