Paragraph 154 DEFINITIONS OF TERMS IN THIS ANNEX

“Spectral efficiency” (5) is a figure of merit parametrized to characterize the efficiency of transmission system which uses complex modulation schemes such as QAM (quadrature amplitude modulation), Trellis coding, QPSK (Q-phased shift key), etc. It is defined as follows:

Spectral efficiency = \frac{Digital transfer rate (bits / second)}{6 dB spectrum bandwidth (Hz)}