High-performance crest factor reduction processor for W-CDMA and OFDM applications

Highly linear wideband power amplifiers (PAs) are needed for code division multiple access (CDMA) and orthogonal frequency division multiplex (OFDM) modulations. Such PAs normally have low operating efficiency because of the high peak-to-average ratio (PAR) of CDMA and OFDM signals. By reducing the PAR of CDMA and OFDM signals, both PA acquisition and operating costs are decreased. We describe the GC1115 crest factor reduction processor, a 1.8M gate device fabricated in 130 nm CMOS process that operates at input and output sample rates up to 130 Msamp/sec. The GC1115 decreases the PAR of W-CDMA test model signals to 5.7 dB while meeting all signal quality requirements of 3GPP TS 25.141. The GC1115 achieves similar PAR improvement on OFDM signals.