The Importance Of Light Channels For RZ And WDM Transmitter System

In this paper, we have considered SC-FDMA for both the links, taking the UE limitations into considerations. The advantages and challenges of using SC-FDMA for downlink are well analyzed in [18].

The multiplexing chain in the downlink is largely comparable to that in the uplink however there are also certain functions that are done in a different way. As like in the uplink, the interleaving is executed in two components, covering both intra-frame and inter-frame interleaving. In addition, the rate matching permits one to stabilise the necessary channel symbol energy for various service qualities. The services can be mapped to more than one code additionally, which is essential when the single code capability in either the terminal or base station is surpassed.

From the beginning, efficiency and speed in the telecommunications industry has advanced at a fast pace owing to fiber optic technology. In 1979, AT&T filled the telecommunications industry with revolutionary ideas by developing a mode for data transmission using a light, called fiber optic cable. This mode produced a bandwidth of 44.736 Mbps and could multiplex 672 trunk circuits on one fiber alone (Cole, M. 2000). However, this development was merely the start of a huge extension to telecommunications, something that would transform the industry constantly.

The high-speed broadband penetration and ongoing growth of the Internet traffic among customers have been the key reasons that are driving the rapid emergence and deployment of optical access networks as a basic bearer network that supports hybrids services for multiple customers while bearing huge capacity. Passive optical network is the most interesting solution for the optical access network to cope with the increasing bandwidth demand and to meet the cost effectiveness. PON can be used for Point to point (P2P) or Point to multi-point (P2MP) configurations. The P2P structure builds a dedicated fiber from a CO to each subscriber which constitutes an ultimate solution to provide much-needed bandwidth to each ONU. In P2MP topologies, the feeder fiber is shared between various customers and terminates at a central office in an Optical Line Terminal. Passive splitters put between the OLT and the ONU are used to split the connection to multiple end points, thus enormously reduces the maintaining cost. Two key technologies are used in passive optical network: the first one known as TDM-PON uses Time Division Multiplexing to multiplex traffic from/to multiple ONUs onto the upstream/downstream wavelength. It requires complex scheduling algorithms and framing technology to support a variety of services. The second is Wavelength division multiplexing passive optical network “WDM PON”. This technology comes to extend the

The power from each individual antenna is proportional to the 1/M. There is algorithm that is V-BLAST algorithm which is used to perform at the receiver site. Taking into account, in the case of uplink there is number of conventional receiver at the base station and they are receiving the signals which are generated from N number of transmitters and therefore they must have considerable interference between the data stream. V-BLAST algorithm at the receiver is used to mitigate the interference between different streams and try to generate the original data stream at the receiver. V-BLAST used optimal combining and interference cancellation technique. The signal which is having the best SNR is retrieved at the receiver. In the figure shown below which illustrates the good performance achieved at the receiver. V-BLAST technique is referred as non-linear technique as it generates

The following report will analyse the current modern techniques used in fibre-optic systems. Briefly examine the origins and history of lightwave systems. Followed by discussing the main techniques that are currently used within the design of fiber-optic, the main concerns regarding theoretical and design issues. Carrying on to discuss the advantages, disadvantages, possible risks and the possible solutions for those. To conclude on the future development of fibre-optic and how the mentioned techniques can be used in other systems.

One direct method for increasing the capacity of a system is to raise the transmission bandwidth per wavelength either optically or electronically. In optical communication, there are two broadly used techniques for increasing the capacity of the transmission. The first technique is to spread-out the bandwidth by adding numerous optical carriers. This technique has already been slow and deployed and it is known as Wavelength Division Multiplexing (WDM). Wavelength Division Multiplexing can benefit to extend the transmission bandwidth by adding various transceivers for the current optical fiber links deprived of the need to install other fiber links. WDM is considered as one of the most cost effective methods to raise the optical fiber link quantity. The second technique is to extend the electronic bandwidth per wavelength relying on the CMOS technology.

This thesis investigates several types of Sigma-Delta modulators in different conditions as a possible solution to the all-digital audio and wifi signal receivers.

SDM (space division multiplexing) has been putforth by Savory. SDM is extremely challenging technology, of requiring developments in all areas of Photonics Technology. The optical communication systems are being upgraded every day .There is a rapid development taking place in this field at the global level in the space division multiplexing. Space Division Multiplexing (SDM) is conceptually simple, SDM is extremely challeng technologically, requiring the development of new fibers, amplifiers, multiplexers, digital signal processing circuits, and other components. The multiplexing means the utilization of channel by the

Abstract— The ultimate goal of Fiber Wireless (FI-WI) networks is to convergence of various optical and wireless technologies under a single infrastructure in order to take advantage of their complementary features and therefore providing a network capable of supporting bandwidth hungry emerging applications for both fixed and mobile clients. The Fi-Wi architecture is based on radio

For years, infrared LED has been merely a system for piping light around corners and into the inaccessible places to allow the hidden to be lighted. But now, infrared LED has evolved into a system of significantly greater importance and use. Throughout the world, it is now being used to transmit voice, television and data signals as light waves. Its advantages as compared with conventional coaxial cable or twisted wire pairs are manifold. As a result, millions of dollars are being spent to put these light wave communication systems into operation.

OFDM is a great technique to handle impairments of wireless communication channels such as multipath propagation. Hence, OFDM is a practical candidate for future 4G wireless communications techniques [1]-[4]. On the other hand, one of the major drawbacks of the OFDM communication system is the drift in reference carrier. The offset present in received carrier will lose orthogonality among the carriers. Hence, the CFO causes a reduction of desired signal amplitude in the output decision variable and introduces ICI. Then it brings up an increase of BER. The effect caused by CFO for OFDM system was analyzed in [7]-[9]. In [7] BER upper bound of OFDM system is analyzed without ICI self-cancellation and BER of OFDM system is analyzed using self-cancellation, but this method is less accurate. In [9], it is indicated that CFO should be less than 2% of the bandwidth of the sub-channel to guarantee the signal to interference ratio to be higher than 30 dB. A critically sampled OFDM system/OQAM system is also not robust to CFO [9], even when optimal pulses are used as shaping filters. Thus, carrier frequency offset greatly degrades system performance. Therefore, practical OFDM systems need the CFO to be compensated with sufficient accuracy, and this has led to a whole lot of literature on CFO estimation algorithms. Most of the existing CFO estimators for OFDM are based on periodically transmitted pilot symbols. Yet, the pilot symbols transmission loses a significant bandwidth,

This is to certify that the work titled “Progressive Image Transmission Using OFDM” submitted by “Aman Pandey(13102288) and Naman Gogia(13102216)” in partial fulfillment for the award of degree of Bachelor of Technology of Jaypee Institute of Information Technology, Noida has been carried out under my supervision. This work has not been submitted partially or wholly to any other University or Institute for the award of this or any other degree or diploma.

Abstract: This paper discusses the design of a fiber optic communication system which is used to support a date rate of about 400Gbps over a length of around 3000Km using a laser power source around to 1550nm. The design includes both the internal and external modulation.

Department of Electronics and communication, Oriental College of technology, Thakral Nagar, Opp. Patel Nagar, Bhopal