diff --git a/targets/PROJECTS/TDDREC/v4_CH_EST/f_ch_est.m b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ch_est.m
new file mode 100644
index 0000000000000000000000000000000000000000..e488b505eec6548b2cd67fcf953ae71f0508fdac
--- /dev/null
+++ b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ch_est.m
@@ -0,0 +1,45 @@
+
+% PURPOSE : channel estimation using least square method
+%% ARGUMENTS :
+%
+% m_sym_T : transmitted symbol, d_N_f x d_N_ofdm x d_N_ant_act x d_N_meas
+% m_sym_R : received symbol, d_N_f x d_N_ofdm x d_N_ant_act x d_N_meas
+% d_N_meas : number of measurements
+%
+% OUTPUTS :
+%
+% m_H_est : estimation of sub-channels, d_N_antR x d_N_antT x d_N_f x d_N_meas
+%
+%**********************************************************************************************
+% EURECOM - All rights reserved
+%
+% AUTHOR : Xiwen JIANG, Florian Kaltenberger
+%
+% DEVELOPMENT HISTORY :
+%
+% Date Name(s) Version Description
+% ----------- ------------- ------- ------------------------------------------------------
+% Apr-29-2014 X. JIANG 0.1 creation of code
+%
+% REFERENCES/NOTES/COMMENTS :
+%
+% - Based on the function "runmeas_full_duplex" created by Mirsad Cirkic, Florian Kaltenberger.
+%
+%**********************************************************************************************
+function m_H_est = f_ch_est(m_sym_T, m_sym_R)
+
+%% ** initialisation **
+[d_N_f,d_N_OFDM,d_N_antT,d_N_meas] = size(m_sym_T);
+d_N_antR = size(m_sym_R,3);
+m_H_est = zeros(d_N_antR,d_N_antT,d_N_f,d_N_meas);
+
+%% ** estimate the subband channel for each measurement and antenna **
+for d_n_meas = 1:d_N_meas
+ for d_n_f = 1:d_N_f
+ m_y = reshape(m_sym_R(d_n_f,:,:,d_n_meas),d_N_OFDM,d_N_antR).'; % squeeze: problem for antenna number = 1 case
+ m_s = reshape(m_sym_T(d_n_f,:,:,d_n_meas),d_N_OFDM,d_N_antT).';
+ m_H_est(:,:,d_n_f,d_n_meas) = m_y*m_s'/(m_s*m_s'); % LS channel estimation
+ end
+end
+
+end
diff --git a/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_rx.m b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_rx.m
new file mode 100644
index 0000000000000000000000000000000000000000..ede1c646657e8bf1d94c611259530a9c53bf8845
--- /dev/null
+++ b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_rx.m
@@ -0,0 +1,46 @@
+%
+% PURPOSE : OFDM Receiver
+%
+% ARGUMENTS :
+%
+% m_sig_R : received signal with dimension ((d_N_FFT+d_N_CP)*d_N_ofdm) x d_N
+% d_N_FFT : total carrier number
+% d_N_CP : extented cyclic prefix
+% d_N_OFDM : OFDM symbol number per frame
+% v_active_rf : active RF antenna indicator
+%
+% OUTPUTS :
+%
+% m_sym_R : transmitted signal before IFFT with dimension d_N_f x d_N_ofdm x d_N_ant_act
+%
+%**********************************************************************************************
+% EURECOM - All rights reserved
+%
+% AUTHOR : Xiwen JIANG, Florian Kaltenberger
+%
+% DEVELOPMENT HISTORY :
+%
+% Date Name(s) Version Description
+% ----------- ------------- ------- ------------------------------------------------------
+% Apr-29-2014 X. JIANG 0.1 creation of code
+%
+% REFERENCES/NOTES/COMMENTS :
+%
+% - Based on the function "genrandpskseq" created by Mirsad Cirkic, Florian Kaltenberger.
+%
+%**********************************************************************************************
+function m_sym_R = f_ofdm_rx(m_sig_R, d_N_FFT, d_N_CP, d_N_OFDM, v_active_rf)
+
+d_N_ant_act = sum(v_active_rf);
+m_sig_R_eff = m_sig_R(:,find(v_active_rf));
+m_sig_R_f = reshape(m_sig_R_eff,(d_N_FFT+d_N_CP),d_N_OFDM,d_N_ant_act);
+
+%** delete the CP **
+m_sig_R_noCP = m_sig_R_f(d_N_CP+1:end,:,:);
+
+%** fft **
+m_sym_R_fft = 1/sqrt(d_N_FFT)*fft(m_sig_R_noCP,d_N_FFT,1);
+%m_sym_R_fft = fft(m_sig_R_noCP,d_N_FFT,1);
+m_sym_R = m_sym_R_fft([363:512 2:151],:,:);
+
+end
diff --git a/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_tx.m b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_tx.m
new file mode 100644
index 0000000000000000000000000000000000000000..73e1fc656cfc2297c35957d4c55ed0c6363c04f7
--- /dev/null
+++ b/targets/PROJECTS/TDDREC/v4_CH_EST/f_ofdm_tx.m
@@ -0,0 +1,59 @@
+%
+% PURPOSE : OFDM Transmitter
+%
+% ARGUMENTS :
+%
+% d_M : modulation order
+% d_N_f : carrier number carrying data
+% d_N_FFT : total carrier number
+% d_N_CP : extented cyclic prefix
+% d_N_OFDM : OFDM symbol number per frame
+% v_active_rf : active RF antenna indicator
+% d_amp : amplitude
+%
+% OUTPUTS :
+%
+% m_sym_T : transmitted signal before IFFT with dimension d_N_f x d_N_OFDM x d_N_ant_act
+% m_sig_T : OFDM signal with dimension ((d_N_FFT+d_N_CP)*d_N_OFDM) x d_N_ant
+%
+%**********************************************************************************************
+% EURECOM - All rights reserved
+%
+% AUTHOR : Xiwen JIANG, Florian Kaltenberger
+%
+% DEVELOPMENT HISTORY :
+%
+% Date Name(s) Version Description
+% ----------- ------------- ------- ------------------------------------------------------
+% Apr-29-2014 X. JIANG 0.1 creation of code
+%
+% REFERENCES/NOTES/COMMENTS :
+%
+% - Based on the function "genrandpskseq" created by Mirsad Cirkic, Florian Kaltenberger.
+%
+%**********************************************************************************************
+function [m_sym_T, m_sig_T] = f_ofdm_tx(d_M, d_N_f, d_N_FFT, d_N_CP, d_N_OFDM, v_active_rf, d_amp)
+
+d_N_ant_act = sum(v_active_rf);
+
+%** constellation table **
+v_MPSK = exp(sqrt(-1)*([1:d_M]*2*pi/d_M+pi/d_M));
+%** transmitted symbol **
+%v_state = [1;2;3;4];
+%rand("state",v_state);
+m_sym_T = v_MPSK(ceil(rand(d_N_f, d_N_OFDM, d_N_ant_act)*d_M));
+
+%** mapping useful data to favorable carriers **
+m_sym_T_ext = zeros(d_N_FFT,d_N_OFDM,d_N_ant_act);
+m_sym_T_ext(2:151,:,:) = m_sym_T(151:300,:,:);
+m_sym_T_ext(363:512,:,:) = m_sym_T(1:150,:,:);
+
+%** ifft **
+m_sig_T_ = sqrt(d_N_FFT)*ifft(m_sym_T_ext,d_N_FFT,1);
+
+%** add cyclic prefix **
+m_sig_T_ = [m_sig_T_(end-d_N_CP+1:end,:,:); m_sig_T_];
+d_L = (d_N_FFT+d_N_CP)*d_N_OFDM;
+m_sig_T = floor(reshape(m_sig_T_,d_L,d_N_ant_act)*d_amp);
+
+end
diff --git a/targets/PROJECTS/TDDREC/v4_CH_EST/s_H_est.m b/targets/PROJECTS/TDDREC/v4_CH_EST/s_H_est.m
new file mode 100644
index 0000000000000000000000000000000000000000..dae3a7830b3ff709c1a3f9d899f9023ad001cb1a
--- /dev/null
+++ b/targets/PROJECTS/TDDREC/v4_CH_EST/s_H_est.m
@@ -0,0 +1,110 @@
+%
+% SCRIPT ID : s_H_est
+%
+% PROJECT NAME : TDD Recoprocity
+%
+% PURPOSE : full transmission and receive train for calibration channel estimation
+%
+%**********************************************************************************************
+% Eurecom - All rights reserved
+%
+% AUTHOR(s) : Xiwen JIANG, Florian Kaltenberger
+%
+% DEVELOPMENT HISTORY :
+%
+% Date Name(s) Version Description
+% ----------- ------------- ------- ------------------------------------------------------
+% May-11-2015 X. JIANG 0.1 script creation v0.1
+%
+% REFERENCES/NOTES/COMMENTS :
+%
+%**********************************************************************************************
+
+%% ** initialisation **
+clc
+close all
+clear all
+s_init_params;
+
+d_M = 4; % modulation order, e.g. 4 means QPSK
+
+%%** frequency **
+d_N_f = 300; % carrier number carrying data
+d_N_FFT = 512; % total carrier number
+d_N_CP = 128; % extented cyclic prefix
+%%** time **
+d_N_OFDM = 120; % number of ofdm symbol per frame
+d_N_meas = 10; % measuement number
+%%** antenna **
+d_N_antA = 4; % antenna number at site a
+d_N_antB = 4; % antenna number at site b
+v_indA = find(v_active_rfA); % active antenna index at site a
+v_indB = find(v_active_rfB); % active antenna index at site b
+d_amp = pow2(12);
+%% ----------------------------------------------------
+m_sym_TA = zeros(d_N_f,d_N_OFDM,length(v_indA),d_N_meas);
+m_sym_TB = zeros(d_N_f,d_N_OFDM,length(v_indA),d_N_meas);
+m_sym_RB = zeros(d_N_f,d_N_OFDM,length(v_indB),d_N_meas);
+m_sig_TA = zeros((d_N_CP+d_N_FFT)*d_N_OFDM,d_N_antA);
+m_sig_TB = zeros((d_N_CP+d_N_FFT)*d_N_OFDM,d_N_antB);
+
+%** simulation**
+
+for d_n_meas = 1:d_N_meas
+ %% -------- tx --------
+ %** tx of site A **
+ [m_sym_TA(:,:,:,d_n_meas), m_sig_TA_] = f_ofdm_tx(d_M, d_N_f, d_N_FFT, d_N_CP, d_N_OFDM, v_active_rfA, d_amp);
+
+ %% -------- channel --------
+ %** Transmission from A to B **
+ m_sig_TA(:,v_indA)= m_sig_TA_*2; %affect the LSB to 0 to set on Tx mode
+ m_sig_TB(:,v_indB)= 1+1i*ones(size(m_sig_TB,1),length(v_indB)); %affect the LSB to 1 to set on Rx mode
+ oarf_send_frame(cardB,m_sig_TB,d_n_bit);
+ oarf_send_frame(cardA,m_sig_TA,d_n_bit);
+ m_sig_R = oarf_get_frame(cardA);
+ m_sig_RB = m_sig_R(1:d_N_OFDM*(d_N_FFT+d_N_CP),d_N_antA+1:d_N_antA+d_N_antB);
+ sleep(0.1);
+ %% -------- rx --------
+ m_sym_RB(:,:,:,d_n_meas) = f_ofdm_rx(m_sig_RB, d_N_FFT, d_N_CP, d_N_OFDM, v_active_rfB);
+
+end
+%keyboard;
+
+%** channel estimation **
+m_H_est_A2B_f = f_ch_est(m_sym_TA, m_sym_RB); %dimension: d_N_antR x d_N_antT x d_N_f x d_N_meas
+m_H_est_A2B_ = zeros(length(v_indB),length(v_indA),d_N_FFT,d_N_meas);
+m_H_est_A2B_(:,:,[2:151 363:512],:) = m_H_est_A2B_f(:,:,[151:300 1:150],:);
+m_H_est_A2B_t = ifft(m_H_est_A2B_,[],3);
+
+%% -------- plot --------
+
+%** channel estimation in frequency domain **
+ m_H_A2B_draw_f = squeeze(m_H_est_A2B_f(1,:,:,1)).';
+ m_H_A2B_draw_t = squeeze(m_H_est_A2B_t(1,:,:,1)).';
+
+ figure(1)
+ plot(real(m_sig_RB(1:1000,v_indB)),'b-');
+ title('received signal at site B (time domain)')
+
+ figure(2)
+ plot(m_sym_RB(100,:,1,1),'*')
+ title('Demodulated symboles at site B')
+
+ figure(3)
+ plot(abs(m_H_A2B_draw_t))
+ title('Impulse Response')
+
+ figure(4)
+ subplot(2,1,1)
+ plot(20*log10(abs(m_H_A2B_draw_f)),'-');
+ title('|h| vs. freq (A2B)')
+ xlabel('freq')
+ ylabel('|h|')
+ ylim([0 100])
+
+ subplot(2,1,2)
+ plot(angle(m_H_A2B_draw_f),'-');
+ title('angle(h) vs. freq (A2B)')
+ xlabel('freq')
+ ylabel('angle(h)')
+
diff --git a/targets/PROJECTS/TDDREC/v4_CH_EST/s_init_params.m b/targets/PROJECTS/TDDREC/v4_CH_EST/s_init_params.m
new file mode 100644
index 0000000000000000000000000000000000000000..31838d44592126ffa57f15e32521fc8a9783dc20
--- /dev/null
+++ b/targets/PROJECTS/TDDREC/v4_CH_EST/s_init_params.m
@@ -0,0 +1,57 @@
+clear all
+close all
+addpath([getenv('OPENAIR_TARGETS') '/ARCH/EXMIMO/USERSPACE/OCTAVE']);
+
+%% -------- ExpressMIMO2 configuration --------
+limeparms;
+
+cardA = 0;
+cardB = 1;
+
+v_active_rfA = [1 0 0 0];
+v_active_rfB = [1 0 0 0];
+
+fc = 1907600000; %3500000000; %fc = 859.5e6; %fc = 2660000000;
+freq_rxA = fc*v_active_rfA;
+freq_txA = freq_rxA; %+1.92e6;
+freq_rxB = fc*v_active_rfB;
+freq_txB = freq_rxB; %+1.92e6;
+
+tdd_config = DUPLEXMODE_FDD+TXRXSWITCH_LSB; %we need the LSB switching for the woduplex script, otherwise we don't receive anything
+rx_gainA = 10*v_active_rfA;%[0 0 0 3];
+tx_gainA = 10*v_active_rfA;%[20 20 20 20]
+rx_gainB = 10*v_active_rfB;
+tx_gainB = 10*v_active_rfB;
+syncmodeA = SYNCMODE_MASTER;
+syncmodeB = SYNCMODE_SLAVE;
+eNB_flag = 0;
+resampling_factorA = [2 2 2 2];%2*v_active_rfA;
+resampling_factorB = [2 2 2 2];%2*v_active_rfB;
+
+rf_modeA = (TXLPFNORM+TXLPFEN+TXLPF25+RXLPFNORM+RXLPFEN+RXLPF25+LNA1ON+LNAMax+RFBBNORM+DMAMODE_TX+TXEN+DMAMODE_RX+RXEN) * v_active_rfA;
+rf_rxdcA = rf_rxdc*v_active_rfA;
+rf_vcocalA = rf_vcocal_19G*v_active_rfA;
+rf_local = [8254744 8255063 8257340 8257340]; %eNB2tx 1.9GHz
+rffe_rxg_lowA = 31*v_active_rfA;
+rffe_rxg_finalA = 63*v_active_rfA;
+rffe_bandA = B19G_TDD*v_active_rfA;
+autocal_modeA = v_active_rfA;
+oarf_stop(cardA);
+%oarf_stop_without_reset(cardA);
+sleep(0.1);
+oarf_config_exmimo(cardA,freq_rxA,freq_txA,tdd_config,syncmodeA,rx_gainA,tx_gainA,eNB_flag,rf_modeA,rf_rxdcA,rf_local,rf_vcocalA,rffe_rxg_lowA,rffe_rxg_finalA,rffe_bandA,autocal_modeA,resampling_factorA);
+
+rf_modeB = (TXLPFNORM+TXLPFEN+TXLPF25+RXLPFNORM+RXLPFEN+RXLPF25+LNA1ON+LNAMax+RFBBNORM+DMAMODE_TX+TXEN+DMAMODE_RX+RXEN) * v_active_rfB;
+rf_rxdcB = rf_rxdc*v_active_rfB;
+rf_vcocalB = rf_vcocal_19G*v_active_rfB;
+rffe_rxg_lowB = 31*v_active_rfB;
+rffe_rxg_finalB = 63*v_active_rfB;
+rffe_bandB = B19G_TDD*v_active_rfB;
+autocal_modeB = v_active_rfB;
+oarf_stop(cardB);
+%oarf_stop_without_reset(cardB);
+sleep(0.1);
+oarf_config_exmimo(cardB,freq_rxB,freq_txB,tdd_config,syncmodeB,rx_gainB,tx_gainB,eNB_flag,rf_modeB,rf_rxdcB,rf_local,rf_vcocalB,rffe_rxg_lowB,rffe_rxg_finalB,rffe_bandB,autocal_modeB,resampling_factorB);
+
+d_n_bit = 16;
+