Efficient design of OFDMA-based programmable wireless radios
EURASIP Journal on Wireless Communications and Networking - Cognitive Radio and Dynamic Spectrum Sharing Systems
Wideband, bandpass, and versatile hybrid filter bank A/D conversion for software radio
IEEE Transactions on Circuits and Systems Part I: Regular Papers - Special section on 2008 custom integrated circuits conference (CICC 2008)
Fast communication: Aliased polyphase sampling
Signal Processing
IEEE Transactions on Circuits and Systems Part I: Regular Papers
Time-interleaved analog-to-digital-converter compensation using multichannel filters
IEEE Transactions on Circuits and Systems Part I: Regular Papers
Circuit noise effect on sampling clock in frequency-domain radio receiver IF digitization
WiCOM'09 Proceedings of the 5th International Conference on Wireless communications, networking and mobile computing
Modeling and transceiver design for asymmetric UWB links with heterogeneous nodes
IEEE Transactions on Communications
4- and 6-GS/s 4-bit frequency-translating hybrid ADCs in 90-nm CMOS
Analog Integrated Circuits and Signal Processing
High-resolution ranging method based on low-rate parallel random sampling
Digital Signal Processing
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This paper presents design algorithms for hybrid filter banks (HFBs) for high-speed, high-resolution conversion between analog and digital signals. The HFB is an unconventional class of filter bank that employs both analog and digital filters. When used in conjunction with an array of slower speed converters, the HFB improves the speed and resolution of the conversion compared with the standard time-interleaved array conversion technique. The analog and digital filters in the HFB must be designed so that they adequately isolate the channels and do not introduce reconstruction errors that limit the resolution of the system. To design continuous-time analog filters for HFBs, a discrete-time-to-continuous-time (“Z-to-S”) transform is developed to convert a perfect reconstruction (PR) discrete-time filter bank into a near-PR HFB; a computationally efficient algorithm based on the fast Fourier transform (FFT) is developed to design the digital filters for HFBs. A two-channel HFB is designed with sixth-order continuous-time analog filters and length 64 FIR digital filters that yield -86 dB average aliasing error. To design discrete-time analog filters (e.g., switched-capacitors or charge-coupled devices) for HFBs, a lossless factorization of a PR discrete-time filter bank is used so that the reconstruction error is not affected by filter coefficient quantization. A gain normalization technique is developed to maximize the dynamic range in the finite-precision implementation. A four-channel HFB is designed with 9-bit (integer) filter coefficients. With internal precision limited to the equivalent of 15 bits, the maximum aliasing error is -70 dB, and with the equivalent of 20 bits internal precision, maximum aliasing is -100 dB. The 9-bit filter coefficients degrade the stopband attenuation (compared with unquantized coefficients) by less than 3 dB