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Many modern position-based applications rely heavily on the Global Navigation Satellite System (GNSS). Most applications require precise position data obtained through sophisticated hardware with a high computational capacity in the receiver. Some cost-effective applications may not require precise position data and require less complex signal processing. The use of efficient hardware and signal processing techniques to reduce the overall cost of a GNSS receiver is an active research topic. This paper considers Global Positioning System (GPS) constellation and proposes two factors to reduce the receiver complexity: sampling frequency and the number of tracking channels. A Keysight GNSS signal generator to record GPS signals, a Software Defined Radio board and a software-based GPS receiver are used in the experimentation. The sampling frequencies are 40, 20, 10 and 5 MHz considered, and tracking channels are reduced from 12 to 6 and then 4. The increase of error in the receiver position with 6 and 4 satellites is considerably small, but the number of tracking channels and signal processing requirements are reduced considerably. The GPS signals are affected by many errors; one of the significant sources of error is multipath propagation. Three distinct GPS multipath scenarios are generated for four satellite signal combinations with the GNSS simulator for the receiver performance analysis. Three multipath mitigation techniques, namely Early Minus Late (EML), Narrow correlator (NC) and strobe correlator (SC) methods, are considered because of their simple structure and fewer signal processing requirements. The error reductions of three multipath scenarios are compared, and the SC method performs better in all three multipath scenarios. [ABSTRACT FROM AUTHOR]

Orthogonal Frequency Division Multiple Access (OFDMA) is now becoming an impeding rather than a sustainable technology for realizing the vision of 5G due to its tight synchronization, orthogonality constraints, and significant bandwidth wastage due to Cyclic Prefix. To overcome this limitation, several non-orthogonal schemes have been introduced as candidates for upcoming 5G technology for providing flexible, reliable, fair and high-speed multiple access to users and/or devices. A combination of Non-Orthogonal Multiple Access (NOMA) and Universal Filtered Multi-Carrier (UFMC) is found suitable for downlink scenario. We propose NOMA-UFMC-based Radio Access (NOMURA) scheme, which is asynchronous, bandwidth efficient and provides higher throughput. The proposed scheme is non-orthogonal in two aspects: (1) NOMA provides resources to different users via power scaling while utilizing same frequency resources, and (2) UFMC allows for a slight delay in synchronization, hence not strictly compliant with orthogonality requirements. The components of the proposed scheme, namely NOMA and UFMC, are backward compatible with OFDMA ensuring trivial application of Multiple Input Multiple Output and other performance enhancement measures already developed for OFDMA. We provide simulation results benchmarked against OFDMA and Filter Bank Multi-Carrier-Filtered Multi-Tone and show that NOMURA is more apt for flexible bandwidth allocations, active cancellation, higher throughput and provides equivalent Bit Error Rate performance under AWGN and Rayleigh fading conditions. [ABSTRACT FROM AUTHOR]

In this study, we propose compressive sampling matching pursuit (CoSaMP) algorithm for sub-Nyquist based electronic warfare (EW) receiver system. In compressed sensing (CS) theory time-frequency plane localisation and discretisation into a N×N grid in union of subspaces is established. The train of radar signals are sparse in time and frequency can be under sampled with almost no information loss. The CS theory may be applied to EW digital receivers to reduce sampling rate of analog to digital converter; to improve radar parameter resolution and increase input bandwidth. Simulated an efficient approach for radar signal recovery by CoSaMP algorithm by using a set of various sample and different sparsity level with various radar signals. This approach allows a scalable and flexible recovery process. The method has been satisfied with data in a wide frequency range up to 40 GHz. The simulation shows the feasibility of our method. [ABSTRACT FROM AUTHOR]