Contents
What is the purpose of channel estimation?
Channel estimation plays an important part in an OFDM system. It is used for increasing the capacity of orthogonal frequency division multiple access (OFDMA) systems by improving the system performance in terms of bit error rate.
What is Channel estimation in MIMO?
The channel estimation is carried out with conventional Least Square (LS) and Minimum Mean Square (MMSE) estimation algorithms. The performance of MIMO-OFDM system is evaluated on the basis of Bit Error Rate (BER) and Mean Square Error (MSE) level.
What is channel estimation in massive MIMO?
Channel estimation is crucial for massive massive multiple-input multiple-output (MIMO) systems to scale up multi-user (MU) MIMO, providing great improvement in spectral and energy efficiency.
How is channel estimation used in OFDM systems?
The channel estimation concept exploits the frequency correlation of the channel. In many OFDM systems this concept can improve channel estimation signiflcantly, even if the channel statistics are not exactly known at a receiver.
Why do we need a channel equalizer in OFDM?
Channel estimation is usually needed in coherent OFDM receivers in order to com- pensate for a frequency-selective channel. For this purpose, a channel equalizer needs to be fed estimates of the subcarrier attenuations. This thesis presents low-rank approxi- mations of the linear minimum mean-squared error channel estimator.
Can a synchronization error cause intercarrier interference?
Synchronization errors in OFDM can cause intersymbol and intercarrier interference. One way to suppress these interferences in OFDM systems is to track the carrier frequency of the received signal and the proper start of the OFDM symbols.
Can a multiuser OFDM system track synchronization?
Furthermore, tracking synchronization of a multiuser OFDM system, which often has been questioned, is feasible using a scheme incorporating the above estimator concept.