Complex Tuner

Features

• Designed for maximum speed (f_MAX > 140 - 260 MHz, depending on device family)
• Optimized for 10-bit input and output datapath word widths (others on request)
• Variable tuning frequency with parameterized frequency word width
• Ideal for the following applications:
  • Digital tuners
  • Digital modulators/demodulators
  • Complex arithmetic
  • Wireless & wired telecommunications systems

Block Diagram

Description

The CommStack Complex Tuner megafunction translates a complex digital signal from one frequency band to another, where the input frequency may be positive or negative and may be fixed or specified by other circuitry in real time.

The Complex Tuner megafunction can be used in a variety of digital tuner and modem applications, with the input signal in almost any format (e.g., AM, BPSK, QPSK, GMSK, 8-PSK, OFDM, or 16- to 256-QAM.)

The datapath is optimized for 10-bit inputs and outputs, but other datapath word widths may be implemented on a customized basis. Additional precision is implemented in the multipliers and output adders to maintain 10-bit accuracy in each component of the complex product. The tuner frequency input is parameterized to support frequency word widths of 10 bits to 40 bits or more. The frequency input may be updated in real time; e.g., as a result of a digital PLL tracking a reference frequency input.

With performance from 140 Mbps to over 260 Mbps, depending on device family, CommStack's Complex Tuner megafunction provides the high speed required in digital signal processing applications.

Device Utilization Examples

CommStack is a partner in the Altera Megafunction Partners Program and has optimized this block for the following Altera CMOS-based PLDs: ACEX™ 1K, FLEX® 10KE, APEX™ 20KE, APEX 20KC, and Mercury™ devices.