High Speed QRD-RLS Implementation for Digital Cancellation

To address the problems of slow cancellation speed and low cancellation ratio of the current digital domain decomposition algorithm in high hopping speed and dramatically fast environment, this paper proposes an algorithm that uses a look-ahead QR decomposition-based recursive least square approach in the complex domain, aim to achieve fast cancellation and interference cancellation in the digital domain with high cancellation ratio. First, we analyze the iterative boundary of the conventional QRD-RLS algorithm, perform the third-order annihilation-reordering look-ahead, derive the iterative formula of the complex domain look-ahead and the structure of the systolic structure, then analyze the timing relationship of each unit, and finally perform the critical path optimization and build the systolic structure model of the third-order look-ahead. Upon comparison with the QRD-RLS algorithm, this method showcases an enhanced cancellation speed while maintaining a high cancellation ratio. Results from simulations indicate that the cancellation ratio of this method remains consistent with the RLS algorithm.