Patent Description:
Wireless communication receiver systems readily receive random signals in addition to the desired signals of interest. In some instances, the received random signals are either of small magnitude or significantly out of the receiver's designed frequency band. The receiver can adequately filter out random signals of this nature without interfering with the processing the desired signals.

However, in other instances, these random signals may occur proximate in frequency to the desired signals, may have magnitudes that are sufficiently large so as to interfere with the processing of the desired signal, or a combination of the two. In some cases, a random signal has a significantly larger signal magnitude than the desired signals. In such cases, these random signals interfere with the proper functioning of receiver components. This may result in overall receiver desensitization or receiver "blocking. " Stated differently, the properties of such interfering signals (e.g., frequency location, magnitude, phase, etc.) often exceed the designed-for tolerances of the receiver chain components. As such, these interfering signals have the potential of impairing receiver sensitivity by blocking the proper operations of the receiver components.

One example of such receiver blocking effects occurs when an interfering signal triggers the receiver's active gain control (AGC) system to reduce the overall gain, which increases the receiver's noise figure (NF) and reduces receiver sensitivity. Another example occurs when the interfering signal saturates one of the receiver's low noise amplifiers (LNAs) causing a decrease in gain, an increase receiver distortions, and an increase in the NF.

<CIT> discloses a method for reducing a blocker signal from an input signal received by a wireless receiver.

<CIT> discloses an apparatus which includes an auxiliary path configured to phase-shift an input signal to generate a cancellation signal, in order to reduce or cancel a blocker signal.

<CIT>discloses a wireless multimode receiver having an off-chip duplex filter associated with a multimode band, and a blocker cancellation circuit disposed on a semiconductor chip.

<CIT> discloses systems and methods for interference reduction in wireless communications.

An object of the present disclosure is to provide a wireless receiver system that effectively neutralizes the effects of received undesired RF blocking signals. In accordance with this objective, an aspect of the present disclosure provides a wireless receiver system according to claim <NUM> operative to receive RF signals that contain a desired signal and a blocking signal. A first module, in communication with RF signals along a first signal path is configured to extract a specimen of the received desired and blocking signals. A second module, in communication with the first module along a second signal path to receive the desired signal and blocking signal specimens is configured to produce a replica of the blocking signal based on the blocking signal specimen, generate an anti-blocking signal based on the blocking signal replica, and introduce the anti-blocking signal to the received desired and blocking signals. As such, the anti-blocking signal destructively interferes with the received blocking signal and effectively neutralizes its effects.

In accordance with additional aspects of the present disclosure, there is provided a method neutralizing wireless blocking signals according to claim <NUM>. The method includes receiving radio-frequency (RF) signals including a desired signal and a blocking signal and extracting a specimen of the received desired and blocking signals by a first module. The method further includes producing a replica of the blocking signal based on the blocking signal specimen by a second module, generating an anti-blocking signal based on the blocking signal replica by the second module, and introducing, by the
second module, the anti-blocking signal to the received desired and blocking signals. In so doing, the anti-blocking signal destructively interferes with the received blocking signal and effectively neutralizes its effects.

The features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:.

It is to be understood that throughout the appended drawings and corresponding descriptions, like features are identified by like reference characters. Furthermore, it is also to be understood that the drawings and ensuing descriptions are intended for illustrative purposes only and that such disclosures are not intended to limit the scope of the claims.

As used herein, the term "about" or "approximately" refers to a +/-<NUM>% variation from the nominal value. It is to be understood that such a variation is always included in a given value provided herein, whether or not it is specifically referred to.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the described embodiments appertain.

It is to be noted that the information conveyed above is specifically intended to provide a contextual reference that is believed to be of possible relevance to the ensuing disclosed embodiments. No admission is intended nor should it be construed that any of the preceding information constitutes prior art against the embodiments described by the present disclosure.

<FIG> (Prior Art) illustrates a high-level functional block diagram of a conventional radio-frequency (RF) receiver system <NUM>. As shown, RF receiver system <NUM> incorporates several fundamental components along the analog receiver chain that are configured to process received RF signal(s) of interest. Such components may include, for example, antenna element(s) <NUM>, initial stage bandpass filter (BPF) <NUM>, one or more initial stage low-noise amplifiers (LNAs) <NUM>, attentuator <NUM>, intermediate stage LNA <NUM>, intermediate stage BPF <NUM>, down-converting mixer (DCM) <NUM>, final stage LNA <NUM>, and low-pass filter (LPF) <NUM>.

RF receiver system <NUM> receives RF signal(s) via antenna element(s) <NUM> disposed at the front end of the receiver chain. The received RF signal(s) are fed to initial stage BPF <NUM> having a center frequency aligned with the desired RF frequency of interest and a bandwidth that filters out signals outside the operational range of interest.

The filtered RF signal(s) are then fed to one or more initial stage LNAs <NUM> to amplify the filtered RF signal(s). The signals amplified by LNA <NUM> are then supplied to attenuator <NUM> for magnitude adjustments/corrections.

The magnitude-adjusted RF signal(s) output by ATTN <NUM> are then further amplified by intermediate stage LNA <NUM> and filtered by intermediate stage filter <NUM>, which are configured to improve RF signal(s) characteristics. The RF signal(s) output by IFF <NUM> are then supplied to DCM <NUM>, which operates to down-convert the signal(s) to a baseband frequency range. These down converted signals are referred to as baseband signals.

The baseband signal(s) are then amplified by final stage LNA <NUM> to provide for proper signal amplification and final stage LPF <NUM> for anti-aliasing purposes. The amplified and filtered baseband signal(s) are subsequently supplied to an analog-to-digital conversion (ADC) unit to convert the baseband signal(s) into digital composite signal(s) suitable for digital signal processing.

However, as discussed above, the signal(s) received by RF receiver system <NUM> may include both the desired RF signal(s) and blocking signal(s). By way of a non-limiting example, <FIG> graphically illustrates a spectral view of a representative scenario in which RF receiver system <NUM> receives a desired RF signal DS along with interfering RF blocking signal IB. The desired signal DS is <NUM> wide and, for tractability purposes, is represented as two constituent continuous-wave (CW) tones S1, S2 approximately -<NUM> dBm in magnitude at frequency locations of <NUM> and <NUM>, respectively.

In turn, blocking signal IB is characterized as a single CW tone having a magnitude of approximately - <NUM> dBm at frequency location <NUM>. In the representative scenario, blocking signal IB is substantially close to the frequency band of interest (e.g., <NUM> apart from constituent signal S2) and is approximately <NUM> dBm higher in power than the desired RF signal DS (i.e., constituent signals S1, S2).

It will be appreciated that the noted spectral properties of desired signal DS (i.e., constituent signals S1, S2) and blocking signal IB are directed to providing representative examples of received RF signals for purposes of illustration only and, are not in any way, intended to be limiting. For example, the embodiments described herein can apply equally, possibly with minor modifications to the implementation that would be understood by those skilled in the art, to modulated received RF signals that may have different frequencies and different magnitudes than the properties noted above. It should also be understood that DS and IB can be understood to be the signals that survive BBF <NUM> and LNA <NUM>.

Given the representative attributes of blocking signal IB (e.g., magnitude and frequency location), there exists the likelihood that signal IB will exceed the tolerances of receiver's <NUM> chain components, which are typically designed to handle and process the expected properties of desired signal DS. The affected components may include LNAs <NUM>, <NUM>, <NUM>, DCM <NUM>, automatic gain control (AGC) (not shown), etc. As such, blocking signal IB has the potential of impairing receiver sensitivity by blocking the proper operations of these receiver components.

<FIG> depicts a high-level functional block diagram illustrating the system of RF receiver <NUM> operative to neutralize the effects of blocking signal(s), in accordance with various embodiments of the present disclosure. Receiver <NUM> implements a blocking signal reduction module <NUM> that may be integrated within conventional receiver system <NUM>. Blocking signal reduction module <NUM> includes components that are configured to produce a replica of blocking signal IB and, in turn, generate an "anti-blocking signal" A-IB that will be subsequently introduced into the main RF signal path of receiver <NUM> to neutralize the effects of blocking signal IB.

In particular, as shown in <FIG>, blocking signal reduction module <NUM> incorporates initial stage coupler CPLR <NUM>, delay element <NUM>, attenuation element ATTN <NUM>, and final stage coupler CPLR <NUM>, along the main RF signal path. Additionally, along a fed-forward parallel signal path, blocking signal reduction module <NUM> incorporates blocking signal isolation submodule <NUM>.

As depicted in the illustrated embodiment, blocking signal reduction module <NUM> forwards the received RF signals, namely, desired signal DS (i.e., constituent signals S1, S2) and blocking signal IB to the input port of initial stage coupler CPLR <NUM>. CPLR <NUM> is configured to extract a small specimen (e.g., -<NUM> dBm) of the received RF signals and direct the specimen signal to the fed-forward parallel signal path via its coupling port to blocking signal isolation submodule <NUM>. By extracting a small specimen of the received RF signals, the output port of CPLR <NUM> minimizes any substantial signal-to-noise ratio (SNR) degradation of the desired DS and blocking IB signals along the main RF signal path.

<FIG> graphically illustrates spectral attributes of the representative desired signal DS and blocking signal IB at the CPLR <NUM> input, in accordance with various embodiments of the present disclosure. As shown, desired signal DS (i.e., constituent signals S1, S2) exhibit magnitudes of approximately -<NUM> dBm with approximately <NUM>° phases at frequency locations of <NUM> and <NUM>, respectively. Moreover, blocking signal IB exhibits a magnitude of approximately -<NUM> dBm with approximately a <NUM>° phase at frequency location <NUM>.

Returning to <FIG>, along the main RF signal path, initial coupler CPLR <NUM> forwards the minimally-reduced RF signals DS, IB to delay element <NUM>. Delay element <NUM> is configured to shift the timing of the desired signal DS (i.e., constituent signals S1, S2) and IB to compensate for any timing differences between the signals and processing delays incurred by blocking signal isolation submodule <NUM>. The delayed signals S1, S2, IB are then forwarded to attenuation element ATTN <NUM> that is configured to correct any magnitude variations of delayed signals S1, S2, IB. The delayed and magnitude corrected signals S1, S2, IB are then supplied to the input of final stage coupler CPLR <NUM>.

Along the parallel RF signal path, the specimen signal that has been provided to blocking signal isolation submodule <NUM> contains operable content and characteristics of desired signal DS and blocking signal IB. As will be described in greater detail below, blocking signal isolation submodule <NUM> is configured to process the specimen signal to isolate the content of blocking signal IB and produce an anti-blocking signal A-IB based on the isolated content of blocking signal IB. This anti-blocking signal A-IB is provided to CPLR <NUM> to close a feed-forward loop.

In turn, blocking signal isolation submodule <NUM> will introduce anti-blocking signal A-IB to receiver system's <NUM> main RF signal path via final stage coupler CPLR <NUM>. The coupled anti-blocking signal A-IB will operate to destructively combine with the original received RF blocking signal IB on the main RF signal path to substantially neutralize its blocking effects.

<FIG> depicts a detailed functional block diagram of blocking signal isolation submodule <NUM>, in accordance with various embodiments of the present disclosure. As shown, blocking signal isolation submodule <NUM> comprises LNA <NUM>, attentuator ATTN <NUM>, image rejection mixer IRM stage <NUM>, LNA <NUM>, low-pass filter LPF <NUM>, attenuator ATTN <NUM>, single sideband mixer stage SSB <NUM>, LNA <NUM>, optional signal distribution element <NUM>, LNA <NUM>, phase correction element <NUM>, and magnitude correction element <NUM>.

As noted above, the feed-forward specimen signal containing the content and characteristics of desired signal DS (i.e., constituent signals S1, S2) and blocking signal IB are introduced to blocking signal isolation submodule <NUM> through the parallel signal path via LNA <NUM> and attenuator ATTN <NUM>. LNA <NUM> and attenuator ATTN <NUM> function to amplify and adjust the signal power of the specimen signal and provide sufficient drive levels for subsequent processing by submodule <NUM>.

The specimen signal is then submitted to image rejection mixer IRM stage <NUM>. IRM stage <NUM> is configured to down-convert the RF frequencies of the specimen signal and suppress the power of desired signal DS (i.e., magnitude of constituent signals S1, S2). This effectively isolates the blocking signal IB portion of the specimen signal and render an isolated blocking IB specimen signal.

Typically, IRM architectures incorporate various components, such as, for example, balanced mixers, in-phase local oscillator (LO) frequency drivers, quadrature couplers, in-phase dividers etc. that implement phasing techniques to down-convert the frequencies of desired signals while suppressing unwanted mixed frequency signal products. Accordingly, the LO frequency of IRM <NUM> should be set to operate between the frequencies of desired signal DS and blocking signal IB.

Therefore, in keeping with the spectral attributes of signals S1, S2, IB noted above for illustrative purposes only, the LO frequency of IRM <NUM> is set to operate at <NUM>. This LO frequency resides between the noted desired signal DS edge (i.e., S2 at <NUM>) and blocking signal IB (i.e., at <NUM>).

<FIG> graphically illustrates spectral attributes of representative output signals of IRM <NUM>, in accordance with various embodiments of the present disclosure. As shown, IRM <NUM> outputs signals that includes isolated blocking IB specimen signal, which has been down-converted to a frequency of approximately <NUM>. In contrast, constituent signals S1, S2, which define the edges of desired signal DS, have been down-converted to frequencies of approximately <NUM> and <NUM>, respectively, with substantially reduced magnitudes. In so doing, IRM <NUM> effectively suppresses desired signal DS in order to render isolated blocking IB specimen signal for subsequent processing.

It is to be noted that, as discussed above, <FIG> depicts a representative scenario in which the originally-received blocking signal IB occurs at an RF frequency higher than desired signal DS (as represented by constituent signals S1, S2). And, for illustrative purposes, the disclosed embodiments have been described in accordance with the representative scenario. However, it will be appreciated that the received blocking signal IB may also appear at a lower frequency than desired signal DS. In practice, it may be difficult to determine in advance where blocking signal IB will occur relative to the desired signal DS frequency location.

To this end, <FIG> depicts IRM output switching module 226A, in accordance with various embodiments of the present disclosure. IRM output switching module 226A may be configured to operate in conjunction with IRM <NUM> to provide the selection of upper sideband (USB) or lower sideband (LSB) signals to ensure the isolation of blocking signal IB.

<FIG> illustrates exemplary switching states for the IRM output switching module 226A, in accordance with various embodiments of the present disclosure. For example, the depicted signal at <NUM> is the IB signal and the depicted signal at <NUM> is the local oscillator (LO). IRM output switching module 226A is configured to pick off either side of the spectrum depending on the switch or toggle control. That is, for "Toggle = <NUM>", only the low-side combination of LO-IF is visible (i.e., LO+IF and <NUM> are ignored); and for "Toggle = <NUM>", only the high-side combination of LO+IF is visible (i.e., signal at LO-IF and <NUM> are ignored).

Returning to <FIG>, the isolated blocking IB specimen signal output by IRM stage <NUM> is subjected to a conditioning process to adjust the drive levels prior to an up-conversion mixing stage. The conditioning process comprises amplification by LNA <NUM> to boost isolated blocking IB specimen signal, filtering by low-pass filter LPF <NUM> to exclude extraneous spurious signals across the bandwidth of interest, and power level adjustment by ATTN <NUM>. LPF <NUM> may be configured to have a wide bandwidth, such as, for example, a bandwidth that excludes all signals beyond <NUM>.

<FIG> graphically illustrates spectral attributes of representative output signals of LPF <NUM>, in accordance with various embodiments of the present disclosure. As depicted, the conditioned isolated blocking IB specimen signal has a magnitude of approximately -<NUM> dBm at <NUM> while all other signals, including constituent desired signals S1, S2 are maintained at negligible values.

Returning to <FIG>, the conditioned isolated blocking IB specimen signal is subsequently forwarded to an up-conversion mixing stage comprising single sideband mixer SSB stage <NUM>. SSB <NUM> operates to up-convert the frequency of the conditioned isolated blocking IB specimen signal to match the frequency location of the originally-received blocking signal IB.

It will be appreciated that SSB architectures employ similar components to their IRM counterparts, such as, for example, balanced mixers, in-phase local oscillator (LO) frequency drivers, quadrature couplers, in-phase dividers etc. In contrast to IRM structures, however, SSB components typically implement phasing techniques to up-convert the frequencies of certain signals while suppressing signals containing unwanted mixed frequency signal products. Therefore, in accordance with various embodiments of the present disclosure, the LO frequency of SSB <NUM> is configured to operate at substantially the same LO frequency employed by IRM <NUM>.

<FIG> graphically illustrates spectral attributes of representative SSB <NUM> output signals, in accordance with various embodiments of the present disclosure. As shown, SSB stage <NUM> has effectively up-shifted the frequency of isolated blocking IB specimen signal to substantially match the original received blocking signal IB frequency location of <NUM> with a magnitude of approximately -<NUM> dBm while all other signals, namely, constituent signals S1, S2 remain at negligible levels. As such, SSB stage <NUM> processes isolated blocking IB specimen signal to embody characteristics of originally-received blocking signal IB.

It will be appreciated that, given the unpredictability of the blocking signal IB location, as discussed above relative to IRM stage <NUM>, SSB stage <NUM> may operate with an SSB output switching module 234A, in accordance with embodiments of the present disclosure. SSB output switching module 234A can be configured to provide the selection between upper sideband (USB) or lower sideband (LSB) signals and may employ an architecture similar to IRM output switching module 226A, as depicted in <FIG>.

With this said, armed with isolated blocking IB specimen signal manifesting attributes of originally-received blocking signal IB, blocking signal isolation submodule <NUM> proceeds to generate an anti-blocking signal A-IB. The anti-blocking signal A-IB will be configured to substantially match the magnitude and frequency characteristics of the originally-received blocking signal IB while having an inverted phase value.

However, it will be appreciated that while the frequency characteristics of isolated blocking IB specimen signal remain substantially constant, other attributes, such as, for example, magnitude, phase, delays, etc. may vary due to electrical and physical properties of the signal path(s) and associated elements. Thus, submodule <NUM> incorporates components that adjust and align the signal properties of anti-blocking signal A-IB to inversely match the properties of originally-received blocking signal IB.

As part of this process, the isolated blocking IB specimen signal output by SSB <NUM> is amplified by LNA <NUM> to maintain drive levels for subsequent processing. However, in some instances, it may be desirable to supply isolated blocking IB specimen signal to more than one receiver element within a multi-receiver system, such as, for example, MIMO and M-MIMO systems. <FIG> depicts signal distribution module <NUM>, in accordance with certain embodiments of the present disclosure. Signal distribution module <NUM> is configured to provide isolated blocking IB specimen signal across multiple receiver paths by employing a switching mechanism that selects the receiver elements of interest. As shown in <FIG>, each receiver element path of signal distribution module <NUM> may respectively implement magnitude, phase, and delay components to compensate for such variances.

Turning back to <FIG>, submodule <NUM> further incorporates LNA <NUM>, phase correction element <NUM>, and magnitude correction element <NUM> to adjust and align the signal properties of isolated blocking IB specimen signal to complete anti-blocking signal A-IB. As noted above, anti-blocking signal A-IB is to be introduced to receiver system's <NUM> main RF signal path via final stage coupler CPLR <NUM>. Therefore, in rendering anti-blocking signal A-IB, LNA <NUM> may be configured to amplify and provide a signal boost to isolated blocking IB specimen signal to compensate for the eventual coupling losses (e.g., -<NUM> dBm) due to coupler CPLR <NUM>.

The boosted isolated blocking IB specimen signal is then forwarded to phase correction element <NUM>, which is configured to shift the phase of the replica IB signal by approximately -<NUM>° (or <NUM>°), based on the received main path signal. This phase shift operates to inversely-match the phase of originally-received blocking signal IB, which is then processed by magnitude correction element <NUM> to adjust the magnitude level. The magnitude-adjusted, inverse-phase signal represents the opposite conjugate of the originally-received blocking signal, thereby establishing anti-blocking signal A-IB.

As a reminder, <FIG> depicts the spectral attributes of the processed main RF path signals prior to final stage coupler CPLR <NUM>, that includes desired signal DS represented by constituent desired signals S1, S2 and the original blocking signal IB. It will be noted that original blocking signal IB exhibits a magnitude of approximately - <NUM> dBm at frequency location <NUM> with a phase of approximately -<NUM>°.

By way of comparison, <FIG> graphically illustrates an exemplary representation of the spectral attributes of anti-blocking signal A-IB provided by blocking signal isolation submodule <NUM> along the parallel signal path. As shown in this representation, anti-blocking signal A-IB substantially matches the magnitude of originally-received blocking signal IB of approximately -<NUM> dBm. However, anti-blocking signal A-IB manifests a phase of approximately <NUM>° that is about <NUM>° (i.e., -<NUM>°) out of phase with the originally-received blocking signal IB phase of approximately -<NUM>°.

Anti-blocking signal A-IB is subsequently introduced to receiver system's <NUM> main RF signal path via final stage coupler CPLR <NUM>. At this final coupling stage, the introduced anti-blocking signal A-IB is combined with the main RF path signals that include the received desired and blocking signals. Upon introduction, anti-blocking signal serves to destructively interfere with the originally-received blocking signal IB to neutralize its effects while leaving the received desired signal intact. CPLR <NUM> receives two inputs. The first, from the main path is largely comprised of DS + IB. The second, from the parallel path, is A-IB. The coupling of these inputs will mitigate the effects of IB by reducing the magnitude of IB by A-IB to effectively isolate DS.

To this end, <FIG> graphically illustrates the spectral attributes of the signals that are output by blocking signal reduction module <NUM> after the final coupling stage, in accordance with various embodiments of the present disclosure. As shown, desired signal DS (i.e., constituent signals S1, S2) substantively maintains its original spectral characteristics, namely, magnitudes of approximately -<NUM> dBm at frequency locations of <NUM> and <NUM>, thereby remaining unaffected. In contrast, originally-received blocking signal IB has been effectively neutralized.

<FIG> depicts a functional flow diagram of process <NUM> for neutralizing blocking signals in conjunction with the wireless receiver system <NUM> described above and in accordance with various embodiments of the present disclosure. As shown, process <NUM> begins at task block <NUM>, in which wireless receiver system <NUM> receives a desired RF signal and an RF blocking signal. As noted above, system <NUM> includes antenna element(s) configured to receive desired RF signals that may also be subject to receipt of undesired RF blocking signals.

Process <NUM> proceeds to task block <NUM>, where system <NUM> extracts a specimen of the received RF desired signal and RF blocking signal. As noted above, system <NUM> employs a coupling mechanism CPLR <NUM> that extracts a diluted specimen (e.g., -20dBm) of the received RF desired and blocking signals.

At task block <NUM>, system <NUM> operates to separate and isolate, from the extracted specimen, the blocking signal IB portion from the desired signal portion. As described, system <NUM> incorporates an image rejection filtering element IRM <NUM> to isolate the blocking signal IB portion of the specimen signal to render an isolated blocking IB specimen signal.

At task block <NUM>, system <NUM> operates to process isolated blocking IB specimen signal to produce anti-blocking signal A-IB. As noted above, system <NUM> implements various elements to condition and adjust the attribute levels of isolated blocking IB specimen signal, which is then supplied to single sideband mixing element SSB <NUM> to up-convert the frequency of the conditioned isolated blocking IB specimen signal to match the frequency location of the originally-received blocking signal. The conditioned isolated blocking IB specimen signal is then forwarded to phase correction element <NUM>, which is configured to translate the phase of the replica signal by approximately -<NUM>° (or <NUM>°) to inversely-match the phase of the originally-received blocking signal. This inverse phase signal represents the opposite conjugate of the originally-received blocking signal to produce anti-blocking signal A-IB.

Finally, process <NUM> proceeds to task block <NUM>, where system <NUM> introduces anti-blocking signal A-IB to the received desired and blocking signals which, in so doing, leaves the received desired signal intact while effectively neutralizing the received blocking signal. As previously described, system <NUM> implements a final stage coupling element CPLR <NUM> that introduces anti-blocking signal A-IB into the main RF signal path containing the received desired and blocking signals. Upon introduction, anti-blocking signal A-IB serves to destructively interfere with the originally-received blocking signal to neutralize its effects.

In this manner, the disclosed embodiments provide an RF receiver system that effectively neutralizes blocking signals while minimizing front-end gain losses and maintaining SNR sensitivity. The disclosed RF receiver system is capable of accounting for CW and modulated blocker occurrences and is adaptably scalable to support single and multiple MIMO/M-MIMO receiver elements.

Claim 1:
A wireless receiver (<NUM>) for neutralizing a blocking signal, comprising:
a first module operative to receive radio-frequency, RF, signals containing a desired signal and a blocking signal along a first signal path (<NUM>→<NUM>→<NUM>) and configured to extract a minor sample portion of the magnitudes of the received desired and blocking signals to produce a specimen signal;
a second module (<NUM>), in communication with the first module along a second signal path, operative to receive the specimen signal and configured to:
isolate the blocking signal from the specimen signal to produce an isolated blocking specimen signal,
generate an anti-blocking signal based on the isolated blocking specimen signal, and
introduce the anti-blocking signal to the received desired and blocking signals, wherein the anti-blocking signal destructively interferes to neutralize the received blocking signal,
wherein the first module includes a first coupling element (<NUM>) configured to extract the minor sample portion of the magnitudes of the received desired and blocking signals to produce a specimen signal and to supply the specimen signal to the second module along the second signal path.