  In LoRa (Long Range), when a collision occurs in the network, each end-device
has to retransmit its colliding frame, which reduces the throughput, and
increases the energy consumption of the end-devices and the delay of the
frames. In this paper, we propose an algorithm to decode colliding synchronized
LoRa signals and thus improve the overall performance of the network. Indeed,
we use successive transmissions of bitmaps by the end-devices to determine the
correct symbols of each colliding frame, instead of retransmitting the whole
frames. Simulation results show that our algorithm is able to significantly
improve the overall throughput of LoRaWAN, and to decrease the energy
consumption and the delay of the transmitters.
