A study of consolidating OFDMA radio networks for downlink in cognitive radio system

Cognitive radio is a great candidate for creating a new fundamental network architecture improving the efficiency of frequency resource usage. In a heterogeneous network, a cognitive radio system composed with a multi-transmission link is required to select the optimized wireless access network to the terminal. To make the proper selection of a wireless access network to the terminal, the relative amount of radio resources in use for each network is an important parameter. We call this parameter the ¿occupation level¿ in this paper, which is one of the most useful parameters for the selection as well as the Received Signal Strength Indicator (RSSI). A wireless access network adopting an Orthogonal Frequency Division Multiple Access (OFDMA) scheme has a certain occupation level in its Up Link/Down Link (UL/DL) resource allocation. The UL/DL resource allocation is not easily accessible from equipment outside the base station; how to extract these data and utilize them is unresolved. In this paper, we propose a new scheme for extracting and utilizing the UL/DL resource allocation for the occupation level of the cognitive radio in a Long Term Evolution (3GPP LTE) network. From the system load point of view, we confirmed the method is practical by examining these data being extracted from an LTE radio system while transmitting full buffered payload data.