Essay On Fiber Communication System

ANS: Direct sequence spread spectrum (DSSS) is a transmission technology used in local area wireless network transmissions. In this technology, a data signal at the sending station is combined with a high data rate bit sequence, which divides user data based on a spreading ratio.

Intiga 6‘s modulation based noise management does not allow channel-specific noise reduction, compared to TriState Noise Management. Modulation based noise management assesses the likelihood of rather constant noise in specific frequency regions and tends to be sensitive to the presence of any noise, whether speech is also

To implement proposed and existing schemes and compared in terms of throughput, delay and packetloss

In section (B) the value of path loss exponent (n=2,3,4) and distance of the range(0.1 to 5.0) were changed in the same log-distance equation to get the received out power in dB and were plotted on the graph, which also signifies that increase in the distance reduces the received out power.

Multicarrier modulation provides immunity to fading caused by data transmission over mul-tipath fading channels or frequency- selective fading channels. Each of the subchannel expe-riences flat fading due to the decreased bandwidth. Also, due to the increase in the symbol period, it provides enhanced immunity to ISI. Another advantage of multicarrier modulation technique is it can provide better spectral efficiency compared to single carrier modulation, since the spectrum of the subcarrier can be overlapped.

5. (DSSS), Direct Sequence Spread Spectrum , frequency Hopping Spread Spectrum (FHSS) and Infrared and Orthogonal Frequency Division Multiplexing(OFDM)

The graph is taken before carrier phase estimation (CPE) in order to analyse the Phase Noise. The required graph for phase noise in terms of average BER for different filter types with varying filter order are drawn in Figure 4.7(a)-(d). The graph is drawn between the average BER and OSNR which shows that with the increase in OSNR the BER decreases.

Just like most other types of technology, cabling and communication are advancing faster than ever before. One of the most promising advances in this area is fiber optic cabling. Fiber optic refers to the technology and the medium associated with the transfer of information as light impulses along a plastic or glass fiber. With the demand for faster communication and network speeds fiber optic is quickly becoming the leading choice in most developed countries. Fiber optic wire is capable of carrying much more information than a conventional copper wire can and electromagnetic interference is much less of an issue with fiber. One single glass fiber can carry the equivalent of one-hundred television channels or one hundred thousand phone

On the Contrary, a properly designed high-index single-ring fiber can support only the radially fundamental modes. It leads to the potential Reduction of the crosstalk induced during mode excitement. To multiplex multiple OAM modes simultaneously, the number of the Eigen modes supported by the fiber should be increased by increasing either the core radius or the refractive index difference between the core and cladding. In this Theory, one dimensional mode

Rapid and exponential increases in data communications are continuing to drive the complexity of our computing, networking and sensing systems. Recently OAM has gained much interest in transmission efficiency and spectral efficiency in optical fiber communications with the ability of carrying independent data streams on orthogonal spatial modes. The key factor in the optical fiber communications using OAM is to design and fabrication of the fiber so as to support the the different modes of OAM.while the free space systems can theoretically use an unlimited number of OAM modes. However achieving the full potential of OAM multiplexing requires an efficient and rotation invariant multiplexer and demultiplexer which can be interfaced with single-mode optical components. Fiber based OAM generation and

One of the most interesting developments in recent years in the field of telecommunication is the use of laser light to carry information over large distances. It has been proved in

Now a day’s communication is an important factor and requirement high data rate for the communication and also require the error free environment. So for these entire requirements we use OFDM. OFDM is used for both wired and wireless communication. OFDM belongs to a broader class of multicarrier modulation (MCM) in which the data information is carried over many lower rate subcarrier [1]. OFDM is a solution of intersymbol interference (ISI). ISI is caused by dispersive channel.

The field of communications is one in which the technologies are changing on an almost daily basis. Numerous different technologies have been pursued over the past few years; each designed to essentially accomplish several basic purposes in terms of community service. Three of the most actively pursued application include interactive distance learning, video conferencing, and entertainment. While it is the first two, video conferencing and interactive distance learning, which would serve to the best advantage in terms of education and business; it is the last, entertainment which has the most appeal to the largest number of people. The application of various communications applications in

gain but decoding complexity is very high. To avoid this, STBCs have been proposed by the effort work of Alamouti for transmit diversity and later Vahid Tarokh, Hamid Jafarkhani and Robert Calderbank made their contributions.[1-3]. This code gives better second order diversity when used with a single receive antenna and fourth order diversity when used with two antennas at the receiver side. But, it is only half rate, because it only transmits two symbols using the two time slots and two transmit antenna.

Furthermore, in order to enable the receiver to identify different phases, phase factor b is required to send to the receiver as sideband information (usually the first sub-block b1, is set to 1). So the redundancy bits account for (V−1) log2 (W), in which V represents the number of sub-blocks, W indicates possible variations of the phase. This causes a huge burden for ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING system, so studying on how to reduce the computational complexity of PTS has drawn more attentions nowadays. The optimization is achieved by searching thoroughly for the best phase factor. Theoretically b= [b1, b2, … , bv ] is a set of discrete values, and numerous computation will be required for the system when this phase collection is very large. For example, if v contains W possible values, theoretically, b will have W^v different combinations, therefore, a total of V• (W^v) IFFTs will be introduced.