Other

James Wight

Alexander Neil Birkett

Johan M Grundlingh

Embodiments of the present invention include systems and methods for optimizing the transmitter and receiver weights of a MIMO system. In one embodiment, the weights are optimized to create and steer beam nulls, such that each transmitted signal is substantially decoupled from all other signals between a MIMO transmitter a MIMO receiver. In another embodiment, the weights are selected such that, the signal strength of each weighted signal transmitted through a communications channel along a respective signal path is substantially equivalent, but for which the weighting vectors are not necessarily orthogonal. In a further embodiment, each transmitted signal is coupled only between its own transmitter and receiver antennas with a gain, or eigenvalue, that is a consequence of the weights, and which is bounded to within a desired range of values while at the same time the weighing vectors are orthogonal. Embodiments employing various decomposition techniques are also provided.

Multiple input, multiple output communications systems

The invention relates to the field of electronics, more particularly to the wire bonds incorporated into an integrated circuit package such as a quad flat pack. a ball grid array or hybrid style module. The present invention takes the normally undesirable wire bond inductance and uses it in an operational circuit where positive inductance is required. The circuit in which the wire bond inductance is used is located primarily in the integrated circuit die housed in the integrated circuit package, but may also include off-die components. In one example, a wire bond is used as the required series inductance in a discrete circuit impedance inverter which consists of two shunt-to-ground negative inductances and one series positive inductance. One of the negative inductances is located on-die, while the other is located off-die.

Integrated circuit incorporating wire bond inductance

A multi-channel RF receiver uses an image rejection mixer (e.g. double quadrature mixer) in the IF down conversion stage for image side band rejection (whereby use of an IF narrow band filter for image rejection may be omitted if desired) and comprises a simplified frequency synthesizer which generates both a 'wandering' IF oscillator frequency and an RF oscillator frequency for the up/down conversion stages (being, for down conversion, from RF to IF and from IF to base band. The IF used for a particular RF carrier (channel) is selected so as to be both an integer (N) sub-harmonic of that RF carrier and within the operating frequency band of the image rejection mixer. Advantageously, the synthesizer comprises only one loop and one VCO, wherein the IF oscillator signal is produced from the RF oscillator signal by means of a frequency divider.

Up / down conversion circuitry for radio transceiver

Up/down conversion circuitry for radio transceiver

Circuits and methods are provided for use in a wireline or wireless transmitter to complement the digital generation of non-constant envelope modulation signals therein. A digital signal processor is configured for deconstructing a predetermined signal having an undesirable property into one or more fragment signals which do not have the undesirable property. In a preferred embodiment the predetermined signal is preconditioned by applying a preconditioning deconstruction process to another signal from which the predetermined signal is derived, whereby that other signal is deconstructed into one or more preconditioned fragment signals having an improved property over the other signal. For OFDM modulation schemes this undesirable property may be a relatively high peak-to-average power ratio. Signals formed from the fragment signals are subject to conversion to analog signals and processing by power efficient, dynamic-range limited analog circuits i.e. S Class power amplifiers (and, for wireless applications, low compression-point up-converters), before being recombined for transmission.

Computational circuits and methods for processing modulated signals having non-constant envelopes

Pseudo-noise (PN) carrier suppression up-converter and pseudo-noise image sideband rejection up-converter and down-converter circuits are provided. The image sideband rejection circuits enable the use of single step up-conversion without the need for the high Q filters associated with two-step up-conversion architectures. For carrier suppression, the frequency spectrum of an input signal is PSK (BPSK or QPSK) spread by a PN signal and the spread signal is up-converted using a PSK (BPSK or QPSK) modulated carrier (local oscillator) modulated by the same PN sequence. In an up-converter, a carrier is QPSK modulated using independent PN sequences and the frequency spectrum of the input signal is QPSK spread using the same independent PN sequences whereby image sideband rejection results upon up-converting the QPSK spread signal in a mixer using the QPSK modulated carrier. In a down-converter, a carrier signal which is QPSK modulated by independent PN sequences is used to down-convert an input signal in a mixer and the resulting down-converted signal is QPSK spread using the same independent PN sequences whereby image sideband rejection occurs.

Growing community of inventors

Ottawa, Canada

James Wight