Adaptive Modulation
Adaptive Modulation is a technique used in communication systems to dynamically adjust the modulation scheme and/or coding rate of a transmitted signal based on the channel conditions. The goal of adaptive modulation is to maximize the data rate while maintaining an acceptable level of bit error rate (BER) or packet error rate (PER). In space and astronautical engineering, adaptive modulation is particularly important for satellite communication systems, where the channel conditions can vary significantly due to factors such as atmospheric attenuation, rain fade, and satellite motion. Adaptive modulation can be implemented using various algorithms, such as the Channel Quality Indicator (CQI) feedback mechanism, which allows the receiver to inform the transmitter about the channel conditions. Other techniques include the use of pilot signals, which are used to estimate the channel quality, and the use of multiple-input multiple-output (MIMO) systems, which can improve the channel capacity by using multiple antennas.
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