Commonwealth Scientific and Industrial Research Organisation

Jian Zhang

Xiaojing Huang

Yingjie Jay Guo

David Eric Humphrey

Joseph Abraham Pathikulangara

Valeriy Dyadyuk

A communication system including a transmitter and a receiver is disclosed. The transmitter transmits frames, at least two consecutive frames containing different training sequences. The receiver receives data communicated from the transmitter over a channel. The receiver combines and jointly processes the at least two consecutive frames transmitted by the transmitter to estimate a channel state of the channel.

Linear equalization for use in low latency high speed communication systems

Disclosed is a wireless transmitter comprising: a module configured to modulate input data bits into data symbols according to a predetermined modulation scheme, and group the data symbols into one or more precoding blocks; at least one symbol insertion module, each configured to insert one or more cancellation symbols into a corresponding precoding block; at least one precoding module, each configured to precode a corresponding precoding block; a subcarrier insertion module configured to concatenate the one or more precoded blocks and to insert at least one cancellation subcarrier into the concatenated precoded blocks to form a precoded OFDM symbol; a module configured to process the precoded OFDM symbol so as to reduce the out-of-band power emitted by the transmitter in transmitting the precoded OFDM symbol, wherein the processing uses the inserted cancellation symbols and cancellation subcarriers; and a module configured to transmit the processed precoded OFDM symbol over a wireless communication channel.

OFDM communications

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 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.

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Beecroft, Australia

Jian Zhang