As the long term evolution (LTE) standard comes to an end, 3rd Generation Partnership Project is discussing further evolution of the LTE to meet the international mobile telecommunications advanced requirements, which is referred to as LTE-Advanced (LTE release 10 and beyond). This article first presents the network infrastructure of the LTE-Advanced, and then provides an in-depth overview of e...

The balanced modulator, which comprises two amplitude-modulation modules, is widely used in phase-modulated communication systems. In practice, the balance between these amplitude-modulation modules is difficult to maintain, and the amplitude and phase imbalances can cause distortion in the signal constellation and introduce undesired interfering tone signal components when such an imperfect mo...

Digital modulation-demodulation technique in modern digital communication system plays a very important role. Carrier synchronization is also one of the key technologies of digital wireless communication. As a kind of four phase shift keying modulation method, QPSK has strong anti-interference ability of the suppressed carrier, which is widely used in digital wireless communications. On this ba...

Orthogonal Frequency Division Multiplexing (OFDM) has recently been used widely in wireless communication systems. OFDM is very effective in combating inter-symbol interference and can achieve high data rate in frequency selective channel. For OFDM communication systems, the frequency offsets in mobile radio channels distort the orthogonality between subcarriers resulting in Inter Carrier Inter...

The next generation wireless communications systems require higher data rates transmission in order to meet the higher demand of quality services. Research in wireless digital communications techniques have been expending very rapidly in the last few decades, resulting more reliable wireless communication systems that operate at higher spectral efficiency. Since there have been an increased in ...

This paper demonstrates the modeling of seawater acoustic channel to obtain the optimum carrier frequency for autonomous underwater vehicle (AUV) wireless communication system. The wireless communication distance of an AUV with its control vessel changes due to the mission at different depths. Current AUV is designed with an operating depth of 0 to 2000m. Therefore, the existing model had limit...

Near-field coupling communication (NFCC) is a technology that uses the surface of the human body as a transmission path. To suppress the radiation signal from the human body, NFCC devices use a carrier frequency of less than 10 MHz. Because the radiation signal has the potential to disturb the other NFCC links, the radiation signal from other devices needs to be suppressed to ensure stable NFCC...

This paper reports on the use of a twisted map digital chaotic sequence as a carrier signal in a COOK system. The sequence generated shows low cross-correlation properties with very large signal space which is desirable for spread spectrum communication. A potentially cost-effective solution for wideband communications is to use a wideband chaotic carrier. COOK offers the simplest solution to c...

The transmission system of wireless communication is induced the channel noise. The potential sources of any noise type, which make and diturb the transmission system in external or internal to the communication system for message delivering. The carrier signal mixed interference signal using the amplitude-locked loop (ALL) can be adopted to separat the co-channel system by operating at same fr...

Security of the digital information is becoming primary concern prior to transmitting the information itself via some media. Information security means protecting information and information systems from unauthorized access, use, disclosure, disruption, modification or destruction. In this proposed method, the carrier file and the secret message are taken into audio format and a pattern matchin...