As with all other common IEEE 802 networks, and certainly all 802.11 physical layers, the OFDM physical protocol unit begins with a preamble. It is composed of 12 OFDM symbols that synchronize various timers between the transmitter and the receiver. The first 10 symbols are a short training sequence, which the receiver uses to lock on to the signal, select an appropriate antenna if the receiver is using multiple antennas, and synchronize the large-scale timing relationships required to begin decoding the following symbols. The short training sequences are transmitted without a guard period. Two long training sequences follow the short training sequences. Long training sequences fine-tune the timing acquisition and are protected by a guard interval.

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DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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