Lianghu, The best book I have read across on measuring signals in the presence of noise is: High Frequency Measurements and Noise, by Douglas C. Smith. It is available directly from Doug through his very informative High Frequency Measurements Web Page at: http://emcesd.com/ Doug talks a lot about doing "null experiments" to find the best test setup, and how to measure the basic noise level of your test setup. I have over 2000 electronics books (24 bookcases full, going on 25) in my personal collection. My book, "Electronic System Design: Interference and Noise Control Techniques", was published by Prentice-Hall in 1987, then translated into Russian and published by Mir in 1990. But I learned more about lab techniques from Doug's book, than I had learned from all my reading and working in the computer/electronics industry for 28 years! John Barnes Advisory Engineer Lexmark International ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu