The GC5316 is a high-density multi-channel communications signal processor integrated circuit that provides both digital downconversion and digital upconversion optimized for cellular base transceiver systems. The device supports both UMTS and CDMA2000 (CDMA) air interface cellular standards.
The chip provides up to 24 CDMA digital downconverter (DDC) and digital upconverter (DUC) channels or 12 UMTS DDC and DUC channels. The GC5316 can also support a combination of CDMA and UMTS channels. The DDC and DUC channels are independent and operate simultaneously.
The chip is ideal for cellular base transceiver systems where a large number of digital radio channels are required. Each of the 24 CDMA (or 12 UMTS) channels can operate independently. On the DDC side there are four 16 bit input ports that can accept real or complex input data. The input ports are driven with parallel data, typically from an analog-to-digital converter. Each downconverter channel can be programmed to accept data from any one of the four input ports.
On the DUC side, there are four 18-bit output ports. Each output port can sum any of the DUC channels in a daisy-chain fashion. This permits creating a stack of CDMA or UMTS signals. These ports can output either real or complex data. Real output data would generally drive one or more D/A converters and output the stack of signals at an intermediate frequency (IF). Complex data (at baseband or an IF) is used when a quadrature modulator upconversion scheme is employed. Complex output data can also be used when the output stack is further processed using crest factor reduction or power amplifier predistortion techniques.
Optimized for CDMA2000-1X and UMTS
Up to 12 UMTS or 24 CDMA2000 Downconverter and Upconverter Channels
Mixed CDMA2000-1X and UMTS Operation
DDC Input and DUC Output Rates to 125 MSPS
Any DDC Can Connect to Any of Four Input Ports
Any DUC Can Sum into Any of Four Output Ports
Real/Complex DDC Inputs and DUC Outputs
Programmable AGC on DDC Outputs
Rx Filtering: 6 Stage CIC, 48 Tap CFIR, 64 Tap PFIR
Tx Filtering: 6 Stage CIC, 47 Tap CFIR, 63 Tap PFIR