Meaning
Degradation of orthogonal frequency division multiplexing signals occurs when subcarriers lose their mutual isolation and leak energy into adjacent channels. In wireless systems, inter-carrier interference arises from frequency offsets or rapid channel variation during transmission. This leakage prevents the receiver from cleanly separating the multiplexed data streams.
Distortion Origin
Doppler shifts caused by high-speed movement between the receiver and transmitter cause a frequency translation of the subcarriers. This shift introduces inter-carrier interference because the peak of one subcarrier no longer aligns with the zero-crossings of the others. Dynamic channel equalization filters attempt to estimate and correct this displacement continuously.
Spectral Distortion
Phase noise in the local oscillators also contributes to the loss of subcarrier separation. High inter-carrier interference raises the error floor of the receiver, limiting the highest modulation and coding scheme that the link can sustain. Hardware designers must select low-noise reference sources to prevent this degradation in multi-carrier transceivers.
Mitigation Strategy
Modern basestation designs employ advanced digital signal processing to cancel cross-carrier leakage. They utilize pilot symbols interspersed within the resource grid to measure the leakage coefficients and subtract the interfering components from the received vector. Applying these complex mathematical corrections on the fly reduces the packet error rate under challenging mobility conditions.
This algorithm prevents receiver saturation and ensures that high-throughput connections remain stable even when the terminal is moving at high speeds along a transport corridor.
