Issue link: https://read.uberflip.com/i/1428356
LoRaWAN Fragmented Data Block Transport v1.0.0 Specification ©2018 LoRa Alliance™ Page 18 of 30 The authors reserve the right to change specifications without notice. 466 467 Figure 1 : 26x52 parity check matrix 468 469 470 471 We can see that the parity matrix consists first of an MxM identity matrix followed by a parity 472 control MxM matrix. 473 The coded fragment P M N is therefore the bit-wise Xor of the uncoded fragment such that 474 ( ) is non-zero. The coded fragments have exactly the same bit length than the uncoded 475 fragments. 476 477 478 Step by Step encoding example: 479 The transmitter must send 2000 bytes allowing up to 50% packet error rate on the radio link. 480 A coding ratio of ½ is selected. For this purpose the 2000 bytes data block will be 481 segmented in 100 fragments of 20 bytes each , each frame will transport 1 fragment. The 482 transmitter will send 100/CR = 200 coded fragments. We will see that the receiver will be 483 able to decode as soon as it receives ~103 frames out of the 200 (depending on the exact 484 combination of frames lost). 485 486