Motorola Corporation

Freescale Semiconductor,inc.

Robert Mark Gorday

Salvador Sibecas

Paul Edward Gorday

Jorge Ivonnet

Eric Thomas Eaton

Mahibur Rahman

Gregory O Snowden

David B Taubenheim

Kevin T McLaughlin

Scott R Humphreys

Glafkos K Stratis

Philip P Macnak

Celestino Anastasio Corral

Stuart S Kreitzer

Gregg E Rasor

Kenneth S Lerner

Clinton Allen Powell

Kenneth Charles Elkin

Leonard Wayne Bennett

Sarah J Fain

Craig J Christmas

Clinton C Powell

Shahriar Enami

A device for minimizing group delay mismatch in a quadrature receiver () having an in-phase channel and a quadrature-phase channel. The device includes a microprocessor () for determining an I/Q phase imbalance between digital signals on an in-phase channel and digital signals on a quadrature-phase channel, and for calculating a group delay mismatch between the in-phase channel and the quadrature-phase channel, and a group delay equalizer (). The group delay equalizer includes a delay line (and) for delaying one of the in-phase channel and the quadrature-phase channel by one of a plurality of delays, based on an amount of group delay mismatch.

Receiver I/Q group delay mismatch correction

A detector () and corresponding method is configured for detecting presence of a data frame. The detector includes a first correlator () that is configured to provide a first plurality of correlations corresponding to similarity between data as received and first information, e.g., an ordered set of coefficients, that denotes the data frame and a second correlator () that is configured to provide a second plurality of correlations corresponding to similarity between the data as received and second information, e.g., another ordered set of coefficients, that denotes the data frame, where the second information includes a portion of the first information. Further included is decision logic () coupled to the first correlator and the second correlator, where the decision logic is configured to provide an indication () that the data frame is present based on the first plurality of correlations and the second plurality of correlations.

Detecting a data frame

A demodulator in a receiver includes a correlator () for de-spreading a spread-spectrum signal, and a decision module () for detecting a preamble and for synchronizing to data frames of the spread spectrum signal. The demodulator includes symbol timers (and) that allow the demodulator to correlate to two preamble symbols simultaneously, where the two preamble symbols occur one-half a symbol period apart. The correlator includes a correlator structure having taps that correct for any frequency offset of a carrier signal. The correlator correlates to each of the two preamble symbols a plurality of times through oversampling, where each correlation compensates for a different amount of frequency offset. By analyzing occurrence of peaks in magnitude of the correlations, the decision module detects the preamble and selects weights for the taps to de-spread data frames received after the preamble.

Hybrid polyphase and joint time-frequency detection

A correlator () for de-spreading a spread-spectrum signal includes a state machine (), a frequency correction look-up table (), a pseudorandom code generator (), and a correlator structure (and). The spread-spectrum signal includes symbols, and each symbol includes a plurality of chips. The correlator structure includes a plurality of taps (and) at which a coordinate rotation digital computer (CORDIC) operation is performed to determine an offset from a nominal carrier frequency of the spread-spectrum signal and to change a phase of each chip of a received symbol, in order to correct a carrier frequency of the spread-spectrum signal while de-spreading the spread-spectrum signal.

Joint de-spreading and frequency correction using a correlator

A multi-mode transmitter () is adapted to modulate a data packet () communicated by a wireless communications signal. The data packet includes a packet header comprising a preamble () and a start of frame delimiter (), and a data payload comprising a payload data length portion () and a payload portion (). The packet header is modulated with a spread spectrum technique. When transmitting a data payload in one mode, the data payload is also modulated with the spread spectrum technique. When transmitting a data payload in another mode, the data payload is modulated with a non-spread spectrum technique.

System and method for transmitting a multiple format wireless signal

An apparatus () and method () for receiving a communications signal. A spread spectrum signal demodulator () is adapted to demodulate a packet header () of a data packet () that is communicated by a wireless communications signal. The packet header () is modulated with a spread spectrum technique and the spread spectrum signal demodulator () produces a packet header detection signal () representing a successful detection of a predefined packet header value. A non-spread spectrum signal demodulator () is communicatively coupled to the spread spectrum signal demodulator () and demodulates, in response to the packet header detection signal (), a non-spread spectrum modulated data payload within the data packet. A data output select () produces demodulated data produced by either one or both the spread spectrum signal demodulator () and the non-spread spectrum signal demodulator ().

System and method for receiving a multiple format wireless signal

A baseband receiver and corresponding methods are arranged and configured to mitigate effects of direct current (DC) distortion and process an Orthogonal Frequency Division Multiplexing (OFDM) signal as provided from a direct conversion radio or receiver. The baseband receiver includes an OFDM demodulator configured to demodulate the OFDM signal, a post processor coupled to the OFDM demodulator and configured to provide symbols corresponding to the OFDM signal, and a compensator coupled to at least one of the OFDM demodulator and the post processor and configured to reduce error rates out of the baseband receiver that result from DC distortion in the direct conversion radio.

Mitigation of DC distortion in OFDM receivers

A WLAN communication system () and method employs mobile WLAN base stations () that include WLAN transceivers () and memory () for storing received messages from one or more mobile WLAN devices (-). The mobile WLAN base stations () serve as moving message carriers or message repeaters of messages for the mobile WLAN devices. In one embodiment, a mobile WLAN base station () receives messages transmitted by several mobile WLAN devices (-), temporarily stores the received messages, and delivers the stored messages to a fixed WLAN base station or another mobile WLAN base station when the mobile WLAN base station () moves to within communication range of the applicable fixed or other mobile WLAN base station.

WLAN communication system and method with mobile base station

An apparatus and method for mixed-media call formatting. A preferred format for a call can be determined from different mixed media communication formats. The mixed media communication formats can include a text format and an audible speech format. A media format mode signal can be sent or received. The media format mode signal can indicate a preferred format for a call. The call can be connected in the preferred format.

Apparatus and method for mixed-media call formatting

A method for sending messages from a particular device to one or more other devices communicants () uses the relative geographic location of the targeted devices as addressing criteria. The particular device forms or joins a network of potential communicants, and exchanges information to determine their relative geographic location with respect to that of the particular device (). The relative geographic location is preferably defined by a directional component and a range component. The communication device then selects for communication those devices that meet specific criteria, such as a specific direction and range, and transmits a message to the selected devices ().

Method of targeting a message to a communication device selected from among a set of communication devices

A reconfigurable logic signal processor system (RLSP) () and method of error checking same in accordance with certain embodiments of the present invention loads configuration data capable of processing an air interface or portion thereof in a wireless system from a configuration storage memory () into reconfigurable resources (), reads back the configuration data from the reconfigurable resources (), reads expected results from the configuration storage memory (), and executes a verification algorithm on the configuration data read back from the reconfigurable resources (). A portion of the reconfigurable resources () of the RLSP system () may be utilized to implement the error checking upon itself. If an error is found in the configuration data, steps can be taken to activate another base configuration data to implement a functional base air interface in a wireless communication system and request downloading (if available) from the network of the erroneous configuration data.

Error checking in a reconfigurable logic signal processor (RLSP)

A processor () time-shares correlators () to process () pilot channels for a plurality of branches to derive pilot symbols for each of the plurality of branches before processing control and data channels. The processor and the correlators cooperate to determine () from the pilot symbols a timing estimate for each of the plurality of branches. A signal quality estimator () determines () from the pilot symbols a signal quality for each of the plurality of branches. Subsequently, the processor cooperates with the correlators to process () the control and data channels of the plurality of branches, in an order determined by a plurality of branch attributes including at least one of the signal quality and the timing estimate determined for each of the plurality of branches.

Method and apparatus for time-sharing a rake receiver structure

An orthogonal frequency division multiplexing (OFDM) transmitter method, consistent with certain embodiments of the present invention arranges OFDM data symbols representing data bits for transmission in a packet. A prescribed pattern of OFDM data symbols are removed () and replaced () with pilot symbols. The packet is then transmitted () to an OFDM receiver that receives the packet () and determines a channel correction factor from the pilot pattern. The receiver then estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data () and uses these correction factors to correct the OFDM symbols representing data (). Arbitrary data are then inserted in place of the pilot symbols (). The OFDM symbols representing data along with the arbitrary data are then decoded using an error correction decoder that corrects the errors induced by substitution of the pilot symbols for data symbols ().

Velocity enhancement for OFDM systems

A system ( ) for dynamic process assignment among a plurality of devices ( ) includes an initial coordinator ( ), a requesting device ( ), and a resource device ( ). The initial coordinator ( ) includes a list of available resources ( ) for each device of the plurality of devices ( ). The requesting device ( ) requests the use of a desired resource. In response to the request from the requesting device ( ), the initial coordinator ( ) identifies an available resource associated with one of the plurality of devices ( ) for use by the requesting device ( ) as the desired resource.

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Wellington, FL, United States of America

Robert Mark Gorday