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

4 Setting Up WB-DSSS in SmartRF Studio

The SmartRF studio contains the settings for the optimized WB-DSSS cases that can be tested from within the GUI. By launching the GUI and connecting CC13x2 launchpads with USB cable, the devices will show up in the GUI’s console. From there, by clicking each one from the list of connected devices, the LaunchPads can be independently configured for TX and RX and a RF link test can be conducted.

Note: Choose Proprietary Mode when prompted to select CC13x2 modes.
GUID-20201216-CA0I-BWS4-QBGB-8LSV5XF5QHV2-low.png Figure 4-1 SmartRF GUI Showing Two CC1352P in List of Connected Devices
GUID-20201216-CA0I-9DVT-P37V-VP7JX7HKTHX6-low.png Figure 4-2 SmartRF Studio Showing WB-DSSS Setup in Transmit Mode
GUID-20201216-CA0I-QS96-LRSM-DQ61GT6MXF2K-low.png Figure 4-3 SmartRF Studio Showing WB-DSSS Setup in Receive Mode

Per default, the WB-DSSS settings in the SmartRF use formatConf.fecMode = 0x0. With this setting, the user can define the first 32-bits of the sync word. The patch will then append this to the remaining 32-bits of the sync word. For example, if syncWord = 0x12345678, the overall sync word will become 0x12345678_3CC3CCCC. The SmartRF studio setup for testing this scenario is shown in Figure 4-2 and Figure 4-3.

Alternatively, the WB-DSSS settings in SmartRF Studio can be changed by setting formatConf.fecMode = 0x8 and formatConf.whitenMode = 0x1. In this mode, the MCE patch overrides any user defined sync word and replaces it with 0x333C_3C33_3CC3_CCCC. This is also compatible with default modes for CC13x0 devices. Note the settings in Figure 4-4.

Note: Changing sync word can affect the BER performance and must be chosen with care.
GUID-20201216-CA0I-RVKG-GX10-4SHFQCSZW6NP-low.png Figure 4-4 SmartRF Studio Showing WB-DSSS Setup in Transmit Mode (note the setup of sync word when testing in SmartRF Studio)
GUID-20201216-CA0I-3HKK-RW87-BPNNNJLWZHPK-low.png Figure 4-5 SmartRF Studio Showing WB-DSSS Setup in Receive Mode (note the setup of sync word when testing in SmartRF Studio)