jks
About
- Username
- jks
- Joined
- Visits
- 30,231
- Last Active
- Roles
- Member, Administrator, Moderator
- Points
- 220
- Location
- Tauranga, New Zealand RF82ci
- Callsign
- ZL4VO/KF6VO
- Additional information
- KiwiSDR support email: support@kiwisdr.com
Reactions
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DDC on FPGA
Hi. That is an excellent question.If you look carefully at the free version of the DUC/DDC compiler provided with Vivado you'll see that it is not general purpose. It is targeted to the cell phone industry (LTE/CDMA) and does not have the bit widths, clock rates and decimation factors needed by the Kiwi.The Kiwi does take advantage of some Vivado IP blocks, like the DDS compiler. And it makes very heavy use of the Artix DSP blocks to save FPGA fabric gates. We also wanted to have a design fully independent of any FPGA manufacturer's architecture in case we need to change devices in the future. It was also a learning experience for us to implement everything from first principles.
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DDC on FPGA
Hi. That is an excellent question.If you look carefully at the free version of the DUC/DDC compiler provided with Vivado you'll see that it is not general purpose. It is targeted to the cell phone industry (LTE/CDMA) and does not have the bit widths, clock rates and decimation factors needed by the Kiwi.The Kiwi does take advantage of some Vivado IP blocks, like the DDS compiler. And it makes very heavy use of the Artix DSP blocks to save FPGA fabric gates. We also wanted to have a design fully independent of any FPGA manufacturer's architecture in case we need to change devices in the future. It was also a learning experience for us to implement everything from first principles. -
QZSS Support [GPS, added in v1.170]
v1.172 adds a switch to the admin page GPS tab called "include alerted?" that overrides the exclusion of alerted sats from the position fix. The alert "A" symbol will appear green instead of red when the sat is actually being used. It will be interesting to see if some position fixes get worse when alerted sats are included.
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QZSS Support [GPS, added in v1.170]
Looks like PRN199 is being acquired now. -
QZSS Support [GPS, added in v1.170]
Okay, v1.170 is released with support for QZSS.
