ofdm系统仿真与关键技术研究.doc

摘要

你、我、他,几乎每天都在进行着通信,通信在我们生活中扮演着极其重要的角色。移动通信已经成为当今通信发展的主流,而无线通信与个人通信在短短的几十年间经历了从模拟通信到数字通信、从OFDM到CDMA的巨大发展,目前又有新的技术的出现,比以CDMA为核心的第三代移动通信技术更加完善,我们称之为“第四代移动通信技术”。
第四代移动通信系统计划以OFDM(正交频分复用)为核心技术提供增值服务,它在宽带领域的应用具有很大的潜力。较之第三代移动通信系统,采用多种新技术的OFDM具有更高的频谱利用率和良好的抗多径干扰能力,它不仅可以增加系统容量,更重要的是它能更好地满足多媒体通信要求,将包括语音、数据、影像等大量信息的多媒体业务通过宽频信道高品质地传送出去。
纵观通信的发展史,第一代模拟系统仅提供语音服务,不能传输数据;,最高可达32kbit/s;第三代移动通信系统数据传输速率可达到2Mbit/s;而我们目前所致力研究的第四代移动通信系统的数据传输速率可达到10~20Mbit/s。虽然第三代移动通信可以比现有传输速率快上上千倍,但是仍无法满足未来多媒体通信的要求,第四代移动通信系统的提出便是希望能满足提供更大的频宽要求。
关键词: 模拟通信数字通信正交频分复用多径干扰
Abstract
You、me、him、almost every day during munication, communication in our lives plays a very important role. munication has e the mainstream of munications, and munications and munications in just a few years gone from munication to munication, OFDM to CDMA from the tremendous development, the emergence of new technologies have more than to the core of the third generation CDMA munication technology is more perfect, we call the "fourth generation munication technology."
The fourth generation munication system plans to OFDM (orthogonal frequency division multiplexing) as the core technology to provide value-added services, broadband applications it has great potential. Jiaozhi third generation munication system, using a variety of new technologies, OFDM has a higher spectrum efficiency and good anti-multipath interference, which not only can increase the system capacity, more importantly, is that it can better meet the needs of munications requirements, will include voice, data, video and other multimedia services through large amounts of information of high quality broadband channel to send out.
Throughout the history munication, the first generation analog systems to provide voice services only and can not transmit data; second-generation digital munication system data transfer rate is only / s, up to 32kbit / s; the third generation munication system Data transfer rate up to 2Mbit / s;