Commonwealth Scientific and Industrial Research Organisation

Yingjie Jay Guo

Xiaojing Huang

Jian Zhang

Mark Hedley

John David Bunton

Valeriy Dyadyuk

John Seward Kot

Andrew Reginald Weily

Ian Maxwell Davis

Boyd Mcgregor Murray

Disclosed is a transmitter for a communication system. The transmitter comprises a sidelobe suppression module configured to apply a suppression matrix to an input vector comprising symbols to be transmitted by the transmitter; a modulation module configured to modulate the precoded vector to a time-domain symbol using a plurality of subcarriers, each symbol in the precoded vector having a corresponding subcarrier; and a digital-to-analog conversion module configured to convert the time-domain symbol to an analog waveform for transmission. The suppression matrix is constructed such that emissions at one or more predetermined suppression distances lying outside a frequency band defined by the subcarriers are set to zero according to a predetermined emission model.

Reducing out-of-band emission

Disclosed is an apparatus for estimating the location of a remote node. The apparatus comprises an antenna array comprising a plurality of elements in a fixed spatial arrangement, at least one element being a transmitting element configured to transmit a first wireless signal to the remote node, and at least two elements being receiving elements configured to receive a second wireless signal transmitted by the remote node in response to the first wireless signal. The apparatus further comprises a signal processing unit connected to the antenna array, the signal processing unit being configured to: estimate a plurality of round trip distances using the wireless signals, each round trip distance being from a transmitting element to the remote node and back to a receiving element; and estimate the location of the remote node using the round trip distance estimates.

Wireless localisation system

A transmission signal pre-processing method and apparatus for out-of-band emission cancellation are disclosed. For each of N subchannels in a band weighting each of N subchannel symbols by a calculated value in the range from 0 to 1 is performed. Precoding said N weighted symbols, organised as an N&#xd7;1 matrix, by multiplication by a unitary matrix is then performed.

Out-of-band emission cancellation

Disclosed is a communication modulator with sample rate conversion. The modulator comprises a symbol mapping module configured to map an input bitstream to a symbol sequence; a pre-distortion module configured to multiply the symbol sequence by a discrete frequency response to produce a pre-distorted symbol sequence; a modulation module configured to modulate the pre-distorted symbol sequence to a time-domain baseband sample sequence; a sample rate conversion module configured to convert the sample rate of the baseband sample sequence to a different sample rate to produce a sample-rate-converted baseband sample sequence; and an up-conversion module configured to up-convert the sample-rate-converted baseband sample sequence to an intermediate frequency signal. The discrete frequency response by which the pre-distortion module multiplies the symbol sequence is configured to compensate for passband droop introduced to the sample-rate-converted baseband sample sequence by the sample rate conversion module.

Arbitrary sample rate conversion for communication systems

Disclosed is a wireless communication signal peak-to-average power ratio reduction, method. The method comprises calculating a peak envelope from an envelope of an input signal using a clipping threshold; smoothing the peak envelope using a window function; mapping the smoothed peak envelope to an attenuation function using the clipping threshold; and applying the attenuation function to the input signal.

Peak-to average power ratio reduction for wireless communication systems

A circularly polarized array antenna () is disclosed. A single layer dielectric substrate () has a ground plane () located on its upper surface of the substrate and covering only part of the upper surface. A plurality of antenna elements (-) are also located on said upper surface of the substrate. Each antenna element has a slot element (-) formed in the ground plane and a respective loading element (-) located within each slot element. The antenna elements being arranged in a regular array where each respective slot element is sequentially rotated in space with respect to adjacent slot elements, and the loading elements generate a perturbation under excitation. A microstrip feed network () is located on the underside of the substrate to provide excitation to each slot element, and including feeds of different lengths to be electrically sequentially rotated in common with spatial rotation of the slot elements. A single microstrip feed point () extends to the edge of the substrate for connection purposes. A reflecting plane is located parallel to and spaced apart from the underside of the substrate. The ground plane extends to cover the entire microstrip feed array.

Circularly polarised array antenna

Disclosed is a hybrid antenna array () comprising a plurality of digital branches (), each digital branch including an analogue beamforming sub-array (e.g.-), each sub-array having a plurality of antenna elements (), a phase shifter () adapted to apply a phase shift to the signal from each antenna element, and a combiner (e.g.-) adapted to combine the phase-shifted signals. Each digital branch also includes a signal chain (e.g.-) adapted to convert the output of the sub-array to baseband. The hybrid antenna array also comprises a digital processing module (), including: an angle of arrival estimation sub-module () adapted to estimate an angle of arrival of a signal at the antenna elements; a phase control sub-module () adapted to control the phase shift applied by each phase shifter depending on the estimated angle of arrival; and a digital beamformer () adapted to combine the baseband signals from the digital branches using a weight vector to form an output signal ().

Hybrid adaptive antenna array

Disclosed is a method of processing a series of data bits for transmission on a transmit link, the method comprising mapping the series of data bits to a series of data symbols; demultiplexing the series of data symbols to a plurality of substreams of symbols; modulating each substream of symbols to a corresponding series of OFDM symbols; and space precoding the plurality of series of OFDM symbols to form one or more series of space precoded OFDM symbols, wherein the demultiplexing is dependent on channel state information for the transmit link.

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Beecroft, Australia

Yingjie Jay Guo