Fig. 3From: Channel estimation via gradient pursuit for mmWave massive MIMO systems with one-bit ADCsThe magnitude of \(\text {unvec}(T_{L}(\nabla h(\mathbf {x})))\in \mathbb {C}^{B_{\text {RX}}\times B_{\text {TX}}}\) at x=0B, namely, after hard thresholding. This shows how hard thresholding on ∇h(x) results in an incorrect estimate of supp(x∗) when A is highly coherent. In this example, M=N=16,BRX=BTX=64,T=20,L=4,SNR=20 dB, and supp(x∗) is widely spreadBack to article page