Learn Wireless Communication from the Basics to the Advanced with "Wireless Communication" by Mullet
Wireless Communication By Mullet Pdf Download
Wireless communication is one of the most fascinating and rapidly evolving fields in engineering. It has revolutionized many aspects of our lives, such as telecommunication, entertainment, navigation, security, health care, and more. However, learning wireless communication can be challenging due to its complexity and diversity. That's why you need a reliable and comprehensive guide that can help you master this subject with ease.
Wireless Communication By Mullet Pdf Download
In this article, we will introduce you to one such guide - the book "Wireless Communication" by Mullet. This book covers all the essential topics and concepts of wireless communication in a clear and concise manner. It also provides numerous examples, exercises, diagrams, tables, and figures to enhance your understanding and practice. Whether you are a student, a teacher, a researcher, or a professional in this field, this book will be an invaluable resource for you.
But before we tell you more about the book and how to download it in PDF format, let's first review some basics of wireless communication. What is wireless communication? Why is it important? How does it work? What are the types of wireless communication? These are some of the questions that we will answer in this article. So let's get started!
What is Wireless Communication?
Wireless communication is the transmission and reception of information without using any physical medium such as wires or cables. Instead, it uses electromagnetic waves or signals that propagate through free space or air. These signals can carry various types of information such as voice, data, video, images, etc.
Wireless communication has many applications in different domains such as:
Telecommunication: Wireless communication enables us to make phone calls, send text messages, access the internet, and communicate with other devices without using wires or cables.
Entertainment: Wireless communication allows us to enjoy various forms of entertainment such as radio, television, music, movies, games, etc. without using wires or cables.
Navigation: Wireless communication helps us to locate our position and direction using devices such as GPS, compass, etc. without using wires or cables.
Security: Wireless communication helps us to monitor and protect our premises and assets using devices such as cameras, sensors, alarms, etc. without using wires or cables.
Health care: Wireless communication helps us to diagnose and treat various health conditions using devices such as pacemakers, implants, scanners, etc. without using wires or cables.
These are just some of the examples of how wireless communication has improved our quality of life and productivity. However, wireless communication also poses some challenges such as:
Limited spectrum: The electromagnetic spectrum is a finite resource that has to be shared among different users and applications. This can cause congestion, interference, and degradation of performance.
Limited power: The wireless devices have to operate on batteries or other sources of power that have limited capacity and lifetime. This can affect the reliability and availability of wireless communication.
Limited security: The wireless signals can be intercepted, modified, or jammed by unauthorized parties. This can compromise the confidentiality, integrity, and authenticity of wireless communication.
Therefore, wireless communication requires careful design, analysis, and optimization to overcome these challenges and achieve the desired objectives.
How Does Wireless Communication Work?
Wireless communication involves four basic steps:
Modulation: The process of encoding the information into a suitable form for transmission over the wireless channel.
Transmission: The process of radiating the modulated signal from the transmitter antenna into the wireless channel.
Propagation: The process of traveling of the transmitted signal through the wireless channel to the receiver antenna.
Reception: The process of capturing the propagated signal by the receiver antenna and converting it back into the original information.
Each of these steps involves various principles and components that we will discuss in more detail in the following sections.
Modulation and Demodulation
Modulation is the process of encoding the information into a suitable form for transmission over the wireless channel. The information can be analog or digital, depending on the source and application. For example, voice is an analog signal that can be modulated by varying the amplitude, frequency, or phase of a carrier wave. Data is a digital signal that can be modulated by assigning different symbols or bits to different levels or patterns of a carrier wave.
The modulated signal is then transmitted over the wireless channel using an antenna. The antenna converts the electrical signal into an electromagnetic wave that can propagate through free space or air. The antenna also determines the directionality and gain of the transmitted signal.
The transmitted signal travels through the wireless channel until it reaches the receiver antenna. The receiver antenna converts the electromagnetic wave back into an electrical signal that can be processed by a demodulator. The demodulator is the reverse process of modulation that decodes the received signal into the original information.
Multiplexing and Multiple Access
Multiplexing is the process of combining multiple signals into one signal for transmission over a common channel. Multiplexing can be done in different ways such as:
Time division multiplexing (TDM): The signals are divided into time slots and transmitted sequentially over the channel.
Frequency division multiplexing (FDM): The signals are assigned different frequency bands and transmitted simultaneously over the channel.
Code division multiplexing (CDM): The signals are assigned different codes and transmitted simultaneously over the channel.
Space division multiplexing (SDM): The signals are transmitted using different spatial directions or beams over the channel.
Multiplexing allows efficient utilization of the channel bandwidth and capacity. However, it also introduces interference among the signals that have to be separated at the receiver.
Multiple access is the process of allowing multiple users to access a common channel for communication. Multiple access can be done in different ways such as:
Time division multiple access (TDMA): The users are divided into time slots and access the channel sequentially.
Frequency division multiple access (FDMA): The users are assigned different frequency bands and access the channel simultaneously.
Antennas and Propagation
Antennas are devices that convert electrical signals into electromagnetic waves and vice versa. Antennas have various properties such as:
Polarization: The orientation of the electric field of the electromagnetic wave.
Directivity: The ability of the antenna to focus the electromagnetic wave in a specific direction.
Gain: The ratio of the power radiated by the antenna in a specific direction to the power radiated by an ideal isotropic antenna.
Impedance: The ratio of the voltage to the current at the terminals of the antenna.
Bandwidth: The range of frequencies that the antenna can operate efficiently.
Antennas can be classified into different types such as:
Dipole antenna: A simple antenna that consists of two conductors of equal length connected to a source or a load.
Monopole antenna: A half of a dipole antenna that is mounted on a ground plane.
Loop antenna: A circular or rectangular antenna that has a loop of wire or tubing.
Yagi-Uda antenna: A directional antenna that consists of a dipole element and several parasitic elements.
Horn antenna: A flared antenna that has a rectangular or circular aperture.
Parabolic antenna: A highly directional antenna that has a parabolic reflector and a feed element.
Array antenna: A combination of multiple antennas that can produce a desired radiation pattern.
Propagation is the process of traveling of the electromagnetic wave through the wireless channel. Propagation can be affected by various factors such as:
Distance: The electromagnetic wave attenuates or loses power as it travels away from the source.
Fading: The electromagnetic wave fluctuates or varies in amplitude, phase, or frequency due to multipath propagation, Doppler effect, or shadowing.
Reflection: The electromagnetic wave bounces off a smooth surface such as a wall or a building.
Refraction: The electromagnetic wave bends or changes direction as it passes through a medium with different refractive index such as air or water.
Diffraction: The electromagnetic wave bends or spreads around an obstacle such as a corner or an edge.
Scattering: The electromagnetic wave disperses or splits into multiple waves due to small irregularities in the medium such as dust or rain.
Propagation can be modeled using different methods such as:
Free space model: A simple model that assumes no obstacles or interference in the wireless channel.
Friis model: A model that considers the distance and frequency of the wireless channel.
Hata model: A model that considers the distance, frequency, and environment (urban, suburban, rural) of the wireless channel.
Okumura model: A model that considers the distance, frequency, environment, and terrain (hills, buildings, etc.) of the wireless channel.
Rician model: A model that considers the line-of-sight and multipath components of the wireless channel.
Rayleigh model: A model that considers only the multipath components of the wireless channel.
Noise and Interference
Noise is any unwanted signal that affects the quality and performance of wireless communication. Noise can be classified into different types such as:
Thermal noise: Noise that is generated by the random motion of electrons in a conductor due to temperature. It is also known as white noise or Johnson-Nyquist noise.
Shot noise: Noise that is generated by the random fluctuations of current in an electronic device due to discrete nature of charge. It is also known as Schottky noise or Poisson noise.
Flicker noise: Noise that is generated by the random fluctuations of current in an electronic device due to defects or impurities. It is also known as pink noise or 1/f noise.
Gaussian noise: Noise that has a normal or bell-shaped probability distribution. It is also known as additive white Gaussian noise (AWGN).
Interference is any unwanted signal that affects the quality and performance of wireless communication. Interference can be classified into different types such as:
Co-channel interference: Interference that occurs when multiple users share the same frequency channel.
Adjacent channel interference: Interference that occurs when the signals from adjacent frequency channels spill over into each other.
Intermodulation interference: Interference that occurs when the signals from different frequency channels mix and produce new signals at different frequencies.
Cross-talk interference: Interference that occurs when the signals from different transmission lines or circuits couple into each other.
Electromagnetic interference: Interference that occurs when the signals from external sources such as power lines, motors, generators, etc. affect the wireless communication.
Noise and interference can be measured using different parameters such as:
Signal-to-noise ratio (SNR): The ratio of the power of the desired signal to the power of the noise.
Signal-to-interference ratio (SIR): The ratio of the power of the desired signal to the power of the interference.
Signal-to-noise-plus-interference ratio (SNIR): The ratio of the power of the desired signal to the power of the noise plus interference.
Bit error rate (BER): The ratio of the number of bits that are received incorrectly to the total number of bits that are transmitted.
Packet error rate (PER): The ratio of the number of packets that are received incorrectly to the total number of packets that are transmitted.
Noise and interference can be reduced or mitigated using different techniques such as:
Filtering: The process of removing or attenuating unwanted signals or frequencies from a signal.
Shielding: The process of enclosing or covering a device or a circuit with a material that can block or absorb electromagnetic waves.
Coding: The process of adding redundancy or extra bits to a signal to detect and correct errors.
Modulation: The process of encoding a signal into a suitable form for transmission over a wireless channel.
Multiplexing: The process of combining multiple signals into one signal for transmission over a common channel.
Multiple access: The process of allowing multiple users to access a common channel for communication.
Diversity: The process of using multiple antennas, frequencies, paths, or times to improve wireless communication.
Error Control and Security
Error control is the process of detecting and correcting errors that occur during wireless communication. Error control can be done in two ways:
Forward error correction (FEC): The process of adding redundancy or extra bits to a signal before transmission to enable the receiver to correct errors without requesting retransmission.
Automatic repeat request (ARQ): The process of requesting retransmission of a signal if errors are detected by the receiver.
Error control can use different codes or algorithms such as:
Parity check code: A code that adds one bit to a signal to indicate whether the number of ones in the signal is even or odd.
Cyclic redundancy check (CRC) code: A code that adds a sequence of bits to a signal based on a polynomial division operation.
Hamming code: A code that adds multiple bits to a signal to enable single-bit error correction and double-bit error detection.
Bose-Chaudhuri-Hocquenghem (BCH) code: A code that adds multiple bits to a signal based on a polynomial algebra operation.
Reed-Solomon code: A code that adds multiple symbols to a signal based on a finite field algebra operation.
Convolutional code: A code that generates multiple output bits for each input bit based on a shift register operation.
Turbo code: A code that combines two convolutional codes with an interleaver operation.
Security is the process of ensuring confidentiality, integrity, and authenticity of wireless communication. Security can be done in two ways:
Encryption: The process of transforming a signal into an unintelligible form using a secret key before transmission to prevent unauthorized access or modification.
Authentication: The process of verifying the identity and validity of a sender or a receiver using a secret key or a certificate before communication to prevent impersonation or spoofing.
Security can use different algorithms or protocols such as:
Data Encryption Standard (DES): An algorithm that encrypts or decrypts a 64-bit signal using a 56-bit key.
Advanced Encryption Standard (AES): An algorithm that encrypts or decrypts a 128-bit, 192-bit, or 256-bit signal using a 128-bit, 192-bit, or 256-bit key.
Rivest-Shamir-Adleman (RSA): An algorithm that encrypts or decrypts a signal using a pair of public and private keys.
Diffie-Hellman: A protocol that enables two parties to exchange a secret key over an insecure channel.
Message Authentication Code (MAC): A code that is appended to a signal using a secret key to verify its integrity and authenticity.
Digital Signature: A code that is generated by the sender using a private key and verified by the receiver using a public key to verify the integrity and authenticity of a signal.
Secure Hash Algorithm (SHA): An algorithm that generates a fixed-length code from a variable-length signal to verify its integrity.
What are the Types of Wireless Communication?
Wireless communication can be classified into different types based on the frequency, range, or technology of the wireless channel. Some of the common types of wireless communication are:
Radio Frequency (RF) Communication
RF communication is the type of wireless communication that uses radio waves to transmit and receive information. Radio waves are electromagnetic waves that have frequencies ranging from 3 kHz to 300 GHz. RF communication has many advantages such as:
It can penetrate through walls and other obstacles.
It can cover long distances and large areas.
It can support multiple users and applications.
However, RF communication also has some disadvantages such as:
It is susceptible to noise and interference from other sources.
It requires licensing and regulation for some frequency bands.
It has limited bandwidth and capacity for some applications.
Some examples of RF communication are:
Amplitude modulation (AM) radio: A type of RF communication that modulates the amplitude of a carrier wave to transmit audio signals. It has a frequency range of 535 kHz to 1.7 MHz and a bandwidth of 10 kHz.
Frequency modulation (FM) radio: A type of RF communication that modulates the frequency of a carrier wave to transmit audio signals. It has a frequency range of 88 MHz to 108 MHz and a bandwidth of 200 kHz.
Television (TV) broadcasting: A type of RF communication that modulates the amplitude and frequency of carrier waves to transmit video and audio signals. It has a frequency range of 54 MHz to 806 MHz and a bandwidth of 6 MHz.
Microwave Communication
Microwave communication is the type of wireless communication that uses microwaves to transmit and receive information. Microwaves are electromagnetic waves that have frequencies ranging from 300 MHz to 300 GHz. Microwave communication has many advantages such as:
It can provide high data rates and capacities for various applications.
It can support line-of-sight and non-line-of-sight propagation modes.
It can use smaller antennas and devices due to shorter wavelengths.
However, microwave communication also has some disadvantages such as:
It is susceptible to attenuation and fading due to atmospheric conditions such as rain, fog, etc.
It requires careful alignment and installation of antennas and devices due to narrow beams.
It may cause interference or health hazards due to high power levels.
Some examples of microwave communication are:
Satellite communication: A type of microwave communication that uses artificial satellites orbiting the earth to relay signals between ground stations. It has a frequency range of 1 GHz to 50 GHz and a bandwidth of up to 500 MHz.
Radar communication: A type of microwave communication that uses microwaves to detect the position,