Dear Friends
i m working on a project --"digitized voice transmission over optical fibers". finding difficulty in recovery of clock & synchronisation at receiver..pls suggest some idea...for details please mail at "dineshbhutani@yahoo.com"
thanks
I second this. For my senior project, we did a fiber optic data link. We ended up going with NRZI encoding for our bitstream. There was an ASIC at the receiver end that took care of the clock extraction and data retiming.
Modern high speed interfaces use NRZI encoding (for USB) and 8B/10B encoding (for PCI-Express, SATA, SAS, etc)
Thanks.
pls also convey whether the ASIC was specially designed for your project or a general purpose for clock recovery..pls mention the no.
Also pls suggest how to convert a ttl multiplexed data into NRZ coding'
poopeater said:
I second this. For my senior project, we did a fiber optic data link. We ended up going with NRZI encoding for our bitstream. There was an ASIC at the receiver end that took care of the clock extraction and data retiming.
Modern high speed interfaces use NRZI encoding (for USB) and 8B/10B encoding (for PCI-Express, SATA, SAS, etc)
Thanks.
pls also convey whether the ASIC was specially designed for your project or a general purpose for clock recovery..pls mention the no.
Also pls suggest how to convert a ttl multiplexed data into NRZ coding'
TTL Multiplexd data means " digitaly encoded multiple channnels multiplexed in time domain --with frames & sysnchronisation e.g E1 or T1 Carrier system....& TTL is Transistor Transistor Logic...0V & 5v working voltage"..
Pls guide how to write the encoder. Thanks
Look for communication chips - there is a category of chips called "serializer" / "deserializer" chips which take a lot of parallel data in, collapse it into a higher frequency serial data stream for compression, and then pull it back out.
fer instance:
**broken link removed**
(or just search for serializer on their site)
or
**broken link removed**
[and it's corresponding serializer] **broken link removed**
If you really want to mess with things, grab an ethernet PHY chip, or SDI interface chip and replace the wire with the fiber optics.
TTL Multiplexd data means " digitaly encoded multiple channnels multiplexed in time domain --with frames & sysnchronisation e.g E1 or T1 Carrier system....& TTL is Transistor Transistor Logic...0V & 5v working voltage"..
Pls guide how to write the encoder. Thanks
I just researched around until I found a copy of a spec on NRZI encoding. Then, using the specification, I wrote my own packet framer and encoder using AHDL.