NI Bluetooth Analysis Toolkit

Demodulation:CFO:Results:Maximum Payload Block Frequency Offset (Hz) Property

  • Updated2023-02-21
  • 2 minute(s) read

Short Name: LE CFO Maximum Payload Block Frequency Offset (Hz)

Property of niBTAnalysis

Returns the maximum frequency offset that the toolkit computes by using preamble and by demodulating the FM signal payload. This value is expressed in Hz.

The toolkit integrates the frequency of the FM demodulated signal starting from the center of the first preamble bit to the center of the first bit following the last preamble bit. For LE-LR-125k packets, the frequency integration is done from the start of the third preamble bit to the end of the 18th preamble bit. This value is recorded as f0 .

For LE-LR-125k packets, the frequency offsets are calculated also for the three 16-bit groups after the 18th bit in the preamble and are recorded as f1 , f2 , and f3 .

The toolkit then integrates the frequency deviation of every x bits in the payload starting from the yth payload symbol and it is repeated until the end of the payload duration. The integral sums are recorded as fn (n≥4 for LE-LR-125k and n≥1 for all other packets).

For LE-Enhanced packets, x = 20 and y = 2.

For LE-LR-125k packets, x =16 and y = 27.

For other LE packets, x = 10 and y = 2.

The toolkit finds the maximum of |fn | over different acquisitions, and adds the corresponding fn sign to the result.

Remarks

The following table lists the characteristics of this property.

Datatype cdbl.gif
PermissionsRead Only
High-level VIs niBT SA LE CFO Get Maximum Payload Frequency Offset
ResettableNo

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