bitload.asv

本程序利用改进的CHOW算法

function [bits_alloc,energy_alloc]  = BitLoad(subchan_gains,total_bits,num_subc,gap,noise,M)

% 应用比特分配算法根据当前的信道特性来达到所期望的比特和能量的分配
% ---------------------
%
% Inputs :
%          subchan_gains    : SubCarrier Gains
%           total_bits     : Total Number of bits 
%            num_subc      : Number of Subcarriers
%            gap           : Gap of the system系统间隔
%            noise         : Noise Power
%               M          : Max Constellation Size最大星座大小
% Outputs:
%          bits_alloc      : Bits allocation for each subchannel
%          power_alloc     : Total Power allocation 
% ---------------------------------------------------------------

% Compute SNR's for each channel
SNR = ComputeSNR(subchan_gains,noise,gap);

% This function just initializes the system with a particular bit 
% allocation and energy allocation using Chow's Algorithm. This is 
% further efficientize using Campello's Algorithm
%这个函数初始化系统，即根据chow算法分配比特数和功率，比campello

[bits_alloc, energy_alloc] = chow_algo(SNR,num_subc,M);

% Form the Energy Increment Table based on the present channel
% gains for all the subchannels in order to be used by Campello
% Algorithm

energytable = EnergyTableInit(SNR,M);

% Efficientize the algorithm using the Campello's algorithm
[bits_alloc,energy_alloc] = campello_algo(bits_alloc,energy_alloc,energytable,total_bits,num_subc,M);