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Liu J.,Tsinghua National Laboratory for Information Sciences and Technology | Zhang Y.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,China Digital TV | Song J.,National Engineering Laboratory for DTV
IEEE Transactions on Broadcasting | Year: 2014

In this paper, we focus on energy-efficient opportunistic multicast scheduling design method and user sleeping mechanism for the scalable video transmission in a wireless network. The goal is to minimize the total energy consumption for the terminal when receiving streaming video with bandwidth constraint and users' minimum QoS requirements. To utilize opportunistic multicast scheduling, unequal erasure protection (UXP) scheme is used for scalable video at the application layer. Considering the encoding characteristics and unequal protection scheme of scalable video, the UXP frame-level QoS is defined. And a low-complexity scheduling algorithm is proposed by transforming frame-level QoS requirement into slot-level QoS requirement within each time slot dynamically. Performance evaluations are firstly conducted for general data service with unlimited number of transmission rates, and then extended to scalable video service with limited number of transmission rates. Simulation results show that our proposed algorithm has less energy consumption of all the multicast users than the conventional scheduling schemes with the same users' QoS requirements guaranteed in both homogeneous and heterogeneous networks. © 1963-12012 IEEE.


Yan K.,Tsinghua National Laboratory for Information Sciences and Technology | Yang F.,Tsinghua National Laboratory for Information Sciences and Technology | Pan C.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,China Digital TV
IEEE Transactions on Broadcasting | Year: 2012

Single frequency network (SFN) is an attractive scheme for the digital television terrestrial broadcasting (DTTB) coverage with efficient utilization of the spectral resources. In this paper, a method featuring low complexity and low workload is proposed to estimate the reception quality under the SFN environment with the maximum delay spread of the artificial multipath no longer than the guard interval. Based on the analysis of error probability and channel capacity, this method supports an unambiguous prediction of the signal-to-noise ratio (SNR) threshold according to the parameters of received signals, which is thus meaningful for system evaluation. We applied this method to the digital television/terrestrial multimedia broadcasting (DTMB) systems, and carried out the laboratory measurements for performance verification. The predicted results show a satisfactory match with the measured results, validating the accuracy and effectiveness of the proposed method. © 2012 IEEE.


Jin H.,Tsinghua National Laboratory for Information Sciences and Technology | Peng K.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,China Digital TV
IEEE Transactions on Broadcasting | Year: 2013

This paper aims to improve the throughput of a broadcasting system that supports the transmission of multiple services with differentiated minimum signal-to-noise ratios (SNRs) required for successful receptions simultaneously. We propose a novel multiplexing method called bit division multiplexing (BDM), which outperforms the conventional time division multiplexing (TDM) counterpart by extending the multiplexing from symbol level to bit level. Benefiting from multiple error protection levels of bits within each high-order constellation symbol, BDM can provide so-called nonlinear allocation of the channel resources. Both average mutual information (AMI) analysis and simulation results demonstrate that, compared with TDM, BDM can significantly improve the overall transmission rate of multiple services subject to the differentiated minimum SNRs required for successful receptions, or decrease the minimum SNRs required for successful receptions subject to the transmission rate requirements of multiple services. © 1963-12012 IEEE.


Xie Q.,China Digital TV | Xie Q.,University of California at Los Angeles | Wang Z.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,China Digital TV
IEEE Transactions on Information Theory | Year: 2014

A polar decomposition of mutual information between a complex-valued channel's input and output is proposed for an input whose amplitude and phase are independent of each other. The mutual information is symmetrically decomposed into three terms: 1) an amplitude term; 2) a phase term; and 3) a cross term, where the cross term is negligible. Theoretical bounds of the amplitude and phase terms are derived for additive white Gaussian noise channels with Gaussian inputs. This decomposition is applied to amplitude phase shift keying with product constellation (product-APSK) design and analysis. It facilitates the product-APSK to achieve a considerable shaping gain at some interesting rates over conventional quadrature amplitude modulation with a similar low complexity. © 1963-2012 IEEE.


Xie Q.,China Digital TV | Wang Z.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,China Digital TV
IEEE Transactions on Wireless Communications | Year: 2012

Amplitude phase shift keying (APSK) constellation is capable of outperforming quadrature amplitude modulation (QAM) in terms of both the mutual information and the error-control performance. However, the lack of simplified demapper prevents its potential applications due to the inherent high computation complexity. In this paper, the concept of APSK using product constellation labeling is introduced, and two simplified demappers are proposed. Theoretical analysis and simulations show that the performance degradation caused by these simplified demappers is negligible, while the complexity is significantly reduced, compared to the traditional Max-Log-MAP demapper. © 2012 IEEE.

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