The 5G radio access network （RAN） architectm＇e is supposed to be split into the central unit （CU） and the distributed unit （DU） in order to support more flexible transport networks and provide enhanced user exp...The 5G radio access network （RAN） architectm＇e is supposed to be split into the central unit （CU） and the distributed unit （DU） in order to support more flexible transport networks and provide enhanced user experience. However, such functional split may also introduce some new technical issues. In this pa- per, we study the data fast retransmission issue introduced by this functional split in different scenarios and solutions are provided to handle this issue. With the fast data retransmis- sion mechanism proposed in this paper, the retransmitted da- ta packets could be identified and handled with high priority. In this way, the data delivery between the CU and DU in 5G RAN is assured.展开更多
Support of many different services, approximately 1000 x increase of current data rates, ultra-low latency and energy/cost efficiencyare among the expectations from the upcoming 5G standards. In order to meet these ex...Support of many different services, approximately 1000 x increase of current data rates, ultra-low latency and energy/cost efficiencyare among the expectations from the upcoming 5G standards. In order to meet these expectations, researchers investigate variouspotential technologies involving different network layers and discuss their tradeoffs for possible 5G scenarios. As one of the mostcritical components of communication systems, waveform design plays a vital role here to achieve the aforementioned goals. Basicfeatures of the 5G waveform can be given in a nutshell as more flexibility, support of multiple access, the ability to co-exist withdifferent waveforms, low latency and compatibility with promising future technologies such as massive MIMO and mm Wave com-munications. Orthogonal frequency division multiplexing(OFDM) has been the dominant technology in many existing standardsand is still considered as one of the favorites for broadband communications in 5G radio access network(RAN). Considering thecurrent interest of industry and academia on enhancing OFDM, this paper drafts the merits and shortcomings of OFDM for 5GRAN scenarios and discusses the various approaches for its improvement. What is addressed in this paper includes not only en-hancing the waveform characteristics, out of band leakage and peak to average power ratio in particular, but also methods to re-duce the time and frequency redundancies of OFDM such as cyclic prefix and pilot signals. We present how the requirements ofdifferent 5G RAN scenarios reflect on waveform parameters, and explore the motivations behind designing frames that includemultiple waveforms with different parameters, referred to as numerologies by the 3GPP community, as well as the problems thatarise with such coexistence. In addition, recently proposed OFDM-based signaling schemes will also be discussed along with abrief comparison.展开更多
文摘The 5G radio access network （RAN） architectm＇e is supposed to be split into the central unit （CU） and the distributed unit （DU） in order to support more flexible transport networks and provide enhanced user experience. However, such functional split may also introduce some new technical issues. In this pa- per, we study the data fast retransmission issue introduced by this functional split in different scenarios and solutions are provided to handle this issue. With the fast data retransmis- sion mechanism proposed in this paper, the retransmitted da- ta packets could be identified and handled with high priority. In this way, the data delivery between the CU and DU in 5G RAN is assured.
文摘Support of many different services, approximately 1000 x increase of current data rates, ultra-low latency and energy/cost efficiencyare among the expectations from the upcoming 5G standards. In order to meet these expectations, researchers investigate variouspotential technologies involving different network layers and discuss their tradeoffs for possible 5G scenarios. As one of the mostcritical components of communication systems, waveform design plays a vital role here to achieve the aforementioned goals. Basicfeatures of the 5G waveform can be given in a nutshell as more flexibility, support of multiple access, the ability to co-exist withdifferent waveforms, low latency and compatibility with promising future technologies such as massive MIMO and mm Wave com-munications. Orthogonal frequency division multiplexing(OFDM) has been the dominant technology in many existing standardsand is still considered as one of the favorites for broadband communications in 5G radio access network(RAN). Considering thecurrent interest of industry and academia on enhancing OFDM, this paper drafts the merits and shortcomings of OFDM for 5GRAN scenarios and discusses the various approaches for its improvement. What is addressed in this paper includes not only en-hancing the waveform characteristics, out of band leakage and peak to average power ratio in particular, but also methods to re-duce the time and frequency redundancies of OFDM such as cyclic prefix and pilot signals. We present how the requirements ofdifferent 5G RAN scenarios reflect on waveform parameters, and explore the motivations behind designing frames that includemultiple waveforms with different parameters, referred to as numerologies by the 3GPP community, as well as the problems thatarise with such coexistence. In addition, recently proposed OFDM-based signaling schemes will also be discussed along with abrief comparison.
