Abstract: A technique for low-complexity high-performance coherent demodulation of GFSK signals involves utilizing a novel phase and frequency tracking mechanism coupled with a trellis search technique to track signal memory in the demodulation process. A method according to the technique may include modeling modulation based upon a trellis. The method may further include estimating unknown parameters, selecting a maximum likelihood path through the trellis, and mapping the maximum likelihood path to an output bit sequence. The technique is also applicable to DSPK and other applicable known or convenient protocols.

Abstract: This specification describes, in part, a technique for dynamic assignment of multiple antennas to different radio subsystems in a wireless device. The technique may include using an adaptive algorithm to allocate antennas to different radio subsystems as a function of, for example, application requirements, power requirements, and/or channel/network conditions. The specification also describes, in part, a technique for adaptively optimizing the use of the assigned antennas and other transmission parameters for each radio subsystem.

Abstract: The invention provides a multiple-antenna wireless multimedia headset with high fidelity sound, peer-to-peer networking capability, seamless handoff between multiple wireless interfaces, multimedia storage with advanced search capability, and ultra low power such that the device is capable of operation without recharging. The headset supports multiple wireless systems such as Wifi (802.11a/b/g/n), Wimax, 3G cellular, 2G cellular, GSM-EDGE, radio (e.g. AM/FM/XM), 802.15 (Bluetooth, UWB, and Zigbee) and GPS. The headset also provides a platform such that applications can access the high fidelity sound system, the speech recognition engine, the microprocessor, and the wireless systems on the device.

Abstract: A wireless multimedia handset can include one or more of wireless system support, a platform to handset features, and multiple features. The multiple features may include, by way of example but not limitation, multiple-antennae, multimedia storage with advanced search capability, a high fidelity sound system, peer-to-peer networking capability, seamless handoff capability, instant hotspot capability, and ultra low power operation such that the handset is capable of operation without recharging by operating solely on solar cells.

Abstract: Portable media devices allow a user to access music or other media stored on the device, and two portable media devices equipped with wireless technology can exchange stored files over the air.

Abstract: An method and apparatus for provisioning multiple Next and fractional T1 along with packet based communications over a shared X-DSL communication link is disclosed. The communication link may be wired or wireless. The current invention provides a method and apparatus for flexibly provisioning businesses and other high bandwidth users, with multiple communication channels and multiple service types, both packet based and SDM/TDM. An efficient and configurable method and apparatus for multiplexing of both packets and STM channels on to a single VDSL frame is disclosed. At the receiver in the NT the VDSL receiver as explained is configured to de-multiplex individual channels and route them to individual users/suits within the building.

Abstract: A method and apparatus for extending existing fiber and local area networks across digital subscriber lines, at matching data rates is disclosed. A DSL transceiver system is disclosed with one or more gateways coupled to at least one digital signal processor (DSP). The DSP in turn couples to a plurality of analog-front-ends (AFE's). Each AFE is coupled via associated hybrid front ends (HFE's) to corresponding subscriber lines. The transceiver or a controller coupled thereto maintains a table of bandwidth requirements and frame types for a variety of sessions. Individual sessions include bandwidth requirements beyond existing XDSL capabilities. The system determines frametype, e.g. 802 and bandwidth requirements, e.g. 100 Mbps for each session and allocates more than one subscriber line accordingly. For each session the divergent bandwidth availability of each of the subscriber lines to which the DSP may be coupled is determined and all or a portion of that bandwidth is allocated to the selected session.

Abstract: The current invention provides a method and apparatus for time domain equalization in an XDSL modem. A received communication channel is analyzed to determine the highest frequency component thereof. Typically, there is an inverse relationship between the length of a subscriber line and the highest frequency component over which communications can be supported. In response to the frequency determination, the sampling rate for the channel is reduced to the lowest sample rate consistent with maintaining signal integrity on the highest frequency component of the channel. The sampling rate reduction may accomplished in the analog portion of the receive path, e.g. the analog-to-digital converter (ADC) or in a digital decimator coupled thereto. Concurrently the demodulator complexity is also scaled back. Where the XDSL protocol is digital multi-tone (DMT) the input sample size to the discrete Fourier transform (DFT) engine is reduced accordingly.

Abstract: A method and apparatus for communicating multi-tone modulated upstream and downstream channels of communication data between a pair of communication devices utilizing a common set of tones for the upstream and downstream channels. The pair of communication devices each include a digital stage configured to assign mutually orthogonal code sequences for encoding and decoding the upstream and downstream channel respectively. The transmit path of the digital stage of each communication device is configured to generate redundancy in the associated communication data in either the time or frequency domain and to encode the redundant communication data with the mutually orthogonal code sequence prior to transmission thereby allowing the communication devices to share a common frequency spectrum of a communication medium for the upstream and downstream communication channels.

Abstract: A Fourier transform processor utilizing discrete circuits each of which is configurable for processing a wide range of sample sizes. A single pipeline supports multiplexed bi-directional transformations between for example the time and frequency domains. In an embodiment of the invention the Fourier Transform processor may be implemented as part of a digital signal processor (DSP). In this embodiment the DSP may implement both the discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) across a wide range of sample sizes and X-DSL protocols. Multiple channels, each with varying ones of the X-DSL protocols can be handled in the same session.

Abstract: A high efficiency line driver is disclosed. The line driver may be applied with equal advantage in wired and wireless communication media to amplify data signals with a minimum of power consumption. In an embodiment of the invention a line driver is disclosed which includes: at least one amplifier, a delay element, a control signal generator and a generator. The at least one amplifier includes at least one bias supply, a signal input and a signal output. The delay element accepts as an input the data signal and delays delivery of the data signal to the at least one line amplifier for amplification. The generator is responsive to a control signal to generate varying voltage levels corresponding thereto on the at least one bias supply of the at least one amplifier. The control signal generator is responsive to the input data signal to detect peaks therein and to generate the control signal corresponding thereto in advance of delivery of the data signal to the amplifier.

Abstract: An apparatus and method is disclosed for channel estimation in an X-DSL communication device. The communication device may include physical or logical modems. The modems may implement one or more of a group of X-DSL protocols including: G.Lite, ADSL, VDSL, and HDSL. The apparatus may be used for determining the location and magnitude of discontinuities or faults within the communication medium to which the X-DSL communication device is coupled. The information provided by the device may be used for line qualification or repair. No additional equipment is required for channel estimation. Instead the apparatus may be located within a single modem or shared between a group of modems. An N bit pseudo random codeword injected into the transmit path is used to generate both a leakage signal and a plurality of reflected signals on the receive path. No timing information is needed from the transmit path.

Abstract: A method and apparatus for time and frequency domain forward error correction (FEC) in a modem which communicates data using multiple discrete sub-channels is provided. The invention may be implemented in hardware, software or firmware. In an embodiment of the invention a modem with a plurality of components forming a transmit path and a receive path is disclosed. The modem communicates data across a wired or wireless communication medium using a multiplicity of discrete sub-channels. The modem includes a transform component and a time domain FEC component. The transform component transforms the multiplicity of discrete sub-channels of a communication between a time domain and a frequency domain on the receive path and vice-versa on the transmit path. The time domain FEC component couples to the transform component. The time domain FEC component has a complementary encoder and decoder portion on the transmit and receive paths respectively.

Abstract: An apparatus and method for reducing interference over a common communication medium, wired or wireless is provided. The apparatus reduces interference from a number of sources using a common architecture which may be used to service a modem pool or discrete modems which share the common communication medium. Interference due to near end cross-talk (NEXT), self-NEXT or echo, and far end cross-talk (FEXT) may all be substantially reduced or cancelled by the apparatus. Additionally, channel characteristics for individual data channels across the common communication medium may be determined. The apparatus provides support for multiple modem protocols including X-DSL protocols such as G.Lite, ADSL, VDSL, SDSL, MDSL, RADSL, and HDSL. The apparatus supports multiple line codes such as the discrete multi-tone (DMT) and carrier less AM/PM (CAP) line codes associated with X-DSL communications. The apparatus may be implemented in hardware, firmware or software.

Abstract: An apparatus and method is provided for minimizing frequency distortion in the transmit path of an XDSL modem implementing digital multi-tone (DMT) line code. The current invention provides a means for both determining and correcting for distortion in the frequency domain. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. In an embodiment of the invention the apparatus may include a calibration phase which may be implemented using the existing analog-to-digital (ADC) conversion and demodulation capabilities on the receive path of the modem. This calibration phase takes place before the training phase associated with establishing communications with a remote site. During the calibration phase a calibration sequence with known spectral characteristics in the frequency domain is injected digitally at the beginning of the transmit path into each of the tone bins of the inverse Fourier Transform engine (IFFT).

Abstract: An X-DSL modem supporting multiple X-DSL line codes including discrete multi-tone (DMT) and carrierless phase and amplitude (CAP). The modem includes: components coupled to one another to form a transmit path and a receive path. The components include an encoder component and a Fourier transform component. The encoder component encodes data associated with a CAP communication channel into QAM symbols and encodes data associated with a DMT communication channel into DMT sub-symbols. The Fourier transform component couples to the encoder component on the transmit path for transforming DMT sub-symbols from a frequency-to-time domain and for transforming QAM symbols from the time-to-frequency domain followed by a filtering in the frequency domain and a subsequent transformation back from the frequency-to-time domain to effect a pulse shaping function without requiring a discrete pulse shaping component in the transmit path.

Abstract: The current invention provides a DSP which accommodates multiple current X-DSL protocols and is further configurable to support future protocols. The DSP is implemented with shared and dedicated hardware components on both the transmit and receive paths. The DSP implements both the discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) portions across a wide range of sample sizes and X-DSL protocols. Multiple channels, each with varying ones of the X-DSL protocols can be handled in the same session. The DSP offers the speed associated with hardware implementation of the transforms and the flexibility of a software only implementation. Traffic flow is regulated in the chip using a packet based schema in which each packet is associated with a specific channel of upstream and downstream data. Header and control information in each packet is used to govern the processing of each packet as it moves along either the transmit path or receive path.

Abstract: A method and apparatus for digital subscriber line (xDSL) communications between one or more digital signal processors (DSPs) and analog front ends (AFEs) each coupled to corresponding subscriber line(s). The apparatus transports channels of data between subscribers and the DSP(s). The apparatus includes a bus for the transport of digital data, a DSP AFE interfaces. The DSP interfaces couples the DSP to the bus. The DSP interface accepts downstream channels of digital data from the DSP and transmits packets each associated with a corresponding one of the downstream channels to the bus. Each of the packets identifies a targeted AFEs coupled to a selected one of the subscriber lines. The AFE interfaces each couple an associated one of the AFEs to the bus. Each of the AFE interfaces transmits selected packets to a selected one of the subscriber lines for the transport to the subscriber.

Abstract: An apparatus and method is provided for minimizing in channel distortion in an X-DSL line driver is disclosed. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. Out of band monitoring of a channel is implemented to adaptively minimize out of band interference and in band distortion. A unique training sequence, suitable for DMT line codes is set forth. The training sequence allows a full spectral characterization of the downstream signal space with a single upstream monitoring tone. The invention may be used with multi-channel X-DSL line drivers interfacing with any of a number of multi-channel supply architectures. The apparatus may be applied with equal advantage to communication protocols other than X-DSL. The apparatus may be applied with equal advantage in wired and wireless media.

Abstract: The current invention provides a digital signal processor which supports multiple X-DSL protocols and a multiplicity of channels on a single chip. Each channel is packetized and each packet includes control information for controlling the performance of the components/modules on the transmit and receive path. Further flexibility is derived from an architecture which incorporates discrete and shared modules on the transmit path and the receive path. The transmit path and receive path modules are collectively controlled by control information in selected ones of the packets and operate on each channel's packets at an appropriate rate, and protocol for the channel. A digital signal processor (DSP) is disclosed which incorporates these features. The DSP exhibits a favorable form factor, and flexibility as to protocols and line codes, and numbers of channels supported.