Patent ID: 7733939

Claim:
A wireless communication device comprising: a receiver and a transmitter, wherein the transmitter comprises a symbol mapper and a spreading module, wherein the symbol mapper is configured to generate, from data, a stream of sub-symbols for each of a plurality of orthogonal frequency division multiplexing (OFDM) subcarriers; wherein the spreading module is configured to spread out the stream of sub-symbols on each of the plurality of OFDM subcarriers by using direct sequence spread spectrum (DSSS) techniques in which the stream of sub-symbols on each of the plurality of OFDM subcarriers is spread across an OFDM subcarrier bandwidth by multiplying the stream of sub-symbols by spreading code sequences of predefined length, each sub-symbol being expanded into a set of chips, the number of chips in the set being related to the predefined length, wherein the transmitter appends, to an outgoing signal to be wirelessly transmitted, a number of copies of short training symbols, the number of copies of the short training symbols equaling the number of chips in the set, the copies of the short training symbols being transmitted between a legacy signal and a proprietary signal.