Low cost E-mail over HF with OFDM and turbo coding techniques
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چکیده
This paper presents a new low cost e-mail system for the HF band (3–30 MHz) based on free software and commodity hardware. The core of the system is a 2500 bps OFDM data modem enhanced by turbo codes and a powerful ARQ protocol. The modem has been deeply tested with a Watterson HF channel simulator [?, ], studying the impact of different configurable parameters and comparing its codification strength against traditional convolutional codes. Once the modem has been studied, the complete e-mail system is tested, firstly with simulations, and finally in true 10MHz links, to show its performance in a real environment. key words: HF, e-mail, turbo codes, OFDM
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