Equalization of the demodulated symbols.
function [ x, B ] = Equalizer( z, C, ParaModulation, modulation )
function [ x, B ] = Equalizer( z, C, ParaModulation, modulation, EqualizerType )
function [ x, B ] = Equalizer( z, C, ParaModulation, modulation, EqualizerType, ParaEqualizer )
The function works for MIMO and SISO systems depending on the type of
equalizer being used. See the help related to the specific equalizer
functions called by the present parent function.
Input arguments:
z: demodulated OFDM symbols. Size: matrix [2*Para.M, ~] if
Para.N_R == 1, multidimensional array [Para.N_R, 2*Para.M, ~]
if Para.N_R > 1.
C: channel impulse response. Multidimensional array [Para.N_R, Para.N_T, ~].
ParaModulation: structure containing the modulation parameters.
EqualizerType: optional (by default 'SingleTap'), determines the type
of equalizer to compute and use. Several options are possible,
depending on the modulation.
'SingleTap': conventional single-tap equalization.
'MultiTapFS': multi-tap equalization using frequency sampling
design (only for FBMC-OQAM).
'MultiTapFullMMSE': multi-tap equalization using general MMSE
design (only for FBMC-OQAM).
'ParallelMultistage': parallel multistage equalization. (only for
FBMC-OQAM).
'FrequencySpreading': frequency spreading equalization. (only for
FBMC-OQAM).
'TimeDomain': time domain equalization directly on the received
signal prior to demodulation.
ParaEqualizer: structure containing parameters of the equalizer.
Depending on the equalizer type, the structure may contain optional
arguments (set to default values) and/or mandatory arguments:
ParaEqualizer.criterion: specific version of the equalizer,
optional, default value: 'ZF'.
ParaEqualizer.B: mandatory if ParaEqualizer.criterion is set to
'Specific'.
ParaEqualizer.r: received signal, mandatory for EqualizerType
'ParallelMultiStage', 'FrequencySpreading' and 'TimeDomain'.
ParaEqualizer.L_eq: number of coefficients of the multi-tap
equalizers, optional, default value: 3.
ParaEqualizer.R: number of additional parallel analysis filterbanks
of the multistage equalizer, optional, default value: 1.
ParaEqualizer.N: block size of the overlap-and-save algorithm,
optional, default value: 4*Para.M.
ParaEqualizer.Kov: discarded samples from each block of N samples,
optional, default value: ceil(length(C(1,1,:))/2)*2.
Ouput arguments:
x: equalized symbols. Size: matrix [2*Para.M, ~] if Para.S == 1,
multidimensional array [para.S, 2*Para.M, ~] if Para.S > 1.
B: (optional, only for SingleTap EqualizerType) equalizing matrices
used at each subcarrier. Size: vector [2*Para.M ,1] if Para.N_T == 1
and multidimensional array [Para.S, Para.N_R, 2*Para.M] otherwise.
See also OFDM_EQUALIZERSINGLETAP, FBMC_OQAM_EQUALIZERSINGLETAP,
FBMC_OQAM_EQUALIZERMULTITAPFS, FBMC_OQAM_EQUALIZERMULTITAPFULLMMSE,
FBMC_OQAM_EQUALIZERPARALLELMULTISTAGE,
FBMC_OQAM_EQUALIZERFREQUENCYSPREADINGRECEIVER,
EQUALIZERTIMEDOMAINOVERLAPANDSAVE.0001 function [ x, B ] = Equalizer( z, C, ParaModulation, EqualizerType, ParaEqualizer ) 0002 % Equalization of the demodulated symbols. 0003 % 0004 % function [ x, B ] = Equalizer( z, C, ParaModulation, modulation ) 0005 % function [ x, B ] = Equalizer( z, C, ParaModulation, modulation, EqualizerType ) 0006 % function [ x, B ] = Equalizer( z, C, ParaModulation, modulation, EqualizerType, ParaEqualizer ) 0007 % 0008 % The function works for MIMO and SISO systems depending on the type of 0009 % equalizer being used. See the help related to the specific equalizer 0010 % functions called by the present parent function. 0011 % 0012 % Input arguments: 0013 % 0014 % z: demodulated OFDM symbols. Size: matrix [2*Para.M, ~] if 0015 % Para.N_R == 1, multidimensional array [Para.N_R, 2*Para.M, ~] 0016 % if Para.N_R > 1. 0017 % 0018 % C: channel impulse response. Multidimensional array [Para.N_R, Para.N_T, ~]. 0019 % 0020 % ParaModulation: structure containing the modulation parameters. 0021 % 0022 % EqualizerType: optional (by default 'SingleTap'), determines the type 0023 % of equalizer to compute and use. Several options are possible, 0024 % depending on the modulation. 0025 % 0026 % 'SingleTap': conventional single-tap equalization. 0027 % 0028 % 'MultiTapFS': multi-tap equalization using frequency sampling 0029 % design (only for FBMC-OQAM). 0030 % 0031 % 'MultiTapFullMMSE': multi-tap equalization using general MMSE 0032 % design (only for FBMC-OQAM). 0033 % 0034 % 'ParallelMultistage': parallel multistage equalization. (only for 0035 % FBMC-OQAM). 0036 % 0037 % 'FrequencySpreading': frequency spreading equalization. (only for 0038 % FBMC-OQAM). 0039 % 0040 % 'TimeDomain': time domain equalization directly on the received 0041 % signal prior to demodulation. 0042 % 0043 % ParaEqualizer: structure containing parameters of the equalizer. 0044 % Depending on the equalizer type, the structure may contain optional 0045 % arguments (set to default values) and/or mandatory arguments: 0046 % 0047 % ParaEqualizer.criterion: specific version of the equalizer, 0048 % optional, default value: 'ZF'. 0049 % 0050 % ParaEqualizer.B: mandatory if ParaEqualizer.criterion is set to 0051 % 'Specific'. 0052 % 0053 % ParaEqualizer.r: received signal, mandatory for EqualizerType 0054 % 'ParallelMultiStage', 'FrequencySpreading' and 'TimeDomain'. 0055 % 0056 % ParaEqualizer.L_eq: number of coefficients of the multi-tap 0057 % equalizers, optional, default value: 3. 0058 % 0059 % ParaEqualizer.R: number of additional parallel analysis filterbanks 0060 % of the multistage equalizer, optional, default value: 1. 0061 % 0062 % ParaEqualizer.N: block size of the overlap-and-save algorithm, 0063 % optional, default value: 4*Para.M. 0064 % 0065 % ParaEqualizer.Kov: discarded samples from each block of N samples, 0066 % optional, default value: ceil(length(C(1,1,:))/2)*2. 0067 % 0068 % Ouput arguments: 0069 % 0070 % x: equalized symbols. Size: matrix [2*Para.M, ~] if Para.S == 1, 0071 % multidimensional array [para.S, 2*Para.M, ~] if Para.S > 1. 0072 % 0073 % B: (optional, only for SingleTap EqualizerType) equalizing matrices 0074 % used at each subcarrier. Size: vector [2*Para.M ,1] if Para.N_T == 1 0075 % and multidimensional array [Para.S, Para.N_R, 2*Para.M] otherwise. 0076 % 0077 % See also OFDM_EQUALIZERSINGLETAP, FBMC_OQAM_EQUALIZERSINGLETAP, 0078 % FBMC_OQAM_EQUALIZERMULTITAPFS, FBMC_OQAM_EQUALIZERMULTITAPFULLMMSE, 0079 % FBMC_OQAM_EQUALIZERPARALLELMULTISTAGE, 0080 % FBMC_OQAM_EQUALIZERFREQUENCYSPREADINGRECEIVER, 0081 % EQUALIZERTIMEDOMAINOVERLAPANDSAVE. 0082 0083 % This file is part of WaveComBox: www.wavecombox.com and is distributed under 0084 % the terms of the MIT license. See accompanying LICENSE file. 0085 % Original author: François Rottenberg, May 8, 2018. 0086 % Contributors: 0087 % Change log: 0088 0089 ParaEqualizer.a=[]; 0090 if isfield(ParaEqualizer,'criterion') ==0 0091 ParaEqualizer.criterion='ZF'; 0092 end 0093 if isfield(ParaEqualizer,'B') ==0 0094 B=[]; 0095 end 0096 if exist ('EqualizerType','var')==0 0097 EqualizerType='SingleTap'; 0098 end 0099 0100 switch ParaModulation.Modulation 0101 case {'CP-OFDM', 'F-OFDM', 'W-OFDM'} 0102 switch EqualizerType 0103 case 'SingleTap' 0104 if strcmp(ParaEqualizer.criterion,'Specific')==1 0105 [x, B] = OFDM_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation, ParaEqualizer.B ); 0106 else 0107 [x, B] = OFDM_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation ); 0108 end 0109 case 'TimeDomain' 0110 if isfield(ParaEqualizer,'r')==0 0111 error('Missing argument: received signal "ParaEqualizer.r"') 0112 end 0113 if isfield(ParaEqualizer,'N')==0 0114 ParaEqualizer.N=4*ParaModulation.M; 0115 end 0116 if isfield(ParaEqualizer,'Kov')==0 0117 ParaEqualizer.Kov=ceil(length(C(1,1,:))/2)*2; 0118 end 0119 [ r_eq ] = EqualizerTimeDomainOverlapandsave( r, C, ParaEqualizer.N, ParaEqualizer.Kov, ParaEqualizer.criterion, ParaModulation ); 0120 x=Demodulator( r_eq, ParaModulation ); 0121 otherwise 0122 error('Equalizer type not defined for CP-OFDM modulation') 0123 end 0124 case 'FBMC-OQAM' 0125 switch EqualizerType 0126 case 'SingleTap' 0127 if strcmp(ParaEqualizer.criterion,'Specific')==1 0128 [x, B] = FBMC_OQAM_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation, ParaEqualizer.B ); 0129 else 0130 [x, B] = FBMC_OQAM_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation ); 0131 end 0132 case 'MultiTapFS' 0133 if isfield(ParaEqualizer,'L_eq')==0 0134 ParaEqualizer.L_eq=3; 0135 end 0136 [ x ] = FBMC_OQAM_EqualizerMultiTapFS( z, C, ParaEqualizer.L_eq, ParaEqualizer.criterion, ParaModulation ); 0137 case 'MultiTapFullMMSE' 0138 if isfield(ParaEqualizer,'L_eq')==0 0139 ParaEqualizer.L_eq=3; 0140 end 0141 [ x ] = FBMC_OQAM_EqualizerMultiTapFullMMSE( z, C, ParaEqualizer.L_eq, ParaModulation ); 0142 case 'ParallelMultistage' 0143 if isfield(ParaEqualizer,'r')==0 0144 error('Missing argument: received signal "ParaEqualizer.r"') 0145 end 0146 if isfield(ParaEqualizer,'R')==0 0147 ParaEqualizer.R=1; 0148 end 0149 [ x ] = FBMC_OQAM_EqualizerParallelMultistage( ParaEqualizer.r, C, ParaEqualizer.R, ParaEqualizer.criterion, ParaModulation ); 0150 case 'FrequencySpreading' 0151 if isfield(ParaEqualizer,'r')==0 0152 error('Missing options argument: received signal "options.r"') 0153 end 0154 [ x ] = FBMC_OQAM_EqualizerFrequencySpreadingReceiver( ParaEqualizer.r, C, ParaEqualizer.criterion, ParaModulation ); 0155 case 'TimeDomain' 0156 if isfield(ParaEqualizer,'r')==0 0157 error('Missing options argument: received signal "options.r"') 0158 end 0159 if isfield(ParaEqualizer,'N')==0 0160 ParaEqualizer.N=4*ParaModulation.M; 0161 end 0162 if isfield(ParaEqualizer,'Kov')==0 0163 ParaEqualizer.Kov=ceil(length(C(1,1,:))/2)*2; 0164 end 0165 [ r_eq ] = EqualizerTimeDomainOverlapandsave( ParaEqualizer.r, C, ParaEqualizer.N, ParaEqualizer.Kov, ParaEqualizer.criterion, ParaModulation ); 0166 x=Demodulator( r_eq, ParaModulation ); 0167 otherwise 0168 error('Equalizer type not defined for FBMC-OQAM modulation') 0169 end 0170 0171 case 'UFMC' 0172 switch EqualizerType %Same equalizer as for CP-OFDM 0173 case 'SingleTap' 0174 if strcmp(ParaEqualizer.criterion,'Specific')==1 0175 [x, B] = UFMC_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation, ParaEqualizer.B ); 0176 else 0177 [x, B] = UFMC_EqualizerSingleTap( z, C, ParaEqualizer.criterion, ParaModulation ); 0178 end 0179 case 'TimeDomain' 0180 if isfield(ParaEqualizer,'r')==0 0181 error('Missing argument: received signal "ParaEqualizer.r"') 0182 end 0183 if isfield(ParaEqualizer,'N')==0 0184 ParaEqualizer.N=4*ParaModulation.M; 0185 end 0186 if isfield(ParaEqualizer,'Kov')==0 0187 ParaEqualizer.Kov=ceil(length(C(1,1,:))/2)*2; 0188 end 0189 [ r_eq ] = EqualizerTimeDomainOverlapandsave( r, C, ParaEqualizer.N, ParaEqualizer.Kov, ParaEqualizer.criterion, ParaModulation ); 0190 x=Demodulator( r_eq, ParaModulation ); 0191 otherwise 0192 error('Equalizer type not defined for UFMC modulation') 0193 end 0194 otherwise 0195 error('Modulation not implemented') 0196 end 0197 0198 0199 end 0200