Wireless Facilities, Inc.

Yoshimi Ltd., Limited Liability Company

Wirless Facilities, Inc.

Baya Hatim

Masood K Tayebi

Ismail Lakkis

Deirdre O'Shea

Saeid Safavi

Cathal O'Scolai

Joseph J Roy

Hoang Xuan Bui

Ulun Karacaoglu

Chi Nche

A system and method providing a frame structure to received channel data sent over an air interface of a wireless communication system. The system and method may allow compensation for transmitting and receiving frequency variations, synchronization at the receiver, and provides a virtual signaling channel which may be used for system alarms and status. In one embodiment, the system uses bit stuffing, a frame preamble and a signaling preamble to transmit data at a high data rate in the ISM band.

Wireless T/E transceiver frame and signaling controller

A system and method of frame synchronization and detection for use in a digital receiver within a communication system. The digital radio communication system includes a receiver for receiving a signal stream that includes data frames. Each frame includes an arbitrary data sequence and a unique word. A predetermined number of contiguous bits from the unique word are appended to the beginning of each data frame to identify the start of the data frame. The communication system comprises a sampling circuit for sampling symbol levels, a filter to implement the cross correlation of the received signal with the stored unique word, a threshold detector circuit to detect when frame synchronization is achieved as well as additional circuitry to refine the estimate from the threshold detection circuit. The design utilizes coherent demodulation. However, the design is equally applicable to non-coherent demodulation. In one embodiment, the sampling rate is assumed to be two samples per symbol. However, the functionality of the proposed design is not limited to two samples per symbol.

Frame synchronization and detection technique for a digital receiver

A system and method of timing estimation for use in a digital receiver within a communication system. An algorithm calculates the timing offset by evaluating the spectral component at the symbol clock frequency. The spectral component is generated using a nonlinearity operation. However, the maximum likelihood non-data-aided timing estimation equation reveals an alternative approximation for the logarithm of the hyperbolic cosine function present in the maximum likelihood equation, which offers a compromise between implementation complexity and variance performance. The estimated timing offset is then fed to a timing correction unit, which calculates the data samples corresponding to the sampling clock phase and removes the redundant samples. The ideal sampled signal is then forwarded to additional synchronization and functional units for further processing.

Non-data aided maximum likelihood based feedforward timing synchronization method

A system and method for converting carrier frequencies of a wireless communication system is provided. The system and method allow expansion of coverage areas of wireless communication systems, such as a mobile/cellular telephone system. In one embodiment, the system converts RF signals in the PCS band to ISM band, and transmits the ISM signals to a distant repeater station. The repeater station receives the ISM signals and down converts the ISM signals to the PCS band. The PCS signals are retransmitted in a new cell thereby creating a new coverage area. Radio frequency signals are down converted to an Intermediate frequency for channel selectivity and narrow band filtering. Channel selectivity circuitry allows quick reuse of other channels in the same cell. The channel selectivity circuitry includes a SAW filter which significantly reduces out of band interference. The system includes a microcontroller to permit use of programmable synthesized sources for the local oscillators thereby facilitating a variety of communication bands to be utilized in the system.

Universal repeater for communication systems

A combiner circuit and method for use in a digital transmitter within a communication system. The combiner circuit receives a number of signal streams that include data frames. Each frame includes an arbitrary data sequence and portions of a unique word. The combiner circuit comprises a plurality of digital preamble circuits which append a predetermined number of contiguous bits from the unique word to each data frame. The system utilizes a plurality of spreaders, shifters, and a summer to further modify the data stream for transmission.

A system and method of buffering data of a wireless communication system. The system and method maintain synchronization, end-to-end signaling and coding overhead bits needed to encapsulate data frames sent over wireless media. Additionally, the system and method compensate for transmitting and receiving clock variations. In one embodiment, the system uses framing of data with preamble, stuffing and signaling bits transmitted synchronously at a high data rate in the Industrial, Scientific and Medical (ISM) bands.

Elastic store for wireless communication systems

A system and method for communication of radio frequency (RF) signals over multimedia signal paths. The invention provides a wireless multimedia carrier (WMC) system capable of receiving a variety of standardized input signals, such as DS0/E0, T1/E1, T2/E2, and/or T3/E3 for transmission using RF channels. The WMC system selectively employs time division multiple access (TDMA) and/or code division multiple access (CDMA) technology. The WMC system transmits the various signal inputs using RF carriers, receives the transmitted signals, and converts the signals to the desired signaling scheme (standard) for forwarding to intended destinations.

Wireless multimedia carrier system

A system and method providing a structure to the data sent over the air interface of a wireless communication system. The system and method allow compensation for transmitting and receiving frequency variations, synchronization at the receiver and provision of a virtual signaling channel for system alarms and status. In one embodiment, the system uses bit stuffing, a frame preamble and a signaling preamble to transmit data at a high data rate in the ISM band.

Wireless T/E Transceiver frame signaling subcontroller

A system and method of timing estimation for use in a digital receiver within a communication system. A timing estimation block is provided within a digital receiver, where the input signal is processed at four or more samples per symbol and the estimation block operates in a feedforward manner. The algorithm calculates the timing offset by evaluating the spectral component at the symbol clock frequency. The spectral component is generated using a nonlinearity operation. However, the maximum likelihood non-data-aided timing estimation equation reveals an alternative approximation for the logarithm of the hyperbolic cosine function present in the maximum likelihood equation, which offers an excellent compromise between implementation complexity and variance performance. The estimated timing offset is then fed to a timing correction unit, which calculates the data samples corresponding to the sampling clock phase and removes the redundant samples. The ideal sampled signal is then forwarded to additional synchronization and functional units for further processing. This method is provided for a variety of digital receivers employing Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA) and or any combination of the principles of the above or other technologies. In accordance with one embodiment of the invention, a digital receiver system comprises an anti-aliasing filter, a sampling unit, a filtering block, a timing estimation block, a timing correction block and additional synchronization and functional units block.

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San Diego, CA, United States of America

Baya Hatim