Physical Layer Engineer I

Company Description: Big Bang Boom Solutions (BBBS) is a Chennai-based deep-tech defence startup focused on developing indigenous defence and security technologies. It operates as a defence solutions integrator that builds advanced systems in areas such as artificial intelligence, UAS/drone technology, electronic warfare, material science, propulsion, communication systems, and data security, aiming to create intellectual property for national defence applications. BBBS develops products such as anti-drone defence systems, see-through armour interfaces, smart surveillance platforms, and other custom defence technologies.

The company has participated in and won multiple iDEX challenges sponsored by the Indian Ministry of Defence, receiving government grants and contracts Job Title: Physical Layer Engineer I Department: Wireless Communications/ GNSS / RF & DSP Systems Location: Chennai Employment Type: Full-Time Experience Level: Mid-Level (1-2 years) Educational Qualification: B.E./B.Tech in Electronics Engineering or Telecommunications Engineering or M.Tech in Communication and Singal Processing Engineering Job Summary: We are seeking a technically skilled Physical Layer Engineer with strong expertise in GNSS signal processing, spoofing/jamming, and SDR-based simulation. The role focuses on the design, generation, and validation of GNSS baseband/RF signals for controlled spoofing and testing applications. The ideal candidate should have a solid foundation in digital signal processing (DSP), GNSS system, and RF front-end systems.

Key Responsibilities: GNSS Signal Analysis & Generation: Design and implement GNSS baseband signal generators for GPS, Galileo, BeiDou, etc. Analyze GNSS constellation, navigation message formats, PRN code structures, and ephemeris data. Signal Acquisition, Tracking & Navigation Decoding: Develop acquisition and tracking algorithms (code & carrier) and perform navigation message decoding and evaluate tracking loop (DLL, PLL, FLL).

Implement time/frequency synchronization and estimate and correct Doppler shifts. DSP & Baseband Processing: Design and implement DSP algorithms for modulation, correlation, and synchronization. Work on I/Q data generation, filtering, upconversion/downconversion, and Doppler modeling.

Perform time and frequency domain analysis (FFT, DFT, filtering). Software-Defined Radio (SDR): Develop, simulate, and test SDR-based GNSS signal chains using GNU Radio, GNSS-SDR, or Python. Integrate SDR platforms like USRP, HackRF, BladeRF, or LimeSDR for signal transmission and testing.

RF & Spectrum Analysis: Work with RF chains, antennas, and front-end components. Use lab test equipment such as VNAs, spectrum analyzers, and signal generators for validation. Documentation & Collaboration: Maintain detailed documentation of designs, test procedures, and results.

Collaborate with cross-functional teams including hardware, software, and systems engineers. Required Skills & Qualifications: 1-2 years of experience in GNSS, RF, and DSP systems development. In-depth understanding of GPS, Galileo, GLONASS, or BeiDou signal characteristics (L1/L2/L5/E1/E5 bands) and message formats, and PRN code generation.

Experience in signal acquisition, tracking, enavigation message decoding, time/frequency synchronization and Doppler correction techniques. Hands-on with GNU Radio and at least one SDR platform (USRP, HackRF, LimeSDR, BladeRF). Solid DSP fundamentals: sampling theory, FFT/DFT, digital filters, correlation, modulation schemes (BPSK/QPSK), and synchronization loops.

Familiarity with RF front-end concepts (ADC/DAC, mixers, LNAs, filters) and laboratory instrumentation (spectrum analyzer, VNA, signal generator). Proficiency in programming languages such as C/C++ and Python. Excellent analytical, debugging, and documentation skills.

Preferred Qualifications: Experience with GNSS-SDR, GPS-SDR-SIM, or similar open-source GNSS toolkits. Familiarity with GNSS spoofing, jamming, and anti-spoofing countermeasures.