An overview of the developments in optical wireless systems viewed from the traditional communications viewpoint of transmitter, channel and receiver is presented. The trends in modulation formats that match information to the optical wireless channel are considered. This is followed by the discussion of recent transmitter and receiver innovations, particularly the utilisation of diversity tran...

There are many recent interests on cooperative communication (CC) in wireless networks. Despite the large capacity gain of CC in small wireless networks, CC can result in severe interference in large networks and even degraded throughput. The aim of this chapter is to concurrently exploit multi-radio and multi-channel (MRMC) and CC technique to combat co-channel interference and improve the per...

This paper explores and compares FER (Frame Error Rate) of a MAC (Medium Access Control) layer in the IEEE 802.11 a/g/n wireless LAN. It is evaluated under the fading wireless channel, using theoretical analysis method. It is analyzed by using the number of stations with both variable payload size and mobile speed on the condition that fading margin and transmission probability are fixed. Espec...

AbsfracfIn this paper, we propose a novel scheme integrating transcoding, SNR scalability and error protection channel coding for video transmission over wireless channels. The target application for such error-resilient transcoding is to provide robust access to the pre-encoded high quality video server from mobile wireless terminals. The high bit rate of pre-encoded video sequence is reduced ...

Wireless services are one of the strongest growth areas in telecommunications today. Dynamic channel allocation schemes have garnered a considerable amount of attention as methods for achieving efficient use of system resources. Various combinations of permanent channel assignment, channel borrowing, shared pools of channels, channel ordering, channel reassignment, and dynamic adjustment of par...

In this paper, we discuss optical encryption and decryption considering wireless communication channels. In wireless communication systems, the wireless channel causes noise and fading effects of the transmitted information. Optical encryption technique such as double-random-phase encryption (DRPE) is used for encrypting transmitted data. When the encrypted data is transmitted, the information ...

Available bandwidth estimation is a vital component of admission control for quality-of-service (QoS) in both wireline as well as wireless networks. In wireless networks, the available bandwidth undergoes fast time-scale variations due to channel fading and error from physical obstacles. These effects are not present in wireline networks, and make estimation of available bandwidth in wireless n...

Wireless technology is creating a revolution in communications. While systems such as broadcast radio and television have been around for many years, many new types of wireless communication systems are emerging such as digital cellular, personal communications services (PCS), and packet radio. Two powerful techniques are usually employed to make communication over wireless mobile fading channe...

Simulations of mobile radio systems require propagation models for determining the channel characteristics for a given arbitrary scenario. Propagation path loss models can be used to predict wireless channel characteristics like received signal strength, multipath effects, and interference. These predictions are an important aspect of simulation of wireless networks and aid in the high-level ne...

The wireless channel of backscatter radio systems is a two-way pinhole channel, created by the concatenation of two standard wireless channels. Pinhole channels cause higher attenuation and deeper fades than common wireless channels. Passive ultra-high frequency radio-frequency identification (UHF RFID) is such a backscatter radio system, with the backscattering tag acting as pinhole. While the...