Quantization Techniques for Accurate Soft Message Combining
Wireless communication is prone to errors due to always changing channel conditions. Multiple transmissions over independent channels can be leveraged by combining erroneous packets. To be able to combine, reliability information for bits, so-called soft-bits, of the previous messages has to be saved. Especially for systems with limited storage capacity, such as sensor nodes, this poses the question of how detailed the stored reliability information has to be in order to achieve a desired performance. The authors compare different reliability information approximations, introduce two quantization options specifically tailored for combining, and compare their Bit Error Rate (BER) performance by simulation.