Embodiments of the present disclosure provide, among other implementations, sequence determining methods. One example method provides a sequence group, and one sequence group number is corresponding to at least two sequences, where one sequence is used for mapping to consecutive subcarriers, and at least one other sequence is used for mapping to equally-spaced subcarriers. In some embodiments of the present disclosure, as high as possible cross-correlation between a sending signal obtained after equally-spaced mapping is performed on a sequence in a sequence group can be determined, and a sending signal obtained after continuous mapping is performed on another sequence in the group.

Embodiments of the present disclosure provide, among other implementations, sequence determining methods. One example method provides a sequence group, and one sequence group number is corresponding to at least two sequences, where one sequence is used for mapping to consecutive subcarriers, and at least one other sequence is used for mapping to equally-spaced subcarriers. In some embodiments of the present disclosure, as high as possible cross-correlation between a sending signal obtained after equally-spaced mapping is performed on a sequence in a sequence group can be determined, and a sending signal obtained after continuous mapping is performed on another sequence in the group.

Fully connected uplink and downlink fully connected relay network systems using pseudo-noise spreading and despreading sequences subjected to maximizing the signal-to-interference-plus-noise ratio. The relay network systems comprise one or more transmitting units, relays, and receiving units connected via a communication network. The transmitting units, relays, and receiving units each may include a computer for performing the methods and steps described herein and transceivers for transmitting and/or receiving signals. The computer encodes and/or decodes communication signals via optimum adaptive PN sequences found by employing Cholesky decompositions and singular value decompositions (SVD). The PN sequences employ channel state information (CSI) to more effectively and more securely computing the optimal sequences.

Fully connected uplink and downlink fully connected relay network systems using pseudo-noise spreading and despreading sequences subjected to maximizing the signal-to-interference-plus-noise ratio. The relay network systems comprise one or more transmitting units, relays, and receiving units connected via a communication network. The transmitting units, relays, and receiving units each may include a computer for performing the methods and steps described herein and transceivers for transmitting and/or receiving signals. The computer encodes and/or decodes communication signals via optimum adaptive PN sequences found by employing Cholesky decompositions and singular value decompositions (SVD). The PN sequences employ channel state information (CSI) to more effectively and more securely computing the optimal sequences.

A method of generating a code sequence in a wireless communication system is disclosed. More specifically, the method includes recognizing a desired length of the code sequence, generating a code sequence having a length different from the desired length, and modifying the length of the generated code sequence to equal the desired length. Here, the step of modifying includes discarding at least one element of the generated code sequence or inserting at least one null element to the generated code sequence.

A method of generating a code sequence in a wireless communication system is disclosed. More specifically, the method includes recognizing a desired length of the code sequence, generating a code sequence having a length different from the desired length, and modifying the length of the generated code sequence to equal the desired length. Here, the step of modifying includes discarding at least one element of the generated code sequence or inserting at least one null element to the generated code sequence.

A multi-user code division multiple access communication method, and corresponding transmitter and receiver include: the transmitter determines a complex-valued spreading sequence to be used by the transmitter, herein each element of the complex-valued spreading sequence is a complex number and values of real and imaginary parts of all elements in the complex-valued spreading sequence are from an M-element set of real numbers, and M is an integer larger than or equal to 2; the transmitter performs spreading processing on data symbols to be sent by using the complex-valued spreading sequence to generate a spread symbol sequence; and sends the spread symbol sequence. The receiver receives signals transmitted by multiple transmitters, and performs reception detection by using an interference cancellation signal detector, herein the complex-valued spreading sequences used by the multiple transmitters are used during detection.

A multi-user code division multiple access communication method, and corresponding transmitter and receiver include: the transmitter determines a complex-valued spreading sequence to be used by the transmitter, herein each element of the complex-valued spreading sequence is a complex number and values of real and imaginary parts of all elements in the complex-valued spreading sequence are from an M-element set of real numbers, and M is an integer larger than or equal to 2; the transmitter performs spreading processing on data symbols to be sent by using the complex-valued spreading sequence to generate a spread symbol sequence; and sends the spread symbol sequence. The receiver receives signals transmitted by multiple transmitters, and performs reception detection by using an interference cancellation signal detector, herein the complex-valued spreading sequences used by the multiple transmitters are used during detection.

Methods, systems, and devices for data scrambling for repeat operations are described. A first device may communicate a data set to a second device as a first set of bits. The first device may use a first scrambling code to scramble the first set of bits and the second device may use a first descrambling code to descramble the first set of bits. Upon determining that the first set of bits was received by the second device with an error, the first device may communicate the data set to the second device as a second set of bits. The first device may use a second scrambling code to scramble the second set of bits and the second device may use a second descrambling code to descramble the second set of bits

Methods, systems, and devices for data scrambling for repeat operations are described. A first device may communicate a data set to a second device as a first set of bits. The first device may use a first scrambling code to scramble the first set of bits and the second device may use a first descrambling code to descramble the first set of bits. Upon determining that the first set of bits was received by the second device with an error, the first device may communicate the data set to the second device as a second set of bits. The first device may use a second scrambling code to scramble the second set of bits and the second device may use a second descrambling code to descramble the second set of bits