How does noise affect communication systems?

2 Types of noise

Noise can be classified into different types based on its statistical properties, such as amplitude, frequency, phase, or distribution. White noise is characterized by a constant power spectrum over a wide frequency range and a Gaussian amplitude distribution. Colored noise is distinguished by its non-constant power spectrum over a frequency range and its specific color name depending on its spectral density, such as pink noise, brown noise, or blue noise. Impulse noise consists of short and high-amplitude pulses that occur randomly in time and have a non-Gaussian amplitude distribution. Lastly, phase noise causes random variations in the phase of a signal, thus affecting the synchronization and coherence of the communication system.

3 Effects of noise

Noise can detrimentally affect the performance and functionality of communication systems in multiple ways. For instance, it can reduce the signal-to-noise ratio (SNR), increasing the bit error rate (BER) and limiting the channel capacity. Additionally, noise can distort the signal shape, frequency, phase, or amplitude, making it difficult to interpret or comprehend information within the communication system. All these factors can significantly impact the quality, accuracy, reliability, efficiency, and bandwidth of a communication system.

4 Mitigation of noise

Noise can be mitigated or minimized through various techniques and methods, such as filtering, amplification, encoding, modulation, and diversity. Filtering involves using devices or algorithms to remove or reduce the unwanted frequencies or components of the noise from the signal. Amplification uses devices or algorithms to increase the signal strength or power relative to the noise level and improve the SNR. Encoding schemes or protocols add redundancy or error correction codes to the signal to enable detection or correction of errors caused by noise. Modulation schemes or protocols change the frequency, phase, or amplitude of the signal according to a predefined pattern or code to make it more resistant or immune to noise. Diversity utilizes multiple channels, antennas, or paths to transmit or receive the same signal and reduce the effects of noise by combining or selecting the best signal.

5 Applications of noise

Noise is not always a negative or undesirable factor in communication systems; it can actually have positive or beneficial effects. For instance, noise can enhance the signal quality or detection through stochastic resonance, dithering, or noise shaping. It can also generate random or secure signals with noise generators, noise encryption, or noise authentication. Additionally, noise can improve the system performance or functionality through noise cancellation, noise injection, or noise adaptation. In other words, noise can be utilized to exploit the nonlinear or dynamic properties of the system or the noise and use the randomness or unpredictability of the noise to provide feedback and control.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?