Date: 10/02/2009

Wideband digital pre-distortion transmit processor with inbuilt CFR block

Texas Instruments introduced a new single-chip wide band digital pre-distortion transmit processor that enables OEMs to improve power efficiency and ultimately reduce the overall power consumed by wireless base-stations.

TI's GC5325 combines a crest factor reduction block (CFR) and a digital pre-distortion block (DPD) to improve power amplifier (PA) efficiencies for Class AB PAs and Doherty PAs. The GC5325 supports multiple PA architectures, multi-mode operation, and various air interface standards including: CDMA2000, WCDMA, TD-SCDMA, OFDMA (WiMAX, LTE), HSPA, and HSPA+.

The GC5325 DPD transmit architecture incorporates a TI floating point DSP to implement the linearization algorithm, which relaxes multi-carrier power amplifier design specifications and increases PA operating efficiencies. The GC5325 device has greater than 100 MHz of DPD bandwidth, which allows correction of over 20 MHz of 5th order distortion products.

GC5325 features and benefits are:

1. High integration reduces design complexity, power consumption, development time, board space, and bill-of-material costs.
2. CFR processing block reduces the peak-to-average ratio (PAR) for multi-channel/multi-carrier signals.
3. Fully adaptive linearization reduces adjacent channel leakage ratio (ACLR) by 20 dB or more.
4. Improves efficiencies to more than 25 % for Class AB PAs and more than 40 % for Doherty PAs.
5. Two GC5325 devices can be used to implement dual-transmitter architecture with a single DSP and shared feedback path for diversity or MIMO applications.
6. DSP linearization algorithm supports existing and emerging wireless standards.
7. Complete signal chain and system evaluation kit reduces time-to-market and design risks.

System level performance can be evaluated with the GC5325 system evaluation kit (GC5325SEK). Engineers can measure PA efficiency, Error Vector Magnitude (EVM), Peak-to-Average Ratio (PAR), and Adjacent Channel Leakage Ratio (ACLR). The GC5325SEK consists of dual-transmitter architecture, supporting transmit-diversity, multiple-input and multiple-output (MIMO), and beam-forming for smart antenna applications. The GC5325 uses a composite base-band input consisting of single or multiple carriers combined into a single digital signal. The GC5325SEK utilizes TI's TMS320C6727 floating-point DSP in addition to the DAC5682z (1GHz dual interpolating DAC), ADS6149 (Low power 14-bit, 250 MSPS ADC), and TRF3703 (400 MHz - 4 GHz IQ Modulator).


Availability:
1. The GC5325 is released for production.
2. The GC5325SEK will be available for ordering in March 2009.

Price:
1. The GC5325 is priced at $89 per 1K units
2. The GC5325SEK is priced at $4,999

For more information, go to www.ti.com