In this paper, the performance of mobile cellular systems with link adaptation (LA) is analytically evaluated. Half- and full-rate vocoders are considered in the analysis. Mathematical expressions for the new call blocking, handoff failure, and forced termination probabilities are obtained. To our knowledge, no similar analysis considering LA exists in the literature. Also, the link quality-aware dual fractional channel reservation (LQA DFCR) scheme is proposed. In LQA DFCR, user differentiation is implemented in terms of link quality. Preference is given to users with good link quality because they require fewer resources than users with bad link quality. Numerical results show that the proposed LQA DFCR scheme effectively increases system capacity: LQA DFCR achieves more than a 11% capacity gain relative to systems with the non priority scheme (NPS) and with LA, and approximately 3% relative to the fair access prioritisation scheme (FAPS) strategy. Numerical results also show that LA yields an approximately 18% capacity increase relative to a cellular system without LA when no admission control is employed (admission control strategies further increase system capacity.) The synergy between LA and admission control strategies yields more than a 31% capacity gain