Communication Engineering Basics

The process of transferring information from a source to a destination.

The physical medium used to transmit signals between a transmitter and receiver.

Converts information into a transmittable signal.

Converts the received signal back into original information.

Signals weaken as they travel over a distance.

Distortion caused by variations in signal amplitude and phase during transmission.

Distortion that occurs due to multiple paths of signal propagation.

Limitations on the amount of data transmitted due to power and frequency constraints.

A communication channel where electromagnetic waves are guided by a physical medium, like copper wires or optical fibers. The channel characteristics are well-defined and understood by the transmitter and receiver.

Two insulated copper wires twisted together to reduce interference. The oldest and most common type of communication cable.

A central copper conductor surrounded by insulation and a copper shield. Provides higher bandwidth than copper wire.

A hollow metal tube that transmits microwaves. Offers very high bandwidth, but is expensive and difficult to install.

A dielectric waveguide that transmits data using light. It uses thin strands of glass or plastic fibers.

Interference between signals traveling through different wires in a cable.

The maximum rate of data transmission that a channel can support.

The weakening of a signal as it travels over a distance.

A type of transmission medium that uses physical wires to transmit signals.

A type of transmission medium that uses electromagnetic waves to transmit signals without physical wires.

Twisted-pair cables are made of two insulated wires twisted together, reducing interference. They are commonly used for telephone lines and low-speed data.

A thin glass fiber that transmits signals using light pulses. Offers high bandwidth and long distances for data transmission.

Signals that are continuous and vary smoothly over time, like audio or video signals.

Signals that are discrete and represent information as a series of values (0s and 1s), like the output of a computer.

A technique that combines multiple signals into a single carrier wave using different frequencies, allowing them to be transmitted simultaneously without interference.

A communication system where information is represented as continuous values, using modulation techniques for transmission.

A communication system where information is represented in digital format, typically as binary digits (bits).

A component in a digital communication system that converts analog signals into digital form.

A component in a digital communication system that introduces redundancy to signal data in a controlled way, helping to correct errors during transmission.

Reducing redundancy in information to be sent, making it more efficient for transmission.

A type of channel encoding that repeats each binary digit a certain number of times, adding redundancy for error detection.

A mapping of a sequence of k-bit data into a unique n-bit sequence, enabling error correction.

In communications, it's the process of modifying a high-frequency carrier signal with information from a message signal. This allows the message to travel a longer distance and be transmitted efficiently.

The carrier signal is typically a sinusoidal wave described by the function f(t) = A sin(ωt + φ), where A represents amplitude, ω stands for the angular frequency, and φ denotes the phase angle.

This type of modulation alters the amplitude of the carrier signal proportionally to the message signal's amplitude. Imagine varying the loudness of a tone to encode information.

This method changes the frequency of the carrier signal according to the message signal's changes. Think of altering the pitch of a musical note to convey information.

This technique modifies the phase of the carrier signal based on the message signal's changes. Imagine shifting the starting point of a wave to represent information.

This modulation type digitally encodes information by altering the amplitude of the carrier signal. The amplitude is changed to represent different digital values.

In this modulation, the carrier signal's frequency is shifted to represent different digital bits. Each bit is encoded by a unique frequency.

This modulation technique uses the phase of the carrier signal to represent digital information. The phase is shifted to encode different digital bits.

It translates digital symbols into analog waveforms for transmission over a physical channel.

It maps each binary digit to a specific signal waveform, enabling the transmission of digital data.

It transmits one of M waveforms for every group of b bits, allowing more information to be packed into each transmission.

It receives the distorted and noisy analog signal and transforms it into tentative decisions about the transmitted symbols.

It converts the estimated information bits from the channel decoder into a format that can be understood by the user.

It provides the physical connection between the transmitter and receiver, allowing signals to travel through it.

These stations amplify and clean up digital signals along the communication path, preventing signal degradation due to noise and distortion.