Reconfigurable NC-OFDM Processor for 5G Communications

Abstract

The proliferation of new wireless communication technologies and services led to a boost in the number of different available communication standards and spectrum usage. As the electromagnetic spectrum is a finite resource, concerns about its efficient management became an important aspect. Given this scenario, Cognitive Radio emerged as a solution for future wireless communication devices, by supporting multiple standards and improving spectrum utilization through opportunistic wireless access. The purpose of this research is to study and design a reconfigurable FPGA-based NC-OFDM baseband processor meeting the requirements of next generation Cognitive Radio devices in terms of multi-carrier, multi-standard communications and spectral agility in changing environments. The processor will be the core of a flexible NC-OFDM transceiver for future 5G communications with support for spectrum aggregation and runtime selection of modulation schemes and active sub-carriers. The goal is to achieve higher levels of system adaptability, upgradeability and efficiency, by employing dynamic partial reconfiguration of FPGAs.

Design of a Real-Time DSP Engine on RF-SoC FPGA for 5G Networks

“…The work in [15] shows FPGAs with a full processing chain for an OFDM transceiver for the IEEE 802.11, IEEE 802.16 and IEEE 802.22 standards. In [17] a non-continuous OFDM FPGA-based baseband architecture utilizes dynamic partial-reconfiguration to adapt its processing datapath and [18] gives the adaptable FFT core. Finally, [16] presents a pilot-based channel estimation technique for a system consisting of a 16-QAM mapper/demapper, 1024-point IFFT/FFT with 798 data samples, 56 pilots and 170 zeros.…”

Improving Energy Efficiency of OFDM Using Adaptive Precision Reconfigurable FFT

“…In modular (divide and conquer) design, addition (multiplication) of 8-, 12-, 16-, and 20-bit operands can be constructed by using 2 (4), 3 (9), 4 (16), and 5 (25) iterations of 4-bit adder (multiplier) block, respectively. Referring to Fig.…”

“…NC-OFDM (Non-Contiguous OFDM) [41] is a promising spectral agile variant of OFDM for dynamic spectrum aggregation [4]. According to the fast-changing wireless systems where various standards/modes should be supported, NC-OFDM CR systems need to change modulation schemes, the number of subcarriers, and FFT/IFFT size at run-time [16].…”

Dynamically reconfigurable LTE-compliant OFDM modulator for downlink transmission

“…Furthermore, upgrades to the current design can be easily done to accommodate other wireless standards. This work is within the scope of the research activities presented in [5] and extends the exploitation of FPGA-based DPR techniques in Software Defined Radio (SDR) and Cognitive Radio (CR) systems initiated in [6] and [7].…”