Co existence of Global Positioning System services (GPS) with cellular and other services and features in a mobile handset presents challenges to GPS performance. Particularly challenging is the over the air (OTA) interface to the GPS receiver that results from carriers like the Global System for Mobile (GSM) and Wideband Code Division Multiple Access (WCDMA) where the transmit (TX) section of the latter could interfere with the performance of the GPS due to TX band noise injected into the GPS band. For the case of WCDMA, the problem is the out of band interference due to the TX wide band noise which has a spectrum that matches the GPS spectrum; both use spread spectrum technology to encode the data. Unlike WCDMA, GSM is built on the Time Division MultipleAccess (TDMA) technology where the user occupies one of eight time slots in the multiple access domain. Also, unlike WCDMA where the transmission is continuous, GSM transmission is pulsed and hence the GPS has to cope with and suffer the degradation due to pulsed interference when it is on in the form of TX noise. In this paper, we introduce an analysis of the WCDMA and GSM TX noise (based on actual hardware scenarios) and their effects on GPS sensitivity. It is worthwhile noting that the analysis and scenarios given in this paper represent real life hardware line up issues based on products that go in the hands of the consumers. In addition fundamental line up characterization will be carried out e. g. lineup noise figure, insertion and mismatch losses.It will also be shown that the severity of the degradation is frequency band dependent i.e. the closer the frequency band to the GPS band, the more severely the degradation is. The degradation will be in the form of an increase in the total system noise figure (~5.5dB). The total system noise figure will contribute a dB for dB in sensitivity degradation i.e. ~5.5 loss in received signal strength. Loss in the received signal power leads to loss of reliable and accurate service and most importantly loss of service in areas where it is needed most.The paper is organized as follows: section I is the introduction where the types of interference and their nature is presented. Section II gives theory and analysis of the sources of noise figure contributions that apply to both WCDMA and GSM.In section III we introduce a generic measurement setup that can be used to characterize the GPS received signal power that incorporates both types of noise. The results of the measurement will be graphed. A comparison in received signal strength will be made between the ideal case, where there is no noise figure at all, the case where the noise figure will be due to the hardware lineup (WCDMA TX is off) and the case where the noise figure is due to the hardware line up and WCDMA TX noise (WCDMA TX is on) in the GPS band. The last curve will be for inserting external LNA in the line up.In section IV we propose mitigation techniques that can either partially or completely eliminate both sources of interference. Some of the techniques w...

In this paper, we show how statistical decision theory can be used to solve real life product problems. Global Positioning System (GPS) performance in a mobile handset degrades whenever it is simultaneously used with a 3G data or voice service. This degradation is due to the 3G transmitter interference. Mitigation methods to interference in GPS have been proposed. However, most of these methods depend on hardware and signal processing or just hardware solutions. In some cases, it maybe difficult to implement these hardware methods, especially in mobile handsets due to its small size, printed circuit board (PCB) layout issues and the added cost. In this paper, a novel signal processing statistical algorithm approach is proposed to mitigate the 3G interference to GPS. This statistical approach utilizes the knowledge of the statistical characteristics and distributions of both the GPS signal and noise. Then the method utilizes the probabilities to make a statistical decision to remove the effect of noise. This method does not require room on the PCB of the mobile handset and therefore no layout challenges arise. In addition, cost is minimized and the product turn in cycle is shortened. This paper offers theoretical as well as practical insight to the GPS operation during 3G call inside the mobile phone.

An effort to reach at an expression for the allowable TX noise levels into the GPS band for the WCDMA transmitters coexisting with the GPS service in a smartphone is made. These allowable noise levels will be for a certain tolerable amount of signal to noise ratio degradation. In developing these equations, the total system noise contributors are taken into consideration with practicality. These contributors include thermal, jammer, noise figure and local oscillator spurious emissions. The effect of changing data rates in WCDMA transmission on GPS acquisition will be the study in this paper.

in this paper, a parallel frequency space search acquisition algorithm for a GPS (Global Positioning System) receiver is implemented using software defined radio (SDR) technology. The proposed algorithm is implemented and tested using National Instruments MyRio real time software processor platform. The results of the proposed algorithm are confirmed and compared with the parallel code phase search algorithm using different implementation platforms. The parallel frequency search implementation is highly recommended for real time and high speed seamless applications in product development and industry platforms where low cost, low complexity with reliable performance is of dire need. The novelty of this approach stands as no published literature has demonstrated parallel frequency search algorithm as an SDR platform using National Instruments Labview on MyRio real time processor environment. In this research, parallel frequency space acquisition of GPS signals on an NI myRio device is implemented. The parallel frequency acquisition is selected because of its moderate code acquisition complexity and its better resource management compared to parallel code phase algorithm, which is considered a large resource consumer.

A mathematical modelling, and a derivation of the main parameters of the Magneto -Dielectric materials (substrate) and their effect on microstrip patch antenna design is shown. The Magneto -Dielectric materials (substrate) is shown to miniaturize the antenna size and enhance the bandwidth when used in the design of the microstrip patch antenna. The progression of the foundational modelling starts with laying out the concepts of the ferrimagnetic materials in terms of their permeability and permittivity, the components of antenna miniaturization. First, a ground free elliptical microstrip patch antenna (GFDSEPA) is simulated for miniaturization purposes at the 900MHz cellular band. A size reduction of almost 50% as well as bandwidth enhancement (100%) is achieved by utilizing the GFDSEPA. More size reduction is achieved by employing the magnetodielectric structure; in this case the commercially available Rogers MAGTREX 555 substrate is used. Other performance parameters show comparable results between the antenna simulated based on dielectric only substrate and the one based on magneto-dielectric substrate. A comparison of the main parameters between the results of this work and other results in the literature is shown. The application of the microstrip patch antenna design in energy harvesting, by using a rectifier circuit, is shown. Layout scenarios of the energy harvester are proposed. The proposed layout of the energy harvester ensures practicality of the proposed design and assures correlation between simulation results and experimental results. Index Terms-Electromagnetic energy harvesting, microstrip patch antenna, antenna return loss, plane radiation, antenna gain, antenna impedance.