Hi Pals, I am developing a least square channel estimation in matlab. I will brief u what i am doing. Let me know if i am doing anything wrong. At the receiver, the frequency domain channel estimation is done by performing a simple division operation i.e., received pilot by transmitted pilot. Once the frequency domain estimates are found we will perform FD interpolation. we are using LS equation, which converts into time domain as well as windowing it to CP length and converting back to frequency domain gives the channel coefficients across all sub carriers. I am using SCM channel and inbuilt AWGN function for channel simulation. If i plot performance graph SNR Vs NMSE, i am not getting a good perfromance and FDE is performing better than LS. But actually after interpolation it should perfrom better. ( LS should perfrom better than FDE) I will just summarize the equations what i am using, r = xh + n H_FDE = r / x; hLS = (F' F)-1 * F' * H_FDE; HLS = Fsc * hLS; Where, F is a twiddle factor matrix only for reference signal position across CP length F' is complex conjugate of F Fsc is a twiddle matrix at all subcarriers across CP length. Please help me if am doing anything wrong. I am not able to find where the issue is. Ur suggestions are always welcomed. Thanks in advance, Sri

# LS channel estimation for LTE

Started by ●January 7, 2008

Posted by ●January 7, 2008

Hi Pals, I am developing a least square channel estimation in matlab. I will brief u what i am doing. Let me know if i am doing anything wrong. At the receiver, the frequency domain channel estimation is done by performing a simple division operation i.e., received pilot by transmitted pilot. Once the frequency domain estimates are found we will perform FD interpolation. we are using LS equation, which converts into time domain as well as windowing it to CP length and converting back to frequency domain gives the channel coefficients across all sub carriers. I am using SCM channel and inbuilt AWGN function for channel simulation. If i plot performance graph SNR Vs NMSE, i am not getting a good perfromance and FDE is performing better than LS. But actually after interpolation it should perfrom better. ( LS should perfrom better than FDE) I will just summarize the equations what i am using, r = xh + n H_FDE = r / x; hLS = (F' F)-1 * F' * H_FDE; HLS = Fsc * hLS; Where, F is a twiddle factor matrix only for reference signal position across CP length F' is complex conjugate of F Fsc is a twiddle matrix at all subcarriers across CP length. Please help me if am doing anything wrong. I am not able to find where the issue is. Ur suggestions are always welcomed. Thanks in advance, Sri