Vol.7 No.4 April 10, 2012
Recent Advanced Technology for Mobile Multimedia Services

Editorial (237-238)
        Xingang Liu

Research Articles:

SSN: A Seamless Spontaneous Network Design around Opportunistic Contacts (239-255)
        Jian-Xiong Yin and Min Chen
Current mobile computing research has identified great potential of device-to-device local collaborations, e.g., crowd sourcing. The utilization of the free wireless radio channels has also been suggested for the benefit of infrastructure. On the other hand, both high transmission ratio and low security risks are considered fully necessary for mobile platform services. We identified such basic application scenario and system requirements, and present design principle of a device-to-device communication framework named Seamless Spontaneous Networks (SSNs). SSN links the applications layers of separated devices by raising APIs so that SSN could be leveraged for high-level data exchange with regards to privacy control, security and delivery to anonymous endpoints. We implemented SSN on Android-based off-the-shelf smartphones and carried out the assessment and analysis of its performance.

Performance Comparison of Airborne Phased-Array and MIMO Radar with Subarrays (256-266)
        Yong-Zhe Li, Hui-Yong Li, Jun Li and Zi-Sun He
A generalized signal model for airborne phased-array (PA) and multi-input multi-output (MIMO) radar with colocated antennas is proposed. This model is based on partitioning the transmit array into a certain number of uniform subarrays that are allowed to overlap. Different subarrays transmit identical waveforms for PA radar while orthogonal or non-coherent ones for MIMO which maintains coherent processing gain in each of them. Passive element-level phase shifting is utilized within each subarray in order to steer the scanning beams. On the basis of the unified model, we focus on the performances of space-time adaptive processing (STAP) and nonadaptive processing technique by formulating and evaluating the signal-to-interference-noise ratio (SINR) for PA and MIMO radar. Beamforming-based modified joint domain localized (BBM-JDL) method is employed as the STAP technique. It is verified that under the same coverage condition, performances of PA and uniform non-overlapped MIMO radar are nearly same, while fully overlapped MIMO radar possesses the potential of achieving higher performance.

A Novel Full-reference Video Quality Assessment Metric for Multimedia Broadcasting Systems  (267-278)
        Xin-Gang Liu, Chao Sun, and Wenjie Yang
In this paper, A novel full reference (FR) video quality assessment (VQA) metric for the multimedia broadcasting systems is proposed. The relationships between the VQA parameters and the quality score obtained by the subjective human visual system (HVS) model of the distorted videos are investigated. Considering the multiple effects which have relationships with the subjective VQ, Spatial frequency analysis (SFA), MSSIM, Matched PSNR (MPSNR) and Edge degradation(ED) are employed to estimate the quality of the video sequences. The simulation results show that our proposed metric can give high correlation with the subjective video quality (VQ) score and has the immersive potential to realize the application to the end-users.

Research on the Effect to the Eigen Modes and Effect of Miniaturization of the Metal Cavity Resonators Partly Occupied by a Magnetic-dielectric Composite Material with ε_r=10 and μ_r=10  (279-284)
        Xiaowei Wang, Jin Pan, and Pengcheng Li
This paper discuss the effect to the Eigen frequency of the metal cavity resonator partly occupied by magnetic-dielectric composite material by simulation and comparison, which is then used to assess the effect of miniaturization. Some important properties are found, which is useful the miniaturization of passive devices for communication.

A 3D Interactive System for 3D Display  (285-304)
        Pei-Jun Lee, Effendi, and Yung-Yen Sun
This paper proposes an interactive 3D picture system for 3D display application which includes the techniques of 3D content synthesis based on 2D image with its depth image and the interaction between the user, picture, and environment. The conversion technique uses depth image based rendering (DIBR) to synthesis 3D image. An adaptive depth map pre-processing method is proposed for DIBR to solve the hole occurring problem on virtual view images. The interaction is achieved based on the measurements of the sensors installed around the system and the methods of interaction tool recognition and speed estimation. To enhance the interaction, some sensors are installed around the picture system so that the scene in the picture can change corresponding to its surroundings. Experimental results show that the proposed system can convert any 2D image into a 3D image with good quality and achieve real-time interaction between the user, picture, and environment successfully. This proposed system can provide a good achievement for 3D display application.

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