SWRA696A April   2021  – November 2021 CC1352P , CC1352P7 , CC1352R

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Acronyms Used in This Document
  3. 2DSSS Encoding Scheme
    1. 2.1 Convolutional Encoder
    2. 2.2 Direct Sequence Spreader
  4. 3Packet Format
  5. 4Setting Up WB-DSSS in SmartRF Studio
  6. 5Setting Up WB-DSSS in Code Composer Studio
  7. 6Measured Results
    1. 6.1 Receiver Performance
      1. 6.1.1 DSSS = 1, 240 kbps, 2-GFSK, 195 kHz Deviation, 1x Spreading
      2. 6.1.2 WB-DSSS 120 kbps, 2-GFSK, 195 kHz Deviation, 2x Spreading
      3. 6.1.3 WB-DSSS 60 kbps, 2-GFSK, 195 kHz Deviation, 4x Spreading
      4. 6.1.4 WB-DSSS 30 kbps, 2-GFSK, 195 kHz Deviation, 8x Spreading
      5. 6.1.5 WB-DSSS Frequency Offset Tolerance
    2. 6.2 Transmitter Performance and FCC 15.247 Measurements
      1. 6.2.1 WB-DSSS 240 kbps, 2-GFSK, 195 kHz Deviation, 1x Spreading
      2. 6.2.2 WB-DSSS 120 kbps, 2-GFSK, 195 kHz Deviation, 2x Spreading
      3. 6.2.3 WB-DSSS 60kbps, 2-GFSK, 195 kHz Deviation, 4x Spreading
      4. 6.2.4 WB-DSSS 30 kbps, 2-GFSK, 195 kHz Deviation, 8x Spreading
  8. 7References
  9. 8Revision History

6.1.5 WB-DSSS Frequency Offset Tolerance

Figure 6-17 and Figure 6-18 show the frequency offset performance of the WB-DSSS scheme. In contrast to narrowband low data rate systems, the crystal accuracy is not critical in this case as the RX bandwidth is relatively large.

From the results, it can be seen that sensitivity remains unchanged for considerable amount of crystal drift (±70 ppm).

GUID-20201216-CA0I-4NK5-CDDD-VPXR1L93VD6M-low.pngFigure 6-17 Frequency Offset Performance (915 MHz, K = 4, DSSS = 1, 240 kbps)
GUID-20201216-CA0I-6XQK-D9DG-LPMVZQSDTH61-low.pngFigure 6-18 Frequency Offset Performance (915 MHz, K = 4, DSSS = 8, 30kbps)