Chirp Spread Spectrum Transceiver Design and Implementation for Real Time Locating System

Kim, Sangdeok; Chong, Jong‐Wha

doi:10.1155/2015/572861

Cited by 11 publications

(3 citation statements)

References 22 publications

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“…This has been some key benefits like OCDM transmissions can satisfy any spectrum mask requirements just by changing their sampling rates, making any prospective switch from OFDM to OCDM with more simpler, as the OCDM signals are compatible with OFDM, the system does not need to redesign in order to use them with separate resource grid set forth in the existing standard. Finally, the windowing technique can directly be used on OCDM system to improve spectral encirclement and reduce OOB power emission [20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

DFT-Spread WR-OCDM Communication System for the Reductions of OOB and PAPR

Rahman,

Ryu

2023

Preprint

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Orthogonal chirp division multiplexing (OCDM) system has been considered as one candidate for the nextgeneration 6G cellular system that will support many new services and applications but will suffer from the sub-THz frequency band. It is anticipated that this will significantly harm the waveform orthogonality of conventional systems and lead to obnoxious intercarrier interference (ICI) and a very high propagation loss on information signals by introducing peak-to-average power ratio (PAPR). As a result, PAPR reduction is the most important aspect of 6G wireless communication system than 4G long-term evolution (LTE), 5G new radio (NR) schemes because it will use the Sub-THz frequency band which has a very high tendency toward propagation loss component. Therefore, spread spectrum technology termed as orthogonal chirp division multiplexing (OCDM) takes into account for the orthogonality of cyclically shifted quadratic chirp signals in order to increase spectral efficiency and reducing PAPR. The OCDM system, however, emits considerable out-of-band (OOB) power. To solve this problem, we suggest a new discrete Fourier transform (DFT)Spread Windowing and Restructuring (WR)-OCDM (DFT-Spread WR-OCDM) method for a suitably acceptable PAPR and OOB power emission reduction. In the system, the OOB power emissions are successfully reduced at the transmitter using time-domain windowing, and relatively shorter in window length is sufficient to satisfy the standard spectral mask. Comparing the proposed scheme to previous OFDM and OCDM systems, simulation findings show that this technique greatly reduces PAPR by about 2 dB and OOB power emission approximately by 64 dB and 70 dB. Additionally, we examine the bit error ratio (BER) performance using AWGN channel. This DFT-Spread WROCDM scheme performs almost similar results as compared to the conventional OFDM, OCDM, and WR-OCDM systems.

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Section: Introductionmentioning

confidence: 99%

DFT-Spread WR-OCDM Communication System for the Reductions of OOB and PAPR

Rahman,

Ryu

2023

Preprint

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“…The area of indoor localization is well researched with numerous techniques based on WiFi [1], UWB [2], RFID [3], chirp spread spectrum modulation [4] and visible light communication [5]. Most prior work requires instrumenting an environment with reference nodes, which are used by mobile nodes to compute their location through proximity, triangulation, trilateration or RSSI signatures.…”

Section: Introductionmentioning

confidence: 99%

Passive Localization Through Light Flicker Fingerprinting

Munir

Dyo

2019

IEEE Sensors J.

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In this paper, we show that the flicker waveforms of various CFL and LED lamp models exhibit distinctive waveform patterns due to harmonic distortions of rectifiers and voltage regulators, the key components of modern lamp drivers. We then propose a passive localization technique based on fingerprinting these distortions that occur naturally in indoor environments and thus requires no infrastructure or additional equipment. The novel technique uses principal component analysis (PCA) to extract the most important signal features from the flicker frequency spectra followed by kNN clustering and neural network classifiers to identify a light source based on its flicker signature. The evaluation on 39 flicker patterns collected from 8 residential locations demonstrates that the technique can identify a location within a house with up to 90% accuracy and identify an individual house from a set of houses with an average accuracy of 86.3%.

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“…While this does not directly impact the LUT size, it reduces the overall memory requirement. This method is inspired by the CSS transceiver design presented in [9] and it has been adapted for LoRa.…”

Section: Introductionmentioning

confidence: 99%

Reducing the Cost of Implementing Filters in LoRa Devices

Stewart

Nguyen

Barton

et al. 2019

Sensors

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This paper presents two methods to optimize LoRa (Low-Power Long-Range) devices so that implementing multiplier-less pulse shaping filters is more economical. Basic chirp waveforms can be generated more efficiently using the method of chirp segmentation so that only a quarter of the samples needs to be stored in the ROM. Quantization can also be applied to the basic chirp samples in order to reduce the number of unique input values to the filter, which in turn reduces the size of the lookup table for multiplier-less filter implementation. Various tests were performed on a simulated LoRa system in order to evaluate the impact of the quantization error on the system performance. By examining the occupied bandwidth, fast Fourier transform used for symbol demodulation, and bit-error rates, it is shown that even performing a high level of quantization does not cause significant performance degradation. Therefore, the memory requirements of LoRa devices can be significantly reduced by using the methods of chirp segmentation and quantization so as to improve the feasibility of implementing multiplier-less filters in LoRa devices.

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Chirp Spread Spectrum Transceiver Design and Implementation for Real Time Locating System

Cited by 11 publications

References 22 publications

DFT-Spread WR-OCDM Communication System for the Reductions of OOB and PAPR

DFT-Spread WR-OCDM Communication System for the Reductions of OOB and PAPR

Passive Localization Through Light Flicker Fingerprinting

Reducing the Cost of Implementing Filters in LoRa Devices

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