Motorola Corporation

Motorola Mobility LLC

James Robert Kelton

Phillip D Rasky

Bruce D Mueller

David Paul Gurney

Kevin Lynn Baum

Mark Conrad Cudak

Brian Keith Classon

Colin D Frank

Kadathur S Natarajan

Nicholas William Whinnett

Roger L Peterson

Michael Russell Mannette

Nikhil Shashank Nadgauda

Michael Russel Mannette

Roger Laurin Peterson

The present invention provides a method/protocol (400, 800) and device (600; 700) for transmitting a synchronous stream of information, in a wireless, centrally controlled communication system. The method includes the steps of parsing the synchronous stream of information into a plurality of predetermined fixed sized blocks and transmitting/retransmitting each fixed size block in a predetermined window of time until one of: reception of each fixed size block is positively acknowledged and each corresponding predetermined window of time has elapsed.

Low complexity protocol method device and system robust in the presence

A network protocol method (300), access point device (600) and peripheral devices (700, 800) provide an efficient centrally coordinated peer-to-peer wireless communications network wherein the access point device: (1) broadcasts a block assignment that specifies a wireless source peripheral device and a wireless destination peripheral device; (2) receives, from the wireless destination peripheral device, sequence information; (3) determines whether the sequence information represents one of: a negative acknowledgment and a positive acknowledgment with a sequence number; (4) forwards an acknowledgment to the wireless source peripheral based on the sequence information, and repeats steps (1)-(4) until N blocks of data, N a predetermined integer, have been transferred from the wireless source peripheral to the wireless destination peripheral.

Network protocol method, access point device and peripheral devices for

A transmitter for a communication system transmits consecutive chips of a signal shifted in phase +/-90 degrees +/- nan angle between 0 degrees and 45 degrees which is a function of a spreading gain.

Rapidly decorrelating spreading sequences for DS-CDMA transceivers

A mobile station (104) in a DS-CDMA communication system (100) has receiver diversity. A first antenna (130) receives signals over a communications channel (101) from a base station (102). A second antenna (132) receives signals which are delayed in a delay element (142) by one or more chip times and combined in a summer (148) with signals from the first antenna. The combined signals are presented to a RAKE receiver (112) for decoding and demodulation. When discernible multipath energy is present to the point where much of the received signal energy is not accounted for in the assigned RAKE receiver fingers, the second antenna is switched out to avoid increasing the level of interference.

DS-CDMA receiver and forward link diversity method

The present invention provides a method, system, subscriber unit, and base/headend unit for a bandwidth efficient multiple user digital communication system that facilitates multiple user reverse link communication using overlapped transmit signal spectra of at least two overlap bandwidth subscriber units. Overlap bandwidth subscriber units receive a forward link signal, each deriving a frequency reference from the forward link signal and a symbol timing reference from the forward link signal, and transmitting a reverse link signal to the base/headend unit that receives a composite reverse link signal of the reverse link signals. Each reverse link signal includes at least one modulated data carrier with distinct carrier frequencies. Each transmitted reverse link signal has a symbol timing responsive to the symbol timing reference, and the frequency spectra of the reverse link signals overlap using overlapped transmit signal spectra of at least two overlap bandwidth subscriber units.

Multiple user communication system, device and method with overlapping

The present invention provides a communication system, device and method of reverse link symbol timing synchronization of transmited signals to facilitate reverse link timing synchronization. A base unit transmits a forward link signal, receives a reverse link signal, and determines a timing offset for signals received on a reverse link timing synchronization channel, wherein the reverse link synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by a multicarrier subscriber unit to facilitate reverse link symbol timing synchronization. A plurality of multicarrier subscriber units receive a forward link signal and transmit a reverse link symbol timing synchronization burst on a reverse link timing synchronization channel wherein the reverse link timing synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by each subscriber unit, and adjusts a timing reference for transmitting signals to facilitate reverse link timing synchronization.

Multicarrier reverse link timing synchronization system, device and

An improved automatic frequency correction acquisition system utilizes an automatic frequency correction (AFC) loop (22) having an acquisition mode in which an estimate of the frequency offset of a received carrier signal is rapidly acquired and a tracking mode in which the automatic frequency correction loop more accurately follows changes of the frequency offset. The AFC is switchable in response to predetermined control signals between the acquisition mode and the tracking mode. A carrier to impairment ratio estimator (36) is coupled with the automatic frequency correction loop (22) for estimating the carrier to impairment ratio of the incoming carrier signal. An automatic frequency correction controller (30) is coupled with the automatic frequency correction loop (22) and with the carrier to impairment ratio estimator (30) and is responsive to the carrier to impairment ratio estimate being at or above a preselected threshold value for producing a tracking control signal (24) comprising one of the predetermined control signals. The automatic frequency correction loop (22) is responsive to the tracking control signal (24) for switching from the acquisition mode to the tracking mode.

Method and apparatus for automatic frequency correction acquisition

A method and apparatus for mitigating error in a received communications signal includes an error mitigation unit (245) which receives and performs mitigation based on an error indication (e.g., a CRC) and a quality indication (QI). The error mitigation unit may include a magnitude adjuster (220) for adjusting the input signal value (e.g., an ADPCM nibble) when the QI is less than a threshold, and a soft correction unit (240) for, when the QI is above the threshold, either soft correcting nibble magnitudes or muting selective nibbles based on further signal information such as differential phase.

Method and apparatus for error mitigating a received communication signal

A digital phase detector 100 receives a limited input signal 108 and inputs it and a reference oscillation 112 into an EXCLUSIVE NOR gate 102. The output 110 of the EXCLUSIVE NOR gate 102 is input to a gated N-bit counter 104, which produces an N-bit representation of the magnitude of the phase 115 of the signal 108. A sign detector 105 determines the sign of the phase of the signal by sampling the resultant 110 and combines the magnitude of the phase 115 with the sign of the phase to produce a digital numeric representation of the phase of the signal 116.

Digital phase detector with integrated phase detection

A method and apparatus reduce power consumption in a subscriber unit of a communication system. The subscriber unit has a processor (10) for processing non-voice messages received from the communication system. The method includes the steps of receiving a communication signal (18) at the subscriber unit, detecting a presence or an absence of non-voice messages (20) in the communication signal, and disabling the processor (24) in response to detecting the absence of non-voice messages in the communication signal. The apparatus includes a receiver (12), a message detector (14) and a controller (16) for carrying out the foregoing steps.

Method and apparatus for reducing power consumption in a subscriber unit

A method and apparatus is provided for encoding a signal within a radio frequency transmitter 10. The method includes the steps of dividing an information bit stream into a set of successive representations of constellation symbols, each with a symbol interval and finite impulse response filtering each constellation symbol of the set of successive representations of constellation symbols to produce at least one filtered symbol sample per symbol interval. The method further includes the steps of vector adding the at least one filtered symbol sample per symbol interval of the set of successive representations of constellation symbols to produce an output constellation symbol. An apparatus is provided with means for implementing the steps of the method. Included within the apparatus is a low-overhead means of selecting modulation method.

Encoding method for constellation symbols of an RF transmitter

An apparatus and method for symbol timing tracking has a decimation index input (42). The decimation index (42) is connected to an upper threshold limiter (44) and a lower threshold limiter (46). The upper threshold limiter (44) is connected to an upper shift register (48). A plurality of cells (52) in the upper shift register (48) are connected to a majority vote logic circuit (54). The majority vote logic circuit (54) is connected to a symbol clock time base (56) and a clocking and clearing control circuit (62). The clocking and clearing control circuit (62) has a clock enable output and a clear signal connected to the upper shift register (48). The lower threshold limiter (46) is connected to a lower shift register (58) that is connected to a second majority vote logic circuit (60).

Method and apparatus for symbol timing tracking

A method of synchronizing a fixed access unit (16) into a time division multiple access (TDMA) system (10). The method includes the steps of receiving a first timing advance channel time slot (86) at the fixed access unit (16), sending a message advanced in time by an offset value over a second time slot (88), receiving an acknowledgment from the TDMA system (10) that the message was received, and advancing a subsequently transmitted communication based on the offset value.

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Oak Park, IL, United States of America

James Robert Kelton