Adaptive algorithms for choosing transmission parameters in dynamic channel conditions

Modern communication systems are designed to be robust while maximizing achieved capacity. To achieve this goal, many standards allow the use a variety of coding schemes, constellations, error coding capabilities and other transmission parameters. The transmission parameters in use should be tailored to the actual channel conditions. Hence, there is a need for algorithms that analyze channel impairments using digital signal processing methods and determine the optimal transmission parameters accordingly. Furthermore, as channel conditions vary over time, these algorithms should be adaptive. The capabilities of the receiver in use should be taken into consideration as well. We present the benefits of developing such adaptive algorithms and demonstrate them in several contemporary standards. In the case of cable modem communication, we present a solution that employs digital signal processor (DSP) based upstream channel analysis (DUCA) adaptive algorithms. Simulation results of such adaptive algorithms are included.