A Programmable Dual Modulator Testbed for MIMO Applications

Abstract

Multiple-input multiple-output (MIMO) systems use multiple transmitters and receivers to increase the capacity and reliability of radio frequency communication links used in multipath and disruptive environments. This paper describes a recently designed hardware testbed that can be used as a modulator and transmitter for MIMO systems which use two transmitters. The testbed consists of a field programmable gate array (FPGA) that generates the I/Q baseband signals for the two transmitters. A wide variety of modulation and coding formats, up to data rates of 10 Mbps, can be implemented by reprogramming the FPGA. The dual I/Q outputs from the FPGA are then fed to a pair of quadrature modulators, which have programmable carrier frequencies from 1,025 to 2,450 MHz. The system is implemented on a single printed circuit board, and has dual RF outputs with programmable power levels up to 0 dBm.