Abstract: A method and system are provided for forward error correction. Embodiments of the present disclosure provide a strong FEC algorithm that performs similarly to RS(255,239) when a simple decoder is used, and scales up linearly to a full-scale decoder that outperforms all 7% algorithms currently in G.975.1. The Forward Error Correction code is suitable for use in optical transport networks (OTN) and other applications requiring high decode performance and high code rate. Embodiments of the present disclosure provide an FEC code that is a cyclically interleaved dual BCH, with simultaneous decode and per-codeword maximum likelihood reconciliation.
Abstract: A method to look at the incoming received data on a SerDes link while running in normal operation without requiring a second receive path or any defined or repeated data patterns to be able to generate statistical eye plots both before and after any internal equalization; generate trajectory eye plots both before and after any internal equalization; estimate TED characteristics (hence also estimate SJ jitter tolerance of the link); estimate complete Channel Impulse Response (hence also estimate the S-parameters of the complete channel); and estimate the decomposed jitter of the complete channel.
Type:
Grant
Filed:
November 30, 2009
Date of Patent:
June 18, 2013
Assignee:
PMC-Sierra US, Inc.
Inventors:
William Dean Warner, Graeme B. Boyd, William Michael Lye
Abstract: Apparatus and methods configure digital predistortion linearizers for power amplification of bandlimited signals using non-linear amplifiers. The predistorter is configured to achieve both crest factor reduction (CFR) and predistortion for linearization. One embodiment advantageously reduces processing requirements conventionally associated with CFR by considering only the in-band component, that is, the information bearing component, of the desired signal to be reproduced for those cases in which the mitigation of in-band error vector magnitude (EVM) is preferred over the reduction of spurious out-of-band emissions.
Abstract: Disclosed is a high-swing voltage-mode transmitter or line driver. The transmitter can operate over a wide range of supply voltages. Increasing the available output swing merely involves increasing the supply voltage; the circuit adapts to maintain the desired output impedance. This allows for a tradeoff between output amplitude and power consumption. Another advantage of the proposed architecture is that it compensates for process, voltage, and temperature (PVT) and mismatch variations so as to keep rise and fall times matched. This feature reduces common-mode noise and hence EMI in systems in which the transmitter is used.
Abstract: A method and system are provided for forward error correction. Embodiments of the present disclosure provide a strong FEC algorithm that performs similarly to RS(255, 239) when a simple decoder is used, and scales up linearly to a full-scale decoder that outperforms all 7% algorithms currently in G.975.1. The Forward Error Correction code is suitable for use in optical transport networks (OTN) and other applications requiring high decode performance and high code rate. Embodiments of the present disclosure provide an FEC code that is a cyclically interleaved dual BCH, with simultaneous decode and per-codeword maximum likelihood reconciliation.
Abstract: Large interfering signals (interferers) with spectra near a desired signal can cause distortion in a wireless receiver due to a non-linear signal path. It is typically a performance advantage to attenuate these interferers earlier in the signal path, rather than later in the signal path, because these interferers can cause saturation of amplifying stages. In certain situations, the frequency offset of an interfering signal, with respect to the desired signal, can be on the order of 10 megahertz (MHz), whereas the center frequencies can be on the order of several gigahertz (GHz). Thus, a filter with “baseband” precision would be needed at radio frequency to notch out the interferer, which is relatively difficult to do. Disclosed is a technique to estimate the relative strength and center frequency of the interferer and to place the center frequency of a notch filter adaptively and precisely at the interferer location.
Abstract: Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).
Type:
Grant
Filed:
January 23, 2009
Date of Patent:
April 23, 2013
Assignee:
PMC-Sierra, Inc.
Inventors:
Ognjen Katic, Paul V. Yee, William D. Warner
Abstract: Alignment-enabled secondary nodes of a DAMA network monitor the alignment of for-transmission data as it is received, and actively align the data frames into encoded blocks such that the number of blocks occupied by encoded data resulting from an unencoded datastream of a particular length is predictable rather than variable. In some embodiments, the network is an Ethernet passive optical network and the alignment includes aligning a XGMII word having a start control code to a first position in a 72 bit word input to a 66B/66B encoder, thereby encoding a start-of-frame (/S/) code to a first byte of an encoded first Ethernet 66b block.
Abstract: A system for redundancy in Ethernet passive optical networks (EPONs) facilitates fast recovery from failure (less than 50 msec), path redundancy of the fiber optic network, and location redundancy of the OLTs. An optical networking unit (ONU) in a normal state monitors input communications, and when the input communications are quiet for a predetermined minimum length of time, the ONU transitions to a lenient state in which: the ONU accepts old and new security keys; upon receiving a packet: the ONU updates an ONU timestamp based on the packet's timestamp; and the ONU transitions to the normal state of operation. While the ONU is in the lenient state if a packet is not received for a predetermined given length of time the ONU transitions to a deregistered state. In this system, main and standby OLTs do not require synchronization of security parameters or synchronization for differences in fiber lengths.
Abstract: Methods for increasing upstream bandwidth utilization in an Ethernet passive optical network (EPON) use in some instances round-down instead of round-up occupancy values reported to an optical line terminal. An optical network unit determines whether the occupancy needs to be round-up or round-down and reports the occupancy in either round-up or round-down report units to the optical network terminal.
Type:
Grant
Filed:
May 27, 2009
Date of Patent:
April 9, 2013
Assignee:
PMC Sierra Ltd
Inventors:
Zachy Haramaty, Jeff Mandin, Valentin Ossman
Abstract: A method and system are provided to detect and correct errors in the Interlaken block code overhead bits. Specifically, a method is provided for determining the original transmitted information with a very high probability of correct interpretation. These approaches can also characterized by their minimal complexity. Further, such a method can operate on the received information in a manner that does not require consideration of special cases. Also, the method does not require the source to send any extra information or alter its current behavior in any way. Thus, the approaches described herein are compatible with all existing Interlaken sources and can provide immediate benefits.
Type:
Grant
Filed:
February 12, 2010
Date of Patent:
April 2, 2013
Assignees:
PMC-Sierra, Inc., Open-Silicon, Inc.
Inventors:
Winston Ki-Cheong Mok, Steven Scott Gorshe, Matthew David Weber
Abstract: An in-band OTDR uses a network's communication protocols to perform OTDR testing on a link. Because the OTDR signal (probe pulse) is handled like a data signal, the time required for OTDR testing is typically about the same as the time required for other global network events, and is not considered an interruption of service to users. A network equipment includes an optical time domain reflectometry (OTDR) transmitter and receiver, each operationally connected to a link to transmit and receive, respectively, an OTDR signal. When an OTDR is to be performed, a network device operationally connected to the link actuates the OTDR transmitter to transmit the OTDR signal on the link during a determined test time based on a communications protocol of the link, during which data signals are not transmitted to the network equipment. A processing system processes the OTDR signal to provide OTDR test results.
Type:
Grant
Filed:
July 8, 2010
Date of Patent:
March 26, 2013
Assignee:
PMC Sierra Israel Ltd.
Inventors:
Lior Khermosh, Christopher Michael Look, Tiberiu Galambos
Abstract: A method and system is provided for securing communication on an EPON. Particularly different types of encrypted messages, each with a respective short MAC SegTAG, may be sent from the OLT to an ONU and from an ONU to the OLT without need for a full SecTAG with an explicit SCI. Discovery and control messages may be encrypted and a security offset may be less than 30 bytes. A packet header including its MAC address may be encrypted.
Type:
Grant
Filed:
January 5, 2010
Date of Patent:
March 12, 2013
Assignee:
PMC Sierra Ltd.
Inventors:
Lior Khermosh, Zachy Haramaty, Jeff Mandin
Abstract: The adverse effects of RF and baseband circuits are mitigated using a post-compensation method wherein a transfer function that would un-distort or complement a distorted waveform is parameterized to a relatively small number of degrees of freedom; and the parameters are estimated in a feedback loop. The error function of the feedback loop is generated by comparing some relatively low-order statistics that are known a priori or can be computed with relative certainty from the decided output waveform—to the statistics of the corrected signal.
Type:
Grant
Filed:
April 4, 2011
Date of Patent:
March 12, 2013
Assignee:
PMC-Sierra, Inc.
Inventors:
Anthony Eugene Zortea, Graeme Barclay Boyd
Abstract: A mixer circuit suitable for broadband RF applications is disclosed. A unique biasing scheme for a conventional Gilbert-cell type 4-quadrant multiplier is used, resulting in relatively good linearity, relatively low noise, and relatively low power consumption. Disclosed techniques provide programmability in gain for the mixer and a broadband frequency of operation. A non-linear feedback loop is wrapped around the circuit to stabilize the common-mode voltage shifts due to programming. In one embodiment, a non-linear switch as load-resistance is used to improve the linearity of the circuit.
Abstract: A method and system are provided for forward error correction. Embodiments of the present disclosure provide a strong FEC algorithm that performs similarly to RS(255,239) when a simple decoder is used, and scales up linearly to a full-scale decoder that outperforms all 7% algorithms currently in G.975.1. The Forward Error Correction code is suitable for use in optical transport networks (OTN) and other applications requiring high decode performance and high code rate. Embodiments of the present disclosure provide an FEC code that is a cyclically interleaved dual BCH, with simultaneous decode and per-codeword maximum likelihood reconciliation.
Abstract: A method of communicating count value information in an Optical Transport Network (OTN) signal frame. The method comprises determining a count value indicating a number of payload bytes to be sent in a next OTN signal frame; determining that a change in the count value (?) with respect to a current count value is within a predetermined range; selecting an inversion pattern indicating the change in the count value; determining a cyclic redundancy check (CRC) code associated with the inversion pattern; and, inserting the inversion pattern and the CRC code in a Generic Mapping Procedure (GMP) overhead of the OTN signal frame.
Abstract: A method of managing forward error correction (FEC) initialization and auto-negotiation in ethernet passive optical networks includes receiving FEC data from an optical network unit (ONU), and the optical line terminal (OLT) responds to the ONU with FEC data. Upon receiving data not forward error corrected from an ONU, the OLT responds with data not coded for FEC. Similarly, upon receiving forward error corrected data from the OLT, the ONU responds with forward error corrected data; and upon receiving data not forward error corrected from the OLT, the ONU responds with data not forward error corrected. The communications quality from the ONU is monitored, if the communications quality is not sufficient, the OLT transmits forward error corrected data to the ONU; otherwise, the OLT transmits non-FEC data to the ONU.
Abstract: A method for simulating a chip is provided. The method initiates with defining a library of components for a processor. Then, the interconnections for a set of pipelined processors including the processor are defined. Next, a processor circuit is generated by combining the library of components and the interconnections for the set of pipelined processors. Then, a code representation of a model of the set of pipelined processors is generated. Next, the signals generated by the code representation are compared to the signals generated by the processor circuit. If the comparison of the signals is unacceptable, then the method includes identifying a cause of the unacceptable comparison of the signals at a block level of the processor circuit. A method for generating a netlist for a pipeline of processors, a method for debugging the processor circuit and computer code for simulating a chip circuit are also provided.
Abstract: An OLT allocates a bandwidth budget and assigns upstream transmission order by receiving upstream transmission requests from a plurality of ONUs. Each ONU's request includes a requested guaranteed bandwidth and a requested best effort bandwidth. Each ONU has respective first and second attribute values. One attribute is given allocation priority over the other attribute. One attribute is given scheduling priority over the other attribute. Within each attribute, an allocation rank and a transmission rank is assigned to the possible attribute values. The bandwidth budget is allocated in accordance with the allocation priority and ranks. The upstream transmissions are scheduled in accordance with the scheduling priority and ranks.