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A software defined GPS and galileo receiver springer
[...]... The receiver employs a wideband analog-to-digital (A/ D) converter that captures all channels of the software radio node The receiver then extracts, downconverts, and demodulates the channel waveform using software on a general-purpose processor The idea is to position a wideband A/ D converter as close to an antenna as is convenient, transfer those samples into a programmable element, and apply digital... Oscillator Voltage Standing Wave Ratio WAAS WGS 84 Wide Area Augmentation System World Geodetic System 1984 1 Signals and Systems The concepts of a signal and a system are crucial to the topic of this book We will consider time as well as frequency domain models of the signals We focus on signals and system components that are important to study software- defined GPS and Galileo receiver design For a detailed... bandpass signal as a signal with frequency content concentrated in a band of frequencies above zero frequency Bandpass signals arise in the GPS and Galileo systems where the information-bearing signals are transmitted over bandpass channels from the satellite to the receiver Let us now consider an analog signal s(t) with frequency content limited to a narrow band of total extent 2W and centered about some... orbital, clock and ionospheric corrections, as well as the integrity provided by satellite-based augmentation systems (SBAS) such as the European Geostationary Navigation Overlay System (EGNOS) and Wide Area Augmentation System (WAAS), L1 accuracies rival that of dual frequency GNSS receivers Only future GNSS wideband signals or additional power will offer performance improvements over the L1 band Lastly,... Loop PRN Pseudo Random Noise PSD Power Spectral Density RF Radio Frequency RHCP Right Hand Circular Polarization RINEX Receiver Independent Exchange Format RNSS Radio Navigation Satellite Service SAW Surface Acoustic Wave SBAS Satellite-Based Augmentation System SDR Software- Defined Radio SISA Signal In Space Accuracy SNR Signal-to-Noise Ratio SOW Second of Week Abbreviations xxi SPS Standard Positioning... identifying the signals present in the collected data sets The implementation of both serial and parallel search acquisition methods are described Chapter 7 describes code and carrier tracking and data demodulation Various delay lock loops (DLL) discriminators are described A phase lock loop (PLL) and a frequency lock loop (FLL) are often used to track a carrier wave signal These elements are critical to refining... These parameters are identified in Figure 1.11 for a bandpass filter 14 1 Signals and Systems |S( f )| |S( f c )| − fc fc 2W f 2W | S( f )| 2|S( f c )| −W 0 W f FIGURE 1.12 Magnitude spectrum of bandpass signal s(t) and complex envelope s(t) 1.5 Representation of Bandpass Signals Signals can also be classified into lowpass, bandpass, and highpass categories depending on their spectra We define a bandpass... enormous amount of information contained in the antenna signal into parts related to the individually tracked satellites Details on purchasing the front-end module designed for this text can be found at: http://ccar.colorado edu/gnss A complete GPS software receiver was implemented in MATLAB The receiver is able to perform acquisition, code and carrier tracking, navigation bit extraction, navigation data... detail Finally, the message structure and contents (navigation data) are dealt with Chapter 4 gives an introduction to the GNSS front-end module consisting of an antenna, filter, amplifier, mixer, and analog-to-digital converter The resulting raw sampled data characteristics are described, and finally miniature GNSS frontend designs, in the form of application specific integrated circuits (ASICs), are... signals A random signal, on the other hand, is a signal about which there is some degree of uncertainty An example of a random signal is a received GPS signal: the received signal contains beside the information bearing signal also noise from disturbances in the atmosphere and noise from the internal circuitry of the GPS receiver; see Chapter 4 for more details Now some basic topics on deterministic and . spectrum shared between GPS and Galileo 39 3.5 ACF for BOC( pn, n) signal 40 3.6 ACFanddiscriminatorsforC/AandBOC(1,1) 40 3.7 ACFforbandlimitedBOC(1,1)signal 41 3.8 Galileo navigation message structure. minimized. Actually we have used most of the present text for various courses during 2004 and 2005, and we are happy to make this material readily available; it can be downloaded from: gps. aau.dk/softgps. What.