This article addresses the issue of when to suppress or not to suppress the transmitted carrier in designing a coherent communication system employing a carrier tracking loop for carrier synchronization. Assuming that a phase-locked loop (PLL) is used whenever there exists a residual carrier and a Costas loop is used whenever the carrier is suppressed, the regions of system parameters that deli...

In this paper, we study the performance of IEEE 802.11 broadcast scheme in multihop wireless networks using an analytical model. Previous works have evaluated the performance of IEEE 802.11 protocol assuming unicast communication, but there has not been an analysis considering broadcast communication. Analyzing performance of broadcast communication is important because multicast communication ...

Abstract The main aim behind the growth of software defined radio is the skill to reconfigure radios, thereby increasing the efficiency in the usage of radio resources. In wireless communication the multipath effect produce interference and also changes in the phase of the signal. In order to correctly recover the transmitted data with minimum error, carrier synchronization is essential. One of...

Counterfactual quantum communication is unique in its own way that allows remote parties to transfer information without sending any message carrier the channel. Although no travels channel at time of successful transmission, it impossible transmit faster than speed light, thus an carrier. In this paper, we address important question What carries counterfactual communication? and optimize resou...

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those o...

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those o...

The multipath components of superwideband (2–17.2 GHz) nonline-of-sight channel responses measured inside several buildings are stable along sections that are 27 cm long on average with a standard deviation of 16 cm. The stability regions of multipath components have an approximately log-normal histogram. An analysis of measured channels that explicitly includes finite spatial areas of visibili...

Three methods for determining distances between a user and a fixed coordinate system are considered. One system is based on 802.11g packet communications, another on HF radio carrier frequency interference, and the final system on a signal transmitted over a radio channel. Emphasis is placed on the use of these systems in indoor, building-sized environments. Tests are performed to examine the e...

In this paper, the wavelength mismatch between the message and the chaotic carrier in the chaotic optical communication with chaos-masking has been experimentally investigated. The results show that the decryption performance of the receiver can be improved when the message wavelength is greater than that of the chaotic carrier. When the wavelength offset is set to 0.12 nm, high-speed secure op...