Abstract: A timing recovery system and method for accelerated clock synchronization of remotely distributed electronic devices is provided. The system includes a phase locked loop, a linear estimator and control logic. The method includes sampling a clock signal received from an electronic device, applying a linear estimation technique to estimate the frequency and phase of the received signal and providing those estimates to a phase locked loop to accelerate the phase locked loop acquisition rate and secure signal lock quickly.
Abstract: A phase synchronizer may operate, for example, to establish synchronization with a phase of a received codeword. The phase synchronizer may include, for example, an input shift register, a first syndrome computing module, a first error detection module, a second syndrome computing module, a second error detection module and a comparator arrangement. The first syndrome computing module may compute syndromes relating to a first potential phase of the codeword. The first error detection module may determine, based upon the first syndromes, a first number of errors associated with the first potential phase of the codeword. The second syndrome computing module may compute syndromes relating to a second potential phase of the codeword. The second error detection module may determine, based upon the second syndromes, a second number of errors associated with the second potential phase of the codeword.
Abstract: A method of handling data packets in a series of network switches is disclosed. An incoming data packet is received at a data port of a first lower capacity switch of the series of network switches and a stack tag is resolved from a header of the incoming data packet. The incoming data packet is forwarded to a first higher capacity switch, on a first stacked connection operating at a first data rate, based on the stack tag. A destination address of said incoming data packet is resolved by the first higher capacity switch and the header of the incoming packet is modified. The incoming data packet is forwarded to a second higher capacity switch, on a second stacked connection operating at a second data rate, based on the resolved destination address, where the header of the incoming data packet is modified and the incoming data packet is forwarded to a second lower capacity switch on a third stacked connection operating at the first data rate.
Abstract: A system and method are used to determine connectivity and/or cable faults of a cable. A signal transmitting and receiving system is coupled to the cable. An analog-to-digital converter (ADC) coupled to the signal transmitting and receiving system. A TDR system coupled to the ADC and a memory, and a controlling system coupled to at least one of the ADC, the TDR system, and the signal receiving and transmitting system. The controlling system includes a controller and one or more state machines that are used to control the TDR system.
Type:
Grant
Filed:
May 28, 2004
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Art Pharn, Peiqing Wang, Siavash Fallahi
Abstract: An apparatus for providing a programmable gain attenuator (PGA) while minimizing the influence of semiconductor switches on the signal being attenuated. An example apparatus comprises a impedance ladder with taps forming the junctions between impedances the PGA is then programmed by grounding the taps through terminating resistors.
Abstract: Low Density Parity Check (LDPC) code decoder using min*, min**, max* or max** and their respective inverses. For the first time, min* processing is demonstrated for use in decoding LDPC-coded signals. In addition, max*, min**, or max** (and their respective inverses) may also be employed when performing calculations that are required to perform decoding of signals coded using LDPC code. These new parameters may be employed to provide for much improved decoding processing for LDPC codes when that decoding involves the determination of a minimal and/or maximal value, or a minimal and/or maximal log corrected value, from among a number of possible values. The total number of processing steps employed within the decoding of an LDPC-coded signal is significantly reduced be employing the min*, max*, min**, or max** (and their respective inverses) decoding processing described herein.
Type:
Grant
Filed:
February 19, 2003
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Ba-Zhong Shen, Kelly Brian Cameron, Hau Thien Tran
Abstract: A shielding apparatus was developed to eliminate electromagnetic waves interference (EMI) to an integrated circuit (IC) die while it is under test. The shielding apparatus comprises a conductive plate having a first and second surfaces and a central opening where the IC device is placed. The first surface includes a first EMI gasketted channel and a central cavity disposed inside of the gasketted channel. The second surface of the apparatus includes a second EMI gasketted channel and the central opening which extends through both the first and second surfaces. When the first surface mates with the surface of automatic test equipments (ATE) interface board, the first gasketted channel forms a tight seal. Similarly, when a plunger from a device handler mates with the second surface, the second EMI gasketted channel forms a seal that blocks out EMI. In this way, the IC device in the central opening of the apparatus is isolated from external EMI.
Abstract: A system and method for acquiring a transmitted spread-spectrum signal uses a matched filter configuration that is preferably employed as a Stage 2 filter in the second phase of an initial signal acquisition procedure performed in the receiver. In operation, a Stage 1 filter matches a sequence which is repeated a number of times according to a second sequence within a secondary synchronization sub-channel of the spread-spectrum signal. The Stage 2 filter of the invention then filters the output of the Stage 1 filter in order to recover a secondary synchronization code. The Stage 2 filters the output of the Stage 1 filter using three matched filters of its own. The first and second filters sample different taps of a sequence output from the Stage 1 filter. The third filter samples a predetermined number of taps overlapping taps for the first and second filters in a way that resolves ambiguities with respect to the identification of the sequence.
Type:
Grant
Filed:
November 28, 2001
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Li Fung Chang, Kapil Chawla, Nelson Sollenberger
Abstract: A system and method for transferring information in a multi-channel, point-to-point environment are described. In one embodiment, a number of processing chips are connected to a bridge bus. A bridge is connected to the bridge bus and to a system bus. In addition, a memory is connected to the bridge.
Abstract: In a communication system, Huffman coding techniques are used to obtain shaping gains for an improvement in data transmission rates. More particularly, a novel method of Huffman shaping is described that achieves a shaping gain of greater than 1 dB. The shaping gain results in a higher data rate transmission in a communication system where transmitted power is constrained.
Type:
Grant
Filed:
July 3, 2001
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Gottfried Ungerboeck, Arthur J. Carlson
Abstract: A telephony system and method is provided that reduces delay and provides better utilization of upstream bandwidth in delivering packet telephony services to a plurality of subscriber lines via a cable modem system. An exemplary system includes a plurality of voice processing modules, a host processor, and a buffer. Each voice processing module receives digital voice signals from a separate set of subscriber lines, compresses the digital voice signals to generate a voice packet, and transfers the voice packet to the buffer. The host processor then assembles a packet by concatenating the voice packets and transmits the assembled packet for delivery over a data network. Because the plurality of voice processing modules process the voice packets in parallel, delay is reduced in the assembly and transmission of the assembled packet.
Abstract: A method and system to determine when a wireless terminal has been paged by a servicing base station. An encoded paging burst is received on a paging channel and then decoded to produce a decoded paging burst. The decoded paging burst is processed to determine if it is a null page. When the encoded paging burst is a null page, it is processed to produce a null page pattern. The wireless terminal may then enter a sleep mode or reduced functionality mode for a predetermined period of time. The wireless terminal awakes from the sleep mode to receive additional encoded paging bursts. Processing the additional encoded paging bursts produces a processed encoded paging burst, which is compared to the null page pattern. When compared favorably, the encoded paging burst is considered a null page, allowing the wireless terminal to re-enter the sleep mode without fully decoding the paging burst.
Abstract: A system for detecting collisions in a shared communications medium, such as a TDMA medium, includes a receive path adapted to generate a first intermediate signal, a second intermediate signal, and a data symbol sequence from an input signal. A preamble detection module generates a correlation metric from the first intermediate signal. A power measurement module generates a power indication signal from the second intermediate signal. A noise measurement module generates a noise indication signal from the second intermediate signal and the data symbol sequence. A processing module is adapted to characterize the input signal as a collision for certain values of correlation metric, power indication signal, and noise indication signal.
Type:
Grant
Filed:
July 30, 2001
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Bruce J. Currivan, Jonathan S. Min, Fang Lu
Abstract: An integrated communications system. A substrate having a receiver disposed on the substrate for converting a received signal to an IF signal, a digital IF demodulator disposed on the substrate and coupled to the receiver for converting the IF signal to a demodulated baseband signal, and a transmitter disposed on the substrate operating in cooperation with the receiver to establish a two way communications path.
Type:
Grant
Filed:
December 15, 2000
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Pieter Vorenkamp, Myles H. Wakayama, Steven Jaffe, Frank Carr, Arnoldus Venes, Peter R. Kinget, Daniel J. Marz, Thinh Nguyen
Abstract: RF communications received by a wireless terminal from a servicing base station are used to determine the downlink quality report and implement link adaptation decisions. This involves first implementing an initial transmission scheme between the servicing base station and the wireless terminal. Next, a current downlink quality report corresponding to the initial transmission scheme is generated by the wireless terminal and received at the servicing base station. This downlink quality report is based in whole or in part on a bit-error probability (BEP). The current downlink quality report that corresponds to the initial transmission scheme is then compared to link adaptation thresholds.
Abstract: A data processor comprising: a register memory comprising an array of memory cells, each cell being addressable by means of an instruction specifying a pair of coordinates that identify the cell in the array.
Type:
Grant
Filed:
March 1, 2006
Date of Patent:
September 12, 2006
Assignee:
Broadcom Corporation
Inventors:
Stephen Barlow, Timothy Ramsdale, Robert Swann, Nel Bailey, David Plowman
Abstract: A high gain, highly linear mixer includes an input section, mixing section, at least one tuning component, and at least one stand by current source. The input section is operably coupled to receive an input voltage signal and perform a linear transconductance thereon to produce an input current signal. The mixing section is operably coupled to mix a local oscillation with the input current to produce a mixed current signal. The tuning component is operably coupled to the mixing section and to convert the mixed current signal into a mixed voltage signal that function as the output of the mixer. The standby current source is operably coupled to the mixing section and provides a standby current to the mixing section.
Abstract: A communication network having at least one access point supports wireless communication among a plurality of wireless roaming devices via a first and a second wireless channel. The access point comprises a first and a second transceiver. The first and second transceivers operate on the first and second wireless channels, respectively. Each of the plurality of wireless roaming devices are capable of communicating on the first and second wireless channel. In one embodiment, the first wireless channel is used to exchange data, while the second channel is used to manage such exchanges as well as access to the first channel. In an alternate embodiment, both channels are used to support communication flow, however the first channel supports a protocol that is more deterministic than that of the second channel. Allocation of ones of the plurality of wireless roaming devices from one channel to the next may occur per direction from the access point.
Abstract: A network switch for network communications includes a first data port interface, supporting a plurality of data ports transmitting and receiving data at a first data rate. A second data port interface supporting a plurality of data ports transmitting and receiving data at a second data rate. A CPU interface communicating with a CPU, an internal memory, a memory management having an external memory interface, and a communication channel are provided. A plurality of lookup tables having address resolution lookup/layer three lookup, rules tables, and VLAN tables are provided. One of the data port interfaces is configured to update the address resolution table based on newly learned layer to addresses and a synchronization process per entry is provided.
Abstract: A single chip radio transceiver includes circuitry that enables detection of radar signals to enable the radio transceiver to halt communications in overlapping communication bands to avoid interference with the radar transmitting the radar pulses. The radio transceiver is operable to evaluate a number of most and second most common pulse interval values to determine whether a traditional radar signal is present. The radio transceiver also is operable to FM demodulate and incoming signal to determine whether a non-traditional radar signal such as a bin-5 radar signal is present. After FM demodulation, the signal is averaged wherein a substantially large value is produced for non-traditional radar signals and a value approximately equal to zero is produced for a communication signal that is not FM modulated with a continuously increasing frequency signal. Gain control is used to limit incoming signal magnitude to a specified range of magnitudes.
Type:
Application
Filed:
May 2, 2006
Publication date:
September 7, 2006
Applicant:
Broadcom Corporation, a California Corporation