FPGA-based digital radio frequency transmitter based on FPGA

Abstract

The invention discloses a FPGA-based digital radio frequency transmitter. The digital radio frequency transmitter comprises a frequency conversion and coding module, a radio frequency digital-to-analog conversion module, a combining and filtering module and an electrically tunable filtering module. The main working process of the FPGA-based digital radio frequency transmitter is as follows: a digital baseband signal is subjected to frequency conversion and coding processing of the LUT mapping module to obtain a 1-bit digital signal of a specific frequency band, the 1-bit digital signal is converted into an analog radio frequency signal through the radio frequency digital-to-analog conversion module, and noise components in the analog radio frequency signal are filtered out through the combining filtering module and the electrically tunable filtering module. According to the invention, except the combination filtering module and the electrically tunable filtering module, other processing modules are FPGA-based digital modules; signals with specific frequency and bandwidth can be defined, the frequency modulation range is wide, the integration level is high, and the requirements of modern wireless communication transmitters are met.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to an FPGA-based digital radio frequency transmitter. Background technique [0002] With the development of wireless communication systems, there is a need for different coding and modulation processing of signals with different frequency bands, rates, and standard standards. Traditional analog transmitters have low integration, poor flexibility, and poor scalability. Difficult to meet the needs of different occasions. For digital transmitters based on digital circuits, baseband signal processing, signal coding, and frequency transfer operations are processed in the digital domain, and the center frequency of the output signal is flexible and controllable. The software openness of the digital transmitter breaks the limitation of the hardware on the traditional transmitter, and has higher flexibility, reconfigurability and efficiency. [0003] Traditional radio transmitters u...

AI Technical Summary

Problems solved by technology

Digital transmitters based on bandpass △Σ modulation only need to adjust △Σ modulation parameters to achieve frequency hopping, but the disadvantage is that there is a feedback loop in the △Σ modulation structure, so it is very difficult to achieve high sampling frequency bandpass △Σ modulation; The advantage of PWM modulated digital transmitter is that PWM modulation is a simple forward comparator, PWM logic is easier to design and achieve higher speed, but its noise shaping effect is not good enough, and high power harmonic noise close to the carrier frequency is introduced , requires additional narrowband filters to suppress out-of-band noise

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