Implementación de un sistema de transmisión multiportadora sobre una plataforma FPGA

Abstract

Multicarrier modulation systems increase the bit rate in digital communications and optimize bandwidth usage compared to single carrier modulation systems. In this work, we implement OFDM and GFDM systems on a Red Pitaya FPGA STEMLab 125-14 platform. Implementing a multicarrier transmission system on an FPGA involves translating complex mathematical concepts into hardware-level operations. Mastery of the hardware description environment is crucial for addressing synthesis and delay issues, enabling the creation of a standalone transmission system without external hardware. The implementation of OFDM and GFDM is based on the vector representation of multicarrier systems, where the characteristics depend on the pulse-shaping filter used. OFDM employs a rectangular pulse, while GFDM uses a raised cosine filter. Both systems utilize 4-QAM symbols and synchronization frames to facilitate signal reception. To evaluate the system, we use the HackRF One device in conjunction with GNU Radio software. The received signal is compared with the theoretical signal using crosscorrelation, and the bit error rate (BER) is measured as a function of distance. The results show that the received signal closely matches the simulated signal and it was observed that GFDM requires 7% more SNR than OFDM to achieve a similar error rate. These findings validate the implementation and lay the groundwork for developing new technologies in multicarrier communication systems.