2月11日至14日,西班牙巴塞罗那,作为目前全球最大移动通信展会——Mobile World Congress 2008(其前身是业界盛名的3GSM大会)如期举行。尽管此前一个月在美国举行的CES2008上也亮相不少新款移动通信产品,但在MWC上诺基亚、索立爱立信和...2月11日至14日,西班牙巴塞罗那,作为目前全球最大移动通信展会——Mobile World Congress 2008(其前身是业界盛名的3GSM大会)如期举行。尽管此前一个月在美国举行的CES2008上也亮相不少新款移动通信产品,但在MWC上诺基亚、索立爱立信和摩托罗拉等业界厂商仍发布了具备相当数量和份量的产品。下面就让我们管中窥豹,了解一下这些将在2008年横扫市场的至酷新品吧!展开更多
Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one servi...Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.展开更多
文摘2月11日至14日,西班牙巴塞罗那,作为目前全球最大移动通信展会——Mobile World Congress 2008(其前身是业界盛名的3GSM大会)如期举行。尽管此前一个月在美国举行的CES2008上也亮相不少新款移动通信产品,但在MWC上诺基亚、索立爱立信和摩托罗拉等业界厂商仍发布了具备相当数量和份量的产品。下面就让我们管中窥豹,了解一下这些将在2008年横扫市场的至酷新品吧!
文摘Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.
