Forward error correction

transmitter to be able to handle the peaks whilst the average power is much lower and this leads to inefficiency. In some systems the peaks are limited. Although this introduces distortion that results in a higher level of data errors, the system can rely on the error correction to remove them. Data on OFDM The data to be transmitted on an OFDM signal is spread across the carriers of the signal, each carrier taking part of the payload. This reduces the data rate taken by each carrier. The lower data

As with the improvement of cameras that produce high quality videos and images, storage needed to store the videos is became a big issue especially for the film makers that have huge video files to store. Thus we need a mechanism that make the videos compact so that they efficiently store on the hard drives and other storage devices. Here comes the compression techniques that makes it possible to remove the redundancy from bit stream of video files so they take less place to be stored. Transmission

blocks in a communications receiver in order to improve overall system performance. It has opened up a new way of thinking in the construction of communication algorithms. This method was introduced in a system of error control for data transmission, called turbo code. This family of Forward Error Codes (FEC) consists of two key design innovations: concatenated encoding and iterative decoding. The turbo principle has been extended into new receiver topologies such as turbo detection, turbo equalization

in turn, can cause a change in the data transmission. As a result of data change or corruption, the idea of channel coding was introduced as a reliable solution to overcome this dilemma. Nowadays, we use some techniques as Forward error correction (FEC) to reduce the errors that might appear during the information transmission over the channel. In this technique, the system adds redundant (extra) bits to identify if a specific bit is corrupted or not and correct it. FEC Channel codes may be classified

frequency division multiplexing (OFDM) system is analyzed over a composite fading channel i.e. generalized K- fading channel. Here, OFDM system is considered which include repetition code to enhance the wireless link performance with simplicity. Symbol error rate (SER) performance is evaluated using binary phase shift keying (BPSK) and 16-qardature amplitude modulation (16-QAM) over generalized-K fading channel. This channel model considers Nakagami-m distribution to define multipath and gamma distribution

we try to derive an approximate PSK constellation. To do so we have to remember how the modulation-based fingerprinting works. Like in several other attacks we use the five characteristics of the signal: frequency error, SYNC correlation, I/Q origin offset, magnitude error and phase error. All these features are used to state the differences to the ideal constellation given in the 802.11 specifications. We extract this features from a captured signal and use them afterward to manipulate the frame we

4.2 Implementation Details 4.2.1 Data Source Random Bernoulli generator generates binary data on a per frame basis. In data output, 144 samples per frame are used, and data rate is 36 Mbps. Figure 4.2: Data Source 4.2.2 Forward Error Correction Coding A typical problem in OFDM based systems is a high Peak-to-Average Power Ratio (PAPR). The available RF power amplifiers usually have a limited linear dynamic range. This is not a problem for constant amplitude signals, however, in OFDM, due to IFFT

application. Codes are used for data compression, cryptography, error-correction and more recently also for network coding. Codes are studied by various scientific disciplines – such as information theory, electrical engineering, mathematics, and computer science – for the purpose of designing efficient and reliable data transmission methods. This typically involves the removal of redundancy and the correction (or detection) of errors in the transmitted data.” (Coding Theory, 2010) There are many

Department of Computer Science Assignment 2 CS 2204: COMMUNICATIONS AND NETWORKING   1. What is crosstalk? How is it minimized in case to twisted pair of wire? Crosstalk can be defined as the interference to a signal path from other localized signal paths. When several lines are close together, the current passing along one line may cause current to flow in one or more adjacent lines. This may be the result of capacitance between the two lines or the effect of inductance. This effect is known

ABSTRACT This paper focus on designing of efficient encoder and decoder blocks which are aimed to reduce the power consumption in Network on Chip. The power consumption in NOC is caused by the links, routers and network interfaces. This is caused because as the number of cores in NOC increases the gap between the links decreases the coupling capacitance value increases due to which the power consumption increases. The proposed scheme does not require any modifications in router and link architecture