tds_papr.m

课程作业

%***************************************************
% 用时域法计算OFDM符号PARP, 采用BPSK调制
% N 载波数   相应符号数为2^N
% M 每符号采样次数  可选4,10,16,32等
% pt 时域信号的包络功率
% papr 每符号内峰均功率比
%---------------------------------------------------
clc; clear
N = 4; M = 16;
pt = zeros(1,(2^N)*M); papr = zeros(1,2^N);
E = (exp(i*2*pi*([0:1:N-1]')*[0:1/M:1-1/M]))/sqrt(N);
for i = 0:(2^N-1) %对每个符号循环
    symbol = dec2bin(i,N);
    temp = zeros(1,M);
    for j = 1:N
        if (symbol(j)=='0') %对符号的每一位循环求和
            temp = temp - E(j,:);
        else
            temp = temp + E(j,:);
        end
    end
    temp = abs(temp).^2   %计算功率
    pt(i*M+1:(i+1)*M) = temp;
    papr(i+1) = 10*log10(max(temp)/mean(temp));
end
figure(1);
subplot(2,1,1);plot(pt);xlim([0 2^N*M]);set(gca,'Xtick',[0:M:2^N*M]);
grid;xlabel('时域采样');ylabel('包络功率(W)');
subplot(2,1,2);plot([0:1:2^N-1],papr);set(gca,'Xtick',[0:1:2^N]);xlim([-0.5  2^N-0.5]);
grid;xlabel('码字');ylabel('峰平功率比(dB)');