Orthogonal modulation using M-sequences and Hadamard transforms

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×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×2n Hadamard transform, discard the zero, and order the sequences again according to the index to retrieve the data.

主权项

1. A method of wireless communication using orthogonal modulation, comprising:
associating a set of data with an ordered set of sequences to produce a first set of modulation sequences for a wireless signal; appending a constant to each sequence in the first set of modulation sequences to produce a second set of modulation sequences for the wireless signal; associating each of the second set of modulation sequences with a set of orthogonal sequences to produce a third set of modulation sequences for the wireless signal; discarding an element of each sequence in the third set of modulation sequences and associating the remaining elements of each sequence in the third set of modulation sequences with a sequence from a set of pseudorandom binary sequences to produce a fourth set of modulation sequences for the wireless signal; and transmitting the wireless signal comprising the fourth set of modulation sequences.