From The Ground Up- An ... | Wireless Communications

: Sample rate conversion (upsampling/downsampling) and Additive White Gaussian Noise (AWGN). Part 2: Digital Communication and Modulation Linear Modulation

The principles of wireless communications manifest across a diverse array of modern commercial technologies, each optimized for specific ranges, data rates, and deployment scenarios: Technology Standard / Frequency Primary Use Case IEEE 802.11 (2.4, 5, 6 GHz) Short (Local Area) High-speed home and office internet networks. Bluetooth IEEE 802.15.1 (2.4 GHz) Very Short (Personal Area) Cable replacement for peripherals, audio, and wearables. Cellular (4G/5G) 3GPP Standards (Sub-6 GHz, mmWave) Long (Wide Area) High-speed mobile data, voice calls, and infrastructure. Satellite L, C, Ku, Ka Bands (1 GHz - 40 GHz) Global / Orbital Wireless Communications from the Ground Up- An ...

splits a high-rate data stream into many low-rate substreams, each transmitted on a separate, orthogonal subcarrier. This makes the system resilient to multipath fading (signals bouncing off buildings and arriving at different times). OFDM is used in Wi-Fi (802.11a/g/n/ac/ax), 4G LTE, 5G NR, and digital TV (DVB-T). Cellular (4G/5G) 3GPP Standards (Sub-6 GHz, mmWave) Long

Designed for low-power, short-range (10–100 m) device connectivity. Bluetooth uses frequency-hopping spread spectrum (79 channels, 1600 hops/sec) to reduce interference. Classic Bluetooth supports data rates up to 3 Mbps, while , introduced in 4.0, focuses on ultra-low power for wearables, sensors, and beacons. BLE 5.x quadruples range and speed (2 Mbps) and adds mesh networking. OFDM is used in Wi-Fi (802

Let me draft. Wireless Communications from the Ground Up: An In-Depth Introduction to Principles, Technologies, and Future Directions

Changing the height (strength) of the wave.

Example: Your Wi-Fi router (802.11ac) might use 256-QAM when you are close to it, falling back to QPSK when you move far away.