AGC Measurement for DAA

Dear Sirs,
I have a question about the AGC measurement. Is there possibile to perform a detect and avoid with DW1000? Is there any api that implement a DAA already?

The user manual of DW1000 shows that it is possible to measure the background noise level in order to choose the less noisy channel. I tried to make this measure recursively for my own purposes but the values I got (using the user manual formula) were very different between them. The pseudocode is the following:

enable agc measurement,

enable rx ,

wait 100 us,

read the value from the sub register: Sub-Register 0x23:1E – AGC_STAT1,

apply the formula (EDV2 βˆ’40) Γ—10^EDG1Γ—π‘†π‘β„Ž, where π‘†π‘β„Ž in my case is 1.3335,

repeat from 1) to 5) each 2 seconds.

Typical values I get for EDV2 when i don’t apply any disturb are from 6 to10. If I apply a disturb in that channel the values I get from EDV2 goes from 4 to10. Why the values are not stable?
Thanks in advance.

I don’t think so.

The noise floor measurement will fail to adequately detect narrow band signals since it averages over a wideband. Thus it will fail to achieve acceptable DAA performance as defined in the regulations. Testing DAA is also complex.

However, the DW1000 can support LDC mitigation (low duty cycle). For EN 302-065-1, this applies in the 3.1 to 4.8 GHz band. This limits any one transmitter to 18 seconds on per hour (0.5% duty cycle average, ~ 25 Hz packet rate at 200 us per packet) which can be adequate for many systems, particularly those that use TDoA style location (which keeps anchor transmit rate down).

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
+1 812 962 9408

Ok, thanks for the reply.