Research Article

Spectrum-Efficient Cognitive Radio Transceiver Using Multiwavelet Filters

Algorithm 2

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 𝑘 t h 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 𝐼 𝑚
 and the 𝑛 t h vector data stream of the user is mapped onto those subbands.
7: The process is repeated until all the 𝑃 data streams of the user are mapped accordingly. The remaining subcarriers
 carry no data and are padded with zeros.