A Design Framework for Cost-Efficient Sorters With Arbitrary Input/Output Constraints

The sorting operation plays a vital role in various signal processing applications. However, due to high hardware complexity resulting from a series of comparisons, designing the cost-efficient sorter is one of the crucial requisites for improving the overall system performance. To obtain the cost-efficient sorting architectures constrained to application-specific input/output conditions, this paper presents a systematic design methodology that effectively eliminates dispensable compare-and-swap (CAS) units. Unlike the previous heuristic approaches, the proposed framework iteratively prunes a CAS unit followed by the validation step. The zero-one principle is newly applied to reduce the validation time for the practical convergence time with massive searching iterations. To expand the search space of the proposed framework, furthermore, we introduce new architectural options and pruning methods, allowing the cost-efficient design results even compared to the state-of-the-art solutions. Targeting the constrained sorters for communication systems, numerous case studies show that the proposed framework successfully removes more than half of CAS units in the baseline sorter design, significantly relaxing the area-time complexity, e.g., 35% reduction compared to the state-of-the-art architecture for 16-input metric sorter in the SCL polar decoder.