Ranking and adaptive ranking CDMA

This paper develops an uplink transmission scheduling scheme, referred to as Ranking CDMA, which selects a subset of users for transmission at each time slot. We introduce long- and short-term metrics that characterize its performance, and devise analytical methods for evaluating these performance measures. It turns out that, although Ranking CDMA has excellent long-term power efficiency compared to traditional CDMA, it suffers from a lack of short-term fairness, which is quantified in our calculations. To alleviate this deficiency, we propose Adaptive Ranking CDMA and analytically show that it yields moderate power-efficiency improvement over traditional CDMA, while maintaining short-term fairness.