Orthogonal Frequency Division Multiple Access (OFDMA) is one of the most promising, demanded and researched modulation and access methods for future mobile wireless networks. Emerging technologies, like Worldwide Interoperability for Microwave Access (WiMAX) or Long Term Evolution (LTE), are adopting OFDMA due to its high spectral efficiency, scalability for high amounts of users and mobility support. In OFDMA, before data is actually transmitted, it must be mapped into a time-frequency matrix through a resource allocation process. This step is critical for a correct network behaviour, and several factors must be taken into account like efficiency, Quality of Service (QoS) fulfillment or power consumption. In this paper, we propose a novel approach for the mapping process of IEEE 802.16e networks, and we compare its performance with several existing algorithms. The effectiveness of our proposal is evaluated in different scenarios by means of extensive simulation.