那位大哥,请帮我看一下这篇文章,麻烦告诉我RF是什么的缩写?

那位大哥,请帮我看一下这篇文章,麻烦告诉我RF是什么的缩写?
RF System Engineer
Job Description
As a RF system engineer,your responsibilities include defining the RF architecture and specification for next-generation communication wireless broadband communication systems.Your responsibilities also include integrating third-party RF solutions into Baseband boards.
Qualifications
MS in electrical engineering
Minimum of 1 year experience in the integration of RF solutions into WiMAX/802.16e baseband boards
At least 3 year experience in RF engineering for wireless communication systems
Understand the RF requirements of WiMAX/16e systems
Extensive experience in using RF test equipments
Hands-on experience in Matlab and calibration of RF systems
Good verbal and written communication skills in English
Communication System Engineer
Job Description
As a communication system engineer,your responsibilities include research,design and implementation of advanced signal processing algorithms for next-generation wireless broadband communication systems.This position requires previous experiences in OFDMA and MIMO physical layer algorithms design and implementation.
Qualifications
MS in electrical engineering,Ph.D.preferred
Minimum of 1 year experience in WiMAX/802.16e OFDMA/MIMO PHY algorithms design
At least 3 year experience in signal processing algorithms and communication systems design
Hands-on experience in Matlab,Simulink,C/C++ and assembly
Good verbal and written communication skills in English