Lucent Technologies Inc.

Stephen Alan Allpress

Robert Atmaram Soni

R Michael Buehrer

Nallepilli S Ramesh

Carmine James Pagano, Ii

Joseph Anthony Tarallo

Qiang Cao

Quinn Li

Lorenz Fred Freiberg

Steven Andrew Wood

Lawrence Howard Ozarow

Roy Baxter Blake

Sridhar Arunachalam

Jie Lin

Reza Mardani

Francis Edward O'Brien

Christopher Nicholas Malvone

Tiejun Shan

Carmine James Pagano

A time division multiple access communication system is disclosed, in which down link data are transmitted over a data channel in repeated time frames each containing a plurality of time slots. Down link set up information is transmitted over a control channel to indicate from which time slot a user terminal should extract data. Each frame on the data channel includes a user packet flag to indicate whether or not each time slot in the frame contains data. Each user terminal is responsive to the set up information and to the user packet flags to extract data from its assigned time slot in those frames which the slot is indicated to contain data.

Time division multiple access communication system

A technique for receiving and transmitting wireless telecommunications through use of a generic architecture is disclosed. The present invention mitigates the complexity of different transceiver operations by allowing a generic architecture to be used in a variety of situations with different channels and different telecommunications standards. An illustrative embodiment of the present invention comprises: receiving uplink analog RF signals at a base station; converting the uplink analog wide-band RF signals into IF uplink digital signals at an analog-to-digital converter; converting the IF uplink digital signals into a number of uplink channels; and demodulating selected narrow-band uplink channels from the total number of narrow-band uplink channels.

Software-defined transceiver for a wireless telecommunications system

Disclosed is a common transmitter architecture having incorporated both open loop transmit diversity schemes using a plurality of binary switches. Employment of binary switches allows for the sharing of certain components whether the transmitter is utilizing a orthogonal transmit diversity (OTD) scheme or a space time spreading (STS) scheme. Accordingly, the number of components in the transmitter is minimized and the complexity of the transmitter is simple enough to be implemented into a single application specific integrated chip.

Transmitter architecture employing space time spreading and orthogonal transmit diversity techniques

Disclosed is a receiver transmitter architecture having incorporated both open loop transmit diversity schemes using a plurality of binary switches. Employment of binary switches allows for the sharing of certain components whether the receiver is utilizing a orthogonal transmit diversity (OTD) scheme or a space time spreading (STS) scheme. Accordingly, the number of components in the receiver is minimized and the complexity of the receiver is simple enough to be implemented into a single application specific integrated chip.

Receiver architecture employing space time spreading and orthogonal transmit diversity techniques

A block radio design is disclosed that prevents the primary analog-to-digital converter from saturating and thus prevents the introduction of intermodulation products into the multi-carrier signal. The block radio comprises a strong signal suppressor that selectively suppresses any carrier signal in the multi-carrier signal before the multi-carrier signal is digitized by the analog-to-digital converter, thus preventing the possibility that the analog-to-digital converter can be saturated. Furthermore, the strong signal suppressor attenuates the stronger carrier signals without affecting the weaker carrier signals. An illustrative embodiment of the present invention comprises: a signal replicator for creating two analog representations on an incoming multi-carrier signal, a scanner that identifies the potentially problematic carrier signals in the multi-carrier signal, a resynthesizer that regenerates the potentially problematic carrier signals, and a signal combiner that subtracts the regenerated carrier signals from the original multi-carrier signal, thus creating a multi-carrier signal in which the potentially problematic carrier signals are attenuated and the weaker carrier signals are left unaffected.

Method and apparatus for strong signal suppression in multi-carrier signals

A plurality of modulated signals are generated for a data stream. Each modulated signal, which contains all of the information in the data stream, is generated at a different carrier frequency. The modulated signals are combined for transmission as a multi-band signal. In one embodiment, the modulated signals are compatible with signals generated in accordance with the IS-95 telecommunications standard. According to this embodiment, wideband data streams are combined with code sequences that are based on the same Walsh code sequences used to generate IS-95 signals. Each wideband data stream is encoded using either a particular Walsh code sequence or its logical negation to generate one coded stream for each carrier frequency used to generate the IS-95 signals. Each coded stream is then modulated at one of the carrier frequencies using spread-spectrum modulation to generate one of a plurality of modulated signals for that wideband data stream, where each modulated signals contains all of the information in the original wideband data stream. Through systematic assignment of Walsh code sequences and their logical negations, and through appropriate spread-spectrum modulation of the wideband data, the resulting multi-band modulated signal for each wideband data stream is assured of being orthogonal to all other such multi-band modulated signals, as well as orthogonal to every IS-95 signal. As such, the invention increases both the user and data-rate capacities of an IS-95 network without requiring any additional carrier frequencies or code sequences beyond those already supported by the IS-95 network.

IS-95 compatible wideband communication scheme

Polyphase channelizing transmitters convert multiple signal channels into a single stream for transmission and corresponding polyphase channelizing receivers process the received stream to recover signals corresponding to the original signal channels. The filter transfer functions for both the transmitters and receivers are designed to have non-recursive numerators and recursive denominators. Such filters can be realized using non-recursive (e.g., finite impulse response (FIR)) filters and recursive (e.g., infinite impulse response) filters on opposite sides of a Fourier transform. For a given application, polyphase structures of the present invention may require fewer coefficients to implement than conventional (e.g., FIR-based) solutions and will therefore be less complex and less expensive.

Recursive filters for polyphase structures

A flexible communications systems provides users with additional communication channels without requiring additional transmitters or receivers by using variable rate Walsh coding. Additionally, the assignment of these additional communication channels is easily managed at the base station by monitoring data backlog and receiver error rates.

Variable rate coding for wireless applications

In a preferred embodiment, an FM demodulator includes an I and Q sampler for generating data samples of I and Q signals of an FM signal. A signal processor derives samples of a modulating waveform of the FM signal from the I and Q data samples, using a Lagrangian interpolation function of the I and Q data samples. Variables include derivatives of the I and Q signals obtained by differentiation of the Lagrangian function. Preferably, the processor further utilizes a correction factor to correct the modulating waveform samples obtained from the Lagrangian-based interpolation, to thereby derive a modulating waveform exhibiting low signal distortion.

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Hoboken, NJ, United States of America

Stephen Alan Allpress