This topic will provide an overview of wireless communication technologies, including the basic principles, advantages, and applications in various fields.
Introduction to Wireless Communication
Key concepts, components, and fundamentals for a solid start in the field.
| Term | Meaning |
|---|---|
| Transmitter | Generates and radiates the RF (radio‑frequency) signal. |
| Receiver | Captures the RF signal and converts it back to the original information. |
| Antenna | Converts electrical signals to/from electromagnetic waves. |
| Frequency (f) | Number of cycles per second (Hz). Determines wavelength (λ = c/f). |
| Bandwidth | Range of frequencies a system can use; directly linked to data rate. |
| Modulation | Process of embedding information onto a carrier wave (e.g., AM, FM, QAM). |
| Multiplexing | Sharing a single channel among multiple signals (e.g., FDMA, TDMA, CDMA, OFDM). |
| Path Loss | Reduction of signal strength with distance and obstacles. |
| Noise | Unwanted random signals that degrade quality (thermal, atmospheric, interference). |
| SNR (Signal‑to‑Noise Ratio) | Ratio of signal power to noise power; higher SNR → better performance. |
| Band | Frequency Range | Typical Applications |
|---|---|---|
| VLF/LF | 3 kHz – 300 kHz | Submarine communication |
| MF | 300 kHz – 3 MHz | AM broadcast |
| HF | 3 MHz – 30 MHz | Short‑wave radio, HF data links |
| VHF | 30 MHz – 300 MHz | FM radio, TV channels 2–13, air‑traffic control |
| UHF | 300 MHz – 3 GHz | TV channels 14–69, cellular 2G/3G, Wi‑Fi (2.4 GHz) |
| SHF | 3 GHz – 30 GHz | Radar, satellite, Wi‑Fi (5 GHz), 5G mmWave |
| EHF | 30 GHz – 300 GHz | Millimeter‑wave 5G, experimental high‑capacity links |
Note: The usable portion for most commercial wireless systems lies between 300 MHz and 30 GHz.