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dash7_mode_2:phy [2013/08/26 23:28]
jpnorair [Encoding]
dash7_mode_2:phy [2014/01/17 00:09] (current)
jpnorair Added RS Coding part
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-===== Encoding ​=====+===== Binary Coding ​=====
  
 All messages are encoded with a PN9 scheme. ​ Optionally, an FEC scheme can also be used.  In the case where FEC is used, the data is encoded with PN9 first and FEC second (or decoded with FEC first and PN9 second). All messages are encoded with a PN9 scheme. ​ Optionally, an FEC scheme can also be used.  In the case where FEC is used, the data is encoded with PN9 first and FEC second (or decoded with FEC first and PN9 second).
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 | ST STM32L ​   | MCU     | SW (confirmed) ​ | SW (confirmed) ​ | est 3.5 dB  | SW decoder tested at 32 MHz | | ST STM32L ​   | MCU     | SW (confirmed) ​ | SW (confirmed) ​ | est 3.5 dB  | SW decoder tested at 32 MHz |
 | ST STM32F ​   | MCU     | SW (confirmed) ​ | SW (confirmed) ​ | est 3.5 dB  | SW decoder tested at 32 MHz | | ST STM32F ​   | MCU     | SW (confirmed) ​ | SW (confirmed) ​ | est 3.5 dB  | SW decoder tested at 32 MHz |
 +
 +===== Block Coding =====
 +Some frames may support an internal block coding scheme. ​ The block code is computed at a layer beneath the binary coding and appended to the end of the frame data.  The specified code is an adaptive Reed Solomon code on a byte field (2^m = 256), using nominal rate (k/n) = 0.8.
 +
 +=== Reed Solomon Data Model ===
 +
 +^     ​Preamble ​    ​^ ​ Sync Word  ^  Frame Data  ^  Frame Parity Block  ^
 +|  32 - 128 bits   ​| ​   16 bits  |    K bytes   ​| ​  N-K (P) bytes      |
 +
 +**Encoding derivation:​** P = 4 + (ceiling(K/​16) * 2) \\
 +**Decoding derivation:​** K = floor((N + 13) / 18)
 +
  
 ===== Channel Access ===== ===== Channel Access =====
dash7_mode_2/phy.txt ยท Last modified: 2014/01/17 00:09 by jpnorair