Nyquist-rate wide-bandwidth sigma-delta modulator for UWB-OFDM systems

作者：Liu Guohua; Zhao Yingxin; Xiang Kun; Li Yanhong; Wu Hong^*

来源：Journal of Information and Computational Science, 2011, 8(13): 2831-2837.

• Analog to digital converters
• Digital-to-analog
• Noise-shaping
• Nyquist rate
• Orthogonal frequency division multiplexing (OFDM)
• Orthogonal frequency division multiplexing systems
• Oversample
• Quantization noise
• Sigma Delta modulator
• Sigma-delta
• Sub-carriers
• Ultra-wide

A novel quantization noise shaping structure without oversample is proposed for sigma-delta modulators which have applications in the design of ultra-wide-band (UWB) orthogonal frequency division multiplexing (OFDM) systems. The Nyquist rate sigma-delta modulator introduces N zeros in the quantization noise spectrum. These zeros are located at the frequencies of UWB-OFDM sub-carriers so that the quantization noise fills the gaps in the spectrum of the UWB-OFDM signal. Consequently, the presented sigma-delta modulator is used for very fast digital-to-analog and analog-to-digital converters in UWBOFDM systems which operate on an ultra wide frequency band. The simulation results are given to illustrate the performance of the modulator.

• 出版日期2011
• 单位南开大学