Nortel Networks Corporation

Rockstar Bidco, LP

William R Kirkland

Daniel Boudreau

Christian Dubuc

David G Steer

Steve Andre Beaudin

Koon Hoo Teo

David A Brown

A transmitter () generates a first set of data symbols and a first pilot symbol () at a first time, and a second set of data symbols and a second pilot symbol () at a different, second time. The first () and second () pilot symbols are each represented by first () and second () pilot carriers, respectively, located at first () and second () predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (), the first () and second () pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (), the first () and second () pilot carriers have third and fourth predetermined values, respectively. A receiver () measures the first, second, fourth and third predetermined values responsive to receiving the first () and second () pilot symbols to determine first, second, third and fourth estimates of channel distortion, respectively, for compensating and recovering the first and the second sets of data symbols.

System and method for I/Q imbalance compensation

A transmitter () generates a first set of data symbols and a first pilot symbol () at a first time, and a second set of data symbols and a second pilot symbol () at a different, second time. The first () and second () pilot. symbols are each represented by first () and second () pilot carriers, respectively, located at first () and second () predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (), the first () and second () pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (), the first () and second () pilot carriers have third and fourth predetermined values, respectively. A receiver () measures the first, second, fourth and third predetermined values responsive to receiving the first () and second () pilot symbols to determine first, second, third and fourth estimates of channel distortion, respectively, for compensating and recovering the first and the second sets of data symbols.

Wireless communication is improved by simultaneously transmitting signals that are orthogonal to received signals. This technique is referred to as Orthogonal Division Duplexing or ODD. Channel characteristics may be estimated based on an analysis of the received signals. Subsequently, techniques used in the transmitting of signals may be adjusted based on the estimated channel characteristics. By using interleaved pilot sub-carriers, each end of a communications link may take measurements of channel conditions. These measurements may be used to adapt the transmission techniques used in the transmitter to the measured channel conditions. Advantageously, this adaptation can occur without the delay in reporting conditions that is characteristic of traditional adaptive communications systems.

Communication using simultaneous orthogonal signals

The use of wideband or software defined radio is attractive in terms of cost reduction since it allows re-use of base stations for different transmission modes. However, wideband radio also introduces the problem of how to deal with high level interfering signals. Presently, such signals saturate parts of the receive circuit&#x2014;typically the ADC. By detecting interference and determining its frequency, it is possible to tune a bandpass or bandpass with notch filter, to take the interfering signal out of the reception band of the receiver thereby taking the ADC out of saturation whilst retaining the ability to resolve low level signals.

Growing community of inventors

Kanata, Canada

William R Kirkland