Satellite Communications/downlink terms
Rajiv kumar yadav wrote at 2013-12-10 16:23:21
Eb/N0- (the energy per bit to noise power spectral density ratio) is an important parameter in digital communication or data transmission. It is a normalized signal-to-noise ratio (SNR) measure, also known as the "SNR per bit". It is especially useful when comparing the bit error rate (BER) performance of different digital modulation schemes without taking bandwidth into account.
Eb/N0 is equal to the SNR divided by the "gross" link spectral efficiency in (bit/s)/Hz, where the bits in this context are transmitted data bits, inclusive of error correction information and other protocol overhead. When forward error correction (FEC) is being discussed, Eb/N0 is routinely used to refer to the energy per information bit (i.e. the energy per bit net of FEC overhead bits); in this context, Es/N0 is generally used to relate actual transmitted power to noise.
The noise spectral density N0, usually expressed in units of watts per hertz, can also be seen as having dimensions of energy, or units of joules, or joules per cycle. Eb/N0 is therefore a non-dimensional ratio.
Eb/N0 is commonly used with modulation and coding designed for noise-limited rather than interference-limited communication, since additive white noise (with constant noise density N0) is assumed.