CCS/CC1350: LOW DATA RATe Operation

- Part of the modem is implemented in hardware, part of it is implemented in software. The software is placed in ROM but it is possible to patch this code by placing part of the code in RAM. A patch can be a bug fix or, as in this case, to add new functionality. The Bit repetition patch is a patch that allows the modem to receive low datarates.
- Maximum deviation: For CC1310, the modem have some restrictions on the allowed combination of values of datarate, RX BW, deviation. The excel sheet in the app note gives the min and max values for some of these parameters given the input . So max deviation just mean the max deviation you can set for a given set of parameters.
- Offset tolerance: Required RX filter bandwidth = Signal BW + 4*ppm xtal*Frequency of operation. Offset tolerance is how many ppm xtal you can have.

What is your usecase? It could be easier to cover what you find unclear based on what you need.

Thanks Ter, for trying to help me with low data rate issue.

I am not radio engineer and some terms and issues are really difficult for me to understand.

Regarding the task I am working on: It is quite simple - I just need to transfer a packet of data reliably on a distance about 1 km. 50kBits data rate transition is loosing packet on that distance. I need to use long range and operations and therefore low data rate.

In order to create needed packet, calculate the timeframe for Receive window on Rx part of the network, I need to understand how the bit repetition process is working. In CC1350 RF user Guide you have many useful diagrams and explanations, illustrating how the RF core commands are working. But there is no any information or  diagrams about how Low Rate bit repetition algorithm operates. Which bits of the packet are repeated, who repeats them, what we have as a result on a Receive Side. what shall we do with this repeated bits on a Receive side. How long the packet appears to be as a result of theat repetition?

Can you advise any more detailed theoretical publication on that issue. Without background and understanding the mechanism it is difficult to move forward.

About terms: Deviation - does it mean a deviation of some parameters from a their standard or normal value? If yes - than what are the parameters we are talking about? All the parameters or some of them?

Sorry for bother you with so many naive questions, but your help would be very nappreciated.

Boris