Changcai Han

Publications (6)0 Total impact

• Conference Proceeding: A Novel Coding Scheme Based on GLD Codes for Cooperative Relay Networks.

  Changcai Han, Xiaoxiang Wang, Weiling Wu, Jianhua Zhang
  Proceedings of the 68th IEEE Vehicular Technology Conference, VTC Fall 2008, 21-24 September 2008, Calgary, Alberta, Canada; 01/2008
• Article: Distributed Generalized Low-Density Codes for Wireless Relay Networks.

  Changcai Han, Weiling Wu
  IEEE Communications Letters. 01/2008; 12:724-726.
• Conference Proceeding: UEP Schemes for Multimedia Transmission in Space-Time Coded Systems

  Changcai Han, Weiling Wu
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  ABSTRACT: A system model based on multilayered space-time trellis codes (ML-STTC) is constructed for multimedia transmission over wireless communication systems with multiple antennas both at the transmitter and the receiver. In this model, Space-time Trellis Code (STTC) and Layered Space-time (LST) architecture are combined to achieve diversity and multiplexing gains provided by multiple-input and multiple-output (MIMO) technology. According to the characteristics of ML-STTC, the unequal error protection (UEP) scheme based on diversity gains is introduced for images first, and then the UEP scheme is strengthened by power allocation among antenna layers. Simulation results reveal the UEP schemes can improve the peak signal-to-noise ratio (PSNR) of reconstructed images in an environment with a moderate range of signal-to-noise ratio (SNR).
  Communications, Circuits and Systems, 2007. ICCCAS 2007. International Conference on; 08/2007
• Conference Proceeding: Adaptive power optimization for space-time coded MIMO systems

  Changcai Han, Dongfeng Yuan
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  ABSTRACT: An optimized power allocation scheme is proposed to compensate for the diversity loss and decrease the error propagation due to the group interference suppression and cancellation (G-ISC) algorithm in multilayered space-time trellis codes (ML-STTC). In the proposed scheme, with high probabilities, the signals in the first group can be correctly detected and their interference to other groups can be cancelled perfectly, which in turn facilitates the detection of the signals in other groups. Simulation results reveal the optimized scheme is adaptive to signal-to-noise ratio (SNR) and can achieve significant performance improvement without adding much delay and complexity.
  Wireless Communications, Networking and Mobile Computing, 2005. Proceedings. 2005 International Conference on; 10/2005
• Conference Proceeding: New research of UEP using source-optimized channel coding or power allocation schemes

  Changcai Han, Dongfeng Yuan, Xiangming Yu
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  ABSTRACT: Two novel kinds of unequal error protection (UEP) schemes using turbo codes combined with embedded zerotree wavelet (EZW) coded image transmission are proposed. According to the characteristics of the EZW coded bit stream, substreams are obtained by dividing the EZW coded bit stream into several segments. Then, the substreams with more importance are better protected using greater transmission power or turbo codes with more decoding iterations, while the less important substreams use lower power or turbo codes with fewer iterations. Simulation results demonstrate how the UEP schemes outperform the equal error protection (EEP) scheme in terms of peak signal-to-noise ratio (PSNR). Furthermore, another new way to save the transmission power is presented, in which the time delay can be greatly reduced while the quality of the image is guaranteed.
  Communications, Circuits and Systems, 2005. Proceedings. 2005 International Conference on; 06/2005
• Conference Proceeding: Variable-Rate Channel Coding for Space-Time Coded MIMO System.

  Changcai Han, Dongfeng Yuan
  Computational Intelligence and Security, International Conference, CIS 2005, Xi'an, China, December 15-19, 2005, Proceedings, Part II; 01/2005