An extensible communication system is described herein. The system includes a first module for receiving a root index value and for generating a constant amplitude zero auto-correlation sequence based on the root value. The system further includes a second module for receiving a seed value and for generating a Pseudo-Noise sequence based on the seed value. The system further includes a third module for modulating the constant amplitude zero auto-correlation sequence by the Pseudo-Noise sequence and for generating a complex sequence. The system further includes a fourth module for translating the complex sequence to a time domain sequence, wherein the fourth module applies a cyclic shift to the time domain sequence to obtain a shifted time domain sequence.

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.

Disclosed is a data transmission method in a mobile communication system. The data transmission method through a code sequence in a mobile communication system includes grouping input data streams into a plurality of blocks consisting of at least one bit so as to map each block to a corresponding signature sequence, multiplying a signature sequence stream, to which the plurality of blocks are mapped, by a specific code sequence, and transmitting the signature sequence stream multiplied by the specific code sequence to a receiver.

Disclosed is a data transmission method in a mobile communication system. The data transmission method through a code sequence in a mobile communication system includes grouping input data streams into a plurality of blocks consisting of at least one bit so as to map each block to a corresponding signature sequence, multiplying a signature sequence stream, to which the plurality of blocks are mapped, by a specific code sequence, and transmitting the signature sequence stream multiplied by the specific code sequence to a receiver.

Digital n-state switching devices are characterized by n-state switching tables with n greater than 4. N-state switching tables are transformed by a Finite Lab-transform (FLT) into an FLTed n-state switching table. Memory devices, processors and combinational circuits with inputs and an output are characterized by an FLTed n-state switching table and perform switching operations between physical states in accordance with an FLTed n-state switching table. The devices characterized by FLTed n-state switching tables are applied in cryptographic devices. The cryptographic devices perform standard cryptographic operations or methods that are modified in accordance with an FLT. One or more standard cryptographic methods are specified in Federal Information Processing Standard (FIPS) Publications. Security is improved by at least a factor n.sup.2.

Digital n-state switching devices are characterized by n-state switching tables with n greater than 4. N-state switching tables are transformed by a Finite Lab-transform (FLT) into an FLTed n-state switching table. Memory devices, processors and combinational circuits with inputs and an output are characterized by an FLTed n-state switching table and perform switching operations between physical states in accordance with an FLTed n-state switching table. The devices characterized by FLTed n-state switching tables are applied in cryptographic devices. The cryptographic devices perform standard cryptographic operations or methods that are modified in accordance with an FLT. One or more standard cryptographic methods are specified in Federal Information Processing Standard (FIPS) Publications. Security is improved by at least a factor n.sup.2.

Various novel concepts and schemes pertaining to non-orthogonal multiple access for wireless communications are described. A group orthogonal coded access (GOCA) scheme is introduced to reduce multi-user interference (MUI) and improve performance. A repetition division multiple access (RDMA) scheme is introduced to differentiate user equipment (UEs) by different repetition patterns. A low-density spreading (LDS) scheme is introduced to reduce MUI and improve performance.

When a plurality of the subcarrier spacing values are applied, a reference signal is generated by using a sequence having a sequence length corresponding to a first ratio of a first subcarrier spacing set for transmission data to the maximum settable subcarrier spacing. The sequence of the reference signal is mapped to a frequency resource at mapping intervals in accordance with a second ratio which is the reciprocal of the first ratio, and the transmission data and the reference signal are transmitted.

A message transmission method and device relating to the field of communications technologies are described that improve an anti-interference capability in message transmission. The method includes generating a scrambling code according to a scrambling code initialization seed, wherein the scrambling code initialization seed meets the following expression: c.sub.init=R.Math.2.sup.a.sup.7+P.Math.(.sup.n.sup.f mod .sup.k+1).Math.2.sup.b.sup.7 and then scrambling a message according to the scrambling code. The method further includes sending the scrambled message to a terminal on a physical downlink shared channel. Because the first time parameter has different values at at least two different moments, scrambling codes determined at the at least two corresponding different moments are different. Therefore, a possibility at which the base station uses a same scrambling code to scramble a same system message repeatedly in a time period is reduced, so that an anti-interference capability in system message transmission is improved.