Software-Defined Radio Transceiver Design Using FPGA-Based System-on-Chip Embedded Platform With Adaptive Digital Predistortion

Abstract

In this paper, a software-defined radio (SDR) based transceiver system is designed and implemented on the system-on-chip (SoC) platform, which consists of a high-speed Arm embedded processor and a reconfigurable field-programmable gate array (FPGA). In the proposed SDR transceiver, the real-time baseband signal generation and adaptive digital predistortion (ADPD) units are implemented on the SoC platform. Memory polynomial model based ADPD solution is implemented to linearize the radio frequency (RF) power amplifiers (PAs). The implementation of the ADPD on a reconfigurable FPGA platform makes the system flexible and cost-effective. The PA characterization, in terms of model extraction and coefficient calculation, is done in real-time. These calculated coefficients are updated in the transmission path to precondition the transmitted signal before it is applied to the PA. The proposed ADPD is applied at the baseband level. Therefore, it can be used for different classes of PA operating at different RF carrier frequencies. A long-term evolution (LTE) signal with 20 MHz bandwidth and 11 dB peak to average power ratio (PAPR) is used for simulation and measurement purposes. The LTE signal is amplified using a GaN-based harmonically tuned continuous Class-F PA in measurement. The performance of the implemented ADPD scheme is analyzed in terms of NMSE, ACPR and EVM. INDEX TERMS Digital predistortion, field-programmable gate array, linearization, memory polynomial, software-defined radios, system-on-chip, transceiver. I. INTRODUCTION As technology is growing, advanced wireless communication devices have become an essential part of the everyone's daily life. These communication devices require high-speed access for voice, video, data and other such applications [1]-[3]. The commercial wireless communication standards are upgraded from 2 nd generation (2G) to 5 th generation (5G) and each generation uses different network protocols and different communication standards [3]. Therefore, all communication devices need to be updated whenever a new generation of wireless communication standard is introduced [3]. Modifying communication devices for different communication standards is a critical and costly affair. Therefore, the demand for a flexible, reconfigurable and programmable communication system that can be easily modified without any hardware cost has been increasing significantly. Software-defined radio (SDR) is a favorable solution to solve such problems. SDR is a rapidly developing technology in the telecommunication industry to develop a flexible and reconfigurable transceiver architecture. SDRs can upgrade their functionality without replacing the hardware on which they are implemented [4] [5]. This feature supports SDR to develop a multifunctionality transceiver device that is suitable for any type of communication standard. Such SDR based programmable communication devices can handle the existing as well as the newly developed wireless communication standards and network protocols. In SDRs, baseband signal proces...

Software Defined Radio Platforms for Wireless Technologies

“…From the hardware side, GPP-based SDR platforms performance can be enhanced by different solutions such as : a) increasing the processing speed of GPP host by using more number of cores (as reported by our work) with higher clock speed, memory and cache, and b) using external hardware accelerators such as GPU, FPGA and DSPs. In literature, these solutions were more or less studied theoretically (using GPU [58], [59], [103], FPGA [56], [91], [104], [105], DSPs [93], [94]) but it's still an open challenge to fully investigate experimentally. In addition, the latency due to the interface between the GPP and external should be considered.…”

Predistortion-Based Linearization for 5G and Beyond Millimeter-Wave Transceiver Systems: A Comprehensive Survey

“…Neural Network-Based Model Waveform Processing at Transmission and Observation Path [67], [81], [89]- [103] [110]- [120], [122], [123] [67], [75], [82]- [88] DAC and ADC nonidealities [29], [130], [133]- [141] RF Sub-Components Effects [130]- [132], [142], [145] [130], [131] Amplitude-Compensated Phase Shifter [78], [79], [148]- [155], [157], [158] Phase-Compensated and Low-Noise Variable Gain Amplifier [44], [149], [159]- [169] SVM-Based Model better output performance. Since the invention of wireless communication, the linearity of transmitting signals hold paramount importance [73], [74].…”

“…On the other hand, a software-defined radio (SDR) based TRX with FPGA utility serves as a contrary solution to alleviate high system cost and hardware integration of commercial black-box TRX drivers. Kumar et al [133] developed a DPD platform with system-on-chip (SoC) embedded SDR-based TRX. It has been shown that the real-time acquisition of PA inverse model coefficients in SDR-based TRX has a fast heuristic convergence speed than that of the commercial DPD TRXs due to the high-speed SoC embedded processors.…”

LOLA SDR: Low Power Low Latency Software Defined Radio for Broadcast Audio Applications

“…Hence, most of SDR integrations for IoT scenarios have used the flexible radios on the gateway side where energy constraints are greatly alleviated [4]. Standalone embedded SDRs are based on SoC [5], [6] or custom multiprocessor architectures based on Network On Chips (NoC) [7]. If it allows portability and flexibility, it also leads to energy consumption several orders of magnitude higher than the requirements for IoT end-devices [8].…”