Introduction to Microservice Architecture Using SpringBoot - Part 1

 

1. What are diversity receivers?

In wireless microphone applications, diversity receivers are often used to improve reception of RF signals. A diversity receiver utilizes two separate, independent antenna systems. The receiver looks at the signal coming in from each antenna, and determines which one is the stronger. It then switches to that stronger signal. The receiver is constantly comparing to see which antenna is providing the better signal, and can quickly switch from one to the other as signal strength changes.

2. What is MRC receiver?

In telecommunications, maximum-ratio combining (MRC) is a method of diversity combining in which:

1. the signals from each channel are added together,

2. the gain of each channel is made proportional to the RMS signal level and inversely proportional to the mean square noise level in that channel. 

3. different proportionality constants are used for each channel.

It is also known as ratio-squared combining and redetection combining. Maximum-ratio combining is the optimum combiner for independent additive white Gaussian noise channels. MRC can restore a signal to its original shape. MRC has also been found in the field of neuroscience, where it has been shown that neurons in the retina scale their dependence on two sources of input in proportion to the signal-to-noise ratio of the inputs.

3. What is the purpose of rake receiver?

A Rake Receiver is a radio receiver which is designed for the purpose to counter the effects of multipath fading. Due to reflections from multiple obstacles in the environment, the radio channel can consist of multiple copies of the transmitted signal having different amplitude, phases or delays.

A rake receiver can resolve this issue and combine them. For this purpose, several sub-receivers are used which are known as "fingers". The idea of a basic rake receiver was first proposed by Price and Green.

4. What is basic principle of working of rake receiver?

The Rake receiver uses a multipath diversity principle. When the signal travels from transmit end to the receive end, it will go through multiple paths. This results into multiple versions of the transmit signals received at the receiver. Each of these signals will have different attenuations and path delays. A rake receiver can detect these different signals separately. These signals are then combined, using the diversity technique called maximum ratio combining. A RAKE receiver rakes through a given time-window and searches for different delayed versions of the same signal. It then employs a variety of techniques to use the different images to decode the signal, rather than using a single image.