Ibiquity Digital Corporation

Other

Westinghouse Electric Corporation

USA Digital Radio, Inc.

Denise Maureen Cammarata

Brian William Kroeger

Roy Ronald Stehlik

Paul James Peyla

Raymond R Cooper

Jeffrey Scott Baird

E Glynn Walden

George Nicholas Eberl

Albert J Fasulo

Richard Edward Martinson

Gregory W Seker

Samuel S Anderson

Keith W Janson

William C Isley, Jr

Perry E King, Jr

Jeffrey D York

A method for weighting orthogonal frequency division multiplexed soft symbols is provided, including the steps of receiving a plurality of sub-carriers modulated by digital information and filtering the sub-carriers to produce complex soft decision outputs. The magnitudes of the soft decision outputs are used to creating a first sequence of data. The differences between successive samples in the first sequence are used to create a second sequence of data. The first and second sequences are used to determine a plurality of weights and the weights are applied to the complex soft decision outputs. A receiver which incorporates the method is also disclosed.

Adaptive weighting method for orthogonal frequency division multiplexed soft symbols using channel state information estimates

This invention provides a method of broadcasting including the steps of providing a broadcast signal in a central frequency band of an FM radio channel; providing a first plurality of sub-carriers in an upper sideband of the FM radio channel; providing a second plurality of sub-carriers in a lower sideband of the FM radio channel; modulating a first group of the first plurality of sub-carriers with a complementary punctured convolution coded encoded version of program material; modulating a first group of the second plurality of sub-carriers with the complementary punctured convolution coded version of the program material; and transmitting the broadcast signal, the first group of the first plurality of sub-carriers and the first group of the second plurality of sub-carriers. In an all-digital version of the invention, the central frequency band may include a plurality of sub-carriers transmitted at a lower power level than that of the sub-carriers in the upper and lower sidebands. These additional sub-carriers can be used to transmit additional data. Transmitters and receivers which utilized the method are also included.

FM in-band-on-channel digital audio broadcasting method and system

A broadcasting method comprising the steps of encoding program material using codes including a first set of bits and a second set of bits, the first set of bits contributing a greater coding gain to the codes than the second set of bits, modulating a plurality of orthogonal frequency division multiplexed carrier signals with the codes, whereby the first set of bits are carried by a first group of the carrier signals and the second set of bits are carried by a second group of the carrier signals, the first group of carrier signals being less susceptible to interference than the second group of carrier signals, broadcasting the carrier signals, receiving the carrier signals, estimating the interference to which the carrier signals in the second group have been subjected to determine if carrier signals in the second group have been corrupted, erasing bits carried by any of the carrier signals which have been determined to be corrupted, and decoding bits of the codes that have not been erased.

Digital audio broadcasting method using puncturable convolutional code

A method for weighting orthogonal frequency division multiplexed soft symbols is provided, including the steps of receiving a plurality of sub-carriers modulated by digital information and filtering the sub-carriers to produce complex soft decision outputs. The magnitudes of the soft decision outputs are used to creating a first sequence of data. The differences between successive samples in the first sequence are used to create a second sequence of data. The first and second sequences are filtered and compensated for differences in effective group delay of the first and second sequences to produce third and fourth sequences. Then these third and fourth sequences are used to determine a plurality of weights and the weights are applied to the complex soft decision outputs. A receiver which incorporates the method is also disclosed.

A broadcasting method encodes program material using convolutional codes having non-puncturable bits and puncturable bits and modulates orthogonal frequency division multiplexed carrier signals with the convolutional codes. The non-puncturable bits are carried by a first group of the carriers and the puncturable bits are carried by a second group of the carriers, where the first group of carrier signals is less susceptible to interference than the second group of carrier signals. The carrier signals are then broadcast to receivers which determine if the carriers in the second group have been corrupted and erase puncturable bits carried by any of the carriers which have been determined to be corrupted. This produces punctured codes which are subsequently decoded to recover the program material.

A mobile terminal for satellite communication of voice data, facsimile and computer information, which consists of an RF transceiver section, and a processor board. The processor board has two digital signal processors and a multi-task control processor for controlling the operation of the two signal processors. Net radio service is implemented in the mobile terminal and includes a priority 1 mode wherein a channel search is performed on a net radio channel database for an available channel if any problem is initially encountered in obtaining control of a specific communication channel such as a channel currently in use or a channel designated for use as a default channel.

Mobile terminal apparatus including net radio service in a mobile

An improved satellite beam acquisition and crossover technique for finding an appropriate satellite beam by searching for and acquiring a strongest pilot channel, searching for signalling channels on the acquired strongest pilot channel and monitoring the acquired signalling channel. Beam acquisition of a continuous wave pilot as in the preferred embodiment is faster and more reliable than beam acquisition of a modulated channel. Moreover, the acquired pilot channel can be used to unambiguously precalibrate the frequency reference of the mobile terminal. Also, acquisition of the pilot ensures that the corresponding satellite beam is not blocked or shadowed immediately prior to searching for a signalling channel, which significantly improves the reliability while reducing the time required for the search process. Mitigation of fading and shadowing is provided by using fast attack, slow decay non-linear filtering.

Satellite beam acquisition/crossover for a mobile terminal

A mobile terminal apparatus for satellite communication of voice data, facsimile and computer information, which consists of an RF transceiver section, an optional cellular board, and a processor board. The processor board has two digital signal processors and a multi-task control processor for controlling the operation of the signal processor.

Growing community of inventors

Owings Mills, MD, United States of America

Denise Maureen Cammarata