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Full-Text Articles in Electrical and Computer Engineering
Spectrally Shaped Generalized Mc-Ds-Cdma With Dual Band Combining For Increased Diversity, Wenhui Xiong, David W. Matolak
Spectrally Shaped Generalized Mc-Ds-Cdma With Dual Band Combining For Increased Diversity, Wenhui Xiong, David W. Matolak
Faculty Publications
A new multicarrier spread spectrum modulation scheme is proposed in this paper. This scheme uses sinusoidal chip waveforms to shape the spectrum of each subcarrier of a multicarrier direct sequence spread spectrum (DS-SS) signal. As a result, each subcarrier has two distinct spectral lobes, one a lower sideband (LSB) and the other an upper sideband (USB). By properly selecting the parameters of the sinusoidal chip waveforms, the two sideband signals can be made to undergo independent fading in a dispersive fading channel. These two independently-faded sideband signals, when combined at the receiver, provide diversity gain to the system. Our analysis …
Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson
Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson
Faculty Publications
Considers trellis decoding of convolutional codes with selectable effort, as measured by decoder complexity. Decoding is described for single parent codes with a variety of complexities, with performance "near" that of the optimal fixed receiver complexity coding system. Effective free distance is examined. Criteria are proposed for ranking parent codes, and some codes found to be best according to the criteria are tabulated, Several codes with effective free distance better than the best code of comparable complexity were found. Asymptotic (high SNR) performance analysis and error propagation are discussed. Simulation results are also provided.