Figure 3From: Uplink User Signal Separation for OFDMA-Based Cognitive RadiosNormalized autocorrelations obtained utilizing a 60-symbol long signal (with FFT size 512) for a block size of 4 × 3 at 30 dB SNR in an AWGN channel. (a) Vertical autocorrelation. (b) Horizontal autocorrelation.Back to article page