From 3c90aa8624ea35982ee34ff66c966bda35cae642 Mon Sep 17 00:00:00 2001 From: OSQZSS Date: Sat, 27 Jun 2015 10:17:50 +0900 Subject: [PATCH] Updated --- README.md | 38 +++++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/README.md b/README.md index 04cb7d8..267099d 100644 --- a/README.md +++ b/README.md @@ -2,13 +2,13 @@ GPS-SDR-SIM generates GPS baseband signal data streams, which can be converted to RF using software-defined radio (SDR) platforms, such as -[bladeRF](http://nuand.com/), HackRF, and USRP. +[bladeRF](http://nuand.com/), [HackRF](https://github.com/mossmann/hackrf/wiki), and USRP. ### Windows build instructions 1. Start Visual Studio. 2. Create an empty project for a console application. -3. On the Solution Explorer at right, add "gpssim.c" to the Souce Files folder. +3. On the Solution Explorer at right, add "gpssim.c" and "getopt.c" to the Souce Files folder. 4. Select "Release" in Solution Configurations drop-down list. 5. Open the Property Pages dialog box and expand the Configuration Properties. 6. Expand the C/C++ node and select the Language property page. @@ -35,23 +35,37 @@ indiviual site navigation files into one. The archive for the daily file is: These files are then used to generate the simulated pseudorange and Doppler for the GPS satellites in view. This simulated range data is then used to generate the digitized I/Q samples for the GPS signal. -For example; + +The bladeRF command line interface requires I/Q pairs stored as signed +16-bit integers, while the hackrf_transfere supports signed bytes. ``` -> gps-sdr-sim brdc3540.14n circle.csv gpssim.bin +Usage: gps-sdr-sim [options] +Options: + -e RINEX navigation file for GPS ephemerides (required) + -u User motion file (required) + -o I/Q sampling data file (default: gpssim.bin) + -f Sampling frequency [Hz] (default: 2.6MHz) + -b I/Q data format [8/16] (default: 8) ``` -### Transmitting the samples with bladeRF +For example: -The TX port of the bladeRF is connected to the GPS receiver under -test through a DC block and a fixed 50dB attenuator. +``` +> gps-sdr-sim -e brdc3540.14n -u circle.csv -b 16 +``` + +### Transmitting the samples + +The TX port of a particular SDR platform is connected to the GPS receiver +under test through a DC block and a fixed 50-60dB attenuator. The simulated GPS signal file, named "gpssim.bin", can be loaded -into bladeRF for playback as shown below: +into the bladeRF for playback as shown below: ``` set frequency 1575.42M -set samplerate 4M +set samplerate 2.6M set bandwidth 2.5M set txvga1 -25 cal lms @@ -60,6 +74,12 @@ tx config file=gpssim.bin format=bin tx start ``` +For the HackRF: + +``` +> hackrf_transfer -t gpssim.bin -f 1575420000 -s 2600000 -a 1 -x 0 +``` + ### License Copyright © 2015 Takuji Ebinuma