Non-Uniform Constellation Mapping for Lower BER in Broadcasting

The patent applies local quality by transitioning from uniform QAM spacing to non-uniform constellation point distribution. Different regions of the constellation diagram have different spacing characteristics - inner points are closer together while outer points are farther apart, optimizing performance for different signal-to-noise ratio conditions and reducing the gap to the Shannon limit.

The patent changes the fundamental parameter of constellation point spacing from uniform to non-uniform. This parameter change allows the system to achieve better BER/FER performance by adapting the distance between constellation points based on their position, thereby reducing the gap from the theoretical Shannon limit while maintaining practical implementability.

The patent applies preliminary action by pre-defining and storing the non-uniform constellation point coordinates and their corresponding bit patterns. The receiver is pre-configured with the same constellation map, allowing it to perform demapping by simple lookup and comparison rather than complex real-time calculations, thus reducing the actual processing complexity during operation.

The patent uses copying by creating and storing reference copies of the non-uniform constellation pattern at both transmitter and receiver. The receiver maintains a copy of the expected constellation points and compares received signals against this reference, simplifying the demapping process while maintaining the performance benefits of non-uniform spacing.