Initial access at millimeter wave frequencies is a challenging problem due to hardware non-idealities and low SNR measurements prior to beamforming. Prior work has exploited the observation that mmWave MIMO channels are sparse in the spatial angle domain and has used compressed sensing based algorithms for channel estimation. Most of them, however, ignore hardware impairments like carrier frequency offset and phase noise, and fail to perform well when such impairments are considered. In this paper, we develop a compressive channel estimation algorithm for narrowband mmWave systems, which is robust to such non idealities. We address this problem by constructing a tensor that models both the mmWave channel and CFO, and estimate the tensor while still exploiting the sparsity of the mmWave channel. Simulation results show that under the same settings, our method performs better than comparable algorithms that are robust to phase errors.Index Terms-Millimeter wave channel estimation, tensor compressed sensing, analog beamforming, channel estimation 1 MT = 31.25KHz, for M = 64). Hence f e = 265.625KHz is chosen. For Agile Link B r , B t , N hash were optimized and set to (4, 4, 4) and (4, 4, 8) for 64 and 128 measurements respectively. The proposed tensor based approach, however, demands 2P + 1 times higher complexity in memory and