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Voice over multi-channel multi-radio WLANs with power capture and imperfect channel

- Siddique, Md, Kamruzzaman, Joarder

  • Authors: Siddique, Md , Kamruzzaman, Joarder
  • Date: 2010
  • Type: Text , Conference paper
  • Relation: 2010 IEEE Wireless Communications and Networking Conference p. 1-6
  • Full Text: false
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  • Description: VoIP offers cheap voice communication which instigated its quick market growth. IEEE 802.11 WLANs offer cheap wireless coverage which can be used to provide VoIP service in mobile devices. But call capacity of such networks is very low compared to wired networks. To increase voice capacity in WLANs incorporation of power capture, increased data rate, and use of multiple channels are of great importance. Moreover, these networks should be carefully designed considering voice quality requirements to avoid call jitter and call drops. We propose an analytical model to estimate VoIP call capacity for multichannel WLANs with consideration for power capture, imperfect channel, and multiple network interfaces. We employed ITU-T E-model to assess voice quality which is used as the limiting factor to ensure that voice quality does not degrade in such networks. The model will be extremely helpful to network designers in planning single channel or multi-channel WLANs.

Time-frequency filter bank: A simple approach for audio and music separation

- Yang, Ning, Usman, Muhammad, He, Xiangjian, Jan, Mian, Zhang, Liming

  • Authors: Yang, Ning , Usman, Muhammad , He, Xiangjian , Jan, Mian , Zhang, Liming
  • Date: 2017
  • Type: Text , Journal article
  • Relation: IEEE access Vol. 5, no. (2017), p. 27114-27125
  • Full Text: false
  • Reviewed:
  • Description: Blind Source Separation techniques are widely used in the field of wireless communication for a very long time to extract signals of interest from a set of multiple signals without training data. In this paper, we investigate the problem of separation of the human voice from a mixture of human voice and sounds from different musical instruments. The human voice may be a singing voice in a song or may be a part of some news, broadcast by a channel with background music. This paper proposes a generalized Short Time Fourier Transform (STFT)-based technique, combined with filter bank to extract vocals from background music. The main purpose is to design a filter bank and to eliminate background aliasing errors with best reconstruction conditions, having approximated scaling factors. Stereo signals in time-frequency domain are used in experiments. The input stereo signals are processed in the form of frames and passed through the proposed STFT-based technique. The output of the STFT-based technique is passed through the filter bank to minimize the background aliasing errors. For reconstruction, first an inverse STFT is applied and then the signals are reconstructed by the OverLap-Add method to get the final output, containing vocals only. The experiments show that the proposed approach performs better than the other state-of-the-art approaches, in terms of Signal-to-Interference Ratio (SIR) and Signal-to-Distortion Ratio (SDR), respectively.
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