[hpsdr] mercury adc

[Bob McGwier]

When you have lots of oversampling (135 MSPS) at 16 bits (giving 90-ish dB)
dynamic range and you follow that with digital downsampling and frequency
conversion or polyphase filter bank channelization,  you get processing
gain.  Suppose we want an SSB receiver (say 4 kHz).

135,000,000/4000  = 135,000/4  = 33750

10log10(33750) = 45 dB theoretical processing gain (if you have unlimited
growth in accumulator depth and perfect multiplication of coefficients,
etc.)


In the perfect case,  every factor of four oversampling adds 6 dB (or so) of
dynamic range or 1 bit of equivalent dynamic range.

Suffice it to say we will not get this much gain for many reasons but 23 dB
is not surprising.  

Bob
N4HY

ARRL SDR Working Group Chair
Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats,
NJQRP, QRP ARCI, QCWA, FRC.
"Trample the slow ....  Hurdle the dead"


-----Original Message-----
From: hpsdr-bounces at lists.hpsdr.org [mailto:hpsdr-bounces at lists.hpsdr.org]
On Behalf Of alex brown
Sent: Wednesday, September 24, 2008 12:46 PM
To: Eric Ellison; hpsdr at lists.hpsdr.org
Subject: [hpsdr] mercury adc

***** High Performance Software Defined Radio Discussion List *****

how do you get 119 db dynamic range of a 16 bit adc surely it should be 96
db

alex
m0gjr
ps this is the 5th time ive sent this message with no response so if you
receve it could you reply anyway even if you dont know the answer

-----Original Message-----
From: hpsdr-bounces at lists.hpsdr.org on behalf of Eric Ellison
Sent: Tue 9/23/2008 11:24 PM
To: hpsdr at lists.hpsdr.org
Subject: [hpsdr] HPSDR Project Mercury going to Production at TAPR
 
***** High Performance Software Defined Radio Discussion List *****


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