【资料名称】：跳频相关

【资料作者】：厂家

【资料日期】：11月

【资料语言】：中文

【资料格式】：DOC

【资料目录和简介】：

1 Introduction
Frequency hopping means that multiple frequencies are used for the transmis-sion
of speech or data in a single connection. Each burst is transmitted on a
fixed frequency, but the frequency is changed between bursts. A burst can
easily be lost when the mobile happens to be located in a fading dip for that
particular frequency, or if it is subjected to interference. The next burst, if on a
different frequency, has a good chance to come through. The coding and
interleaving scheme in GSM is constructed so that loss of a single burst shall
have minimal influence on the speech quality.
A predefined set of frequencies is used in each cell. The mobile and the base
station change frequency between every burst, i.e. 217 times per second. The
same sequence is used in the uplink and in the downlink.