acpr intermodulation
The ACPR is usually defined as the ratio of the average power in the adjacent frequency channel (or at a specified frequency offset) to the average power in the transmitted frequency channel.
ACPR or spectral regrowth is generated by intermodulation distortion between the signal components that make up the spread-spectrum direct-sequence modulated signal.
For example in CDMA/WCDMA ACPR1 (adjacent) is 80% due to IM3 (third order) products, when ACPR2 (alternate) is 80% due to IM5 (fifth order) products.