In order to address the needs of narrow band communication, eNB-based processing and/or UE-based processing is provided to achieve robust detection of cell ID and SFN timing location using NB-SSS. A base station constructs a NB-SSS signal using a root index of a Zadoff-Chu (ZC) sequence, a scrambling code, a cyclic shift or phase ramping sequence, and an interleaving sequence, wherein a combination of the ZC root index, the scrambling code index, the cyclic shift or phase ramping sequence index, and the interleaving sequence index signals information for a cell identifier (e.g., PCID) and frame timing. The ZC sequence used may be a long ZC sequence constructed to span a total number of tones allocated to an SSS sequence or may be a concatenation of multiple ZC sequences, wherein the concatenated ZC sequences span a total number of tones allocated to an SSS sequence.

A method and apparatus having a synchronization signal sequence structure for low complexity cell detection is provided. The method includes establishing a set of a plurality of synchronization signal sequences to be used in connection with a communication target. Each one of the plurality of synchronization signal sequences includes at least a first sub-sequence, which includes either a first preselected sequence or a complex conjugate of the first preselected sequence, and a second sub-sequence, which includes either a second preselected sequence or a complex conjugate of the second preselected sequence. The second preselected sequence is different than the first preselected sequence, and is different than the complex conjugate of the first preselected sequence. Further, a length of the first sub-sequence and a length of the second sub-sequence are smaller than a length of the synchronization signal sequence. A signal including a synchronization signal is then received, where the synchronization signal comprises one of the synchronization signal sequences from the set of the plurality of synchronization signal sequences, and the synchronization signal is then detected.

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 herein achieve a method and system for selecting non-coherent spreading sequences with binary alphabets {0, 1} with variable spreading factors. The method generates circular shift equivalent sets of spreading sequences by circularly shifting base sequences with elements {1, 0} and having at least one variable spreading factor. The method determines whether each spreading sequence in the circular shift equivalent set meets pre-defined spreading sequence criteria. The spreading sequence criteria comprise balanced criteria, a non- repetition criteria, non-circular criteria, and conjugate criteria. Furthermore, the method selects the spreading sequence from expansions of at least one spreading sequence from the circular shift equivalent sets in response to determining that the spreading sequences in the circular shift equivalent sets meets the pre-defined spreading sequence criteria.

In the multiple short sequence based SRS, multiple items of sequence data having a short sequence length corresponding to a partial band are used for transmitting SRS in discontinuous bands. In the multiple short sequence based SRS, a terminal specifies a frequency domain to be used for transmitting a reference signal using predetermined sequence data, applies a phase shift index associated with the specified frequency domain to the reference signal, and transmits the reference signal to which the phase shift index is applied by using the specified frequency domain.

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.

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.

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.

A method of performing cell search includes receiving a primary synchronization signal (PSS) comprising a primary synchronization code (PSC) and receiving a secondary synchronization signal (SSS) comprising a first secondary synchronization code (SSC) and a second SSC, wherein the SSS includes a first SSS and a second SSS, the first SSC and the second SSC are arranged in that order in the first SSS, and the second SSC and the first SSC are arranged in that order in the second SSS. Detection performance on synchronization signals can be improved, and cell search can be performed more reliably.

It is possible to solve the problem that a downstream control information amount is significantly increased if allocation information is periodically reported because no allocation method of a default E-DCH resource configuration is defined for a preamble signature. A base station and a mobile station decide a default resource configuration by using a total number of resource configurations or a value obtained from the total number.