Detecting Repetitive Data Signals

Abstract

An apparatus for detecting repetitive information in data packets communicated between a first node and a second node over a wireless network comprises a processing circuit configured to collect a plurality of samples of a data communication signal transmitted at respective times between the first node and the second node over the wireless network, group the collected samples into a plurality of sequences of samples, combine the sequences of samples into at least one combined signal, and generate a signal indicative of repetitive information in a plurality of data packets carried by the data communication signal based on an analysis of the at least one combined signal.

Description

[Technical field]

[0001] This application claims priority to Israel Patent Application No. 276678, filed August 12, 2020, which is incorporated herein by reference.

[0002] The present invention, in some embodiments of the invention, relates to detecting repetitive information in a data signal, and more particularly, but not exclusively, to detecting repetitive information in data packets. [Background technology]

[0003] In wireless data communications, the ability to extract data from a received signal depends heavily on the signal to noise ratio (SNR) of the received signal. Many factors can cause a low SNR at a receiver, such as a long distance between the receiver and the transmitter and / or high interference at the receiver. In a low SNR condition, it may not be possible to extract data (e.g., data packets) from the received signal.

[0004] In some cases, it is desirable to detect portions of a data signal that are repeated within multiple packets, or even within all packets. An example of such repetition is shown in Figure 1, where data packets 1 through N all repeat the same bit sequence in the same bit positions.

[0005] For example, source and / or destination addresses may be repeated in multiple packets transferred between the same source and the same destination. The source and destination addresses are usually in the same bit positions in a packet. If the rate and coding modulation scheme are kept constant, the address symbols are also kept in the same positions in the packet signal. For example, in orthogonal frequency-division multiplexing (OFDM), the source and destination addresses are located in the same OFDM frame and on the same OFDM subcarriers. Further examples of repetitive signals are preambles and synchronization signals that are constant within multiple packets.

[0006] At high SNR, data packets are detectable in the signal and therefore the arrival time of each data packet is known. Based on the arrival time of each of the received data packets and thanks to the high SNR of the received signal, the content of the data packets (e.g., control information and data payload) can be determined and compared among multiple data packets to identify repeated information within multiple data packets. However, this is not possible at low SNR, when the arrival time of the received data packets is unknown and / or the content of the data packets cannot be determined. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide an apparatus, system, computer program product, and method for detecting repeated information within multiple data packets carried by a data communication signal. [Means for solving the problem]

[0008] When a data communication signal is received with an insufficient SNR, it may not be possible to detect the data packets in the received signal, and even if the data packets are detected, it may not be possible to extract the data from them.

[0009] Embodiments of the present invention combine samples of a data communication signal (referred to herein as signal samples or samples) into one or more united signals (united signal(s)) to increase the SNR of information that is repeated within multiple data packets (referred to herein as repeated information). With a better SNR, the contents of control fields and / or data payloads that are repeated within multiple packets may be detected even under poor channel conditions.

[0010] Signal samples are grouped into sequences (referred to herein as sample sequences). For example, data signals may be grouped such that each signal sequence is expected to contain only one data packet (if the sampling and grouping is precisely synchronized to the reception time of the actual data packets). Samples are combined into one or more combined signals to increase the SNR of information repeated within multiple data packets. In some embodiments, data sample values ​​are combined directly. In other embodiments, data packets are detected within the samples and a combined signal is created after data packet detection.

[0011] The combined signal is analyzed to detect the presence or absence of repetitive information in the collected packets and / or to extract the repetitive information from the combined signal.

[0012] Some embodiments of the present invention are particularly useful when there is limited information about the transmitted signals (e.g., cycle, coding, and modulation scheme, etc.). Sampled data packets are combined in various ways to form multiple combined signals, which are then analyzed (separately or in combination) to determine whether repetitive information is present in at least one of the multiple combined signals. Thus, various hypotheses regarding carrier frequencies, frequency hopping cycles, data packet reception times, etc. may be analyzed until an effective combination of samples is obtained.

[0013] According to a first aspect of some embodiments of the present invention, there is provided an apparatus for detecting repetitive information in a data packet communicated between a first node and a second node over a wireless network, the apparatus including a processing circuit, the processing circuit comprising: collecting samples of a data communication signal transmitted between a first node and a second node over a wireless network at a plurality of respective times; Collected samples are grouped into sequences of multiple samples, combining the sequences of samples into at least one combined signal; and generating a signal indicative of repetitive information within a plurality of data packets carried by the data communications signal based on an analysis of the at least one combined signal; It is configured as follows.

[0014] According to some implementations of the first aspect of the present invention, the apparatus further includes a sampler configured to sample the baseband input signal and provide the samples to the processing circuit for collection.

[0015] According to a second aspect of some embodiments of the present invention, there is provided a method for detecting repetitive information in a data packet communicated between a first node and a second node over a wireless network, the method comprising: collecting samples of a data communication signal transmitted at a plurality of respective times between a first node and a second node over a wireless network; grouping the collected samples into sequences of samples; combining the sequences of samples into at least one combined signal; and generating a signal indicative of repetitive information within a plurality of data packets carried by the data communications signal based on the analysis of the at least one combined signal; Includes.

[0016] According to some implementations of the first or second aspect of the present invention, the analysis includes identifying a presence or absence of repetitive information within the at least one combined signal, and the signal indicative of the repetitive information includes an indicator of the identified presence or absence of repetitive information within the plurality of data packets.

[0017] According to some implementations of the first or second aspect of the present invention, the analysis comprises extracting repetitive information from the at least one combined signal, and the signal indicative of the repetitive information comprises the extracted repetitive information.

[0018] According to some implementations of the first or second aspect of the present invention, each of the sequences of samples is only one data packet.

[0019] According to some implementations of the first or second aspect of the present invention, a data communication signal between a first node and a second node is monitored.

[0020] According to some implementations of the first or second aspect of the present invention, a baseband input signal is sampled and the samples are provided for collection.

[0021] According to some implementations of the first or second aspect of the present invention, a frequency transformation is applied to each of the sequences of samples prior to the combination (combining step) of the sequences of samples into at least one combined signal.

[0022] According to some implementations of the first or second aspect of the present invention, for at least one of the combined signals, the sequences of samples are combined by forming a weighted linear combination of the sequence of samples with a delayed version of the sequence of samples.

[0023] According to some implementations of the first or second aspect of the present invention, the weighting coefficients of the weighted linear combination are selected according to the conditions of the communication channels of the network.

[0024] According to some implementations of the first or second aspect of the present invention, the sequences of samples are combined by specifying a plurality of sets of weighting coefficients and forming, for each of the sets of weighting coefficients, a respective combined signal that is a weighted linear combination of a delayed version of the sequence of samples and the plurality of sequences of samples. A signal indicative of repetition information is generated if repetition information is identified in at least one of the respective combined signals.

[0025] According to some implementations of the first or second aspect of the present invention, for at least one of the combined signals, the sequence of samples comprises: detecting a respective data packet for each of the sequences of samples; calculating weights for combining the sequences of samples into a combined signal using at least one of a preamble and a synchronization sequence of the data packet; forming a weighted linear combination of the sequence of samples and a delayed version of the sequence of samples using the calculated weights; are combined by

[0026] According to some implementations of the first or second aspect of the present invention, the sequence of samples comprises: detecting a respective data packet for each of the sequences of samples; performing symbol detection on the detected data packets to obtain respective symbol sequences; Linear combination of symbol sequences and are combined by

[0027] According to some implementations of the first or second aspect of the present invention, the sequence of samples comprises: detecting a respective data packet for each of the sequences of samples; decoding each of the detected data packets into a respective bit sequence; For each location in the combined signal, select the bit level that occurs in the majority of the bits at this location in the respective bit sequences. are combined by

[0028] According to some implementations of the first or second aspect of the present invention, for at least one of the combined signals, the sequence of samples comprises: detecting a respective data packet for each of the sequences of samples; For each location in the combined signal, select the bit level that is most likely to appear at this location based on an analysis of the likelihood ratios of the detected data packets. are combined by

[0029] According to some implementations of the first or second aspect of the invention, respective sets of sequences of samples of a data communication signal are collected for each phase of a regular cycle of frequency. At least one combined signal is formed for each set of sequences of samples. A signal indicative of repetitive information is generated if repetitive information is detected in at least one of the respective combined signals.

[0030] According to some implementations of the first or second aspect of the invention, respective sets of sequences of samples of the data communication signal are collected for each phase of a number of cycles of the frequency. At least one combined signal is formed for each set of sequences of samples. A signal indicative of repetitive information is generated if repetitive information is detected in at least one of the respective combined signals.

[0031] According to some implementations of the first or second aspect of the present invention, the collection of samples is synchronized to detected data packets received from one of the first node and the second node.

[0032] According to some implementations of the first or second aspect of the present invention, the collection of samples is synchronized to a detected request packet.

[0033] According to some implementations of the first or second aspect of the present invention, the collection of samples is synchronized to the detected response packet.

[0034] According to some implementations of the first or second aspect of the present invention, the collection of samples is synchronized to a cycle time of a plurality of detected data packets transmitted from at least one of the first node and the second node.

[0035] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein may be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0036] Implementation of a method and / or system of an embodiment of the present invention may include performing or completing selected tasks manually, automatically, or a combination thereof. Furthermore, some selected tasks may be implemented using an operating system, by hardware, software, or firmware, or a combination thereof, depending on the actual instrumentation and equipment of the embodiment of the method and / or system of the present invention.

[0037] For example, hardware that performs selected tasks in accordance with embodiments of the present invention may be implemented as a chip or circuit.

[0038] Selected tasks according to embodiments of the invention may be implemented as software, as software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of the methods and / or systems described herein are performed by a data processor, such as a computing platform executing instructions. The data processor optionally includes volatile memory for storing instructions and / or data, and / or non-volatile storage, e.g., magnetic hard disks and / or removable media, for storing instructions and / or data. Optionally, a network connection is also provided. Optionally, a display and / or a user input device, such as a keyboard or mouse, are also provided.

[0039] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following figures and detailed description, and it is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.

[0040] Several embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. Referring now in detail and specifically to the drawings, it is stressed that details are shown by way of example and for purposes of illustratively discussing embodiments of the present invention. In this regard, the description taken together with the drawings will make apparent to those skilled in the art how embodiments of the present invention may be practiced. [Brief description of the drawings]

[0041] [Figure 1] 1 is a diagram of a sequence of data packets, including repetitive information. [Figure 2A] 1 is a simplified block diagram of an apparatus for detecting repetitive information in data packets communicated over a network, according to an embodiment of the present invention. [Figure 2B] 1 is a simplified block diagram of a repetition information detector for monitoring communication between two nodes, according to an exemplary embodiment of the present invention. [Diagram 3] 1 is a simplified flowchart of a method for detecting repetitive information in data packets communicated over a network, according to an embodiment of the present invention. [Figure 4] 2 is a simplified diagram illustrating the processing of a data communication signal according to an exemplary embodiment of the present invention. [Diagram 5] 1 illustrates frequency hopping transmission with cycle length N. [Figure 6] 1 is a simplified diagram of nodes communicating over a wireless data communications network; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The present invention, in some embodiments of the invention, relates to detecting repetitive information in a data signal, and more particularly, but not exclusively, to detecting repetitive information in data packets.

[0043] Embodiments of the invention relate to processing samples of a communication signal to increase the SNR of a sequence of bits or symbols that is repeated within a number of data packets (i.e., data packets having repetitive information), to detect the presence of a particular sequence of repeated bits or symbols, and / or to enable extraction of the repetitive information from the data packets. As described in more detail below, samples of a data communication signal are collected and one or more combined signals are created from samples of a number of data packets carried by the sampled communication signal. The combined signals are analyzed to detect whether repetitive information (such as a specified data sequence) is present within the data packets.

[0044] In some cases, the goal is to determine whether a known data sequence (e.g., a packet preamble) is present within multiple data packets without the ability to actually detect the data packets (e.g., as a result of a long distance between the receiver and the sender, or due to high interference at the receiver). For example, a user may want to know if a response packet is present with a particular frequency, or the source and destination addresses. While it may not be possible to detect a particular data sequence within just one sampled data packet, it may be possible to detect a particular data sequence if samples from multiple data packets are properly combined.

[0045] In other cases, it is desirable to determine whether an unspecified data sequence is repeated within multiple data packets. For example, in many communication protocols, the source and destination addresses are present in every packet. Thus, in data communication between the same source and the same destination, the source and destination addresses are usually in the same bit positions in the packet. If the rate and the coding and modulation scheme are kept constant, the address symbols may even be kept in the same positions in the packet signal. (For example, in OFDM, the address symbols are located in the same OFDM subcarriers, in the same OFDM frame, and contain the same values.) If the SNR is too low, it is not possible to extract the source and destination addresses from a sample of just one data packet. However, by combining samples of several data packets into a combined signal, the SNR of the repeated source and destination addresses can be increased enough that the contents of the fields can be extracted.

[0046] The repetitions may be identified at various levels of signal processing (e.g., before or after data packet detection within the samples of the data communications signal). When the data communications signal samples are combined into a combined signal after data packet detection (e.g., at the data symbol or bit level), some initial processing may be performed on the samples to detect the data packets.

[0047] Before describing at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples, as the invention is capable of other embodiments or of being practiced or carried out in various ways.

[0048] The present invention may be a system, method, and / or computer program product, which may include a computer-readable storage medium (or media) having computer-readable program instructions for causing a processor to perform aspects of the present invention.

[0049] A computer readable storage medium may be a tangible device that can hold and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. Although not exhaustive, a list of more specific examples of computer-readable storage media includes portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disk (DVD), memory sticks, floppy disks, mechanically encoded devices such as punch cards or raised structures in grooves on which instructions are recorded, and any suitable combination of the foregoing. As used herein, computer-readable storage media should not be construed as being themselves transitory signals, such as electric waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., light pulses passing through a fiber optic cable), or electrical signals transmitted through wires.

[0050] The computer-readable program instructions described herein can be downloaded from the computer-readable storage medium to the respective computing / processing device or to an external computer or storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical transmission fiber, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface of each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium within the respective computing / processing device.

[0051] The computer readable program instructions for carrying out the operations of the present invention may be either source code or object code written in any combination of one or more programming languages, including assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or object-oriented programming languages, such as Smalltalk, C++, and traditional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may be executed completely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or completely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA) may execute computer readable program instructions by utilizing state information of the computer readable program instructions to dedicate the electronic circuitry to perform aspects of the invention.

[0052] Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer readable program instructions.

[0053] Such computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to manufacture a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus produce means for performing the specified functions / actions of one or more blocks of the flowcharts and / or block diagrams. Such computer readable program instructions may also be stored on a computer readable storage medium that can direct a computer, programmable data processing apparatus, and / or other device to function in a particular manner, such that a computer readable storage medium having instructions stored thereon includes an article of manufacture including instructions that perform the specified functional / action aspects of one or more blocks of the flowcharts and / or block diagrams.

[0054] The computer-readable program instructions may also be loaded into a computer, other programmable data processing apparatus, or other device and cause the computer, other programmable apparatus, or other device to execute a series of operational steps to generate a computer-implemented process, such that the instructions executing on the computer, other programmable apparatus, or other device perform the specified functions / actions of one or more blocks of the flowcharts and / or block diagrams.

[0055] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or part of instructions, including one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions shown in the blocks may be performed out of the order shown in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may be executed in the reverse order, depending on the functionality required. It will also be noted that each block of the block diagrams and / or flowchart diagrams, and combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a dedicated hardware-based system or a combination of dedicated hardware and computer instructions that performs the specified functions or functions.

[0056] 1) Repetition detector Reference is now made to Figure 2A, which is a simplified block diagram of an apparatus for detecting repetitive information in data packets communicated over a network, in accordance with an embodiment of the present invention. The apparatus, designated herein as repetitive information detector 200, includes processing circuitry 210 and, optionally, a communications interface 220.

[0057] The processing circuitry 210 collects, at respective times, a number of samples of wireless communication signal transmissions between nodes of the wireless communication network. The samples are grouped into sequences of samples (denoted as sample sequences) and the sample sequences are combined into one or more combined signals. The combined signals are analyzed and, based on the analysis, a signal (denoted as an indicator signal) is generated that is indicative of the repeating information in the data packets.

[0058] The repetitive information detector 200 is not a node (or part of a node) of a wireless communication network and does not participate in wireless communications between nodes.

[0059] The iterative information detector 200 optionally monitors wireless communications between the two nodes. Monitoring may be performed on the transmissions of only one of the nodes, for example, when the strength of the transmission signal received from the other node is not large enough. This monitoring may be used to obtain information to be used at a later stage of the iterative information detection process. For example, monitoring the wireless communications between the nodes may help to estimate the timing and frequency of packet transmissions used by the nodes.

[0060] Reference is now made to Figure 2B, which is a simplified diagram of a repetitive information detector monitoring communication between two nodes, according to an exemplary embodiment of the present invention. Node A 240 and Node B 250 perform data communication over a wireless network.

[0061] Wireless communications between node A 240 and node B 250 are received by antenna 260 and processed by receiver 270. In the embodiment of FIG. 2B, sampling is performed by receiver 270, which provides samples to repetitive information detector 260. In other exemplary embodiments, repetitive information detector 260 includes signal processing functionality. In this case, receiver 280 can provide an unsampled signal (e.g., an analog baseband signal) to repetitive information detector 260, which performs downconversion and sampling before combining the sample sequences into a combined signal and analyzing the combined signal to detect the repetitive information.

[0062] The types of analyses that may be performed on the combined signal include, but are not limited to, the following: i) Signal Presence Detection ii) Preamble Detection iii) Synchronization iv) Frequency correction v) Equalization, and vi) Constellation bit extraction

[0063] Optional examples for combining sample sequences into a combined signal include, but are not limited to, the following: a) Form a weighted linear combination of sequences of signal samples, where there is a delay between the sequences, as shown in Equation 1 below. b) detecting data packets within the signal samples and combining the detected data packets using preamble and / or synchronization sequences of the data packets; c) detecting data packets in the signal samples, performing symbol detection on the detected data packets, and linearly combining the data symbols. d) detecting data packets in the signal samples, decoding each sampled data packet into bits, and for each location in the combined signal, selecting a bit level that occurs for a majority of the bits at that location in the data packet. e) detecting data packets in the signal samples and selecting the bit level that is most likely to occur at each location in the data packet, which may be calculated, for example, by performing a likelihood ratio analysis of the detected data packets and / or by calculating the probability in another manner (e.g., by a linear combination of bit probabilities at a given location in multiple data packets);

[0064] Optionally, the samples in each sample sequence are expected to correspond to one and only one data packet.

[0065] Optionally, the grouping of signal samples into sample sequences is synchronized to one or more of the following: a) Transmissions received from a different source (i.e., not from the node receiving the data packet being analyzed for repetition information) b) The cycle time of some detected data packets c) Known parameters of the communication signal (e.g., cycle time and frequency hopping pattern). An exemplary embodiment for establishing the timing of grouping signal samples is described in Section V below.

[0066] 2A, the repetitive information detector 200 optionally includes a communication interface 220. Different embodiments of the communication interface 220 may input a signal at one or more stages of receiving the signal (e.g., RF, baseband, digitized after analog to digital conversion, etc.).

[0067] Non-limiting examples of signals that communication interface 220 can input include, but are not limited to, the following: 1) Radio Signals - The communications interface 220 optionally includes a radio receiver 221 (e.g., an RF receiver) that can receive radio signals carrying data packets and also perform signal processing such as down-conversion and sampling of the received communications signals. 2) Downconverted Data Signal - The communications interface 220 optionally includes a sampler 222 that inputs and samples an analog baseband signal. The sampler 222 may also perform analog to digital (A / D) conversion on the baseband signal samples. And 3) Digital Signals - The communication interface 220 optionally inputs sample values ​​in digitized form after the received communication signal is sampled and undergoes A / D conversion.

[0068] An optional embodiment for ensuring that data packets are sampled with the correct time stamp is described in Section V below.

[0069] As used herein, the term "data sequence" means a sequence of symbols or bits within a data packet. Note that the term "data sequence" is not limited to the data payload within a data packet, but may include the contents of other portions of a data packet.

[0070] As used herein, the term "repeated information" means a data sequence that is present in multiple data packets.

[0071] As used herein, the term "detecting repetitive information" means determining whether a specified or unspecified data sequence is repeated within multiple data packets.

[0072] As used herein, the terms "sample of a communication signal," "signal sample," and "sample" refer to the respective levels of a communication signal (before or after downconversion) at multiple sampling times.

[0073] As used herein, the terms "sequence of samples" and "sample sequence" mean a sequence of consecutive samples of a communications signal.

[0074] As used herein, the term "collecting samples" means storing or buffering a series of samples of a communication signal so that they can be later combined into one or more combined signals.

[0075] As used herein, the terms "combining a sequence of samples" and "sample sequences are combined" mean performing an operation (e.g., mathematical, logical, numerical, etc.) on the sample sequences that results in a single signal. Combining the signals optionally includes detecting data packets in the sequences and performing an operation on the detected data packets.

[0076] As used herein, the term "combined signal" refers to the result of combining multiple sample sequences.

[0077] As used herein, the term "time stamp" refers to the time at which a communication signal is sampled. Each sample has its own time stamp. For a given packet, the time stamp of the first sample in the packet indicates the time at which sample collection for that packet should begin.

[0078] The analysis optionally includes detecting whether repetitive information is present or absent in one or more of the combined signals, and the indicator signal indicates whether repetitive information is present or absent in the data packet. The analysis further optionally includes identifying whether a particular signal is present or absent in one or more of the combined signals. In some cases, the indicator signal may be generated only if the presence of repetitive information is identified.

[0079] The analysis alternatively or additionally includes extracting repetitive information from one or more of the combined signals, and the indicator signal includes the extracted repetitive information. Further optionally, the indicator signal is not generated unless repetitive information is extracted from the one or more combined signals.

[0080] The repetition information optionally includes one or more of the following: a) Packet preamble (also referred to as the preamble signal in this specification) b) Packet synchronization sequence (also referred to herein as synchronization signal) c) Source address d) the destination address, and e) A sequence of data bits and / or data symbols

[0081] The sampled data packets are optionally combined into a single combined signal and analysis is performed on the single combined signal. This approach minimizes the amount of processing and analysis required to generate the indicator signal and can be beneficial when parameters of the data packet transmission are known.

[0082] Alternatively, the sampled data packets are combined into multiple combined signals and the analysis is performed on the multiple combined signals. Each combined signal is effectively a hypothesis about how the signals should be combined. The analysis tests various hypotheses to determine whether repetitive information can be detected and / or extracted from one or more of the combined signals. This approach is useful when parameters of the data packet transmission are unknown (e.g., in frequency hopping signals where the carrier frequency cycle is unknown).

[0083] Exemplary embodiments for detecting the presence of a specified data sequence (e.g., synchronization and / or preamble sequences) repeated within multiple data packets under various frequency hopping schemes are described in Sections 3.2-3.3 below. Exemplary embodiments for detecting whether an unspecified data sequence is repeated within multiple data packets under various coding and modulation transmission schemes are described in Sections 4.1-4.3 below.

[0084] The repetitive information detector 200 optionally includes an internal memory 230 that can be used to store signal samples such that the stored samples are easily accessible for analysis by the processing circuitry 210.

[0085] The processing circuitry optionally performs further signal processing on the extracted repetitive information (eg, demodulating the extracted repetitive information into data symbols or data bits).

[0086] 2) How to detect repeated information in data packets Reference is now made to FIG. 3, which is a simplified flowchart of a method for detecting repetitive information in data packets communicated over a network, in accordance with an embodiment of the present invention.

[0087] At 310, samples of a communication signal transmitted between two nodes are collected at different respective times. 310 optionally includes sampling the communication signal after downconversion. Alternatively, the data signal sample values ​​may be input via a digital communication interface. The device performing the sample collection is not involved in the communication between the two nodes.

[0088] At 305, optionally, a data communication signal between the two nodes is monitored, for example, to determine whether and / or when to collect a sample of the communication signal.

[0089] At 320, the samples are grouped into sample sequences. Optionally, the length of each sample sequence is selected such that each sample sequence contains samples from only one data packet, where the start of each sample sequence is correctly aligned with the first sample of the data packet.

[0090] At 330, multiple sample sequences are combined into one or more combined signals. The sample sequences are optionally combined by operations on the signal sample values ​​themselves (e.g., by weighted linear combinations as described in Section 4.1). Alternatively, data packets are detected within the sample sequences and combining is performed at the data packet, symbol, or bit level (as described in Section 5).

[0091] At 340, the one or more combined signals are analyzed and an indicator signal is generated if a result of the analysis indicates that repetitive information is present in the multiple data packets. The indicator signal is optionally generated only if repetitive information is identified in and / or extracted from one or more of the combined signals.

[0092] In some cases, communication networks may use frequency hopping transmissions (with or without a known cycle). To collect samples of signals carrying data packets, the communication signals are downconverted from their current frequency before the samples are collected and / or combined (see, for example, FIG. 4). If the current carrier frequency is unknown, samples may be collected for communication signals at multiple carrier frequencies. From the samples collected at various frequencies, several combined signals may be formed and analyzed to determine whether repetitive information is detected in one or more of the combined signals.

[0093] In a first exemplary embodiment, a frequency hopping signal is transmitted over a fixed cycle of frequencies. A respective set of sample sequences is collected for each phase of the cycle. For each of the sets, one or more combined signals are formed. An indicator signal is generated if repetitive information is detected in at least one of the combined signals.

[0094] In a second exemplary embodiment, the frequency hopping signal is transmitted over certain cycles of frequency, but the cycles themselves are unknown. A respective set of sample sequences is collected for each phase of a number of cycles of the transmission frequency, where each of the cycles is an estimate of a possible cycle of the frequency being used for transmission. For each of the sets, one or more combined signals are formed. An indicator signal is generated if repetitive information is detected in at least one of the combined signals.

[0095] Reference is now made to Figure 4, which is a simplified diagram illustrating the processing of a data communication signal, according to an exemplary embodiment of the present invention. In this example, an indicator signal indicates whether a specified data sequence has been detected in the combined signal. Assuming the SNR is too low to detect the data sequence in just one data packet, this means that the specified data sequence has been repeated in multiple data packets.

[0096] At 410, the modulated analog signal containing the data packets is downconverted and filtered.

[0097] At 420, the downconverted signal is sampled and an analog-to-digital (A / D) conversion is performed on the samples. An exemplary embodiment for aligning the sampling time with the arrival time of the data packets is described in Section V below.

[0098] At 430, the signal samples are collected in a buffer.

[0099] At 440, the buffered samples are combined into one or more combined signals.

[0100] At 450, the combined signals are analyzed and an indicator signal is generated if a specified data sequence is detected in at least one of the combined signals.

[0101] In some exemplary embodiments, the repetitive information detector performs all of the processing steps shown in Figure 4. In alternative embodiments, some or all of the downconversion and filtering (410), sampling and A / D conversion (420), and collection in a buffer 430 may be performed externally. The repetitive information detector obtains the stored signal samples at 440 and combines the signal samples into a combined signal.

[0102] 3) Combining sample sequences into a combined signal The manner in which the samples are combined into a combined signal may depend on the quality of the received communication signal. An embodiment for combining the sampled data packets into a combined signal is now described.

[0103] In a first optional embodiment, which may be performed before detecting data packets (e.g., when the SNR is too low to detect data packets in the communication signal), the samples are combined by a weighted linear combination of sequences of samples into a combined signal, as described further below.

[0104] If the quality of the received signal is sufficient to detect a data packet from the signal samples, but the SNR is not high enough to extract repetitive information from the identified data packet, alternative optional embodiments may be implemented after data packet detection. Exemplary embodiments include, but are not limited to, the following: a) Optionally, combining the sampled data packets into a single data packet by performing a linear combination of delayed versions of the signal samples using the preamble of the data packets, and / or the synchronization sequence, and / or part of the payload itself. b) Perform symbol detection on the sampled data packets and linearly combine the symbol sequences to obtain the respective symbol sequences. Symbols can, for example, be obtained from each packet (before or after equalization, but before demapping or any other symbol-to-bit method), or be coherently averaged with LLRs [log-likelihood-ratios] before demapping to bits (or any other method of extracting bits from symbols, such as MLSE decoding). c) decoding each of the sampled data packets into a respective bit sequence and, for each location in the combined signal, selecting the bit level that occurs for the majority of the bits at that location in the bit sequence; d) Select the bit level that is most likely to appear at each location within the data packet.

[0105] As used herein, the term “delayed version of a signal sample” refers to x k Here, [nm] denotes samples of multiple data packets (packets 0 to K-1) with delay m.

[0106] 3.1) Weighted linear combination Optionally, the sampled data packets are combined into a combined signal, which is a weighted linear combination of sequences of samples of the communication signal with different delays of the sequences, as shown in Equation 1 below. The expected arrival times of the data packets are known, but it is unknown whether the data sequences are actually present in the data packets. If the data sequences are repeated within the sampled data packets, the combination of the samples by linear combination increases the SNR of the repeated data sequences, so that the data sequences can be more easily detected by detection mechanisms (e.g., cross correlation with a reference sequence).

[0107] Using a weighted linear combination to form the combined signal is particularly useful when it is desirable to detect the presence of a fixed data sequence (e.g., a packet preamble) or a fixed variant of a set of possible data sequences (such as a packet synchronization sequence). Note that the combined signal may still contain contaminants such as channel response and frequency offset.

[0108] The samples of the data packet may be combined by performing a weighted linear combination according to Equation 1.

number

[0109] h k,m The weighting coefficients are optionally selected according to the conditions of the communication channel, for example by channel estimation, MRC (Maximum Ratio Combining), and / or other channel equalization methods. Channel estimation may be performed by cross-correlation of the input signal with a reference signal (if one of them is known), or by cross-correlation of the input signals with each other.

[0110] Optionally, multiple combined signals are formed for the same sample using different (usually predefined) weighting sets. An analysis is performed on each of the combined signals. An indicator signal is generated when the presence of repetitive information is identified in and / or extracted from at least one of the combined signals.

[0111] An exemplary embodiment of detecting a specified data sequence using multiple predefined weighting sets is described in the following pseudocode.

number

[0112] 3.2) Detection of a known data sequence in a frequency hopping transmission with a fixed known cycle Optionally, a weighted linear combination method is used to determine the presence or absence of a known data sequence or a fixed variation of a possible data sequence (e.g., synchronization and / or preamble sequences) in a frequency hopping transmission with a constant known cycle. In this type of transmission, packets are transmitted at known time intervals and at different frequencies. The frequency sequence is repeated after N packets have been transmitted (as shown in FIG. 5).

[0113] The processing circuitry collects samples at a number of known frequencies according to a fixed cycle.

[0114] In a first exemplary embodiment, only one combined signal is formed for each phase of the frequency cycle (where the term phase means a time in the N sequence of carrier frequencies). In other words, if the frequency cycle is repeated every N data packets, N combined signals are formed. The combined signal combines samples at each possible phase of the frequency hopping signal. Each of the combined signals is analyzed to detect whether a known data sequence (or a variant) is present, for example by cross-correlation of each of the combined signals with the data sequence being sought. If one of the phases contains multiple instantiations of the known data sequence (or a variant), then a detection will occur in that phase. An indicator signal is generated if the data sequence (or one of the variants of the sequence) is detected in at least one of the respective combined signals.

[0115] In a second exemplary embodiment, a plurality of combined signals are formed for each phase of the frequency cycle, each of the combined signals being associated with a respective weighting set h k,m The data samples are generated using h k,m The sets are combined in order. k,m If repetitive information is found (and in the current phase d), the procedure is stopped. In this case, the procedure can be described by the following pseudocode:

number

[0116] In a third exemplary embodiment, the detection of the repetitive information also includes a quality figure of merit, which represents the quality of the detection decision. The correct phase of the sampled data packet is determined based on the quality figure of merit. The procedure can be described in the following pseudocode:

number

[0117] In a fourth exemplary embodiment, the frequency cycle is constant, but the constant cycle is {N0, N1, ..., N u}, in which case the selection of samples to combine is also looped over all frequency cycle possibilities.

number

[0118] 3.3) Detection of repetitive information in frequency hopping scenarios with constant unknown cycles or no cycles Networks communicate in frequency hopping, possibly over known frequencies, but the cycle may be unknown or even not constant. For such cases, the techniques utilized for a fixed known cycle in section 3.2 above can be adapted by collecting the signals into a possible set formed using several hypotheses, or by performing correlations between the signals.

[0119] Optionally, the processing circuitry collects respective sets of sampled data packets at a known frequency for multiple cycle lengths (either a fixed cycle length or different cycle lengths). For each set of sampled data packets at the fixed cycle or different cycle lengths, at least one respective combined signal is formed. Each of the combined signals is analyzed. An indicator signal is generated when repetitive information is identified in and / or extracted from at least one of the respective combined signals.

[0120] If the timing of data packet acquisition and / or sampling is based on data packets received from another source (e.g., see Sections 5.1 or 5.2 below), then a hypothesis of the estimated cycle may be made based on the time difference between every two received packets, or by the integer denominator of the two receptions. For example, if receptions are detected at times 20 ms, 50 ms, and 70 ms, then the possible cycles may be 2 ms, 5 ms, and 10 ms.

[0121] 4) Detection of repetitive information within detected data packets Optionally, data packets are detected within the sample sequences, the sample sequences are combined after data packet detection, and further optionally, each sample sequence is decoded into a respective data packet.

[0122] This technique is useful when the SNR is high enough to detect data packets in a communications signal, but not high enough to extract bits from the data packets.

[0123] Exemplary embodiments of combining detected data packets within a signal sample include, but are not limited to, the following: A) Using the preamble and / or synchronization sequences in the data packets. B) Perform symbol detection on the sampled data packets and linearly combine the data symbol sequences to obtain the respective symbol sequences. C) Decoding each of the sampled data packets into a respective bit sequence and, for each location in the combined signal, selecting the bit level that occurs for the majority of the bits at this location in the respective bit sequence. D) Select the bit level that is most likely to appear at each location within the data packet.

[0124] Without going into further details of the extraction of information bits after de-interleaving, descrambling and FEC (forward error correction) decoding, note that in an exemplary embodiment, we extract the PHY layer bits (just before the mapping stage). These stages can be performed separately. Since the bits are constant and go through the same stages such as interleaving, scrambling and FEC encoding, there is a high probability that most of the bits are also constant at the PHY layer level.

[0125] The repeated bits or symbols may contain information including, but not limited to: a) Source address b) Destination Address c) a cell identifier, and d) Any other information that remains constant across packets.

[0126] 4.1) Detection of co-located repeated data bits for a given rate and coding modulation This exemplary embodiment relates to detecting repeated data bits or symbols that are in the same position (i.e., at the same bit index from the packet start bit) within a detected data packet when the rate and coding modulation are constant.

[0127] To combine the entire data packets (similar to exemplary embodiment A above), the data packets need to be transmitted by the transmitter at the same frequency. Optionally, if the data packets are not transmitted at the same frequency, the receiver performs frequency correction to convert all data packets to the same baseband frequency to ensure that the data packets do not have a frequency offset between them. In an alternative optional embodiment, if the detected data packets being combined share the same frequency, frequency offset correction before combining can be omitted since no frequency offset between the packets is expected.

[0128] When combining detected data packets at the symbol level (as in exemplary embodiment B above), the packets may arrive at different frequencies (e.g., in a frequency hopping scenario). In addition, coherent averaging may be performed after adjusting the phase between symbols, and is only necessary if the symbols are prior to equalization. If the SNRs differ between the averaged symbols, a weighted linear combination may be applied.

[0129] 4.2) Detection of co-located repeated data bits when rate and coding modulation are not constant If the rate or coding modulation is not constant, it is not possible to directly perform the exemplary embodiments A to C for all detected data packets.

[0130] Optionally, detected packets sharing the same rate and coding modulation are selected and then processed similarly to the constant rate and coding modulation combination of data packets described in section 4.1 above.

[0131] If only the rate changes but the coding is the same (for example, using the same forward error correction but not using puncturing), exemplary embodiments B and C can be used. Before demapping or any other arbitrary bit extraction method, averaging of bit-by-bit metrics such as LLR can be performed. Also, bit averaging can be performed after bit extraction. A weighted sum combination can be used, whereby lower rate bits (which in this case have a higher SNR, which is the bit energy-to-noise ratio) can receive higher rate bits with a larger weight.

[0132] If the same forward error correction (FEC) is used but the puncturing is different, exemplary embodiment C can be used. Unpunctured bits (before or after mapping) are combined, improving the SNR of the bits while considering the punctured bits that do not require averaging. For example, if the bits without puncturing are X0, X1, X2, X3, there are Y0, Y1, Y2, Y3 in another packet, and there are Z0, Z1, Z3 after puncturing (rate 3 / 4) in another packet, the bits can be averaged as follows. (X0 + Y0 + Z0) / 3, (X1 + Y1 + Z1) / 3, (X2 + Y2) / 2, (X3 + Y3 + Z3) / 3

[0133] 4.3) Detection of Repeated Data Bits Not Located in the Same Location Optionally, if the repeated information is not at the same position within the data packet but the coding scheme is the same (for example, without puncturing), the location of the repeated bits is detected by correlation between packets.

[0134] 5) Align the Sample Sequence with the Arrival Time of the Data Packet To correctly combine the signal samples into one combined signal, it is necessary to align the samples included in the sample sequence with the sampling time of the data packet.

[0135] The sampling of the data packets is optionally synchronized to data packets detected in transmissions between nodes engaged in wireless communication (e.g., from node A or node B in FIG. 2B). The sampling of the data packets is further optionally synchronized to at least one of the following: a) request packets detected in signals received from different sources; and b) Response packets detected in the received signal from different sources

[0136] To illustrate this technique, reference is now made to FIG. 6, which is a simplified diagram of nodes communicating over a wireless data communications network. In FIG. 6, Node A 610 and Node B communicate over a wireless network. It is desirable to detect and / or extract repetitive information from a signal transmitted from Node A. A receiver 630 receives a transmission from Node A 610 with a very low SNR. However, a transmission from Node B 620 is received by the receiver 630 with a sufficiently good SNR to detect a data packet in the signal transmitted from Node B. Thus, the grouping of signal samples into sample sequences may be synchronized to the timing of a data packet detected in the received Node B signal.

[0137] Alternatively or additionally, the time stamp for grouping the samples into a sample sequence may be based on a cycle time of multiple detected data packets.

[0138] The following is an illustrative example of collecting samples at appropriate sampling times.

[0139] 5.1) Sampling based on received request or response packets In a first exemplary embodiment, the timing of sampling of data packets is established based on request or response packets received from different sources (eg, Node B).

[0140] Node B may be sending a response packet to node A (e.g., an acknowledgement packet or a clear-to-send packet). Node B may also be sending actual data to node A, which returns a response packet. Another possibility is that nodes A and B are doing TDD communication, with each side transmitting in its own turn.

[0141] Optionally, if a transmission from a different source (e.g., node B) is received with a suitable SNR, the time stamp for collecting the required packet (e.g., from node A) is set to a fixed time interval before or after the start or end time of the data packet received from node B. Since a response packet is usually sent after the end of a request packet, the time stamp for collecting the next data packet is at a fixed time interval after the end of the request packet received from the different source. Since a request packet is usually sent before a response packet, the time stamp for collecting the next data packet is at a fixed time interval before the expected start time of the next request packet from the different source.

[0142] 5.2) Synchronization by received data packets In a second exemplary embodiment, data packet transmissions are assumed (or known) to have a certain cycle time. Furthermore, some of the data packets transmitted to node A are detectable. The sampling time stamps may further be based on transmissions from another source (e.g., request and / or response packets received from a different source, as in section 5.1 above).

[0143] Optionally, the cycle time of the data packet reception is estimated according to the detectable data packets. The cycle time is calculated by examining the timing corresponding to the following Equation 2, or by calculating the part of the reception {T nCycle T can be found by any other integer linear optimization criteria that examines the cycle T, where the vector of} is known.

number

[0144] If an estimate of T exists (e.g., the cycle time is known excluding clock error), Equation 2 can be modified to Equation 3:

number

[0145] Knowing the cycle time and first phase, the required signals can be captured at the expected time stamp according to Equation 4. Sample collection time stamp (n) = (cycle time) n + (first phase) (4)

[0146] 5.3) Synchronization of fixed frequency or frequency hopping transmissions with known cycle times In this scenario, the cycle time of the data packet transmission is fixed and known (or there are multiple possible cycle times known). Furthermore, the radio signal is transmitted at a single known frequency (or within a known list of frequencies) or with a fixed frequency hopping sequence. In the case of frequency hopping, the frequency list is at least partially known and there is a fixed cycle of transmitted frequencies (i.e., F1,F2,...FN,F1,F2,...FN...).

[0147] Sampling of data packets is performed every cycle with a known time stamp. Several overlapping acquisitions may also be performed.

[0148] For example, a signal with a known cycle of 10 ms is sent on four known frequencies {F1,F2,F3,F4} with a known frequency hop cycle. A typical packet length is expected to be 1 ms. So every 10 ms we expect a 1 ms signal, and every 40 ms we expect a signal of the same frequency.

[0149] A frequency Fk is selected from the list and the received signal is filtered only for Fk. Groups of signals longer than 1 ms, for example 2 ms, are collected. If the start times of the signals are an integer multiple of 40 ms from each other, the signals are added to the same group. Thus, group 1 contains signals starting at times 0, 40, 80, 120, .... Group 2 contains 2 ms signals starting at times 1, 41, 81, 121, ... (note the 1 ms overlap). Group 3 contains 2 ms signals starting at times 2, 42, 82, 122, .... Signals are collected in this way until the final group contains 2 ms signals starting at times 39, 79, 119, 159, ....

[0150] For each of the groups, a similar approach to that described above can be applied to determine whether a signal is present within this group of signals. For example, many linear combinations of the signals in the group can be made and the result can then be passed through a detection scheme.

[0151] If the correct packet cycle or hop cycle is unknown but there are several possible hop cycles, each possible hop cycle may be tested until a signal is found.

[0152] 5.4) Synchronization of dynamic frequency hopping patterns with possible known cycle times In this scenario, the cycle time of the transmission is fixed and known (or there are multiple possible cycle times known), and the frequency hopping pattern is dynamic (i.e., the order of frequencies transmitted in each cycle may change and / or all frequencies do not need to be transmitted in every cycle).

[0153] In this case, there may be a correlation between the two acquisitions, and the two signals will only be associated with the same group if the correlation between the two signals is high enough.

[0154] The correlation between the two signals can be calculated as in Equation 5.

number

[0155] If the transmission uses a fixed rate and coded modulation scheme, the packets may be correlated either before symbol extraction (i.e., raw signal), after symbol extraction and before bit metrics (such as log-likelihood ratios per bit or group of bits) are created, or after bit metrics are created (and before FEC decoding, if present). The frequency offset and channel response may be expected to remain approximately constant, with only the phase expected to change (e.g., sampling phase, local oscillator phase). For multiple-in multiple-out (MIMO) transmissions, multiple channels may be expected to change similarly (e.g., phase changes in the same way), and other transmission parameters may be expected to remain constant (e.g., frequency offset and / or channel response).

[0156] In summary, the embodiments presented herein provide a solution to the technical problem of detecting and / or extracting data from received data packets under low SNR conditions that would otherwise make such detection and / or extraction impossible. Samples of communication signal samples are processed as described above to increase the SNR of information (e.g., sequences of symbols) that are repeated within multiple data packets to a level that allows for detection and / or extraction of the repetitive information. Techniques are also presented for aligning signal sequences upon receipt of data packets. Proper alignment enhances the effectiveness of combining multiple sample sequences into a combined signal, thereby further improving the SNR of the repetitive information.

[0157] The above described methods are used in the manufacture of integrated circuit chips.

[0158] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code that includes one or more executable instructions that perform the specified logical function. It should also be noted that in some alternative implementations, the functions shown in the blocks may be performed out of the order shown in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may be executed in the reverse order, depending on the functionality required. It should also be noted that each block of the block diagrams and / or flowchart diagrams, and combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a dedicated hardware-based system or a combination of dedicated hardware and computer instructions that perform the specified functions or actions.

[0159] The description of various embodiments of the present invention has been presented for illustrative purposes and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used in this specification are selected to best explain the principles of the embodiments, practical applications, or technical improvements across the art as seen in the market, or to allow other skilled in the art to understand the embodiments described herein.

[0160] It is anticipated that many related data packet formats, communication signal transmission methods, frequency hopping transmissions, rates and / or encodings of transmitted data, signal sampling, techniques for combining sequences, correlation techniques, data packet detection techniques, and techniques for extracting data symbols and / or bits from detected data packets will be developed during the life of the patent from the filing of this application until its expiration, and all such new techniques are intended to be included a priori within the scope of the terms data packet, communication signal, frequency hopping, rate, encoding, sampling of communication signals, sequence combination, correlation, data packet detection and extraction.

[0161] The terms "comprises," "comprising," "includes," "including," "having" and conjugations of these verbs mean "including but not limited to." This term encompasses the terms "consisting of" and "consisting essentially of."

[0162] The phrase "consisting essentially of" means that the composition or method may include additional ingredients and / or steps only if the additional ingredients and / or steps do not materially alter the basic and novel characteristics of the claimed composition or method.

[0163] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" can include a plurality of compounds, including mixtures of compounds.

[0164] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and / or to exclude the incorporation of features from other embodiments.

[0165] The word "optionally" is used herein to mean "included in some embodiments and not included in other embodiments." Any particular embodiment of the present invention may include multiple "optional" features unless such features are inconsistent.

[0166] Throughout this application, various embodiments of the invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Thus, the description of a range should be considered to specifically disclose not only each numerical value within that range, but also all possible subranges. For example, the description of a range such as 1 to 6 should be considered to specifically disclose not only each numerical value within that range, e.g., 1, 2, 3, 4, 5, and 6, but also subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc. This applies regardless of the breadth of the range.

[0167] Whenever a numerical range is given herein, the numerical range is meant to include any recited numbers (fractional or integer) within the given range. The phrases "ranging between" a first reference number and a second reference number, and "ranging from" a first reference number to a second reference number, are used interchangeably herein and are meant to include the first and second reference numbers and all fractional and integer numbers between the reference numbers.

[0168] It should be understood that certain features of the invention that are described for clarity in the context of separate embodiments can also be realized in combination in only one embodiment. Conversely, various features of the invention that are described for brevity in the context of only one embodiment can also be realized separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features that are described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment cannot function without that element.

[0169] While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0170] All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, the section headings should not be construed as necessarily limiting.

Claims

1. 1. An apparatus for detecting repetitive information in data packets communicated between a first node and a second node over a wireless network, the apparatus comprising: Processing Circuit wherein the processing circuitry comprises: collecting a plurality of samples of data communication signals transmitted between the first node and the second node over the wireless network at respective times; Grouping the collected samples into a plurality of sequences of samples; combining said multiple sequences of samples into at least one combined signal; and generating a signal indicative of repetitive information within a plurality of data packets carried by the data communication signal based on an analysis of the at least one combined signal; It is configured as follows: the at least one combined signal is a plurality of combined signals, each combined signal being a hypothesis about how the collected signals should be combined, the plurality of combined signals representing different hypotheses; moreover a) respective sets of sample sequences are collected for each phase of a constant cycle of frequency, and a combined signal of said plurality of combined signals is formed for each set, wherein a signal indicative of said repetitive information is provided if repetitive information is detected in at least one of said combined signals; and b) a respective set of sample sequences is collected for each phase of a number of cycles of a transmission frequency, each cycle being an estimate of a possible cycle of the frequency used for transmission, and a combined signal of said plurality of combined signals is formed for each of said sets, wherein a signal indicative of said repetition information is provided if repetition information is detected in at least one of said combined signals; The device is at least one of a) and b) above.

2. 2. The apparatus of claim 1, wherein the analysis includes identifying a presence or absence of repetitive information in the at least one combined signal, and the signal indicative of the repetitive information includes an indicator of the identified presence or absence of repetitive information in the plurality of data packets.

3. The apparatus of claim 1 , wherein the analyzing comprises extracting repetitive information from the at least one combined signal, and the signal indicative of the repetitive information comprises the extracted repetitive information.

4. 2. The apparatus of claim 1, wherein each of the plurality of sequences of samples comprises only one data packet.

5. The apparatus of claim 1 , wherein the processing circuitry is further configured to monitor the data communication signals transmitted between the first node and the second node.

6. The apparatus of claim 1 , further comprising a sampler configured to sample a baseband input signal and provide the samples to the processing circuit for said collection.

7. The apparatus of claim 1 , wherein a frequency transformation is applied to each of the plurality of sequences of samples prior to the combining of the plurality of sequences of samples into the at least one combined signal.

8. The apparatus of claim 1 , wherein the processing circuitry is configured to perform the combining by forming a weighted linear combination of the plurality of sequences of samples and delayed versions of the plurality of sequences of samples.

9. The apparatus of claim 8 , wherein the processing circuitry is configured to select weighting coefficients of the weighted linear combination according to conditions of a communication channel of the network.

10. The processing circuitry comprises: Specifying a plurality of sets of weighting coefficients; forming, for each of said sets of weighting coefficients, a respective combined signal that is a weighted linear combination of said plurality of sequences of samples and delayed versions of said plurality of sequences of samples; and wherein a signal indicative of repetition information is generated if repetition information is identified in at least one of the respective combined signals.

11. The processing circuitry comprises: detecting a respective data packet for each of said plurality of sequences of samples; calculating weights for combining the multiple sequences of samples into a combined signal using at least one of a preamble and a synchronization sequence of the data packet; forming a weighted linear combination of the plurality of sequences of samples and delayed versions of the plurality of sequences of samples using the calculated weights; The apparatus of claim 1 , configured to perform the combination by:

12. The processing circuitry comprises: detecting a respective data packet for each of said plurality of sequences of samples; performing symbol detection on the detected data packets to obtain respective symbol sequences; linearly combining said symbol sequences; The apparatus of claim 1 , configured to perform the combination by:

13. The processing circuitry comprises: detecting a respective data packet for each of said plurality of sequences of samples; decoding each of the detected data packets into a respective bit sequence; selecting, for each location in the at least one combined signal, a bit level that occurs in a majority of the bits at said location in said respective bit sequences; The apparatus of claim 1 , configured to perform the combination by:

14. The processing circuitry comprises: detecting a respective data packet for each of said plurality of sequences of samples; selecting, for each location in the at least one combined signal, a bit level that is most likely to occur at said location based on an analysis of likelihood ratios of the detected data packets; The apparatus of claim 1 , configured to perform the combination by:

15. 2. The apparatus of claim 1, wherein the processing circuitry is configured to collect the samples synchronously with detected data packets received from one of the first node and the second node.

16. The apparatus of claim 1 , wherein the processing circuitry is configured to collect the samples synchronously with a detected request packet.

17. The apparatus of claim 1 , wherein the processing circuitry is configured to collect the samples synchronously with a detected response packet.

18. 2. The apparatus of claim 1, wherein the processing circuitry is configured to collect the samples synchronously with cycle times of a plurality of detected data packets transmitted by at least one of the first node and the second node.

19. 1. A method for detecting repetitive information in data packets communicated between a first node and a second node over a wireless network, comprising: collecting samples of data communication signals transmitted between the first node and the second node over the wireless network at a plurality of respective times; grouping the collected samples into a plurality of sequences of samples; combining said plurality of sequences of samples into at least one combined signal; and generating a signal indicative of repetitive information within a plurality of data packets carried by said data communication signal based on said analysis of said at least one combined signal; Including, the at least one combined signal is a plurality of combined signals, each combined signal being a hypothesis about how the collected signals should be combined, the plurality of combined signals representing different hypotheses; moreover a) respective sets of sample sequences are collected for each phase of a constant cycle of frequency, and a combined signal of said plurality of combined signals is formed for each set, wherein a signal indicative of said repetitive information is provided if repetitive information is detected in at least one of said combined signals; and b) a respective set of sample sequences is collected for each phase of a number of cycles of a transmission frequency, each cycle being an estimate of a possible cycle of the frequency used for transmission, and a combined signal of said plurality of combined signals is formed for each of said sets, wherein a signal indicative of said repetition information is provided if repetition information is detected in at least one of said combined signals; The method according to claim 1, wherein the method is at least one of a) and b) above.

20. 20. The method of claim 19, wherein the analysis comprises identifying the presence or absence of repetitive information in the at least one combined signal, and the signal indicative of the repetitive information comprises an indicator of the identified presence or absence of repetitive information.

21. 20. The method of claim 19, wherein the analyzing comprises extracting repetitive information from the at least one combined signal, and the signal indicative of the repetitive information comprises the extracted repetitive information.

22. 20. The method of claim 19, further comprising the step of monitoring the data communication signal between the first node and the second node.

23. 20. The method of claim 19, further comprising the steps of sampling a baseband input signal and providing said samples to said acquiring step.

24. 20. The method of claim 19, further comprising the step of applying a frequency transform to each of the plurality of sequences of samples prior to the combining step of the plurality of sequences of samples into the at least one combined signal.

25. 20. The method of claim 19, wherein the combining step comprises forming a weighted linear combination of the multiple sequences of samples and delayed versions of the multiple sequences of samples.

26. 26. The method of claim 25, further comprising the step of selecting weighting coefficients of the weighted linear combination according to conditions of communication channels of the network.

27. The combining step comprises: specifying a plurality of sets of weighting coefficients; forming, for each of said sets of weighting coefficients, a respective combined signal that is a weighted linear combination of said plurality of sequences of samples and delayed versions of said plurality of sequences of samples; 20. The method of claim 19, comprising: a signal indicative of the repetitive information is generated if repetitive information is identified in at least one of the respective combined signals.

28. A computer program comprising computer program code, which when executed by a processor, causes the processor to: collecting samples of a data communication signal transmitted over the wireless network between the first node and the second node at a plurality of respective times; grouping the collected samples into a plurality of sequences of samples; combining said plurality of sequences of samples into at least one combined signal; and generating a signal indicative of repetitive information within a plurality of data packets carried by said data communication signal based on said analysis of said at least one combined signal; Detected by the at least one combined signal is a plurality of combined signals, each combined signal being a hypothesis about how the collected signals should be combined, the plurality of combined signals representing different hypotheses; moreover a) respective sets of sample sequences are collected for each phase of a constant cycle of frequency, and a combined signal of said plurality of combined signals is formed for each set, wherein a signal indicative of said repetitive information is provided if repetitive information is detected in at least one of said combined signals; and b) a respective set of sample sequences is collected for each phase of a number of cycles of a transmission frequency, each cycle being an estimate of a possible cycle of the frequency used for transmission, and a combined signal of said plurality of combined signals is formed for each of said sets, wherein a signal indicative of said repetition information is provided if repetition information is detected in at least one of said combined signals; 2. A computer program product according to claim 1, wherein the computer program product is at least one of a) and b) above.

29. 10. The apparatus of claim 1, wherein the collected signals are collected for communication signals of multiple carrier frequencies, and the multiple combined signals are formed from samples collected at the various carrier frequencies and analyzed to determine whether repetitive information is detected at one or more of the multiple carrier frequencies.

30. The apparatus of claim 1 , wherein the multiple combined signals are formed from the same samples using different sets of weightings.

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