MIMO Rate-2 Encoding via DFT Segmentation and Antenna Diversity

The patent segments the transmitted symbols into multiple groups and assigns them to different transmit antennas through block coding. The encoding scheme divides the input symbol stream into blocks, applies orthogonal transformations (such as DFT), and distributes transformed symbols across multiple antennas, achieving both high transmission rate and maximum diversity through systematic segmentation of the signal flow.

The patent introduces a new dimensional approach by using orthogonal transformations (time-domain to frequency-domain conversion via DFT) and spatial distribution across multiple antennas. This transforms the original symbol sequence into a multi-dimensional structure where diversity is achieved through both temporal spreading and spatial distribution, resolving the contradiction between rate and reliability.

The patent employs orthogonal copying mechanisms where each transmitted symbol is replicated across multiple antennas through orthogonal transformations. The block code structure creates redundant copies of symbol information distributed across antennas, allowing the receiver to recover original data through simple correlation operations, thus achieving high diversity with low decoding complexity.

The patent changes the fundamental parameters of the encoding scheme by using orthogonal matrices (such as DFT matrices) instead of conventional space-time codes. This parameter change enables the system to achieve rate-2 transmission with N transmit antennas while maintaining constant decoding complexity regardless of the number of antennas, as the orthogonal structure allows for efficient zero-forcing or simple correlation-based decoding.