Research Article
Spectrum-Efficient Cognitive Radio Transceiver Using Multiwavelet Filters
1: The binary spectrum information vector is obtained. | 2: CAS tries to determine CSI of each free subband available within the BOI. | 3: CSI of the CR node under consideration along with the neighboring nodes are obtained. | 4: Based on the information obtained, CAS assigns subbands for the considered CR node. Two consecutive subbands will be | allocated for the same user. The subbands with maximum SNR is the primary choice. | 5: If the specified CR as well as a competing neighbor has maximum SNR at the consecutive subbands, other CSI factors | such as channel delay, phase offset will be taken into consideration to make the final decision. | 6: Once the user and band is fixed, final decision is made and that subband index is included in the spectrum index vector | and the vector data stream of the user is mapped onto those subbands. | 7: The process is repeated until all the data streams of the user are mapped accordingly. The remaining subcarriers | carry no data and are padded with zeros. |
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