Date Added: Jul 2010
In the scenario of dynamic spectrum access application for Cognitive Radio (CR), the spectrum-side-lobe problem of OFDM (orthogonal frequency division multiplexing) must be considered. A pre-coding ahead of IDFT (inverse discrete Fourier transformation) is presented to suppress the In-Band-Out-of-Sub-Band (IBOSB) radiation. Its design is based on generalized eigen-value problem. In order to improve its performance for practical application, one column of the pre-coding matrix can be inverted to reduce the signal Peak-to-Average-Power-Ratio (PAPR) to a lower level. At the receiver, iterative soft detection with interference cancelation is adopted to detect the pre-coded data and further employs the frequency diversity.