## What is channel estimation in OFDM?

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 techniques?

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 channel estimation and Equalization?**

Channel estimation provides information about distortion of the transmission signal when it propagates through the channel. This information is then used by equalizers so that the fading effect and/or co-channel interference can be removed and the original transmitted signal can be restored.

**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.

## What is capacity of a channel?

The channel capacity, C, is defined to be the maximum rate at which information can be transmitted through a channel. The fundamental theorem of information theory says that at any rate below channel capacity, an error control code can be designed whose probability of error is arbitrarily small.

### What are channel taps?

A tap in this context is just a point on the delay line corresponding to a certain delay. The signals from each tap can then be “summed” and the composite signal then represents what a real radio wave might look like as received by a receiver and when subject to multipath fading.

**Is OFDM a modulation technique?**

Orthogonal frequency division multiplexing (OFDM) is a modulation technique that is used in several applications ranging from cellular systems (3GLTE, WiMAX), wireless local area networks (LANs), digital audio radio, underwater communications, and even optical light modulation.

**What is post equalization Sinr?**

1Post-equalizer SINR refers to the SINR of the received signal after channel estimation and equalization stages of the baseband.

## What is channel estimation in 5G?

Channel estimation is essential in a Multiple Input Multiple Output (MIMO) wireless communication in 5G. In the MIMO system, numerous antennas are utilized on the sender and receiver sides for enhancing spectral efficiency and reliability. The channel estimation can improve the exactness of the received signal.

### What is channel Matrix in MIMO?

The rank of the channel matrix is thus an indicator of how many data streams can be spatially multiplexed on the MIMO channel. The rank and condition of a channel matrix also exist for every possible matrix dimension and thus for every possible MIMO constellation!

**What is maximum data rate of a channel?**

It is generally computed in bits per second (bps). Higher data rates are expressed as Kbps (“Kilo” bits per second, i.e.1000 bps), Mbps (“Mega” bits per second, i.e.1000 Kbps), Gbps (“Giga” bits per second, i.e. 1000 Mbps) and Tbps (“Tera” bits per second, i.e. 1000 Gbps).

**What is a channel model?**

A channel model is a mathematical representation of the effects of a communication channel through which wireless signals are propagated. The channel model can represent the power loss incurred by the signal as it travels through the wireless medium.

## How many subcarriers are in OFDM?

Because of the 78.125 KHz spacing, an OFDMA 20 MHz channel consists of a total of 256 subcarriers (tones) as depicted in Figure 2.

### What is Guard Band in OFDM?

Guard bands have two uses. They protect users of adjacent systems from spillage, or spectrum spread, of our signal into their band. They protect us from the spillage of an adjacent system’s signals into our band. To protect adjacent systems, they are generated with no energy in them.

**What are two types of techniques used for Equalisation?**

The are two types of equalizers: Time domain equalizers and frequency domain equalizers.

**What is channel matrix?**

A channel state matrix can provide the information needed to determine whether spatial multiplexing is possible for multilayer data transmission. Simple indicators for evaluating the mobile radio channel are derived from the channel matrix.

## What is pilot contamination in massive MIMO?

Within massive multiple-input-multiple-output (Massive MIMO) system, pilot contamination (PC) is deemed as a stumbling block in boosting the spectral efficiency (SE) regarding fifth-generation (5G) wireless communication network.