References
Theory:
By Akira Matsuzawa at Tokyo Institute of Technology
http://www.ssc.pe.titech.ac.jp/materials/VLSICS03_shortcourse_matsu_homepage.pdf
Practical receiver/transmitter circuits:
From Analog Devices
http://www.analog.com/library/analogDialogue/archives/43-09/EDCh%204%20rf%20if.pdf