中国科技论文在线 ulse response of MIMO NC-OFDM channels. Theoretical simulations show that the new channel estimation methods in spectrum utilization and performance than existing MIMO NC-OFDM channel estimation methods have improved significantly. Key words: Communication and Information System; Multiple-input multiple-output non-contiguous orthogonal frequency division multiplexing; Cognitive Radio; Compressed 35 Sensing; channel estimation; Sparsity Adaptive Matching Pursuit