Abstract: A method for compensating for a sampling clock-offset includes calculating a positive threshold and a negative threshold of pulse-shaped data symbols to be received, calculating a positive sum ratio and a negative sum ratio from received samples, and compensating for a sampling clock-offset in response to the positive sum ratio being less than or equal to the positive threshold and the negative sum ratio being less than or equal to the negative threshold.

Abstract: A method and device for transmitting a preamble sequence is disclosed. A transmitter according to an embodiment may extract a first sequence for a non-coherent receiver and a second sequence for a coherent receiver, from ternary preamble sequences including elements ?1, 0 and 1, and map the first sequence and the second sequence to a preamble including a plurality of bits to generate a third sequence that the non-coherent receiver and coherent receiver support.

Abstract: The present invention describes a method and system for simultaneous transmission of data to coherent and non-coherent receivers. The method at the transmitter includes retrieving a base ternary sequence having a pre-defined length, obtaining one or more ternary sequences corresponding to data to be transmitted and transmitting the obtained one or more ternary sequences by the transmitter. The method steps at the receiver includes receiving one or more ternary sequences corresponding to the data transmitted, demodulating each of the received ternary sequences by correlating with all cyclic shifts of the base ternary sequence by the receiver if the receiver is a coherent receiver, demodulating each of the received ternary sequences by correlating with all cyclic shifts of the absolute of the base ternary sequence by the receiver if the receiver is a non-coherent receiver and detecting the transmitted data based on the cyclic shifts corresponding to maximum correlation values.

Abstract: 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.

Abstract: A method and apparatus for a collision-free carrier sense multiple access (CSMA) are provided. The method of a node associated with a beacon enabled carrier sense multiple access (CSMA)-based wireless communication network through an access point (AP) includes receiving a beacon from the AP, the beacon comprising a back-off prime number and a beacon random number, and generating a back-off interval based on the beacon random number, the back-off prime number, a mapped identification (ID) of the node, and a current time slot of a frame of the beacon. The method and apparatus provide a collision-free CSMA scheme for a beacon enabled CSMA-based wireless communication network. In the collision-free CSMA scheme, uniformly distributed back-off intervals may be generated in a distributed fashion at each node for a CSMA-based wireless communication network. The back-off intervals may be correlated among the nodes even though the nodes do not communicate with each other.

Abstract: Provided is a method of generating an orthogonal set in a quasi-synchronous spread spectrum system, the method including selecting a two-level autocorrelation sequence at a sequence selector, selecting a first indices set and a second indices set from the two-level autocorrelation sequence, and generating two quasi-orthogonal sets using the first indices set and the second indices set, at an orthogonal code generator.

Abstract: A method of per-tone spreading in single carrier block transmissions, includes generating a block of modulated symbols, and performing the per-tone spreading on the block of the modulated symbols. Also, a transmitter configured to perform per-tone spreading in single carrier block transmissions, includes a modulator configured to generate a block of modulated symbols, and a spreader configured to perform the per-tone spreading on the block of the modulated symbols.

Abstract: A method of timing synchronization in sub-band based ultra wideband systems, includes obtaining a coarse estimate of an offset in a time domain at a sub-sampled rate, and obtaining a fine estimate of the offset in an analog domain. The method further includes correcting a timing in the analog domain by transforming the fine estimate to an equivalent phase for the correcting.

Abstract: A method of a transmitter, includes multiplying a data sequence by a first code, and multiplying a training sequence by a second code that is orthogonal to the first code. The method further includes adding the multiplied data and training sequences, and transmitting, to a receiver, the added data and training sequences.

Abstract: A method of generating a pair of orthogonal sets with a spreading factor N for a direct sequence spread spectrum communication system, includes selecting a two-level autocorrelation sequence of a period of N?1, the two-level autocorrelation sequence including elements, each of which includes a value of 1 or 0, and obtaining binary sequences based on the two-level autocorrelation sequence. The method further includes obtaining quasi-orthogonal sets based on the two-level autocorrelation sequence and the binary sequences, and generating the pair of the orthogonal sets based on the quasi-orthogonal sets.