From 7c383be1542368f2601015d9fc2a417197677677 Mon Sep 17 00:00:00 2001 From: Harsh Sharma <92harshsharma@gmail.com> Date: Wed, 13 Jun 2018 13:24:54 -0500 Subject: Initial Commit --- util_spectral_scan/readme.md | 79 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 util_spectral_scan/readme.md (limited to 'util_spectral_scan/readme.md') diff --git a/util_spectral_scan/readme.md b/util_spectral_scan/readme.md new file mode 100644 index 0000000..6bcd33e --- /dev/null +++ b/util_spectral_scan/readme.md @@ -0,0 +1,79 @@ + ______ _ + / _____) _ | | + ( (____ _____ ____ _| |_ _____ ____| |__ + \____ \| ___ | (_ _) ___ |/ ___) _ \ + _____) ) ____| | | || |_| ____( (___| | | | + (______/|_____)_|_|_| \__)_____)\____)_| |_| + (C)2014 Semtech-Cycleo + +Background Spectral Scan for LoRa gateway +========================================= + + +1. Introduction +---------------- + +This software is used to scan the spectral band where the LoRa gateway operates. +It simply computes a RSSI histogram on several frequencies, that will help to +detect occupied bands and get interferer profiles. +It logs the histogram in a .csv file. + +This utility program is meant to run on the LoRa gateway reference design +SX1301AP2 (with FPGA and additionnal SX127x). + +The background RSSI scan is a diagnostic tool and must be run on top of the +gateway activity. Moreover the two SX1257 radios have to be configured in RX +mode to optimize the matching impedance with SX127x. The 32MHz clock provided +to the SX127x is available once SX1301 has enabled the two SX1257 radios, so +the background RSSI scan must be launched after the packet forwarder. + +Note: if the FPGA running the spectral scan also supports Listen-Before-Talk +feature (LBT), the LBT feature has to be enabled and running before launching +util_spectral_scan. For example, if the lora_pkt_fwd runs in background, it has +to use a global_conf.json file with "lbt_cfg.enable" set to true. + +2. Command line options +------------------------ + +`-h` +will display a short help + +`-f start:step:stop` +Frequency vector to scan in MHz: start:step:stop +Valid range: start > 800, step > 0.005, stop < 1000 + +`-b` +Channel bandwidth to be used to configure the SX1272x radio for scanning in KHz +Valid values: [25,50,100,125,200,250,500] + +`-n` +Total number of RSSI points. +Valid range: [1..65535] + +`-l` +Log file name + +Note: For FPGA image that provides LBT support, the spectral scan gets less +flexible. The following parameters have constraints: + - Frequency step: has to be multiple of 100KHz + - Channel bandwidth: hardcoded to 200KHz + - Number of RSSI points: 16641 + +3. Usage +--------- + +The format of the log file is the following: +Freq_1, RSSI_1, histo_1, ...., RSSI_128, histo_128 +Freq_2, RSSI_1, histo_1, ...., RSSI_128, histo_128 +... + +RSSI_n is the nth value of RSSI in dBm + +Default setup: +- freq 863 : 0.2 : 870 +- 65535 RSSI points in total at 32kHz rate +- 125KHz channel bandwidth + +Example with frequencies from 865 MHz to 870 MHz, by step of 100KHz, BW 200KHz +10000 RSSI points processed at 10kHz rate, saved in "log.csv": +./util_spectral_scan -f 865:0.1:870 -n 10000 -b 200 -l "log" -- cgit v1.2.3