Methods and systems for reducing impulse disturbances

Abstract

A machine-implemented method for reducing impulse noise in quadrature amplitude-modulated (QAM) carriers, comprising: receiving quadrature amplitude-modulated (QAM) carriers at a receiver (602); generating equalized samples of the QAM carriers by equalizing the QAM carriers by the receiver (602); receiving equalized samples of the QAM carriers from the receiver (602); determining a symbol quality measure for a symbol based on equalized samples of at least one of the carriers in the symbol, wherein determining the symbol quality measure comprises determining distances between carriers in the symbol and points of corresponding quadrature amplitude-modulated constellations, and determining the symbol quality measure based on the determined distances;Determining a running background signal quality measure based on symbol quality measures determined for several symbols, wherein determining the running background signal quality measure comprises determining the running background signal quality measure as the mean of the symbol quality measures of the several symbols; generating a first control to reduce carrier quality measures of all data carriers in the symbol when the symbol quality measure exceeds a first threshold which varies with fluctuations in the background signal quality measure, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and wherein generating the first control comprises generating the first control to reduce the SNR of all data carriers in the symbol when the symbol quality measure exceeds the first threshold; routing the first control to the receiver (602);Estimating, by the receiver, of LLR (Log-Likeihood Ratios) for bits led in constellation points of the data carriers for multiple symbols based on the corresponding SNR; forward error correction (FEC), by the receiver (602), of the estimated LLR; and downscaling, by the receiver (602), of the estimated SNR of all data carriers in the symbol before estimating LLR based on the first control element.

Description

STATE OF THE ART

[0001] Linked codes are a class of error-correcting codes that combine an inner code and an outer code to provide exponentially decreasing error probability and polynomial-time decoding complexity as block length increases.

[0002] Conventional cable networks include coaxial cables and / or a combination of fiber optics and coaxial cables, the latter of which can be referred to as a hybrid fiber-coaxial or HFC network.

[0003] In a cable network, sporadic impulse noise or noise bursts can occur, which may take place at an average rate of approximately 10 Hz. Noise burst durations can be in the range of approximately 20 microseconds (μs), which is sufficient to affect one or more symbols of a multi-carrier signal, such as an orthogonal frequency-division multiplexed (OFDM) signal. Conventional cable systems use single-carrier quadrature amplitude modulation (QAM), which is less affected by impulse noise than a multi-carrier signal, such as an OFDM-modulated signal.

[0004] Conventional cable systems use chained FEC (forward error correction) codes, which include an inner trellis code and an outer RS ​​(Reed-Solomon) code.

[0005] Conventional cable receivers reduce impulse noise or noise bursts by de-nesting between trellis decoding and RS decoding. This may not be practical for unconcatenated codes, such as an LCPC (low-density parity check) code. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. Figure 1 is a flowchart of a procedure for symbolically reducing impulse noise across all data carriers of a signal.

[0007] Fig. Figure 2 is a representation of an OFDM signal that includes carriers c(1) to c(m).

[0008] Fig. Figure 3 is a flowchart of another method for symbolically reducing burst noise or impulse noise across all data carriers.

[0009] Fig. Figure 4 is a block diagram of a reduction system for symbolically reducing burst noise across all data carriers of a signal.

[0010] Fig. Figure 5 is a block diagram of a system that shows exemplary implementations of aspects of the mitigation system of Fig. 4 includes.

[0011] Fig. Figure 6 is a block diagram of a system that includes a receiver and a burst noise or impulse noise reduction system.

[0012] Fig. Figure 7 is a block diagram of a computer system designed to reduce impulse interference in a receiver.

[0013] Fig. 8 is a block diagram of a processor and a memory of Fig. 7, where storage includes primary storage, secondary storage and offline storage.

[0014] Fig. Figure 9 is a block diagram of a system that includes a processor, memory / storage, a user interface and a communication system, which includes an impulse noise mitigation system.

[0015] In the drawings, the first position(s) of a reference number identify the drawing in which the reference number first appears. DETAILED DESCRIPTION

[0016] This document reveals methods and systems for reducing burst noise, also known as impulse noise.

[0017] The methods and systems can be implemented in combination with non-chained FEC (forward error correction) such as LCPC (low-density parity check) code.

[0018] A non-concatenated FEC code like LDPC can provide significantly higher receiver gain compared to a concatenated FEC code. This increased gain can allow for higher data rates.

[0019] The methods and systems disclosed herein can be implemented using one or more of the various QAM-based modulation techniques, including multi-carrier modulation techniques such as OFDM (orthogonal frequency division multiplexing) and / or other multi-carrier modulation techniques, single-carrier (SC) QAM systems with frequency domain equalization (SC-FDE) and / or SC QAM systems with frequency division multiplexing (SC-FDM).

[0020] Each point of a 2 n A 64-QAM constellation represents n bits. For example, a 64-QAM constellation comprises 2 6 = 64 points and each of the 64 points represents a unique set of 6 bits.

[0021] Each constellation point can be associated with a unique phase and amplitude, and the n bits of a constellation point can be transmitted by modulating a carrier signal with the phase and amplitude of the constellation point. The n bits can be referred to as the bits carried in a constellation point of a data carrier, or equivalently, the bits carried in a data carrier constellation point.

[0022] Under ideal conditions, a set of n bits carried in a data carrier constellation point can be demodulated based on the phase and amplitude of the carrier. In practice, a log likelihood ratio (LLR) can be calculated for each of the n bits to indicate the probability (likelihood) that the corresponding bit is logic 1 or logic 0. For a 64-QAM carrier, LLRs are calculated for 6 bits. The LLRs can be referred to as soft values ​​or soft decisions. The LLRs can be processed with forward error correction (FEC), as will be discussed later. Fig. 6 is described.

[0023] The methods and systems disclosed herein can be implemented in one or more of a wide variety of communication systems, including, without limitation, cable systems such as HFC cable systems, and can be implemented in a physical layer of a network, such as an HFC (hybrid fiber-coaxial) network.

[0024] Methods and systems are disclosed here for illustrative purposes with reference to OFDM and LDPC. However, the methods and systems disclosed here are not limited to OFDM or LDPC.

[0025] Fig. 1 is a flowchart of a process 100 for the symbol-based reduction of impulse interference across all data carriers of a signal. The method 100 will be discussed below with reference to Fig. 2 described. The procedure 100 However, this is not based on the example of Fig. 2 limited.

[0026] Fig. Figure 2 is a representation of an OFDM signal. 200 with carriers 202 , which are also referred to as c(1) to c(m).

[0027] The signal 200 includes symbol periods or symbols 204 , which are regulated by protection intervals 206 can be separated.

[0028] The carriers 202, or a subset thereof, exhibit associated carrier quality measures (carrier QM) 212 on, which are also referred to here as QM per carrier. The carrier QM 212 may include a relatively long-term signal quality measure, such as a long-term estimate of the signal-to-noise ratio (SNR), which may be based on variances in corresponding channel estimates observed over multiple symbols.

[0029] At 102 in Fig. 1. Symbol quality measures (Symbol-QM) 208 for symbols 204 of the signal 200 calculated. The symbol-QM 208 can also be referred to as QM per symbol.

[0030] Each symbol-QM 208 can be derived from rectified samples of one or more carriers 202 in the corresponding symbol 204 can be calculated. For example, the symbol-QM 208(k) from one or more of the carriers c(1) to c(m) in the symbol 204(k) will be calculated.

[0031] Symbol-QM 208 can be determined based on a difference or error measure of the carrier(s), which can indicate a noise level. The symbol QM 208(k) This can be determined, for example, based on distances between carriers and points in corresponding QAM constellations. For a data carrier, the distance can be determined with reference to a constellation point closest to the rectified sample value. For a pilot carrier, the distance can be determined with reference to a known constellation point associated with the pilot carrier.

[0032] The QM 208(k) can be calculated as the average or mean of squared distances for multiple supports in the symbol 204(k) to be calculated. The QM 208(k) can be calculated as the mean squared error MSE(k), which can be expressed as follows: where x(i) represents a position of an i-th carrier in a symbol; p(i) represents a constellation point; S represents a set of carriers for which distance is calculated in the symbol k; and L is the number of carriers over which MSE(k) is calculated.

[0033] S can handle all pilot and data carriers of the signal. 200 or comprise a subset thereof. For example, if a subset of carriers 202 Since the subset of carriers is characterized as relatively noisy, it can be excluded from S.

[0034] S can include a combination of pilot carriers and data carriers, or it can be limited to pilot carriers or data carriers.

[0035] In the following examples, a symbol-based quality management system can be used. 208For illustrative purposes, MSE(k) may be used. Unless explicitly stated otherwise, the use of MSE(k) is not limited to a single MSE.

[0036] At 104 in Fig. 1. A background signal quality measure (background QM) is used. 210 based on several symbol-based quality management systems 208 determined. The background QM 210 can be expressed as a running average or mean over several symbols or symbol periods 204 calculated and / or managed and can be represented as AVG_MSE(k).

[0037] The background QM 210 can be calculated and / or carried out non-recursively over N symbols, as in the following Eq. (2), or with recursive averaging, as in the following Eq. (3). AVG_MSE(k) = AVG_MSE(k – 1) + MSE(k) – MSE(k – N) N Gl. (2) AVG_MSE(k) = (1 – α)AVG_MSE(k – 1)+ αMSE(k); 0 < α Eq. (3)

[0038] Recursive averaging modifies a previously known value and therefore requires little or no storage.

[0039] Non-recursive averaging can be performed over a rectangular sliding window of symbols, where each symbol has the same weight. Alternatively, non-recursive averaging can be performed over a non-rectangular sliding window of symbols, where the weight varies with the symbol's position in the window. A non-rectangular sliding window can use a combination of rectangular and non-rectangular weighting. Non-rectangular weighting can, for example, include exponential weighting.

[0040] The following examples illustrate the background QM 210 For illustrative purposes, it may be referred to as AVG_MSE(k). Unless explicitly stated otherwise here, the mention of AVG_MSE(k) is not limited to a single MSE.

[0041] As described above, the background QM210 Thus, a single overall quality measure is averaged across multiple symbols and carriers. In contrast, each carrier-based quality management system is 212 a single quality measure for a single carrier, which is represented by several symbols 204 calculated or estimated. And in contrast, the symbol-QM 208 a quality measure of a single symbol 204 , which can be averaged over multiple carriers.

[0042] As described below, the background QM 210 and symbol-QM 208 used to create symbols 204 to identify those affected by burst noise. Burst noise is then described in relation to the individual symbols. 204 reduced by the carrier's QM 212 for all carriers in the symbol, or by setting LLR values ​​to indicate that each bit of that carrier is a deletion. Carrier QM downgrading 212in the symbol and / or the deletion of carriers 212 The symbol can reduce the impact of burst noise in the symbol during downstream FEC.

[0043] For example, a burst of noise can last approximately 20 μs, and a symbol or symbol period 204 The time interval can be in the range of 80 μs. The noise burst can therefore consist of only 1 or two symbols. 204 Impairing. Specifically, the noise burst can cause the symbol-QM to 208 the 1 or two symbols 204 the background QM 210 exceed by an amount sufficient to impair the accuracy and / or reliability of the downstream forward error correction (FEC).

[0044] At 106 in Fig. 1. Symbol-QM 208 with the background QM 210 compared to symbol-QM 208 to identify the background QM 210exceed an amount sufficient for downstream decoding of the corresponding symbol 204 , which may be due to a burst of noise. In Fig. 2. MSE(k) can be compared with AVG_MSE(k).

[0045] At 108 will be for each in 106 identified symbol-QM 208 Burst noise with reference to the corresponding symbol 204 reduced by carrier-QM 212 for all carriers in the symbol 204 be downgraded or by increasing the carrier's LLR values 212 This is used to indicate that each bit of each carrier is a deletion in the symbol. Fig. 2. The carrier QM 212 in the symbol 204(k) MSE(k) will be downgraded if MSE(k) exceeds AVG_MSE(k) sufficiently.

[0046] The carrier's QM 212 can be downgraded by a predetermined amount or factor. Alternatively, the carrier's quality management can be used. 212based on a scale to which a symbol-QM 208 the background signal QM 210 exceeds, may be downgraded, and can be proportional to the extent to which the symbol-QM 208 the background signal QM 210 exceeds, will be downgraded.

[0047] The proportional downgrading scheme given in equation (4) below is the optional way to downgrade the carrier QM if the burst noise behaves like additive white Gaussian noise (AWGN) over a carrier (i.e., frequency) domain, the carrier QM 212 for the symbol 204(k) as in Eq. (4) be downgraded proportionally: QM(i, k) = QM(i,k) AVG_MSE(k) MSE(k) Gl. (4) where QM(i, k) is the carrier QM of carrier i in symbol k.

[0048] The carrier's QM 212 They can be downgraded linearly, stepwise, exponentially, and / or combinations thereof. The carrier QM 212can be downgraded to such an extent that the carriers are essentially deleted in the symbol k.

[0049] The carrier's QM 212 They can be explicitly deleted by setting LLR values ​​as described below.

[0050] For example, in 106 MSE(k) can be compared with several thresholds that can vary with fluctuations in AVG_MSE(k). At 108 Long-term SNR estimates for all data carriers in the carriers are possible. 212 for the symbol 204(k) MSE(k) can be downgraded if it lies between a first and second threshold. Conversely, if MSE(k) exceeds the second threshold, LLRs can be set to reduce carrier load. 212 in the symbol 204(k) to delete.

[0051] Additional examples of carrier QM downgrading and setting LLR to delete carriers in a symbol will be given later with reference to Fig. 3 given.

[0052] The procedure100 can be described below with reference to Fig. 3 will be implemented as described.

[0053] Fig. 3 is a flowchart of a process 300 for symbol-based reduction of burst noise or impulse noise across all data carriers. The method 300 will be discussed below with reference to Fig. 2 described. The procedure 300 However, this is not based on the example of Fig. 2 limited.

[0054] At 302 A symbol noise figure for a symbol k is calculated based on equalized samples of one or more carriers in the symbol k. The symbol noise figure can be based on squared distances, as above with reference to 102 in Fig. 1 described. In Fig. 2 becomes MSE(k) for the symbol 104(k) calculated.

[0055] At 304MSE(k) is compared to a first threshold that varies based on fluctuations in a background noise level. The first threshold can be defined or calculated as the product of a background noise level and a multiplier, referred to here as the first threshold factor. 304 The background noise level is represented as AVG_MSE(k), and the multiplier as "A". The first threshold can also be referred to as a lower threshold or a moderate threshold.

[0056] When MSE(k) is present 304 If the value is smaller than the first threshold, the symbol k can be considered less than moderately distorted, and at 306 Carrier QM in the symbol k will remain intact.

[0057] Since MSE(k) is less than moderately distorted, it is also possible with 306 A decision must be made to update AVG_MSE(k) with MSE(k). This decision can be made at the first threshold, as with... 304The displayed value is based on a specific threshold, or it can be based on one or more other thresholds. Selectively updating AVG_MSE(k) depending on a noise measure of MSE(k) can help prevent noise burst contamination of AVG_MSE(k).

[0058] If at 304 If MSE(k) is greater than or equal to the first threshold, carrier QM of all data carriers in the symbol k can be downgraded or LLR values ​​can be set to delete all data carriers in the symbol k, as described above.

[0059] In Fig. 3 will be a second threshold at 308 used to differentiate between deterioration of carrier QM during a symbol at 310 and identifying carriers for explicit deletion at 312 to select.

[0060] At 308MSE(k) is compared to a second threshold that is larger than the first threshold and also varies with fluctuations in the background noise level. The second threshold can be defined or calculated as the product of the background noise level and a multiplier, referred to here as the second threshold factor. 308 The background noise is represented as AVG_MSE(k), and the multiplier is represented as "B". The second threshold can also be referred to as the higher threshold, upper threshold, or excessive noise threshold.

[0061] When MSE(k) is present 308 If MSE(k) is smaller than the second threshold, then by definition it is equal to the first threshold or lies between the first and second thresholds, and the symbol k can be considered moderately corrupted.

[0062] At 310 If the symbol k is considered to be moderately corrupted, all data carriers using the symbol k will be downgraded.

[0063] If at 308 MSE(k) at least equal to the second threshold at 308 If MSE(k) is significantly distorted, then MSE(k) can be considered significantly distorted. 312 All data carriers are identified for deletion by the symbol k.

[0064] At 314 k is incremented to evaluate a subsequent symbol.

[0065] At 316 The equalized sample values ​​are calculated according to the intact carrier quality management at 306 processed 310 Carrier quality management downgraded and / or at 312 Carrier quality management identified for deletion.

[0066] Fig. Figure 4 is a block diagram of a mitigation system. 400 for symbol-wise reduction of burst noise across all data carriers of a signal. The system 400 The system is described below with reference to the examples above. 400 However, it is not limited to the examples above.

[0067] The system400 includes a symbol-based quality management module 402 for calculating symbol-QM 404 based on equalized sample values 406 , as above with reference to 102 and / or 302 described.

[0068] The system 400 It also includes a background signal QM module. 408 to calculate a background signal QM 410 based on symbolic quality management 404 , as above with reference to 104 described.

[0069] The system 400 It also includes a threshold generator. 412 to generate one or more thresholds 414 based on the background signal QM 410 and one or more multipliers or threshold factors 416 , as above with reference to 108 , 304 and / or 308 described.

[0070] The system 400 also includes a comparator 418 for evaluating signal quality management404 based on threshold(s) 414 , as above with reference to 106 , 108 , 304 and / or 308 described.

[0071] The system 400 It also includes a carrier decision module. 420 to provide decisions 422 regarding carriers in a symbol based on comparative results 424 , as above with reference to 108 , 306 , 310 and / or 312 described.

[0072] The system 400 can create a selector 426 to select or omit a symbol-QM 404 from background QM 410 based on a threshold 414 , as above with reference to 306 described, include.

[0073] Fig. 5 is a block diagram of a system 500 , which are exemplary implementations of modules of the system 400 includes.

[0074] In Fig. 5 includes the symbol-QM module 202 a distance calculation module 502 to calculate a noise measure 504 for each of one or more carriers in a symbol k, each based on a distance between the corresponding carrier and a QAM constellation point, as above with reference to 102 described.

[0075] The QM module 202 It also includes an MSE module 506 for calculating symbol-QM 404 as MSE(k) based on noise measures 504 , as described above with reference to Eq. (1).

[0076] In Fig. 5 includes the background signal module 408 an averaging module 508 to calculate the background signal QM 410 as AVG_MSE(k), as described above with reference to Eq. (2) and (3).

[0077] In Fig. The threshold generator comprises 5. 412 Multipliers510-1 until 510-j , each to generate a corresponding threshold 414-1 until 414-j as the product of AVG_MSE(k) and a corresponding multiplier or threshold factor 416-1 until 416-j .

[0078] The threshold 414-1 is shown here as the lower threshold, which is the first threshold at 304 in Fig. 3 can correspond to the threshold. 414-j is shown here as the upper threshold, which is the second threshold 308 in Fig. 3 can correspond to the threshold. 414-1 can be greater than the threshold 414-j be. One or more other thresholds 414 can be smaller or larger than the threshold 414-1 and / or the threshold 414-j be.

[0079] In Fig. The comparator comprises 5 418 Comparators 512-1 until 512-j each to compare the symbol-MSE(k) with a corresponding threshold 414and to provide a corresponding result 424 for the carrier decision module 420 .

[0080] A system like the one above with reference to Fig. 4 and / or Fig. 5 described can be implemented in a receiver system, such as the following with reference to Fig. 6 described, to be implemented.

[0081] Fig. 6 is a block diagram of a system 600 , that a recipient 602 and a burst noise reduction system 604 includes the burst noise reduction system. 604 can be done as above with reference to the noise reduction system 400 and / or 500 can be configured as described.

[0082] The recipient 602 includes a tuner 606 to select and sample a channel of an input signal 610 The input signal 610It can be received via cable and / or fiber. The selected channel may contain an OFDM signal.

[0083] The recipient 602 It also includes an analog-to-digital converter (ADC) 612 for digitizing sample values 608 of the selected channel.

[0084] The recipient 602 It also includes a filter and automatic gain control module, together with 616 shown, for removing adjacent and unwanted out-of-band signals from the digitized samples. 614 .

[0085] The recipient 602 It can include phase-locked loops to recover clock and frequency data.

[0086] The recipient 602 includes an FFT module 624 (Fast Fourier Transform) for converting sampled values 618 in a frequency range.

[0087] The recipient 602It also includes a symbol timing recovery module. 620 to generate an FFT carrier 622 for the FFT module 624 .

[0088] The recipient 602 It also includes a channel estimator and equalizer, together with 628 shown, for estimating channels for carriers of the OFDM signal from corresponding frequency range samples. 626 and to equalize the frequency range sampling rates 626 .

[0089] The OFDM signal can include pilot tones modulated with known modulation (e.g., BPSK or QPSK), as well as known pseudorandom sequences. The pilot tones can be used for clock and frequency synchronization, channel estimation, and / or equalization.

[0090] The canal assessor and equalizer 628 can also include carrier quality measures (QM) 640 for data carriers. The carrier quality management 640This can include an estimated long-term noise measure for each carrier of the OFDM signal, such as a long-term SNR estimate. The long-term SNR for a carrier can be estimated based on variances in corresponding channel estimates observed over many symbols.

[0091] The recipient 602 also includes a frequency decoupling unit 632 for unnesting or randomizing the carrier arrangement and a time unnester 636 for dispersing randomized carriers 634 a symbol k between LDPC data blocks 638 The Time Unboxer 636 It can include a folding de-nesting machine or a block de-nesting machine. A folding de-nesting machine can utilize storage space relatively efficiently.

[0092] Frequency and time de-nesting can be performed with reference to all data carriers of the ODFM signal, except for pilot carriers.

[0093] As further described above, a carrier can be modulated with a phase and amplitude of a constellation point to transmit n bits associated with the constellation point, and LLRs can be computed for the n bits.

[0094] In Fig. The recipient includes 6 602 an LLR module 642 to calculate LLR 644 for n bits of each data carrier in a symbol k. The LLR 644 can be based on the dispersed randomized carriers in data blocks 838 and the carrier quality management described below will be calculated.

[0095] The recipient 602 also includes a bit de-nesting machine 646 for unnesting bits from LLR 644 as LLR estimates 648 .

[0096] The recipient 602 It also includes an FEC module, which is referred to here as an LDPC decoder. 650 (Low-Density Parity Code) is used to decode bits652 from the LLR estimates 648 based on carrier-specific quality management, such as long-term SNR estimates per carrier.

[0097] The performance of the LDPC decoder 650 depends on the quality of the LLR estimates 648 Burst noise can lead to deteriorated LLR estimates. 648 for affected symbols.

[0098] The mitigation system 604 is designed to make decisions 660 to generate what are here referred to as carrier-QM downgrading decisions 662 and carrier deletion decisions 664 comprehensively presented, as described in one or more of the examples above.

[0099] The recipient 602 a module includes 668 to downgrade carrier QM in a symbol k according to the decisions 662 .

[0100] The recipient 602 also includes a module 670 to set LLR 644, in order to effectively delete all carriers in a symbol k, according to the decisions 660 .

[0101] Lowering carrier QM and / or setting LLR values ​​as described here can affect the LDPC decoder. 650 to help optimally recover data bits from symbols affected by burst noise.

[0102] The frequency decoupling machine 632 and the time unboxer 636 Can symbol carriers be accessed via a sufficient number of LDPC data blocks? 638 disperse so that none of the data blocks contains more than a relatively small number of carriers to be demoted or deleted in a given symbol.

[0103] The modules 668 and 670 Carriers can remain intact during the symbol k if the decisions 660 no downgrade decision 662 or deletion decision 644 for the symbol k.

[0104] The recipient 602 can a BCH code module 672 to correct errors in the bit 652 include.

[0105] Methods and systems disclosed herein may be implemented in hardware, firmware, a computer system, a machine and combinations thereof, including discrete and integrated circuits, application-specific integrated circuits (ASICs) and / or microcontrollers, and may be implemented as part of a domain-specific integrated circuit encapsulation or system-on-a-chip (SOC) and / or a combination of integrated circuit encapsulations.

[0106] Fig. 7 is a block diagram of a computer system 700 , which is designed to reduce impulse interference in a receiver. The computer system 700 will be discussed below with reference to Fig. 4 described. The computer system 700 However, this is not based on the example of Fig. 4 limited.

[0107] The computer system 700 comprises one or more computer instruction processor units and / or processor cores, referred to here as processors 702 These are shown to be used for executing instructions from a computer program. The processor 702 It may include a general-purpose instruction processor, a controller, a microcontroller, or any other instruction-based processor.

[0108] The computer system 700 also includes storage 704 for holding computer program(s) 706 and data 708 .

[0109] Computer program(s) 704 include instructions to cause the processor to 702 executes or performs a process or procedure, such as that described below. The computer program 706 It can also be referred to as software, computer program logic, and / or machine-readable logic. The computer program 706may be encoded in a computer-readable medium, which may include a non-volatile medium.

[0110] The data 708 may include data that the processor 702 during the execution of computer program(s) 706 is intended to be used and / or those processed by the processor 702 when running computer program(s) 706 be generated.

[0111] The storage 704 may include one or more types of storage, which are described below in relation to Fig. 8 will be described.

[0112] Fig. Figure 8 is a block diagram of the processor. 702 and the storage 704 , whereby the storage 704 primary storage 802 , secondary storage 804 and offline storage 806 includes.

[0113] Primary storage 802 includes registers 808 , processor cache 810and main memory or system memory 806 The registers 808 and the cache 810 can the processor 702 be directly accessible. The main memory 806 can the processor 702 be directly and / or indirectly accessible via a memory bus. The primary storage 802 may include volatile memory, such as random access memory (RAM) and variants thereof, including but not limited to static RAM (SRAM) and / or dynamic RAM (DRAM).

[0114] Secondary storage 804 can the processor 702It may be indirectly accessible through an I / O (input / output) channel and can include non-volatile memory, such as read-only memory (ROM) and variants thereof, including, but not limited to, programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM). Non-volatile memory can also include non-volatile RAM (NVRAM), such as flash memory. Secondary storage 804 It can be configured as a mass storage device, such as a hard drive or disk drive, a flash memory drive, a USB stick or key, a floppy disk and / or a Zip drive.

[0115] Offline storage 806 It may include a physical device driver and an associated removable storage medium, such as an optical disc.

[0116] In Fig. 7 include computer program(s) 706 Instructions for reducing impulse control disorders (reduction) 710, in order to cause the processor 702 equalized sample values 406 evaluates impulse control disorders and makes decisions 422 calculated to reduce phase noise in one or more of the equalized samples, as in one or more of the examples described here.

[0117] The reduction instructions 710 include symbolic QM instructions 712 , in order to cause the processor 702 Symbol-QM 404 calculated, which may include MSE(k), as in one or more of the examples described here.

[0118] The reduction instructions 710 They also include background signal QM instructions. 714 , in order to cause the processor 702 Background signal QM 410 calculated values ​​that may include AVG_MSE(k), as in one or more of the examples described here.

[0119] The reduction instructions 710They also include threshold generator instructions. 716 , in order to cause the processor 702 one or more thresholds 414 based on the background signal QM 410 and one or more corresponding threshold factor(s) 416 calculated, as in one or more of the examples described here.

[0120] The reduction instructions 710 They also include comparator instructions. 718 , in order to cause the processor 702 Symbol-QM 404 with one or more thresholds 414 compares, as in one or more of the examples described here.

[0121] The reduction instructions 710 They also include directives for carrier decision-making. 720 , in order to cause the processor 702 decisions 422 based on comparative results 424provides, as in one or more of the examples described here.

[0122] For example, the recipient 730 Calculate quality measures per carrier (carrier-based quality management), such as long-term SNR, and make a decision. 422 This may include a decision to downgrade the carrier quality management for all data carriers in one symbol, as described in one or more examples here.

[0123] Alternatively or additionally, the recipient can 730 Calculate LLR as described above, and make a decision 422 This may include a decision to set the LLR to identify all data carriers as erased in one symbol, as in one or more of the examples described here.

[0124] The computer system 700 can communication infrastructure 740 for communication between devices and / or equipment of the computer system 700 include.

[0125] The computer system 700 can be one or more I / O devices (input / output) and / or controllers 742 for communication with one or more other systems, such as communication with the recipient 730 , include.

[0126] In one embodiment, the computer program includes 706 furthermore, recipient instructions 724 , in order to cause the processor 702 one or more characteristics of the recipient 730 implemented, which includes one or more characteristics of the recipient 602 in Fig. can include 2.

[0127] The methods and systems disclosed herein may be applied to one or more of a variety of systems, such as those described below. Fig. 9 described, can be implemented. However, the methods and systems disclosed here are not limited to the examples of Fig. 9 limited.

[0128] Fig. 9 is a block diagram of a system 900 with a processor system 902 , storage or storage 904 , a user interface system 910 and a communication system 906 as an interface between an external communication system or network 940 and the processor system 902 and / or user interface system 910 .

[0129] The communication system 906 can be designed to use a channel 942 , which may include a cable, fiber optics and / or a wireless connection, signals from the communication network 940 to receive.

[0130] The communication system 906 It can be designed to transmit multiple selectable signals (OFDM signal) over the channel 942 to receive.

[0131] The communication system 940 can include, without restriction, a media content provider to the system 900To provide media. The communication system 940 This could include, for example, a cable television provider.

[0132] The communication system 906 includes a receiver 944 for demodulating and decoding the data 946 from via channel(s) 942 received signals. The receiver 944 can be done as above with reference to the recipient 602 in Fig. be configured as described in section 6.

[0133] The communication system 906 also includes a recipient 944 of the impulse disturbance reduction system 948 for the provision of mitigation decisions 952 based on equalized sample values 950 , as described in one or more examples.

[0134] The storage 904 can be one or more of the above with reference to Fig. The 8 described features include and can be used by the processor system 902, the communication system 906 and / or the user interface system 910 be accessible.

[0135] The user interface system 910 can be a monitor or display 932 and / or a human interface device (HID) 934 include the HID 934 The user interface system can include, without limitation, a keyboard, a cursor device, a media presentation control (e.g., a TV remote control), a touch-sensitive device, a motion and / or image sensor, a physical device, and / or a virtual device, such as a virtual keyboard displayed on the monitor. 910 can an audio system 963 which may include a microphone and / or a speaker.

[0136] The system 900The enclosure may include, but is not limited to, a rack-mount enclosure, a desktop enclosure, a laptop enclosure, a notebook enclosure, a netbook enclosure, a tablet enclosure, a telephone enclosure, a set-top box enclosure, and / or any other conventional enclosure and / or enclosure developed in the future. The processor system 902 , the storage 904 , the communication system 906 , the user interface system 910 and / or parts thereof may be positioned inside the housing.

[0137] The system 900 or parts thereof can be implemented in one or more integrated circuit chips and can be implemented as a system on a chip (SoC).

[0138] A procedure or process for reducing impulse control disorders, as disclosed herein, may include the following: Determining symbol quality measures for a symbol of a signal based on equalized sample values ​​of one or more carriers of the symbol; Determining a running background signal quality measure based on symbol quality measures of multiple symbols; and Generating an initial control to downgrade carrier quality measures of each of one or more data carriers in the symbol when the symbol quality measure exceeds an initial threshold that varies with fluctuations in background signal quality.

[0139] The procedure may also include the following: Determining distances between carriers in the symbol and points of corresponding QAM constellations; Determining the symbol quality measure as an MSE of the distances; and Determining the background signal quality measure as the average of symbol quality measures of multiple symbols.

[0140] The procedure may include updating the background signal quality measure with the symbol quality measure if the symbol quality measure is below the first threshold.

[0141] The procedure may involve determining an amount by which the carrier quality measures are to be downgraded, based on the extent to which the symbol quality measure exceeds the first threshold. The procedure may involve determining the amount on a linear scale and / or selecting one of several downgrading increments.

[0142] The carrier quality measures include an estimated signal-to-noise ratio (SNR) for each data carrier, and the method may include generating the first control element to reduce the SNR of all data carriers in the symbol if the symbol quality measure exceeds the first threshold. The method may further include: Estimating LLR (Log-Likelihood Ratios) for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; FEC (forward error correction) of the estimated LLR; and Downgrading the estimated SNR of all data carriers in the symbol based on the first control element before estimating LLR.

[0143] The FEC can include LDPC (Low-Density parity checking).

[0144] The method may include generating a second control element to identify all data carriers in the erasure symbol when the symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure. The second threshold is higher than the first threshold. The method may further include: Estimating LLR (Log-Likelihood Ratios) for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; FEC (forward error correction) of the estimated LLR; and Setting the estimated LLR of identified disks to indicate that the identified disks will be erased in the symbol, based on the second control and before the FEC.

[0145] The FEC can include LDPC (Low-Density parity checking).

[0146] The carrier quality measures can include an estimated signal-to-noise ratio (SNR) for each data carrier, and the procedure can further include the following: Generating the first control element to reduce the SNR of all data carriers in the symbol when the corresponding symbol quality measure exceeds the first threshold; and Creating a second control to set the estimated LLR of all disks in the symbol to specify that all disks in the symbol will be erased if the corresponding symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure, where the second threshold is higher than the first threshold.

[0147] Examples herein disclose means for carrying out a procedure as described above.

[0148] A system, machines, and a computer system for implementing a method as described above are disclosed herein. For example, and without limitation, a computer-readable or machine-readable storage medium can be encoded with a computer program, program code, instructions, or software which, when executed, cause a machine or processor to perform the functions described above.

[0149] Methods and systems are disclosed here by means of functional modules that represent their functions, features, and relationships. At least some of the boundaries of these functional modules have been arbitrarily defined here for ease of description. Alternative boundaries may be defined as long as the specified functions and relationships are adequately implemented. Although various embodiments are disclosed here, it is understood that they are given as examples. The scope of protection of the claims is not to be limited by any of the exemplary embodiments disclosed herein.

Claims

[1] Machine-implemented method for reducing impulse disturbances in quadrature amplitude modulated or QAM carriers, comprising: Receiving equalized sample values ​​of the QAM carriers from a receiver; Determining a symbol quality measure for a symbol based on equalized sample values ​​of at least one of the carriers in the symbol; Determining a running background signal quality measure based on symbol quality measures determined for multiple symbols; Generating a first control element to downgrade carrier quality measures of all data carriers in the symbol when the symbol quality measure exceeds a first threshold that varies with fluctuations in the background signal quality measure; and Routing the first control element to the receiver. [2] The method of claim 1, further comprising: Determining the symbol quality measure based on equalized sample values ​​of multiple carriers in the symbol. [3] Method according to claim 1, further comprising: Determining distances between carriers in the symbol and points of corresponding quadrature amplitude-modulated constellations; Determining the symbol quality measure as a mean squared error of the distances; and Determining the running background signal quality measure as the average of the symbol quality measures of the multiple symbols. [4] Method according to claim 1, further comprising: Update the running background signal quality measure with the symbol quality measure when the symbol quality measure is below the first threshold. [5] The method of claim 1, further comprising: Determining an amount by which the carrier quality measures are to be downgraded, based on the extent to which the symbol quality measure exceeds the first threshold. [6] Method according to claim 5, wherein determining an amount comprises determining the amount on a linear scale. [7] Method according to claim 5, wherein determining an amount comprises selecting one of several gradation increments. [8] Method according to claim 1, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and wherein the generation comprises the following: Generating the first control element to reduce the SNR of all data carriers in the symbol when the symbol quality measure exceeds the first threshold. [9] The method of claim 8, further comprising in the receiver the following: Estimating LLR (Log-Likelihood Ratios) for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; Forward error correction (FEC) of the estimated LLR; and Downscaling the estimated SNR of all data carriers in the symbol before estimating LLR based on the first control. [10] Method according to claim 9, wherein the FEC comprises LDPC (Low-Density Parity Checking). [11] Method according to claim 1, further comprising: Generating a second control to identify all data carriers in the erasure symbol when the symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure, where the second threshold is higher than the first threshold. [12] Method according to claim 11, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and the method further comprises the following in the receiver: Estimating LLR (Log-Likelihood Ratios) for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; Forward error correction (FEC) of the estimated LLR; and Set estimated LLR identified disks to indicate that the identified disks in the symbol will be erased before FEC, based on the second control. [13] Method according to claim 12, wherein the FEC comprises LDPC (Low-Density Parity Checking). [14] Method according to claim 1, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and wherein the generation comprises the following: Generating the first control element to reduce the SNR of all data carriers in the symbol when the corresponding symbol quality measure exceeds the first threshold; and Creating a second control to set the estimated LLR of all disks in the symbol to specify that all disks in the symbol will be erased if the corresponding symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure, where the second threshold is higher than the first threshold. [15] System for reducing impulse disturbances in quadrature amplitude modulated or QAM carriers, comprising: an input for receiving equalized sample values ​​of the QAM carriers from a receiver; a symbol quality module for determining a symbol quality measure for a symbol based on equalized sample values ​​of at least one of the carriers in the symbol; a background signal quality module for determining a running background signal quality measure based on quality measures determined for multiple symbols; a decision module for generating a first control element for downgrading carrier quality measures of all data carriers in the symbol when the symbol quality measure exceeds a first threshold that varies with fluctuations in the background signal quality measure; and an output to direct the first control element to the receiver. [16] System according to claim 15, wherein the symbol quality module is designed to determine the symbol quality measure based on equalized sample values ​​of multiple carriers in the symbol. [17] System according to claim 15, wherein: the symbol quality module is designed to determine distances between carriers in the symbol and points of corresponding quadrature amplitude-modulated constellations, and to determine the symbol quality measure as a mean squared error of the distances; and The background signal quality module is designed to determine the current background signal quality measure as the average of the symbol quality measures of the multiple symbols. [18] System according to claim 15, wherein the background signal quality module is designed to update the running background signal quality measure with the symbol quality measure when the symbol quality measure is below the first threshold. [19] System according to claim 15, wherein the decision module is designed to determine an amount by which the carrier quality measures are to be downgraded, on the basis of an extent to which the symbol quality measure exceeds the first threshold. [20] System according to claim 19, wherein the decision module is designed to determine the amount on a linear scale. [21] System according to claim 19, wherein the decision module is designed to select one of several gradation increments. [22] System according to claim 15, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and wherein: The decision module is designed to generate the first control element to reduce the SNR of all data carriers in the symbol when the symbol quality measure exceeds the first threshold. [23] System according to claim 22, wherein the receiver comprises: a log-likelihood ratio or LLR module for estimating LLR (log-likelihood ratios) for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; a forward error correction (FEC) module for processing the estimated LLR; and a module for downgrading the estimated SNR of all data carriers in the symbol before the LLR module based on the first control element. [24] System according to claim 23, wherein the FEC module comprises a module for LDPC (Low-Density Parity Checking). [25] System according to claim 15, wherein the decision module is further configured to generate a second control element for identifying all data carriers in the symbol for deletion when the symbol quality measure exceeds a second threshold which varies with fluctuations in the background signal quality measure, wherein the second threshold is higher than the first threshold. [26] System according to claim 25, wherein the receiver comprises: a log likelihood ratio or LLR module for estimating LLR for bits located in constellation points of the data carrier for multiple symbols based on the corresponding SNR; a forward error correction (FEC) module for processing the estimated LLR; and a module for setting estimated LLR of identified disks to indicate that the identified disks in the symbol will be erased, prior to the FEC module based on the second control. [27] System according to claim 26, wherein the FEC module comprises a module for LDPC (Low-Density Parity Checking). [28] System according to claim 15, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier and wherein the decision module is further designed to: Generating the first control element to reduce the SNR of all data carriers in the symbol when the corresponding symbol quality measure exceeds the first threshold; and Creating a second control to set the estimated LLR of all disks in the symbol to specify that all disks in the symbol will be erased if the corresponding symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure, where the second threshold is higher than the first threshold. [29] Non-volatile computer-readable medium encoded with a computer program for reducing impulse noise in quadrature amplitude modulated or QAM carriers, wherein the computer program includes instructions that cause a processor to: Receiving equalized sample values ​​of the QAM carriers from a receiver; Determining a symbol quality measure for a symbol based on equalized sample values ​​of at least one of the carriers in the symbol; Determining a running background signal quality measure based on symbol quality measures determined for multiple symbols; Generating a first control element to downgrade carrier quality measures of all data carriers in the symbol when the symbol quality measure exceeds a first threshold that varies with fluctuations in the background signal quality measure; and Routing the first control element to the receiver. [30] Computer-readable medium according to claim 29, further comprising instructions to cause the processor to determine the symbol quality measure based on equalized sample values ​​of multiple carriers in the symbol. [31] Computer-readable medium according to claim 29, further comprising instructions that cause the processor to do the following: Determining distances between carriers in the symbol and points of corresponding quadrature amplitude-modulated constellations; Determining the symbol quality measure as a mean squared error of the distances; and Determining the running background signal quality measure as the average of the symbol quality measures of the multiple symbols. [32] Computer-readable medium according to claim 29, further comprising instructions to cause the processor to update the running background signal quality measure with the symbol quality measure when the symbol quality measure is below the first threshold. [33] Computer-readable medium according to claim 29, further comprising instructions to cause the processor to determine an amount by which the carrier quality measures are to be downgraded on the basis of an extent to which the symbol quality measure exceeds the first threshold. [34] Computer-readable medium according to claim 33, further comprising instructions to cause the processor to determine the amount on a linear scale. [35] Computer-readable medium according to claim 33, further comprising instructions to cause the processor to select one of several downgrade increments. [36] Computer-readable medium according to claim 29, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier, further comprising instructions that cause the processor to: Generating the first control element to reduce the SNR of all data carriers in the symbol when the symbol quality measure exceeds the first threshold. [37] Computer-readable medium according to claim 29, further comprising instructions to cause the processor to generate a second control element for identifying all data carriers in the erasure symbol when the symbol quality measure exceeds a second threshold which varies with fluctuations in the background signal quality measure, wherein the second threshold is higher than the first threshold. [38] Computer-readable medium according to claim 29, wherein the carrier quality measures comprise an estimated signal-to-noise ratio (SNR) for each data carrier, further comprising instructions that cause the processor to: Generating the first control element to reduce the SNR of all data carriers in the symbol when the corresponding symbol quality measure exceeds the first threshold; and Creating a second control to set the estimated LLR of all disks in the symbol to specify that all disks in the symbol will be erased if the corresponding symbol quality measure exceeds a second threshold that varies with fluctuations in the background signal quality measure, where the second threshold is higher than the first threshold.