function [plan_up,plan_down]=setupPSDplan(plan, psd_up, psd_down, method, nosignal,capval);
%% ===========================================================================
%setupPSDplan - Generate a PSD description from a simple list
%
% Parameter:    plan		PSD mask description
% Parameter:    psd_up		PSD-mask for upstream
% Parameter:    psd_down	PSD-mask for downstream
% Parameter:    method  	Interpolation method ('Linear' or 'Log-Linear')
% Parameter:    nosignal  	Signal level when not sending 
% Parameter:    capval  	Maximum signal level
% Returns:      plan_up 	PSD plan for upstream
% Returns:      plan_down 	PSD plan for downstream
%
% Example(s):
%   [tmp_upstream,tmp_downstream]= setupPSDplan({...
%      fmin 'u' .138e6 'd' 2.0e6 'u' 4.3e6, 'd' 7.1e6 ...
%      'u' 10.1e6 'd' 14.35e6 'u' fmax }, ...
%      upstream_val, downstream_val, 'Log-Linear', -120);
%
% Algorithmic details:
%
% Reference:
%% ===========================================================================

%% ===========================================================================
% Copyright (C) 1999 by Telia Research AB, Lulea, Sweden; All rights reserved. 
% Project       : FSAN duplex model
% Author(s)     : Tomas Nordstrom (Tomas.B.Nordstrom@@Telia.se)
%               : Daniel Bengtsson (Daniel.J.Bengtsson@Telia.se)
%		          : Frank Sjöberg
%
% CVS:       $Id: setupPSDplan.m,v 1.4 2000/04/06 13:45:52 uvan Exp $
%% ===========================================================================
% Change History
%      1999-01-14 (ToNo) Created
%      1999-07-27 (FS)   Modified from setupPSDplan to handle non-flat PSD
%      2000-04-06 (UvAn) Changed default value for "nosignal" to -140
%% ===========================================================================
global ex;

if nargin<3,
    error('Not enough input arguments.');
end

if nargin<4
   method = 'Linear';		% Default interpolation method is linear
end;

if nargin<5,
    nosignal=-140;         % Default value; old value -> nosignal=ex.param.backgroundNoise;
end

if nargin<6,
    capval=0;
end

plen=length(plan);
if plen<3,
    error('setupPSDplan must have length > 3');
end;

if ischar(plan{1}) | ischar(plan{plen}),
    error('Start and stop setupPSDplan with a frequency.');
end;

plan_up=[];
plan_down=[];
for i=1:2:plen-2,
    start=plan{i};
    direction=plan{i+1};
    stop=plan{i+2};
    if ischar(start) | ischar(stop),
        error('Frequencies should be around a direction.');
    end;
    if stop<start
        error('Frequencies must be increasing.');
    end;
    switch direction
        case 'u'
           tmp_psd = internal_calcPSD(psd_up, method, [start stop], nosignal,capval);
           plan_up = [plan_up start nosignal tmp_psd stop nosignal];
        case 'd'
           tmp_psd = internal_calcPSD(psd_down, method, [start stop], nosignal,capval);
           plan_down = [plan_down start nosignal tmp_psd stop nosignal];
        case 'n'
            plan_up=[plan_up start nosignal stop nosignal];
            plan_down=[plan_down start nosignal stop nosignal];
        otherwise
            estr=sprintf('Unknown direction %s', direction);
            error(estr);       
    end;
end;


function PSD=internal_calcPSD(data, method, f, nosignal,capval);
   
data=[f(1) nosignal data f(length(f)) nosignal]; % Fix glitch in last band
freq=data(1:2:length(data));
level=data(2:2:length(data));

bigindex=level>capval;
level(bigindex)=capval.*ones(1,sum(bigindex)); % cap the top 
data(2:2:length(data))=level;

idx(1) = max(find(freq<=f(1)));
idx(2) = min(find(freq>=f(2)))-1;

for nn =1:2
   switch method
       case 'Linear'
          tmp=(f(nn)-freq(idx(nn)))/(freq(idx(nn)+1)-freq(idx(nn)));
       case 'Log-Linear'
          tmp=(log(f(nn))-log(freq(idx(nn))))/(log(freq(idx(nn)+1))-log(freq(idx(nn))));
       otherwise
           fprintf('Undefined Interpolation');
           break;
   end;
  PSD(nn) = level(idx(nn))+(level(idx(nn)+1)-level(idx(nn)))*tmp;   
end;
PSD = [f(1) PSD(1) data(idx(1)*2+1:idx(2)*2)  f(2) PSD(2)];