GSM系统中质量等级与C/I之间有没有简单的映射关系啊？哪个高手知道的请教一下，谢谢啦！

质量等级是按照误码率的大小来划分的 0级是误码率<0.2%   
                                                                      1级是0.2%<误码率<0.4%
                                                                      2级是0.4%<误码率<0.8%
                                                                      3级是0.8%<误码率<1.6%
                                                                      4级是1.6%<误码率<3.2%
                                                                      5级是3.2%<误码率<6.4%
                                                                      6级是6.4%<误码率<12.8%
                                                                      7级是误码率>12.8%