National Engineering Laboratory for DTV

Beijing, China

National Engineering Laboratory for DTV

Beijing, China
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Liu S.,Tsinghua National Laboratory for Information Sciences and Technology | Yang F.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,National Engineering Laboratory for DTV
IEEE Transactions on Power Delivery | Year: 2016

In this paper, an optimal interleaving scheme with maximum time-frequency diversity is proposed to combat against the narrowband interference (NBI) and time-domain impulsive noise for orthogonal frequency-division multiplexing (OFDM) systems in power-line communications (PLC). To improve the anti-NBI and anti-TIN performance, we propose two criteria based on which the optimized interleaving scheme is designed: 1) to increase the number of different OFDM blocks for one forward error correction (FEC) codeword, which is aimed at TIN mitigation and 2) to increase the number of different subcarriers mapped to the data symbols in one FEC codeword, which is aimed at NBI mitigation. Simulations show that the proposed interleaving scheme can effectively reduce the impairments caused by NBI and/or TIN in OFDM systems under PLC environments and, hence, achieve better performance than the conventional block interleaving scheme. © 1986-2012 IEEE.


Ding W.,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 | Dai L.,Tsinghua National Laboratory for Information Sciences and Technology | And 2 more authors.
IEEE Transactions on Broadcasting | Year: 2014

Time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) has advantages in spectral efficiency and synchronization. However, its iterative interference cancellation algorithm will suffer from performance loss especially under severely fading channels with long delays and has difficulty supporting high-order modulations like 256 QAM, which may not accommodate the emerging ultra-high definition television service. To solve this problem, a channel estimation method for OFDM under the framework of compressive sensing (CS) is proposed in this paper. Firstly, by exploiting the signal structure of recently proposed time-frequency training OFDM scheme, the auxiliary channel information is obtained. Secondly, we propose the auxiliary information based subspace pursuit (A-SP) algorithm to utilize a very small amount of frequency-domain pilots embedded in the OFDM block for the exact channel estimation. Moreover, the obtained auxiliary channel information is adopted to reduce the complexity of the classical SP algorithm. Simulation results demonstrate that the CS-based OFDM outperforms the conventional dual pseudo noise padded OFDM and CS-based TDS-OFDM schemes in both static and mobile environments, especially when the channel length is close to or even larger than the guard interval length, where the conventional schemes fail to work completely. © 1963-12012 IEEE.


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.


Liu S.,Tsinghua National Laboratory for Information Sciences and Technology | Yang F.,Tsinghua National Laboratory for Information Sciences and Technology | Zhang C.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,National Engineering Laboratory for DTV
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | Year: 2015

A narrowband interference (NBI) estimation and mitigation method based on compressive sensing (CS) for communication systems with repeated training sequences is investigated in this letter. The proposed CS-based differential measuring method is performed through the differential operation on the inter-block-interference-free regions of the received adjacent training sequences. The sparse NBI signal can be accurately recovered from a time-domain measurement vector of small size under the CS framework, without requiring channel information or dedicated resources. Theoretical analysis and simulation results show that the proposed method is robust to NBI under multi-path fading channels. Copyright © 2015 The Institute of Electronics Information and Communication Engineers.


Song J.,Tsinghua National Laboratory for Information Sciences and Technology | Song J.,National Engineering Laboratory for DTV | Song J.,China Digital TV | Jin H.,Tsinghua National Laboratory for Information Sciences and Technology | And 3 more authors.
IEEE Transactions on Vehicular Technology | Year: 2015

A two-user Gaussian broadcast channel (GBC) with finite input constellations is addressed in this paper. The constellation-constrained capacity region for the two-user GBC by recently proposed bit-division multiplexing (BDM) is derived. BDM can be seen as a practical implementation of constellation-constrained nonlinear superposition coding (SC). For comparison, the constellation-constrained capacity region for the two-user GBC by traditional constellation-constrained linear SC is also computed. With similar implementation complexity, BDM outperforms traditional constellation-constrained linear SC with lower shaping loss in the capacity defined in this paper. Analytical results show that the upper boundary of the capacity region for the two-user GBC can be well approached by BDM with amplitude phase-shift keying modulation, which could be considered as the preliminary demonstration on the applicability of BDM in practical systems. © 1967-2012 IEEE.


Cheng T.,Tsinghua National Laboratory for Information Sciences and Technology | Peng K.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,National Engineering Laboratory for DTV | Song J.,Tsinghua National Laboratory for Information Sciences and Technology
IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, BMSB | Year: 2013

The performance degradation of each step from Shannon limit to implementation for the second generation digital video broadcasting - terrestrial (DVB-T2) system is analyzed in this paper, from three aspects: the time-frequency bandwidth loss, imperfect coded modulation scheme, and other implementation issues. The analysis results intuitively show the weak parts that still exist in the DVB-T2 system, and also provide guidelines for system improvement in the future. © 2013 IEEE.


Cheng T.,Tsinghua National Laboratory for Information Sciences and Technology | Cheng T.,National Engineering Laboratory for DTV | Peng K.,Tsinghua National Laboratory for Information Sciences and Technology | Peng K.,National Engineering Laboratory for DTV | And 5 more authors.
IEEE Transactions on Broadcasting | Year: 2015

Multiple-input multiple-output (MIMO), which can provide ultrahigh data transmission rate, is one of the key technologies for the next generation digital terrestrial television broadcasting (DTTB) standards. This paper proposes a near-capacity MIMO bit-interleaved coded modulation scheme with either independent or iterative demapping (BICM/BICM-ID) for the DTTB system. First, the amplitude phase shift keying (APSK) constellation with Gray mapping is proposed to replace the conventional Gray quadrature amplitude modulation (QAM) counterpart. From the perspective of average mutual information analysis, Gray-APSK has certain shaping gain compared to Gray-QAM for both independent and iterative demapping schemes. Besides the APSK constellation, a novel bit interleaver named bit mapping, which takes into account the unequal error protection of both APSK constellations and low-density parity-check codes, is proposed to further improve the system performance. The tool of extrinsic information transfer chart is utilized to analyze and design the optimal bit mapping for the BICM/BICM-ID scheme. Bit error rate simulations are finally carried out to verify the superiority of the proposed MIMO coded modulation scheme. © 1963-12012 IEEE.


Cheng T.,Tsinghua National Laboratory for Information Sciences and Technology | Cheng T.,National Engineering Laboratory for DTV | Cheng T.,China Digital TV | Peng K.,Tsinghua National Laboratory for Information Sciences and Technology | And 8 more authors.
2015 IEEE Wireless Communications and Networking Conference, WCNC 2015 | Year: 2015

Multiple-input multiple-output (MIMO) is one of the key technologies for the next generation digital terrestrial television broadcasting (DTTB). This paper proposes a near-capacity MIMO bit-interleaved coded modulation (BICM) scheme for DTTB systems. The amplitude phase shift keying (APSK) constellation with Gray mapping is applied to the BICM scheme. From the perspective of average mutual information, APSK has the advantage of shaping gain compared to its quadrature amplitude modulation (QAM) counterpart. Moreover, a new kind of bit interleaver named bit mapping, which takes into account the unequal error protection of both APSK and low-density parity-check (LDPC) codes, is proposed to further improve the system performance. The tool of extrinsic information transfer chart is utilized to help analyze and design the optimal bit mapping. Bit error rate simulations are carried out to verify the superiority of the proposed MIMO system. © 2015 IEEE.


Gao Z.,Tsinghua National Laboratory for Information Sciences and Technology | Gao Z.,National Engineering Laboratory for DTV | Zhang C.,Tsinghua National Laboratory for Information Sciences and Technology | Zhang C.,National Engineering Laboratory for DTV | And 3 more authors.
IEEE Vehicular Technology Conference | Year: 2014

In time-domain synchronous OFDM (TDS-OFDM) system for digital television terrestrial multimedia broadcasting (DTMB) standard, the baseband OFDM signal is upsampled and shaping filtered by square root raised cosine (SRRC) filter before digital-to-analog converter (DAC). Much of the work in the area of timing synchronization for TDS-OFDM focuses on frame synchronization and sampling clock frequency offset recovery, which does not consider the sampling clock phase offset due to the upsampling and SRRC filter. This paper evaluates the bit-error-rate (BER) effect of sampling clock phase offset in TDS-OFDM system. First, we provide the BER for M-order quadrature amplitude modulation (M-QAM) in uncoded TDS-OFDM system. Second, under the condition of the optimal BER criterion and additive white Gaussian noise (AWGN) channel, we propose a near optimal sampling phase estimation criterion based on frequency-domain response. Simulations demonstrate that the proposed criterion also has good performance in actual TDS-OFDM system with channel coding over multipath channels, and it is superior to the conventional symbol timing recovery methods for TDS-OFDM system. © 2014 IEEE.


Cheng T.,Tsinghua National Laboratory for Information Sciences and Technology | Peng K.,Tsinghua National Laboratory for Information Sciences and Technology | Yang F.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,Tsinghua National Laboratory for Information Sciences and Technology | Yang Z.,National Engineering Laboratory for DTV
IWCMC 2014 - 10th International Wireless Communications and Mobile Computing Conference | Year: 2014

Digital video broadcasting-next generation handheld (DVB-NGH) is the first broadcasting standard that incorporates multiple-input multiple-output (MIMO) techniques to overcome the Shannon limit of single antenna systems. This paper contributes to analyze the performance of the DVB-NGH MIMO coded modulation system. The detailed performance degradation from information-theoretic limit to implementation by average mutual information and extrinsic information transfer analysis is presented, which provides an insight guideline for future system improvement. Finally, bit error rate simulations are carried out to verify the analysis. © 2014 IEEE.

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