| 摘要 |
Methods, systems, and devices are described for orthogonal modulation of signals using maximal length sequences and Hadamard transforms. Modulation symbols to be transmitted are arranged into sequences indexed from 1 to 2n — 1 for some integer n. A constant is added to the beginning of each sequence, which is then multiplied by a Hadamard matrix of size 2n x 2n. The resulting sequences will be orthogonal and will have a first value of zero. The first value is discarded, and the sequence are reordered and associated with m- sequences. The signal is then transmitted. A cyclic prefix may also be transmitted. Upon receiving the transmission, a receiver may discard the cyclic prefix or use it for channel equalization. The receiver may then reorder the received signal, insert a zero, apply the 2n x 2n Hadamard transform, discard the zero, and order the sequences again according to the index to retrieve the data. |
