A Theoretical Survey of the Spreading Modulation of the New GPS Signals (L1C, L2C, and L5)

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pseudolite indoor geolocation system. A C-CDMA pseudolite indoor geolocation system consists of four C-CDMA pseudolites and one or more C-CDMA receivers. The purpose of this paper is to provide the requirements for building C-CDMA pseudolites and a C-CDMA receiver.First, the pseudolite is assumed stationary and the geolocation information consists of the transmitter position and time. For each pseudolite this information is 4-ary encoded data at a symbol rate of 1 KHz. For example, an encoded geolocation signal is spread using a Kasami sequence which runs at a rate of 1.023 MHz and then the signal is modulated on [10 15 20 25] MHz carrier signals each one of which corresponds to each of pseudolite respectively via a Quadrature Phase-Shift Keying (QPSK) modulator to resist interference encountered in an indoor geolocation environment. A total of four pseudolites are simulated to enable a geolocation solution for the receiver. The spreading modulation is that of a Variable Binary Offset Carrier (VBOC) VBOC(2,1,) which we have examined previously to provide a better spectrum utilization than the BOC(2,1) and definitely much better than the PSK.Second, the receiver consists of four channels each one of which is assigned to a single transmitter. On each receiving channel the received signal is down-converted, de-spread using the Kasami sequence, demodulated and decoded.Third, the channel consists of the following models: a realistic indoor path loss, realistic Rayleigh and Rician fading channels, receiver thermal noise, phase frequency offset, and additive white Gaussian noise. The system will include the ability to perform distance measurement; to take into consideration the effect of transmitter clock stability on position accuracy; such effects will include the transmitter and receiver oscillator drift (short term stability) on positioning accuracy; the signal processing on the receiver design will include techniques for detecting an extremely week Line-of-Sight (LOS) signal and for maintaining lock on the LOS signal in the presence of severe multipath. Journal of Geolocation, Geo-information, and Geo-intelligence 47It is expected that this paper will provide the required overview for first designing the system components utilizing as much as possible commercial of the shelf components and provide the framework for Giftet Software solution products one of which is a global software solutions for a C-CDMA pseudolite indoor geolocation system to operate under heavy multipath and low signal to noise ratio environment. Simulation results in MATLAB and Simulink are provided.

Section: Signal Designmentioning

confidence: 94%

Section: Pseudolite (Or Transmitter)mentioning

confidence: 99%

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Requirements of a C-CDMA Pseudolite Indoor Geolocation System

Progri¹,

Michalson

Wang

et al. 2017

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“…Initially, the signal design approach for pseudolite applications [8], [31]- [38] was primarily driven by the mentality of achieving user performance metrics; however, it was not until very recently that various signal waveforms articulate new objectives of various signal design teams in the 21 st century in Indoor Geolocation SystemsTheory and Applications [6], and Geolocation of RF SignalsPrinciples and Simulations [38].…”

Section: Introductionmentioning

confidence: 99%

VBOC1(a) GMGM Waveforms and ACF PSO: Part 2--Theory and Simulations

Progri¹

2018

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except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of the publication of trade names, trademarks, service marks, or similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.Abstract-This paper examines the 1() generalized multidimensional geolocation modulation (GMGM) waveforms, their time domain representation, the autocorrelation function (ACF), power spectral density (PSD) function, and the ACF pure signal optimization (PSO) for the generalized subcarrier parameter frequency, ( = {1, ⋯ , 8}); i.e., this paper is an extension of the work that was performed for 1() GMGM waveforms and ACF PSO for the generalized subcarrier parameter frequency, ( = {1, 2, 3, 4}).There are a number of reasons why the extension of this work is important.First, it is not really obvious or intuitive how this extension is done. Second, so far no one has produced results to clearly demonstrate that this extension does not change the performance results 1() GMGM waveforms and ACF PSO aside from my preliminary investigation. Third, this extension now serves as building block. One, should be able to easily extend this work for values of = {9, 10, , ∞}; i.e., this work is really the closes thing to a complete poof that we can give.Afterwards, by employing any of the optimization algorithms such as sum, product, and MMSE on GPS L1C (6,1) signals such as VBOC1(6,1,0.5) we are able to produce ACFs that are one hundred percent more efficient than the corresponding ACFs of the GPS L1C (6,1) signals. Hence, we have the provision for a new L1C signal:(1,1,29/33,0.5) on the data and (6,1,4/33,0.5) on the pilot.I am also making provision for the new signal in the military code of the current M-code from the current (2,1) to the (8,1,4/33,0.5) in which the data is (2,1,29/33,0.5).Journal of Geolocation, Geo-information, and Geo-intelligence methods. 1 ( ) = | | 1 ( ) ⏟ ={1,2,⋯,8,⋯∞} , 0 ≤ | | ≤ 12 1 ( ) ⏟ ={5,⋯8,⋯∞} , 12 ≤ | | ≤ 24 0, | | ≥The first part of 1 ( ) is exactly the same as (22) in [1] which was proved to be correct for values of = {1, ⋯ ,4}.The second part of is the 1 ( ) extension of the = {5, ⋯ ,8}.The proof of theorem 2 is straightforward. However, one always wanders how the ACF of 1( ) was produced.The ACF is the result of integration. In previous publications[1], [2], [7], [8] we have shown how to produce the ACF of 1( ) for special cases. Because of the periodicity of the ACF is it straightforward to extend the ACF by just plugging in the = {5, ⋯ ,8} values. The details of this extension will be provided in a separate journal paper when we discuss the most general case for = {1, 2, 3, ⋯ ∞}. The closed form expression of 1 ( ) = 1 ( = , , ) ( ) is given by:

“…These kinds of diversities would be for example code; frequency; antenna; and space. The first three kinds of diversities are currently well known and well understood in the community and implemented in the signal structure i and depicted in the GNSS signal design ii [15]- [25].…”

Section: Introductionmentioning

confidence: 99%

GPS L5 Signal Acquisition and Tracking under Unintentional Interference or Jamming

Progri¹

2017

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Moreover, if the acquisition of the P(Y) code is lost, due to reasons that are explained in the paper, then the reacquisition of the P(Y) code will again depend on the acquisition and tracking of the C/A code. Therefore, for most commercially available receivers, the reliable acquisition and tracking of the C/A code is critical for the entire operation of a GPS receiver.However, it is well-known the vulnerability of the GPS C/A code signal acquisition to unintentional interference or jamming. The main theme of this paper is the reexamination of the GPS C/A code signal acquisition and tracking under the situation of the unintentional interference or jamming. A variety of jamming signals are considered such as: periodic, deterministic; aperiodic, deterministic; and noisy type signals or non-deterministic.However, the majority of vendors are still producing correlator type receivers. As shown by the simulation results of this paper and other previous publications a sliding correlator type of receiver used to acquire and track the C/A code or L 5 code can be easily jammed by a similar C/A code replica or L 5 code replica at power levels 10 dB or higher above noise power. GAMES, GILS, and GIANT are not the most economically viable solutions in the market to handle GPS protection of the civilian receivers. A maximum likelihood GPS receiver, which considers all the signals in the environment, can be used to acquire and track successfully the C/A and the L 5 GPS signals when the jamming signal power are in the range or 10 dB or higher above the noise power. In summary, the direction of designing acquisition and tracking receivers for future C/A L 1 code or L 5 GPS signals should go towards joint signal 20 Journal of Geolocation, Geo-information, and Geo-intelligence acquisition and tracking. There are three main challenges with these types of receivers: algorithm complexity, computational power, and test with real data. All these remain to be studied and analyzes further in the future. I think it is going to be a breakthrough in the state of the art of GPS receivers when these algorithms are ultimately implemented and a lot more work is required to arrive at that point which some of it is going to be published in future publications.