Agency for Science, Technology and Research

National University of Singapore

Chin Keong Ho

Sumei Sun

Zhongding Lei

Yan Wu

Ying Chang Liang

Ho Wang Fung

Ping He

Francois Po Shin Chin

Zheng Wang

Yeow Khiang Chia

Peng Hui Tan

Yuan Li

Chin Ming Pang

Kay Chuan Benny Tan

Zhaohui Cai

Behrouz Farhang-Boroujeni

There is provided a method of inventory control for an inventory including items sequentially arranged on one or more structures, each item having a radio frequency tag associated thereto, the tag having stored therein an identifier for identifying the associated item. The method includes: obtaining data in relation to multiple items arranged in a row on a structure, the data comprising multiple sets of identifiers detected from interrogating the tags of the plurality of items at a plurality of instances along the row; determining a sequence of detected items in the row based on the data obtained, the sequence including estimated relative positions of the detected items in the row; and determining whether an item of the detected items in the row is misplaced based on the estimated relative position of the item in the row and a reference relative position of the item in the row.

Method of inventory control and system thereof

A method of communication comprising determining whether to use distributing coding between a source (S), relay (R) and destination (D), based on a predetermined transmission rate; if the determination is positive, determining a forward error correction scheme using distributed Alamouti space-time coding, wherein the scheme is determined based on the predetermined transmission rate, a channel signal-to-noise ratio (SNR) and a network topology; relaying coded data from the S to the D using the determined forward error correction.

Method of communication

A transmitter () for transmitting a signal, the signal comprising a plurality of signal values, the signal values being grouped to at least one signal value block. The transmitter comprises a pre-transformation unit () adapted to process each signal value block by a pre-transformation to produce a block of modulation symbols, wherein the pre-transformation comprises a phase rotation of the signal block values, which corresponds to the multiplication of the signal value block with a phase rotation matrix. The transmitter also comprises a modulation unit () adapted to modulate at least one carrier signal based on the modulation symbols and a sending unit () adapted to send the modulated carrier signal.

Method for transmitting a digital signal, method for receiving a digital signal, transmitter and receiver

A method for processing a data signal received via a communication channel is described, comprising determining a first matrix comprising components describing characteristics of the communication channel and inverting the first matrix by sub-dividing the first matrix into at least four sub matrices, inverting a first sub matrix of the four sub matrices generating a second matrix by multiplying a second sub matrix of the four sub matrices with the inverted first matrix and a third sub matrix of the four sub matrices, determining the difference matrix between the second matrix and a fourth sub matrix of the four sub matrices inverting the difference matrix and calculating the inverted matrix based on the inverted difference matrix. The data signal is processed using the inverted first matrix.

Method for processing a data signal, data processing unit and computer program product

A method of determining a residual frequency offset between a transmitter and a receiver in a transmission of data via a communication channel, is described, wherein the message is transmitted from the transmitter to the receiver via the communication channel and the message comprises at least one short preamble (), at least one long preamble () and user data (). The at least one long preamble () comprises residual frequency offset determination information based on which the residual frequency offset is determined.

Method for determining a residual frequency offset, communication system, method for transmitting a message, transmitter, method for processing a message and receiver

A method for transmitting a digital signal is described, wherein the digital signal is to be transmitted by a plurality of antennas and a 2-domain pre-transformation is carried out, i.e., in course of a pre-transformation modulation symbols assigned to subcarriers having different frequencies and assigned to subcarriers sent by different antennas are linearly combined.

Method for transmitting a digital data stream, transmitter, method for receiving a digital data stream and receiver

A transmitter that has a determination unit for determining a plurality of symbols () such that each symbol () has a tail component () and the plurality is determined in such a way that the tail components () are substantially equal and a tone generation unit for arranging the plurality of symbols () to form a plurality of long preambles () such that the plurality of long preambles () are tone-interleaved.

Transmitter, method for generating a plurality of long preambles and communication device

A method for equalizing a digital signal received via at least one communication channel is described, wherein a block of received signal values is processed by a block-iterative equalizer (). The equalizer comprises a feedback unit () and a feed-forward unit () each corresponding to the multiplication by a respective matrix. The matrices are updated in the iterative process.

Method for equalizing a digital signal and equalizer

A method for detecting a signal received via a communication channel, the communication channel being affected by noise, is described, wherein the received signal is processed according to a filtering step (), the filtering step comprises multiplication of at least one component of the received signal with a filter coefficient and the filter coefficient comprises a noise variance offset which corresponds to the variance of the noise.

Method for detecting a signal, detector and computer program product

A signal reconstructing section (), a receiver having the signal reconstructing section (), a communication system having the receiver, and a method for reducing noise in a transformed signal having a plurality of signal components and using the signal reconstructing section () are described. The signal reconstructing section () of the receiver has a detector () for detecting the transformed signal, decision modules () each having an input () coupled to output () of the detector, and a reconstructing module () having inputs () respectively coupled to output () of the decision modules (). The reconstructing module () is adapted to reconstruct one or more subcarriers of the plurality of subcarriers a predetermined number of times to thereby form a noise-reduced transformed signal. Reconstruction of the one or more subcarriers is performed one at a time or two or more simultaneously.

Receiver having a signal reconstructing section for noise reduction, system and method thereof

A direct current (DC) offset estimation, frequency offset estimation, and compensation system (), receives data packet () with preamble (). A DC offset estimator () and a frequency offset estimator () operate concurrently to produce estimates of DC and frequency offsets of the data packet (), which are determined from a portion of the preamble () as it is received. As the data packet () is received, a compensator () receives the estimates of DC and frequency offsets and compensates the remaining portion of the data packet () to produce a DC and frequency compensated data packet (). Concurrent operation of the DC estimator () and the frequency offset estimator () advantageously allows more time to produce the estimates of DC and frequency offsets.

Method and apparatus for frequency offset estimation, and system utilizing same

In a multi-channel communication system () data () and pilot data () are combined to provide a composite signal comprising discrete data signals (), each having a data portion () and a pilot data portion (). The composite signal is transmitted and a corresponding composite signal received on a communication channel having varying characteristics. An added pilot semi-blind (APSB) channel estimator () and equalizer () apply a converging iterative process to estimate the characteristics of the communication channel and the transmitted data.

Growing community of inventors

Singapore, Singapore

Chin Keong Ho