%?Repeated?Clipping?and?Filtering--PAPR?Simulation
%
%?Reference:?J.?Armstrong?New?OFDM?peak-to-average?power?reduction?scheme.
%?
%?Author:?Bin?Jiang
%?National?Mobile?Communication?Research?Laboratory
%?Southeast?University?210096?Nanjing?China
%?Email:?bjiang@seu.edu.cn

clear?all;?clc;?close?all;
K??=?128;???????????????????????????????????????????????????????????????????%?SIZE?OF?OFDM?Symbol
IF?=?2;?????????????????????????????????????????????????????????????????????%?Interpolation?factor?（Oversampling?factor）
N??=?K*IF;??????????????????????????????????????????????????????????????????%?SIZE?OF?FFT
CR?=?4;?????????????????????????????????????????????????????????????????????%?Clipping?ratio?（linear?4?<==>log?6dB）
QPSK_Set??=?[1?-1?j?-j];
??
ITERATE_NUM?=?4;
MAX_SYMBOLS??=?1e4;
PAPR_Orignal?=?zeros（1MAX_SYMBOLS）;
PAPR_RCF?????=?zeros（ITERATE_NUMMAX_SYMBOLS）;
for?nSymbol=1:MAX_SYMBOLS
????Index?=?randint（1Klength（QPSK_Set））+1;
????X?=?QPSK_Set（Index（1:））;???????????????????????????????????????????????%?Orignal?Frequency?domain?signal
????XX?=?[X（1:K/2）?zeros（1N-K）?X（K/2+1:K）];
????
????x?=?ifft（XX[]2）;??????????????????????????????????????????????????????%?Time?domain?signal
????Signal_Power?=?abs（x.^2）;
????Peak_Power???=?max（Signal_Power[]2）;
????Mean_Power???=?mean（Signal_Power2）;
????PAPR_Orignal（nSymbol）?=?10*log10（Peak_Power./Mean_Power）;
????
????for?nIter=1:ITERATE_NUM
????????%?Clipping
????????x_tmp?=?x（Signal_Power>CR*Mean_Power）;
????????x_tmp?=?sqrt（CR*Mean_Power）*x_tmp./abs（x_tmp）;
????????x（Signal_Power>CR*Mean_Power）?=?x_tmp;
????????
????????%?Filtering
????????XX?=?fft（x[]2）;
????????XX（K/2+（1:N-K））?=?zeros（1N-K）;
????????x?=?ifft（XX[]2）;?
????????
????????%?PAPR?Compute
????????Signal_Power?=?abs（x.^2）;
????????Peak_Power???=?max（Signal_Power[]2）;
????????Mean_Power???=?mean（Signal_Power2）;
????????PAPR_RCF（nIternSymbol）?=?10*log10（Peak_Power./Mean_Power）;
????end
end

[cdf0?PAPR0]?=?ecdf（PAPR_Orignal）;
[cdf1?PAPR1]?=?ecdf（PAPR_RCF（1:））;
[cdf2?PAPR2]?=?ecdf（PAPR_RCF（2:））;
[cdf3?PAPR3]?=?ecdf（PAPR_RCF（3:））;
[cdf4?PAPR4]?=?ecdf（PAPR_RCF（4:））;

%--------------------------------------------------------------------------
semilogy（PAPR01-cdf0‘-b‘PAPR11-cdf1‘-r‘PAPR21-cdf2‘-g‘PAPR31-cdf3‘-c‘PAPR41-cdf4‘-m‘）
legend（‘Orignal‘‘One?clip?and?filter‘‘Two?clip?and?filter‘‘Three?clip?and?filter‘‘Four?clip?and?filter‘）
xlabel（‘PAPR0?[dB]‘）;
ylabel（‘CCDF?（Pr[PAPR>PAPR0]）‘）;
xlim（[0?12]）
grid?on


%想問下我看了下一些文檔CR的定義是CR?=?Amax/sqrt（Pin），是限幅的最大幅度與均方根功率的比值
%所以是不是把程序中的
%????????x_tmp?=?x（Signal_Power>CR*Mean_Power）;
%????????x_tmp?=?CR*Mean_Power*x_tmp./abs（x_tmp.^2）;
%????????x（Signal_Power>CR*Mean_Power）?=?x_tmp;
%改成?Ax=abs（x）;
%????????A=CR*sqrt（Mean_Power）;
%????????x_tmp?=?x（Ax>A）;
%????????x_tmp?=?x_tmp*A./abs（x_tmp）;???????????????????????????????????????????
%????????x（Ax>A）?=?x_tmp;
%更合理一些呢？

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????3028??2007-07-04?13:33??01\Clipping?and?Filtering-PAPR.m

?????文件???????3054??2007-07-04?13:09??01\PTS-PAPR.m

?????文件???????1418??2007-06-01?11:14??01\SLM-PAPR.m

?????目錄??????????0??2013-06-04?08:51??01

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?????????????????7500????????????????????4