How is Shannon capacity calculated?

How is Shannon capacity calculated?

R = B log 2 ( 1 + SNR ) bps, where SNR is the received signal-to-noise power ratio. The Shannon capacity is a theoretical limit that cannot be achieved in practice, but as link level design techniques improve, data rates for this additive white noise channel approach this theoretical bound.

What does the Shannon capacity have to do with communication?

The Shannon limit or Shannon capacity of a communication channel refers to the maximum rate of error-free data that can theoretically be transferred over the channel if the link is subject to random data transmission errors, for a particular noise level.

What does Nyquist theorem have to do with communication?

Nyquist’s theorem specifies the maximum data rate for noiseless condition, whereas the Shannon theorem specifies the maximum data rate under a noise condition. The Nyquist theorem states that a signal with the bandwidth B can be completely reconstructed if 2B samples per second are used.

What are the techniques for increasing channel capacity in satellite communication?

There are many multiple access techniques for satellite communication. These are frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), SDMA, paired carrier multiple access (PCMA), multiple input-multiple output (MIMO), etc.

What kind of coding is needed to approach the Shannon limit?

According to the information theory, optimum coding is needed to approach the Shannon limit [2]. Forward error correction (FEC) is one type of coding schemes capable of providing substantial coding gain with small overhead [55].

What is the performance of the Shannon limit?

With the use of 3-bit soft decision, a net coding gain of 10.2 dB was demonstrated at 10 Gb/s with a FEC overhead of 25% using a block turbo code (BTC) [106]. The performance of the demonstrated BTC is about 2.2 dB from the Shannon limit [106].

Is the Shannon capacity of a transmitter known?

The Shannon capacity for many wireless channels of interest is unknown and depends not only on the channel but also on whether the transmitter and/or the receiver can track the channel variations. For cases where the capacity is known, there is typically a large gap between actual performance and the capacity.

Are there any FEC codes within the Shannon limit?

While powerful forward error correction (FEC) codes within 1 dB of the Shannon limit have been developed (e.g. [20]) and demonstrated for both photon counting [21–25] and coherent RXs [26], realizing them with low-SWAP implementations or at high data rates is still a practical limitation.