Qinghua Zhao

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This paper investigates the tradeoffs between source coding, channel coding and spreading in CDMA systems, operating under a fixed total bandwidth constraint. We consider two systems, each consisting of a uniform source with a uniform quantizer, a channel coder, an interleaver, and a direct sequence spreading module. System A is quadrature phase-shift keyed(More)
This paper investigates the tradeoffs of source coding, channel coding and spreading in CDMA systems. We consider a system consisting of an image source coder, a convolutional channel coder, an interleaver, and a direct sequence spreading module. With different allocations of bandwidth to source coding, channel coding and spreading, the system is analyzed(More)
— In general, a power amplifier utilizes battery energy more efficiently with a higher transmission power. For a given message, a given bandwidth constraint and a given performance constraint, different allocations of the bandwidth among source coding, channel coding and modulation result in different amounts of battery usage. We propose a method to(More)
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