bladeRF further test

[pchat-imm]

Hello all,

I have followed #222, and successfully use bladeRF A4 as the gNB. I use CPE as an UE and successfully continuously ping to the core server (open5gs) and open youtube at 480p for 5 hours. Then I come back to try other scenario includes

• MIMO (Enabling MIMO with srsRAN Project #102), by using two pairs of antennae, and add nof_antennas_dl: 2 nof_antennas_ul: 2
• increase srate from 23.04 to 46.08

However, both case is unsuccessful. I would like to ask for general idea, does anyone success with bladerf A4 other than default setting. Thank you

Note:

• The MIMO cases returns

--== srsRAN gNB (commit 4cf7513e9) ==--

Using more than two DL antennas might make the MAC PDU larger than what is supported in the UDP wrapper. Use PCAP DLT type to avoid pcap corruption.
srsRAN ERROR: Invalid configuration detected.

• The increase srate result in overflow

--== srsRAN gNB (commit 4cf7513e9) ==--


The PRACH detector will not meet the performance requirements with the configuration {Format B4, ZCZ 0, SCS 30kHz, Rx ports 1}.
Lower PHY in quad executor mode.
N2: Connection to AMF on 127.0.0.2:38412 completed
Cell pci=1, bw=40 MHz, 1T1R, dl_arfcn=627340 (n78), dl_freq=3410.1 MHz, dl_ssb_arfcn=626400, ul_freq=3410.1 MHz

Available radio types: uhd.
[INFO] [UHD] linux; GNU C++ version 10.5.0; Boost_107400; UHD_4.7.0.0-0-ga5ed1872
[INFO] [LOGGING] Fastpath logging disabled at runtime.
[DEBUG] [MPMD] Discovering MPM devices on port 49600
[DEBUG] [MPMD] Discovering MPM devices on port 49600
[DEBUG] [MPMD] Discovering MPM devices on port 49600
[DEBUG] [MPMD] Discovering MPM devices on port 49600
[DEBUG] [MPMD] Discovering MPM devices on port 49600
[DEBUG] [MPMD] Discovering MPM devices on port 49600
No device type given, found device with address 'backend=libusb,device=0x04:0x03,driver=bladerf,instance=0,label=BladeRF #0 [6685e220..5e1a5c78],serial=6685e220048b4304b28eb62a5e1a5c78,type=soapy'
Making USRP object with args 'type=soapy'
[INFO] [UHDSoapyDevice] bladerf_open_with_devinfo()
[INFO] [UHDSoapyDevice] bladerf_get_serial() = 6685e220048b4304b28eb62a5e1a5c78
[INFO] [UHDSoapyDevice] setSampleRate(Rx, 0, 4.000000 MHz), actual = 4.000000 MHz
[INFO] [UHDSoapyDevice] setSampleRate(Tx, 0, 4.000000 MHz), actual = 4.000000 MHz
[INFO] [UHDSoapyDevice] setSampleRate(Tx, 0, 46.080000 MHz), actual = 46.080000 MHz
[INFO] [UHDSoapyDevice] setSampleRate(Tx, 1, 46.080000 MHz), actual = 46.080000 MHz
[INFO] [UHDSoapyDevice] setSampleRate(Rx, 0, 46.080000 MHz), actual = 46.080000 MHz
[INFO] [UHDSoapyDevice] setSampleRate(Rx, 1, 46.080000 MHz), actual = 46.080000 MHz
[WARNING @ host/libraries/libbladeRF/src/board/bladerf2/common.c:356] The total sample throughput for the 2 active channels, 92.16 Msps, is greater than the recommended maximum sample throughput, 80 Msps. You may experience dropped samples unless the sample rate is reduced, or some channels are deactivated.
==== gNB started ===
Type <h> to view help
Late: 0; Underflow: 0; Overflow: 13322;
Late: 0; Underflow: 0; Overflow: 13410;
Late: 0; Underflow: 0; Overflow: 13402;
Late: 0; Underflow: 0; Overflow: 13412;
Late: 0; Underflow: 0; Overflow: 13412;
Late: 0; Underflow: 0; Overflow: 13423;
Late: 0; Underflow: 0; Overflow: 13422;

• gnb default setting, without any change

amf:
  addr: 127.0.0.2                                               # The address or hostname of the AMF.
  bind_addr: 127.0.0.1                                            # A local IP that the gNB binds to for traffic from the AMF.

cu_cp:
  inactivity_timer: 7200

ru_sdr:
  device_driver: uhd                                            # The RF driver name.
  # device_args: type=bladeRF
  # clock: internal                                                       # Specify the clock source used by the RF.
  # sync: internal                                                        # Specify the sync source used by the RF.
  srate: 23.04                                                  # RF sample rate might need to be adjusted according to selected bandwidth.
  # srate: 30.72
  # srate: 46.08
  otw_format: sc12
  # tx_gain: 20                                                  # Transmit gain of the RF might need to adjusted to the given situation.
  # tx_gain: 70
  tx_gain: 89
  # rx_gain: 15                                                   # Receive gain of the RF might need to adjusted to the given situation.
  rx_gain: 60

cell_cfg:
  dl_arfcn: 627340                                                # ARFCN of the downlink carrier (center frequency).
  band: 78                                                        # The NR band.
  channel_bandwidth_MHz: 20                                      # Bandwith in MHz. Number of PRBs will be automatically derived.
  # channel_bandwidth_MHz: 40
  common_scs: 30                                                  # Subcarrier spacing in kHz used for data.
  plmn: "90170"                                                   # PLMN broadcasted by the gNB.
  tac: 7                                                          # Tracking area code (needs to match the core configuration).
  pci: 1                                                          # Physical cell ID.

# pdsch:
     # mcs_table: qam256            

log:
  filename: /tmp/gnb.log                                          # Path of the log file.
  all_level: debug                                             # Logging level applied to all layers.

pcap:
  mac_enable: true                                               # Set to true to enable MAC-layer PCAPs.
  mac_filename: /tmp/gnb_mac.pcap                                 # Path where the MAC PCAP is stored.
  ngap_enable: true                                              # Set to true to enable NGAP PCAPs.
  ngap_filename: /tmp/gnb_ngap.pcap                               # Path where the NGAP PCAP is stored.
  
metrics:
    enable_json_metrics: true       # Enable reporting metrics in JSON format
    addr: 172.19.1.4                # Metrics-server IP
    port: 55555                     # Metrics-server Port

[HaoxinSEU]

Hi,

I think one thing you can do is to change the otw_format to 8 bits, and enable the oversampling feature. This would require you to change the code in Soapy, since it is not enabled by default.

This would make the achievable sampling rate higher.

You can check this page for reference: https://www.nuand.com/2023-02-release-122-88mhz-bandwidth/

Hope this helps.
Haoxin

[pgawlowicz]

@pchat-imm any update on this issue?