What is fec rate

A suggested adjacent carrier interference allowance in link budgets is 28 dB on each side. You choose. If you can avoid high spectral density carriers adjacent to low spectral density carriers it will help.

For a spectrum analyser view of the spectrum see this page. Read up the manufacturers data on the spacing appropriate for your choice of technology. The spacing between your own carriers is your business. At the edge of your paid-for transponder bandwidth, follow the rules set by the satellite operator to minimise interference to and from adjacent bandwidth leases. A really good explanation of digital modulation.

Turbo code, adjacent carrier interference, allocated bandwidth and occupied bandwidth mentioned. Forward error correction Forward error correction is applied to the customer's information data at the transmit end. Home page VSAT information. Latitude and longitude explanation Link budget calculator Satellite beam design IET satellite communications summer school. Symbol rate. The minimum distance of their concatenation is at least d min1 d min2. Figure 4 shows transmission of an interleaved code.

More advanced FEC codes, such as turbo codes [2] and low-density parity-check LDPC codes [3], have been invented by academics and adopted by industry in the last several decades to approach Shannon limit or channel capacity [1].

There are four critical factors to consider when selecting a proper FEC code and coding scheme for a particular communication system. To maintain high throughput or avoid significantly increasing link rate the code rate needs to be high. To compensate channel loss or relax signal to noise ratio SNR or bit error rate BER requirements at decision slicers in the receiver a large coding gain is desirable. The landscape of FEC technology for wire line communication systems is shown in Figure 5 from [4] and includes both electrical and optical links.

High-gain FEC codes such as low density parity check LDPC codes and Turbo product codes TPC are normally considered for long-distance optical transmission systems with the cost of larger coding latency and complexity. For low latency applications, short simple block codes with a moderate coding gain and complexity could be used.

Berrou, A. Glavieux, and P. IEEE Intl. ICC 93 , pp. Theory , IT, January NLP programming automates the translation process between computers and humans by manipulating unstructured data words in the context of a specific task conversation.

View Full Term. By clicking sign up, you agree to receive emails from Techopedia and agree to our Terms of Use and Privacy Policy. Forward error correction FEC is a digital signal processing technique used to enhance data reliability.

It does this by introducing redundant data, called error correcting code, prior to data transmission or storage. FEC provides the receiver with the ability to correct errors without a reverse channel to request the retransmission of data. The first FEC code, called a Hamming code, was introduced in the early s. It is a method adopted to obtain error control in data transmission where the transmitter sends redundant data. Only a portion of the data without apparent errors is recognized by the receiver.

This allows broadcasting data to be sent to multiple destinations from a single source. FEC adds redundancy to transmitted information using a predetermined algorithm. The redundant bits are complex functions of the original information bits. Bits are sent multiple times, because an error may appear in any of the samples transmitted. FEC codes generally detect the last set of bits to determine the decoding of a small handful of bits.