GC5325,pdf(GC5325 Wideband Dig

The GC5325 is a wideband digital predistortion transmit processor that includes a crest factor reduction (CFR) block and a digital predistortion (DPD) block with its associated feedback chain and capture buffers. The GC5325 processes composite input bandwidths of up to 20 MHz and processes DPD sample rates of up to 140 MHz. The GC5325 accepts a composite signal over an interleaved parallel interface at a data rate of up to 140 MSPS. The GC5325 CFR block reduces the peak-to-average ratio (PAR) of wideband digital signals provided in quadrature (I/Q) format, such as those used in third-generation (3G) code division multiple access (CDMA) wireless and orthogonal frequency division multiple access (OFDMA) applications. The GC5325 DPD block reduces adjacent-channel leakage ratio (ACLR), or out-of-band energy, by 20 dB to 30 dB or more.