http://repository.iiitd.edu.in/xmlui/handle/123456789/398 Sat, 11 Apr 2026 03:05:02 GMT 2026-04-11T03:05:02Z http://repository.iiitd.edu.in/xmlui/handle/123456789/526 USRP based through wall radar Goyal, Sangeeta; Ram, Shobha Sundar (Advisor); Bohara, Vivek Ashok (Advisor) Radar systems for detecting the humans present behind the wall are powerful tools for law enforcement, military and elderly care. Walls are complex propagation mediums that introduce attenuation, refraction and multipath to the radar signals. These radar waveforms provide significant attenuation to the signal (from 0 dB to 20 dB one way path loss). Hence, a radar platform that is reconfigurable in terms of carrier frequency, transmitted waveform etc. may be especially useful for test and measurement purposes in a variety of through-wall scenarios. In this work, we have used a software defined radio platform using universal software radio peripheral and Labview to implement a through-wall radar system. We have implemented two waveforms - a continuous wave (CW) signal and an orthogonal frequency division multiplexing (OFDM) signal at a carrier frequency of 3 GHz. A CW radar provides micro-Doppler signatures of humans. An OFDM radar additionally provides range information but due to system constraints, the realized range resolution is poor. Both the radar configurations have been tested in free space and through-wall conditions to detect the presence of one or more humans. Thu, 01 Sep 2016 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/526 2016-09-01T00:00:00Z http://repository.iiitd.edu.in/xmlui/handle/123456789/525 Asynchronous 1R-1W dual-port SRAM by using single-port SRAM Bharath, K; Fell, Alexander (Advisor) With the advancement in technology nodes, the number of components operating in different clock domains on System on Chip (SoC) increases. To support the processing of data between these components, the demand of an asynchronous multi-port memory on SoC is rising. This paper introduces an asynchronous multi-port memory with dedicated write and read ports. The memory architecture is based on the Single-Port SRAM (SP-SRAM) that can be generated in larger capacities with good performance compared to the Dual-Port SRAM (DP-SRAM). The proposed design has been evaluated by comparing existing dual-port 1R-1W and 2RW designs in Ultra Thin Body and Box Fully Depleted Silicon on Insulator (UTBB- FDSOI) technology. A 2048 words of 64 bit memory shows 15%, 35%, 28% and 4.5% improvement in read power, write power, read-write power and performance respectively over conventional 1R-1W DP-SRAM with equal area. The same size memory with area optimization technique shows 50% area advantage over conventional 1R-1W DP-SRAM but with degradation in performance. Thu, 01 Dec 2016 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/525 2016-12-01T00:00:00Z http://repository.iiitd.edu.in/xmlui/handle/123456789/505 Compressed sensing based underwater acoustic channel estimation using two dimensional frequency characterization Ansari, Naushad; Gupta, Anubha (Advisor) Underwater acoustic (UWA) channel estimation in shallow water depths is a challenging problem due to rapidly fluctuating transients in the acoustic channel impulse response. Transmitted signal undergoes nonstationary reflections at the moving sea surface and rough sea bottom before being received via multiple paths at the receiver. These non-stationary reflections along with unpredictable surges of energy due to surface focusing events render the channel delay spread challenging to localize. In this work, we present compressed sensing (CS) based underwater acoustic channel estimation techniques at the intersection of time, frequency and sparsity. Specifically, following are the key contributions of this work. First, a 2D frequency domain representation of the channel is obtained via a carefully chosen transmitted signal design. This modeling transforms the problem of channel estimation to channel recovery in 2D Fourier domain. Interestingly, this framework is similar to K-space based image reconstruction used in Magnetic Resonance Imaging (MRI) where CS is used extensively for signal recovery. It is observed that the channel is sparser in the 2D Fourier domain in comparison to the channel in time domain. Thus, the proposed frequency domain representation allows CS framework to be inherited naturally. Here, it is pertinent to add that this framework has been proposed for the first time in UWA. Second, we introduce non-uniform compressing sampling for shallow water acoustic communications. Specifically, techniques presented in this work perform random CS at different sampling rates across different frequency bands in the 2D frequency domain. We propose non uniform CS with prior information and non-uniform modified-CS with the prior information method for channel estimation wherein application domain knowledge is utilized with reference to frequency domain characteristics of the shallow water channel. Thus, this work illustrates the use of CS methods but by appropriately rooting them in this application domain. We present numerical validation of proposed techniques based on channel estimates from field experiments as well as a public domain channel simulator that has recently been tested against data from different field trials. Fri, 01 Jan 2016 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/505 2016-01-01T00:00:00Z http://repository.iiitd.edu.in/xmlui/handle/123456789/494 Cognitive spectrum sharing protocols for energy harvesting wireless sensor nodes Peer, Mansi; Bohara, Vivek Ashok (Advisor) Energy consumption is one of the primary concerns in the deployment of futuristic wireless sensor networks. On one hand due to advent of technologies such as Internet of Things (IoT), there has been tremendous growth in development of wireless sensor nodes, however, on the other hand these nodes are energy constrained, hence have limited lifetime. Energy harvesting from radio frequency (RF) signals has been proposed as a viable solution to alleviate this problem. Most of the recent work in the field of RF energy harvesting has involved cooperative relaying and cognitive radio networks. But now energy harvesting techniques have been employed to cooperative spectrum sharing framework as well. In this work, a hybrid time switching and power splitting spectrum sharing protocol for energy harvesting wireless sensor nodes is proposed. In the developed framework, an energy constrained sensor node adopts a time switching and power splitting based relaying protocol to harvest energy and spectrum from primary user. In exchange, it helps the primary user to achieve its target rate of performance. We have analyzed the impact of time duration allocated for energy harvesting and information reception/transmission at sensor node on the Quality of Service (QoS) of primary user. Further, we have proposed another energy harvesting and spectrum sharing protocol for multiple sensor nodes that not only optimizes the performance of primary system but also simultaneously maintains a satisfactory QoS of the secondary system. We have analyzed how increase in the number of energy harvesting sensor nodes improve the primary and secondary performance. Tue, 06 Dec 2016 09:53:04 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/494 2016-12-06T09:53:04Z