Skip to content

Commit

Permalink
plot more OFDM symbols for 1876954_7680KSPS_srsRAN_Project_gnb_short_…
Browse files Browse the repository at this point in the history 
…2 test case
  • Loading branch information
@catkira
catkira committed Aug 15, 2023
1 parent 65a8217 commit 8c32fd7
Show file tree
Hide file tree
Showing 2 changed files with 65 additions and 13 deletions.
22 changes: 13 additions & 9 deletions hdl/Decimator_Correlator_PeakDetector_FFT.sv
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,14 @@ module Decimator_Correlator_PeakDetector_FFT
localparam FFT_OUT_DW = 32,
localparam FFT_LEN = 2 ** NFFT,
localparam CIC_RATE = FFT_LEN / 128,
localparam MAX_CP_LEN = 20 * FFT_LEN / 256
localparam MAX_CP_LEN = 20 * FFT_LEN / 256,
localparam SFN_MAX = 1023,
localparam SUBFRAMES_PER_FRAME = 20,
localparam SYM_PER_SF = 14,
localparam SFN_WIDTH = $clog2(SFN_MAX),
localparam SUBFRAME_NUMBER_WIDTH = $clog2(SUBFRAMES_PER_FRAME - 1),
localparam SYMBOL_NUMBER_WIDTH = $clog2(SYM_PER_SF - 1),
localparam OUT_USER_WIDTH = SFN_WIDTH + SUBFRAME_NUMBER_WIDTH + SYMBOL_NUMBER_WIDTH + BLK_EXP_LEN + 1
)
(
input clk_i,
Expand All @@ -34,6 +41,8 @@ module Decimator_Correlator_PeakDetector_FFT
output SSS_valid_o,
output [FFT_OUT_DW-1:0] m_axis_out_tdata,
output m_axis_out_tvalid,
output m_axis_out_tlast,
output [OUT_USER_WIDTH-1:0] m_axis_out_tuser,

// debug outputs
output reg peak_detected_debug_o,
Expand All @@ -42,6 +51,7 @@ module Decimator_Correlator_PeakDetector_FFT
output wire [15:0] sync_wait_counter_debug_o,
output reg fft_demod_PBCH_start_o,
output reg fft_demod_SSS_start_o,
output reg fft_demod_tlast_o,
output [IN_DW-1:0] m_axis_PSS_out_tdata,
output m_axis_PSS_out_tvalid
);
Expand Down Expand Up @@ -88,12 +98,6 @@ wire fft_sync;
assign fft_result_debug_o = fft_result;
assign fft_sync_debug_o = fft_sync;

localparam SFN_MAX = 1023;
localparam SUBFRAMES_PER_FRAME = 20;
localparam SYM_PER_SF = 14;
localparam SFN_WIDTH = $clog2(SFN_MAX);
localparam SUBFRAME_NUMBER_WIDTH = $clog2(SUBFRAMES_PER_FRAME - 1);
localparam SYMBOL_NUMBER_WIDTH = $clog2(SYM_PER_SF - 1);
localparam USER_WIDTH = SFN_WIDTH + SUBFRAME_NUMBER_WIDTH + SYMBOL_NUMBER_WIDTH + $clog2(MAX_CP_LEN);

reg [IN_DW - 1 : 0] fs_out_tdata;
Expand Down Expand Up @@ -170,9 +174,9 @@ BWP_extractor_i(
.s_axis_in_tlast(fft_demod_out_tlast),

.m_axis_out_tdata(m_axis_out_tdata),
.m_axis_out_tuser(),
.m_axis_out_tuser(m_axis_out_tuser),
.m_axis_out_tvalid(m_axis_out_tvalid),
.m_axis_out_tlast(),
.m_axis_out_tlast(m_axis_out_tlast),
.PBCH_valid_o(PBCH_valid_o),
.SSS_valid_o(SSS_valid_o)
);
Expand Down
56 changes: 52 additions & 4 deletions tests/test_Decimator_Correlator_PeakDetector_FFT.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,19 @@ def _twos_comp(val, bits):
val = val - (1 << bits)
return int(val)

def phase_comp(sym, f_c, NFFT, sym_idx):
assert NFFT >= 8
f_s = 3840000 * (NFFT - 7)
sample_pos = 0
for i in range(sym_idx):
CP_LEN = (20 if (i % 14) in [0, 7] else 18) * (NFFT - 7)
sample_pos += CP_LEN * (NFFT - 7)
sample_pos += 2**NFFT
CP_LEN = (20 if (sym_idx % 14) in [0, 7] else 18) * (NFFT - 7)
sample_pos += CP_LEN * (NFFT - 7)
sym_comp = np.array(sym) * np.exp(1j * 2 * np.pi * f_c / f_s * sample_pos)
return sym_comp

class TB(object):
def __init__(self, dut):
self.dut = dut
Expand Down Expand Up @@ -71,6 +84,8 @@ async def simple_test(dut):
if os.environ['TEST_FILE'] == '30720KSPS_dl_signal':
expected_N_id_1 = 69
expected_N_id_2 = 2
expected_rx_syms = 100
f_c = 0
waveform /= max(waveform.real.max(), waveform.imag.max())
dec_factor = int((2048 * fs // 30720000) // (2 ** tb.NFFT))
assert dec_factor != 0, f'NFFT = {tb.NFFT} and fs = {fs} is not possible!'
Expand All @@ -85,6 +100,8 @@ async def simple_test(dut):
elif os.environ['TEST_FILE'] == '772850KHz_3840KSPS_low_gain':
expected_N_id_1 = 291
expected_N_id_2 = 0
expected_rx_syms = 100
f_c = 772850000
delta_f = -4e3
waveform *= 2**19 # exported files from sdrangel are scaled like this
waveform = waveform * np.exp(-1j*(2*np.pi*delta_f/fs*np.arange(waveform.shape[0])))
Expand All @@ -94,6 +111,8 @@ async def simple_test(dut):
elif os.environ['TEST_FILE'] == '1876954_7680KSPS_srsRAN_Project_gnb_short_2':
expected_N_id_1 = 0
expected_N_id_2 = 1
expected_rx_syms = 25 * 12 * 14 * 2 # 2 subframes
f_c = 1876954000
delta_f = 0
waveform *= 2**19 # exported files from sdrangel are scaled like this
waveform = waveform * np.exp(-1j*(2*np.pi*delta_f/fs*np.arange(waveform.shape[0])))
Expand Down Expand Up @@ -130,12 +149,16 @@ async def simple_test(dut):
EXTRA_IDLE_CLKS = 0 if PSS_IDLE_CLKS >= tb.MULT_REUSE else tb.MULT_REUSE // PSS_IDLE_CLKS - 1 # insert additional valid 0 cycles if needed
print(f'additional idle cycles per sample: {EXTRA_IDLE_CLKS}')
clk_div = 0
MAX_CLK_CNT = 100000 * FFT_LEN // 256 * (1 + EXTRA_IDLE_CLKS)
if os.environ['TEST_FILE'] == '1876954_7680KSPS_srsRAN_Project_gnb_short_2':
MAX_CLK_CNT = 1000000 * FFT_LEN // 256 * (1 + EXTRA_IDLE_CLKS)
else:
MAX_CLK_CNT = 100000 * FFT_LEN // 256 * (1 + EXTRA_IDLE_CLKS)
peaks = []

tx_cnt = 0
sample_cnt = 0
while (len(received_SSS) < SSS_LEN) and (clk_cnt < MAX_CLK_CNT):
rx_syms = []
while (((len(received_SSS) < SSS_LEN) or (len(rx_syms) < expected_rx_syms)) and (clk_cnt < MAX_CLK_CNT)):
await RisingEdge(dut.clk_i)
if (clk_div == 0 or EXTRA_IDLE_CLKS == 0):
data = (((int(waveform[tx_cnt].imag) & ((2 ** (tb.IN_DW // 2)) - 1)) << (tb.IN_DW // 2)) \
Expand Down Expand Up @@ -171,9 +194,16 @@ async def simple_test(dut):

if dut.SSS_valid_o.value.integer == 1:
# print(f"rx SSS[{len(received_SSS):3d}]")
received_SSS.append(_twos_comp(dut.m_axis_out_tdata.value.integer & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2)
+ 1j * _twos_comp((dut.m_axis_out_tdata.value.integer>>(FFT_OUT_DW//2)) & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2))
sym = _twos_comp(dut.m_axis_out_tdata.value.integer & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2) \
+ 1j * _twos_comp((dut.m_axis_out_tdata.value.integer>>(FFT_OUT_DW//2)) & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2)
received_SSS.append(sym)

if dut.m_axis_out_tvalid.value.integer == 1:
sym = _twos_comp(dut.m_axis_out_tdata.value.integer & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2) \
+ 1j * _twos_comp((dut.m_axis_out_tdata.value.integer>>(FFT_OUT_DW//2)) & (2**(FFT_OUT_DW//2) - 1), FFT_OUT_DW//2)
rx_syms.append(sym)


assert clk_cnt < MAX_CLK_CNT, "timeout, did not receive enough data"
assert len(received_SSS) == SSS_LEN

Expand All @@ -186,6 +216,11 @@ async def simple_test(dut):
ideal_SSS_sym = tb.fft_dbs(ideal_SSS_sym, FFT_OUT_DW / 2)
ideal_SSS_sym *= np.exp(1j * (2 * np.pi * (CP_LEN - CP_ADVANCE) / FFT_LEN * np.arange(FFT_LEN) + np.pi * (CP_LEN - CP_ADVANCE)))
ideal_SSS = ideal_SSS_sym[SSS_START:][:SSS_LEN]

# phase compensation for SSS symbol
received_SSS = phase_comp(received_SSS, f_c, NFFT, 4) # SSS is always at symbol number 4 within a slot assuming ssb_idx == 0
ideal_SSS = phase_comp(ideal_SSS, f_c, NFFT, 4)

if 'PLOTS' in os.environ and os.environ['PLOTS'] == '1':
ax = plt.subplot(4, 2, 1)
ax.plot(np.abs(ideal_SSS_sym))
Expand Down Expand Up @@ -228,6 +263,19 @@ async def simple_test(dut):
axs[1, 1].set_title('model PBCH')
plt.show()

rx_syms = np.array(rx_syms)
print(f'received {len(rx_syms)} ressource elements')
if ('PLOTS' in os.environ and os.environ['PLOTS'] == '1') and (os.environ['TEST_FILE'] == '1876954_7680KSPS_srsRAN_Project_gnb_short_2'):
_, axs = plt.subplots(1, 3, figsize=(15, 5))
SC_PER_SYM = 25 * 12 # assume NFFT = 9
sym = rx_syms[SC_PER_SYM*0 : SC_PER_SYM*1]
axs[0].plot(np.real(sym), np.imag(sym), '.')
sym = rx_syms[SC_PER_SYM*1 : SC_PER_SYM*17]
axs[1].plot(np.real(sym), np.imag(sym), '.')
sym = rx_syms[SC_PER_SYM*17 : SC_PER_SYM*28]
axs[2].plot(np.real(sym), np.imag(sym), '.')
plt.show()

# peak_pos = np.argmax(received[:np.round(fs * 0.02).astype(int)]) # max peak within first 20 ms
peak_pos = peaks[0]
print(f'first peak at {peak_pos}')
Expand Down

0 comments on commit 8c32fd7

Please sign in to comment.