Parallel Digital Predistortion Design on Mobile GPU and Embedded Multicore CPU for Mobile Transmitters

Abstract

Digital predistortion (DPD) is a widely adopted baseband processing technique in current radio transmitters. While DPD can effectively suppress unwanted spurious spectrum emissions stemming from imperfections of analog RF and baseband electronics, it also introduces extra processing complexity and poses challenges on efficient and flexible implementations, especially for mobile cellular transmitters, considering their limited computing power compared to basestations. In this paper, we present high data rate implementations of broadband DPD on modern embedded processors, such as mobile GPU and multicore CPU, by taking advantage of emerging parallel computing techniques for exploiting their computing resources. We further verify the suppression effect of DPD experimentally on real radio hardware platforms. Performance evaluation results of our DPD design demonstrate the high efficacy of modern general purpose mobile processors on accelerating DPD processing for a mobile transmitter.

Digital Predistortion for 5G Small Cell: GPU Implementation and RF Measurements

“…both the suitability of a GPU and a SIMD-enabled CPU for filtering, whereas this work concentrates only on GPUs for filtering purposes. It can be seen from the table that the demonstrated sample rates are around twofold compared to the previous work, acknowledging that in this work the DPD has 10 branches and memory depth 1, whereas in [18] the DPD had 5 branches and a memory depth of 5.…”

“…Processing unit Peak throughput (Msamples/s) Kepler GPU @ 852 MHz [18] 153.5 Maxwell GPU @ 998 MHz [18] 221.8 ARMv7 CPU @ 2.32 GHz [18] 214.4 ARMv8 CPU @ 1.91 GHz [18] 200.1 HD 530 GPU (HD) @ 1.05 GHz 401.7 UHD 620 GPU (NEO) @ 1.15 GHz 483.6…”

“…As a consequence, in this paper the high throughput computation is achieved with a GPU. Previous works have shown that GPU implementations can achieve similar data rate performances as the FPGA equivalents, with the added benefit of design flexibility [18].…”