Where an interferer transmits at a frequency that lies outside the nominal pass-band of the wanted signal, the level of interference experienced is a function of a) the interferer’s spectral leakage, as defined by its emission power spectral density, and b) the frequency response of the filtering at the receiver. These two effects can be characterised by the interferer’s adjacent-channel leakage ratio (ACLR) and the receiver’s adjacent channel selectivity (ACS) respectively, as illustrated in Figure 450.
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In other words, for a received interferer power at a frequency offset from the wanted signal, and for an ACIR (function of the frequency offset), the experienced interference power is reduced by the ACIR as sketched in Figure 450.
Figure 450: Interference as a result of limited ACLR and ACS
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