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Author: search.filters.author.Wardkein, ParamoteSubject: search.filters.subject.chirp spread spectrum

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    A Novel Multi-Slope Chirp Modulation and Demodulation with Instantaneous Chirp Rate Estimation
    (2026-05-01)
    Magkeethum, Apiwat
    ;
    Saechia, Sukkharak
    ;
    Wardkein, Paramote
    The growth of Internet of Things (IoT) applications is driving demand for Low-Power Wide-Area Networks (LPWANs) to support higher data rates with the same energy efficiency. While Long Range (LoRa) provides excellent noise immunity and receiver sensitivity, its data rate might be insufficient for some applications, including those real-time applications in which LoRa is required to have infrequent transmissions to maintain low power consumption. In this paper, a novel modulation is introduced to address these limitations by utilizing narrowband chirp to represent a data symbol with chirp slopes, called a multi-slope chirp signal. At the receiver, a new blind non-coherent detection technique is also presented to recover the proposed signal. The simulation results confirm that the proposed scheme can successfully transmit information at 2 to 4 bits per symbol, and when compared to LoRa SF 6, it reduces the Time-on-Air (ToA) by half and also achieves an improvement in spectral efficiency in the frequency domain.
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    Novel Double Slope Frequency Shift Chirp Symbol
    (2024-01-01)
    Kirasamuthranon, Lerson
    ;
    Wardkein, Paramote
    ;
    Koseeyaporn, Jeerasuda
    One of the most significant concerns in serial digital communication is the synchronization of data bits between the transmitter and receiver. Therefore, the preferred coding symbols should contain an inherited clock signal. The cyclic-shift chirp, which is primarily used in long-range systems, employs a single slope in a symbol, which contains few information for synchronization. Hence, two new forms of cyclic-shift chirp symbols are proposed herein. The associated coding schemes are based on the use of a dual slope within one symbol. Synchronization is inherited in the coding symbol using a dual slope. Additionally, both proposed coding schemes utilize the same decoding technique. The decoded chirp symbol is in the form of a pulse width modulation signal, which can be used for synchronization and retrieving data bits from their duty cycle. The simulation results show that the coding and decoding processes of the proposed coding schemes align with those of a theoretical framework. The error performance analysis for the proposed detection scheme is given and the results of error probability analysis are consistent with the simulation results. Moreover, under a Rayleigh fading channel, the proposed coding schemes provide superior performance compared with other comparable coding schemes.
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    Coding and Coherent Decoding Techniques for Continuous Single Slope Cyclic Shift Chirp Signal
    (2023-06-01)
    Kirasamuthranon, Lerson
    ;
    Wardkein, Paramote
    ;
    Koseeyaporn, Jeerasuda
    Chirp signals are currently widely used in broad-band and spread spectrum communications due to their ad-vantageous features, such as immunity to fading noise, low power consumption, consistent long-range transmission, and constant bandwidth. As a result, they are applied at the physical layer of the Internet-of-Things (IoT). This study proposes two techniques for encoding and decoding 4-cyclic shift chirp symbols, based on addition and subtraction oper-ations. The proposed techniques have simple structures that can be easily implemented using analog circuits. The pro-posed encoding techniques reveal obviously the relationship between cyclic-shift chirp symbols and pulse modulating signals (PWM, PPM, and PAM), which is rarely discussed in prior research. Moreover, the circuit for encoding and decoding of the proposed technique is implemented by dis-crete commercial devices at low frequency (25–35 kHz) which is suitable for sonar and communication under water; however this proposed technique is not limited to only low frequency but is also capable of being used in high frequency band as well which experimental and simulation result show agreeing well with each other.