一、前言据新闻报导,日本总人口目前已突破一亿两千万。迄今为止各方面的竞争都很激烈,而且居住困难,无形中就给今后的年青一代增添一种精神压力,认为这是一个有待解决的严重问题。特别是日本的国土窄小有限,买地盖房等事情已日趋困难。如果回过头来再展望一下电波世界,也同样抱有不安的心情。在流动过程中为跟离别的人通话,必须要借助无线通信。但是,为了通信,需要占有一定的频段。然而能够使用的频段是有限的,这跟买地建房是同样的道理,也是相当困难的。为此,许多研究人员为使更多的人享受到无线通信的好处,正在日夜努力。作为解决措施来说,虽然有各种方法,但研究出的最简便方法是在带宽尽量变窄的状态下仍能继续通信,即研制窄带调制解调技术。本文对这一主题将作系统的技术展望和内容整理。 I. Introduction According to news reports, the total population of Japan has now exceeded 120 million. So far the competition in all fields has been fierce and living difficulties have virtually added mental stress to the younger generation in the future as a serious problem to be solved. In particular, Japan’s territory is narrow and limited, and buying land for housing has become increasingly difficult. If you look back and then look at the wave of the world, also have uneasy feelings. To communicate with other people in the process of flow, you must use wireless communication. However, in order to communicate, it needs to occupy a certain frequency band. However, the frequency band that can be used is limited, which is the same as building a house and it is quite difficult. To this end, many researchers are working day and night to make more people enjoy the benefits of wireless communications. As a solution to this problem, although there are various methods, the simplest method that has been developed is to continue the communication under the condition that the bandwidth is as narrow as possible, that is, the development of narrowband modem technology. This article will make a systematic technical outlook and content collation on this topic.