What is channel estimation and Equalization?

What is channel estimation and Equalization?

Channel Estimation & Equalization The function of channel estimation is to form an estimate of the amplitude and phase shift caused by the wireless channel from the available pilot information. The equalization removes the effect of the wireless channel and allows subsequent symbol demodulation.

What is LTE channel estimation?

Channel estimation plays an important part in an OFDM system. To facilitate the estimation of the channel characteristics, LTE uses cell-specific reference signals (pilot symbols) inserted in both time and frequency. These pilot symbols provide an estimate of the channel at given locations within a subframe.

What is equalization in LTE?

The equalizers used in LTE are frequency domain equalizers where a known input signal X(z) in the frequency domain at the transmitter is transmitted through the rf channel. Having the the transmitted signal X(z) and the received signal Y(z), H(z) is then calculated by the ratio of Y(z)/ X(z).

How is channel estimation done?

Channel estimation can be carried out in different ways: with or without the help of a parametric model, using frequency and/or time correlation properties in the wireless channel, blind methods or those based on training pilots, adaptive or non-adaptive methods.

What is meant by channel estimation?

Channel Estimation is the process of finding correlation between the array of complex numbers on the left and the array of complex numbers on the right. The detailed method of the estimation can very depending on the implementation.

What is channel estimation in MIMO?

MIMO. systems use multiple antennas to transmit and receive. signals. Channel Estimation means to estimate channel. parameters from the received signal.

How is channel state information calculated?

Channel state information (CSI) is basically calculated using the pilot signals used during transmission and compared with the received pilot signals, while the SNR reflects the strength of the transmitted signal in respect of the channel noise.

What is meant by channel estimation in wireless communication?

One of vital parts of the mobile wireless channel is channel estimation, which is a method used to significantly improve the performance of the system, especially for 4G and Long Term Evolution (LTE) systems. Channel estimation is done by estimating the time-varying channel frequency response for the OFDM symbols.

What is channel estimation in digital communication?

Channel estimation is a challenging problem in wireless communications. Transmitted signals are typically reflected and scattered, arriving at the receiver along multiple paths. Due to the mobility of the transmitter, the receiver, or the scattering objects, the channel changes over time.

What is channel estimation in MIMO-OFDM?

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.

How is the LTE downlink channel estimation function configured?

The channel estimation function is configured by the structure cec. lteDLChannelEstimate assumes the first subframe within the resource grid is subframe number enb.NSubframe and therefore the subframe number must be set prior to calling the function.

How is CQI used in UE channel estimation?

Used by the UE to estimate the channel and report channel quality information (CQI) to the base station. Used for equalization of PMCH transmissions. Used in UL transmission for channel estimation and for coherent demodulation. Used by the UE to obtain the cell identity and frame timing.

How is channel estimation performed for multi antenna?

Because no other antenna transmits data at these locations in time and frequency, channel estimation for multi-antenna configurations can be performed. The channel estimation algorithm extracts the reference signals for a transmit/receive antenna pair from the received grid.

How is MMSE equalization used in MMSE calculation?

MMSE equalization using channel and noise estimation is applied and finally the received and equalized resource grids are plotted. The cell-wide settings are specified in a structure enb.