Variable depth hybrid beamforming

Abstract

An apparatus may include antenna elements arranged in tiles. The apparatus may include analog beamforming elements coupled with the plurality of antenna elements and analog to digital converters (ADCs) coupled with the analog beamforming elements. The apparatus may include digital signal processing (DSP) layers, where a first DSP layer includes first combining cells for combining signals from the ADCs and a second layer includes combining cells for combining signals from the first combining cells. The combining cells may be configurable for linearly weighting signals input to the combining cells or applying a true time delay function to the signals input to the combining cells. The apparatus may include a signal processing manager coupled with the plurality of DSP layers that determines one or more of the plurality of DSP layers to implement the true time delay based on one or more characteristics of the radio frequency beam.

Description

VARIABLE DEPTH HYBRID BEAMFORMINGCROSS-REFERENCES

[0001] The present Application for Patent claims priority to U.S. Provisional Patent Application No. 63 / 573,995 by Medawar et al., entitled “VARIABLE DEPTH HYBRID BEAMFORMING,” filed April 3, 2024, assigned to the assignee hereof, and hereby incorporated into the present Application for Patent by reference.BACKGROUND

[0002] The following relates generally to communications, including variable depth hybrid beamforming.

[0003] In radio frequency (RF) and microwave systems such as satellite or other wireless communication systems, large scale antenna arrays may be employed and signals from antenna elements or sub-elements (e.g., antenna tiles and antenna subtiles) may be combined or processed in a variety of manners to support beamforming and other processing in efforts to increase communications quality, coverage, and efficiency. However, some such approaches may be improved.SUMMARY

[0004] The described techniques relate to variable depth hybrid beamforming.

[0005] An apparatus is described. The apparatus may include a plurality of antenna elements arranged in a plurality of tiles, each tile of the plurality of tiles comprising a subset of the plurality of antenna elements, where the plurality of antenna elements are configured to receive a radio frequency beam. The apparatus may include a plurality of analog beamforming elements coupled with the plurality of antenna elements, a plurality of analog to digital converters (ADCs) coupled with the plurality of analog beamforming elements, and a plurality of digital signal processing (DSP) layers coupled with the plurality of ADCs, where a first layer of the plurality of DSP layers includes a first plurality of combining cells configurable for combining respective subsets of signals from the plurality of ADCs, where a second layer of the plurality of DSP layers includes a second plurality of combining cells configurable for combining signals from the first plurality of combining cells, and where each of the first plurality of combining cells and the second plurality of combining cells are configurable for linearly weighting signals input to the combining cells or applying a truetime delay function to the signals input to the combining cells. The apparatus may include a signal processing manager coupled with the plurality of DSP layers, where the signal processing manager is configured to determine one or more of the plurality of DSP layers to implement the true time delay based at least in part on one or more characteristics of the radio frequency beam.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 shows an example of a satellite communication system that supports variable depth hybrid beamforming in accordance with examples described herein.

[0007] FIGs. 2 A and 2B show examples of resources for a satellite communication system that supports variable depth hybrid beamforming in accordance with examples described herein.

[0008] FIG. 3 shows an example of a beamforming architecture that supports variable depth hybrid beamforming in accordance with examples as disclosed herein.

[0009] FIG. 4 shows an example of a signal path that supports variable depth hybrid beamforming in accordance with examples as disclosed herein.

[0010] FIG. 5 shows an example of a system that supports variable depth hybrid beamforming in accordance with examples as disclosed herein.DETAILED DESCRIPTION

[0011] In satellite communication systems, beamforming operations may be performed to steer beams in particular directions or to use particular resources for communications (e.g., between a satellite and a terrestrial communications entity). In some such scenarios, beamforming may be achieved through the use of various mechanisms. For example, analog beamforming may employ analog signal weighting, digital beamforming may employ digital combining and weighting, and hybrid beamforming may employ combinations of analog and digital beamforming. Analog and digital beamforming may employ phase shifters to create time differences between signals from different elements. Additionally or alternatively, some systems may employ true time delay (TTD) elements to reduce beam squint across larger system frequency ranges. In addition, some system may support multi-beam processing, which may form multiple simultaneous beams using the same antenna array. However, such mechanisms may be statically located at positions within the processing pipeline or may be limited to some types of processing, reducing flexibility and increasing power consumption(e.g., when a processing block is active even when no processing is to be performed at that position in the processing pipeline).

[0012] The subject matter described herein provides for the use of vertically distributed beamforming, TTD, and multi-beam processing at one or more digital signal processing (DSP) layers and for flexible configuration thereof. Signals received at antenna elements of an antenna array may be fed through analog beamformers and analog to digital converters (ADCs), after which one or more combining cells may process the signals across multiple DSP layers. For example, at a first layer after the ADCs, combining cells may perform simple combination and / or weighting operations, TTD operations, or both, and such operations may accept either single beams or multiple beams as inputs. Each layer of combining cells may perform simple combinations and / or weighting, TTD operations, or both (e.g., for either single or multiple beams). The various combining cells may be configured (e.g., for linear combinations and / or weighting, for TTD, or both, for either single beams or multiple beams) across the various layers depending on communications conditions, use cases, power considerations, one or more other factors or characteristics described herein, or any combination thereof. Further, at some portions of combining cells where some processing is not desired, such portions of a combining cell may be deactivated (e.g., in cases involving selectable processing activation) or not configured (e.g., in cases involving programmable logic). Though examples regarding reception of signals are illustrated and described above, similar architectures and / or configurations may be applied for transmission of signals via the antenna array as well. In at least these ways, a device with an antenna array may apply appropriate beamforming and other operations to promote communications quality (e.g., an improved signal-to-noise ratio (SNR)), reliability, and efficiency, all while reducing power consumption of the antenna array and related processing.

[0013] Aspects of the disclosure are initially described in the context of satellite communication systems. Aspects of the disclosure are then described with reference to an antenna array. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, block diagrams, and flowcharts that relate to variable depth hybrid beamforming.

[0014] FIG. 1 shows an example of a satellite communication system 100 that supports variable depth hybrid beamforming in accordance with examples described herein. Satellite communication system 100 may include a ground system 135, terminals 120, and satellite system 101. The ground system 135 may include a network of access nodes 140 that areconfigured to communicate with the satellite system 101 via a feeder link 132. The access nodes 140 may be coupled with access node transceivers 145 that are configured to process signals received from and to be transmitted through corresponding access node(s) 140. The access node transceivers 145 may also be configured to interface with a network 125 (e.g., the Internet) — e.g., via a network device 130 (e.g., a network operations center, satellite and gateway terminal command centers, or other central processing centers or devices) that may provide an interface for communicating with the network 125.

[0015] Terminals 120 may include various devices configured to communicate signals with the satellite system 101. Although terminals 120 are illustrated as being on aircraft, terminals 120 may include fixed terminals (e.g., ground-based stationary terminals), or mobile terminals mounted on mobile platforms (e.g., boats, aircraft, ground-based vehicles, and the like), or a combination of fixed and mobile terminals. A terminal 120 may communicate data and information with an access node 140 via the satellite system 101 . The data and information may be communicated with a destination device such as a network device 130, or some other device or distributed server associated with a network 125.

[0016] Terminals 120 may include an antenna assembly which may also include various hardware for mounting an antenna. An antenna assembly may also include circuits and / or processors for converting (e.g., performing frequency conversion, modulating / demodulating, multiplexing / demultiplexing, filtering, forwarding, etc.) between radio frequency (RF) satellite communication signals, and satellite terminal communications signals transmitted between the antenna and a satellite terminal receiver. For mobile terminals, the antenna assembly may be mounted on the outside of the mobile platform (e.g., outside of the fuselage of an aircraft). Additionally, or alternatively, the terminal 120 may include a transceiver, which may be mounted on the inside or outside of the mobile platform and may include circuits and / or processors for performing various RF signal operations (e.g., receiving, performing frequency conversion, modulating / demodulating, multiplexing / demultiplexing, etc.).

[0017] The satellite system 101 may include a single satellite 105, or a network of satellites 105 that are deployed in space orbits (e.g., low earth orbits, medium earth orbits, geosynchronous orbits, geostationary orbits, etc.). One or more satellites 105 included in satellite system 101 may be equipped with multiple antennas (e.g., one or more antenna arrays). In some examples, the one or more satellites 105 equipped with multiple antennas may each include one or more antenna panels that include an array of evenly distributedantennas (which may also be referred to as antenna elements). In some examples, a satellite may be equipped with an antenna array including antennas that are unevenly distributed across a large region. The ground system 135 may also contain access nodes 140 with multiple antenna array elements.

[0018] The satellite system 101 may have a large aperture size, which may be spanned by the antenna arrays or multiple satellites of the satellite system 101. The satellite system 101 may use the one or more satellites to support beamforming techniques within the coverage area 155 of the satellite system to increase a utilization of resources used for communications. Beamforming, including using multiple-input multiple-output (MIMO) techniques, may be used to exploit multipath signal propagation and increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers over the same frequency resources. The multiple signals may, for example, be transmitted by a transmitting device (e.g., a satellite system) via a set of antennas in accordance with a set of weighting coefficients.Likewise, the multiple signals may be received by a receiving device (e.g., a satellite system) via a set of antennas in accordance with a set of weighting coefficients. Each of the multiple signals may be associated with a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords).

[0019] In some examples, some or all of the antenna elements on the satellite and / or the ground system may be arranged as an array of constituent receive and / or transmit feed elements that cooperate to enable various examples of on-board beamforming (OBBF), ground-based beamforming (GBBF), end-to-end beamforming, or other types of beamforming. In the GBBF implementation, there may be multiple transmit or receive antennas on the ground system access node(s).

[0020] To determine weighting coefficients to apply to the set of antennas such that N spatial layers are formed, an (M x N) MIMO matrix may be formed, where M may represent the quantity of antennas of the set of antennas. In some examples, M may be equal to N. The MIMO matrix may be determined based on a channel matrix and used to isolate the different spatial layers of the channel. In some examples, the weighting coefficients are selected to emphasize signals transmitted using the different spatial layers while reducing interference of signals transmitted in the other spatial layers. Accordingly, processing signals received at each antenna of the set of antennas (e.g., a signal received at the set of antennas) using the MIMO matrix may result in multiple signals being output, where each of the multiple signalsmay correspond to one of the spatial layers. In some examples, the weighting coefficients used for MIMO communications may be referred to as beam coefficients or beamforming coefficients, and the multiple spatial layers may be referred to as beams or spot beams.

[0021] The elements of the MIMO matrix used to form the spatial layers of the channel may be determined based on channel sounding probes communicated between a satellite system 101 and one or more devices. Channel sounding probes include reference signals transmitted periodically between a satellite system and a device (e.g., a terminal) coupled with the satellite system. For example, a channel sounding probe may be periodically transmitted from a terminal to the satellite system, or from the satellite system to a terminal, or both, and may include a sequence that is known to the transmitter and receiver (e.g., based on a terminal identifier or other parameters known to the transmitter and receiver). The receiving device (e.g., the terminal or the satellite system) may use the received channel sounding probe to evaluate the connection by correlating a received channel sounding probe to the expected signal for the channel sounding probe (e.g., to determine a signal strength, an interference, etc.) and make decisions based thereon. Due to the periodicity of the signal, the receiving device may know when the signal should be received.

[0022] Beamforming techniques may be used to shape or steer a communication beam 150 along a spatial path between a satellite system 101 and a geographic area. A communication beam 150 may be formed by determining weighting coefficients for antenna elements of an antenna array that result in the signals transmitted from or received at the antenna elements being combined such that signals propagating in a particular orientation with respect to an antenna array experience constructive interference while others experience destructive interference. Thus, beamforming may be used to transmit signals having energy that is focused in a direction of a communication beam 150 and to receive signals that arrive in a direction of the communication beam 150 with increased signal power (relative to the absence of beamforming). The weighting coefficients may be used to apply amplitude offsets, phase offsets, TTD, or combinations thereof to signals carried via the antennas.

[0023] In some examples, the weighting coefficients applied to the antennas may be used to form multiple communication beams 150, each associated with a different direction, where the multiple communication beams 150 may be used to communicate multiple signals having the same frequency at the same time to different user terminals. This may be referred to as multi-beam processing, and may support multiuser MIMO. The weighting coefficients used for beamforming may be referred to as beam coefficients, and the multiple signals may bereferred to as beam signals. The resulting communication beams 15- may be referred to herein as beamformed spot beams, spot beams, or beams.

[0024] The amplitude and phase of each weighting coefficient may be calculated given the antenna array and reflector geometry and location and the desired beam locations. However, due to inaccuracies (e.g., in the satellite location, array orientation, geometry, atmospheric scintillation effects, etc.), such an approach may not be practical. Instead, the weighting coefficients may be calculated by continuously measuring the MIMO propagation channel characteristics (e.g., pairwise channels from each system antenna element to each terminal antenna element) and adjusting the weighting coefficients based on the changing channel characteristics. The measured MIMO channel characteristics may include pairwise gain and phase response and noise level and may be referred to as MIMO channel state information (CSI). Once the MIMO CSI is available, the weighting coefficients may be derived by solving a set of equations or applying a set of adaptation formulas. Various beamformer calculation and adaptation techniques may be used, including minimum mean square (MMSE) beamformer, zero forcing beamformer, MIMO sphere decoder, and others.

[0025] The beamformed communication beams 150 may be associated with a set of resources of the satellite system 101. The set of resources may include frequency resources, time resources, and polarization resources. Beamformed communication beams 150 may overlap spatially without interfering if they are associated with different resources. For example, a given frequency range for the satellite system 101 may be divided into frequency resources or channels, and a given amount of time may be divided into different recurring time slots, where a frequency resource may be used to carry a beam signal (e.g., a modulated signal carried in a beamformed spot beam) on one of the recurring time slots. By doing this, beamformed communication beams 150 may overlap spatially without interfering if they are associated with different frequency and / or time resources. In addition, multiple polarizations may be used such that two beamformed communication beams 150 may overlap spatially without interfering if they are associated with different polarizations.

[0026] FIG. 2A shows an example of resources 200-a for a satellite communication system that support variable depth hybrid beamforming in accordance with examples described herein. Resources 200-a may correspond to frequency divisions of a satellite communication system. For example, a frequency range 205 (e.g., a frequency band) may be divided up into a set of different frequencies or frequency channels 210 (e.g., frequency channel 210-a, frequency channel 210-b, frequency channel 210-c, frequency channel 210-d)that carry the signals between the satellite communication system and the terminals. The resources 200- a may correspond to the frequency channels 210 of the frequency range 205.

[0027] Each frequency channel 210 may carry signals associated with a single terminal (e.g., at a time). For example, each frequency channel 210 may carry a single modulated signal. Information (e.g., data, control information) may be modulated onto the modulated signal using a variety of single-carrier or multi-carrier modulation techniques (e.g., Orthogonal Frequency Division Multiplexing (OFDM), Direct Sequence Spread Spectrum (DSSS), linearly pre-coded OFDM (LP-OFDM)). A beamformed spot beam may be associated with one or more frequency channels 210.

[0028] In the example of FIG. 2A, the resources 200-a may correspond to the frequency channels 210. That is, each frequency channel 210 may be a separate resource 200-a. As such, in this example the number of available resources may correspond to the number of frequency channels, N.

[0029] FIG. 2B shows another example of resources 200-b for a satellite communication system that support variable depth hybrid beamforming in accordance with examples described herein. In this example, frequency channels 210 may again be used to carry the signals associated with the terminals. In addition, the frequency channels 210 may be time multiplexed. That is, each frequency channel 210 may be configured to carry signals to the terminals in time slots that repeat after a period of time. For example, a time period 215 may be divided into a set of sub-periods or time slots t (e.g., time slot tl, time slot t2, time slot t3, time slot tm) each having a length 225. Each frequency channel 210 may carry a signal to a different terminal during each time slot t, although in some cases multiple time slots within a time period 215 may be allocated to the same terminal. For example, each frequency channel 210 may carry a single modulated signal during each time slot t. Information (e.g., data, control information) may be modulated onto the modulated signal using a variety of single- carrier or multi-carrier modulation techniques (e.g., OFDM, DSSS, LP-OFDM).

[0030] At the completion of the time period 215, the process may repeat such that each frequency channel 210 may carry further signals associated with the different terminals in a resource period. As a result, the frequency channel 210 may be used for communication with the terminal during one time slot t per time period 215. In some examples, a terminal may be assigned to more than one time slot per time period, and thus communication with a terminal may occur over more than one time slot per time period for the frequency channel 210.

[0031] In the example of FIG. 2B, the resources 200-b may correspond to the combination of frequency channels 210 and time slots t in a time period 215. That is, each unique combination of frequency channel 210 and time slot t may be a separate resource 200-b. As such, in this example the number of available resources may correspond to the number of frequency channels times the number of time slots, or N x m. Thus, this example may provide more resources that the example of FIG. 2A.

[0032] In addition to being multiplexed in time or frequency, different polarizations may be used to define the resources for assignment to beamformed spot beams. For example, a set of resources may include a first sub-set of resources associated with a first polarization and a second sub-set of resources associated with a second, orthogonal, polarization. The first and second polarizations may be any orthogonal polarizations, and may be linearly polarized or circularly polarized (e.g., a right-hand circular polarization (RHCP), a left-hand circular polarization (LHCP)). Thus, a set of resources available for assignment to beamformed spot beams may be defined according to frequency resources (e.g., frequency channels), time resources (e.g., sub-periods of resource periods), or polarization resources.

[0033] In some examples, the types of resources may be combined. For example, in the same system, one or more frequency channels may be divided into time slots and one or more other frequency channels may be used, undivided, as separate resources. Other combinations are also possible.

[0034] FIG. 3 shows an example of beamforming architecture 300 that supports variable depth hybrid beamforming in accordance with examples as disclosed herein.

[0035] The beamforming architecture 300 may include multiple antenna elements. For example, the beamforming architecture 300 may include multiple tiles 310 of antenna elements, which may include subtiles 312. The tiles 310 may be in a plane, and a scan angle for the array of tiles 310 may be measured from a line that is orthogonal from the plane. For example, lower scan angles may be closer to the line that is orthogonal from the plane, while higher scan angles may be further from the line (e.g., closer to parallel with the plane). In some examples, each subtile 312 may include or be associated with a single antenna element or with multiple antenna elements. In some examples, each subtile 312 may be coupled with an analog beamformer 314, which may perform one or more analog beamforming operations on the signal received from the subtile 312. In some examples, each analog beamformer 314 may include a variable phase shifter, a variable gain amplifier, one or more other processingelements, or any combination thereof, to perform analog beamforming operations on the signals received from the subtiles 312.

[0036] The ADCs 316 may digitize the signals from the analog beamformers 314, so that following processing may be performed in the digital domain (e.g., at the combining cells 318 in the various digital layers, such as layer 0, layer 1, and layer 2 (and, optionally, one or more additional layers)). In some examples, because the overall beamforming results from both analog and digital functional blocks, processing may be referred to as “hybrid.”

[0037] In some examples, one or more elements of the digital portion of the beamforming architecture 300 may include multiple combining cells that perform one or more DSP operations, such as combining (e.g., linearly weighting according to beam coefficients), TTD operations, or both, which may be performed on a single beam or on multiple beams. In some examples, such processing may be carried out via one or more elements of the combining cell 318, which may include a combiner 320 that combines multiple signals (optionally applying one or more weights to one or more of the signals to be combined, where weights may include amplitude or phase components, or both), a TTD unit (TTDU), such as the TTDU 322, that applies TTD operations to one or more signals, a multi-beam unit (MBU), such as the MBU 324 that may aid in processing multiple beams (e.g., vita the combiner 320, the TTDU 322, or both). Additionally, or alternatively, the TTDU may additionally or alternatively be characterized as a TTD process. Further, the MBU may additionally or alternatively be characterized as a multi-beam process. Thus, references to a TTDU and an MBU may include a TTD process and a multi-beam process, respectively.

[0038] For example, the combiner 320 may sum input signals (e.g., according to beam weights) and forward them to a following DSP stage (e.g., another combining cell 318). In some examples, a combiner 320 may be used and other processing may not be used, such as in situations in which the antenna array (e.g., the collection of tiles 310) is relatively orthogonal to a scan direction or the device that employs the antenna array is scanning at relatively low angles for a given instantaneous bandwidth. In such cases, when the instantaneous bandwidth increases, the maximum scan angle at which a beam squint stays negligible (or below a beam squint threshold) may decrease.

[0039] The TTDU 322 may be employed to perform TTD operations after which the delayed signals may be summed, weighted, or combined (e.g., by the combiner 320) and passed on to the next stage. Such an approach may be used in cases in which an instantaneousbandwidth at a given scan angle is such that the analog phase rotation (e.g., that which may be performed by the analog beamformers 314) or digital combining according to beam weights is not enough to prevent significant beam squint (e.g., beam squint exceeding a beam squint threshold) or excessive side lobes in a communication pattern of the antenna array. It is worth noting that the phase rotation applied by analog beamformers or digital combining is intrinsically a frequency dependent operation. As such, it may not be desirable for use in connection with a wideband signal, whereas the TTDU 322 may apply a constant delay across different frequencies.

[0040] The MBU 324 may be employed to aid the combining cell 318 in managing multiple beams. For example, in a case in which a combining cell 318 is to process multiple beams, the input streams may be digitally duplicated to generate and process M different beams in the same combining cell 318 or in another combining cell 318 (e.g., via a combiner 320, a TTDU 322, or both). In some cases, a subtile 312 may include a single antenna element and the digital path may be duplicated in a combining cell 318 of layer 0 (e.g., soon after the ADC 316) to process M independent beams. It is worth noting that the same would apply if the analog subtile 312 had multiple elements, but the digital scan range may be reduced due to high directivity of the analog tile and grating lobes.

[0041] The combining cells 318 may he arranged in multiple DSP layers. For example, Figure 3 depicts layer 0, layer 1, and layer 2, though additional or alternative layers may also be employed. For example, the DSP layers may begin at layer 0, (e.g., a first digital layer that is the first DSP layer to process signals after the ADCs 316) and progress to Layer N, where / V < log_2 QuantityOf AnalogT ties . At Layer N, the signal may be fully beamformed as a result of operations performed at the analog beamformers 314, the one or more DSP layers, or any combination thereof. As the signals pass through the various stages of manipulation towards layer N, the associated SNR increases.

[0042] In some cases, the SNR at layer 0 may be small or potentially even negative. In such a case, fewer bits may be employed for processing (e.g., at a combining cell 318), optionally including one or more extra bits for additional “safety” headroom, such as to protect against jammers or interference. Further, in some examples, the quantity of bits used for processing at each digital layer may increase in step with progress through the layers (e.g., layer 2 may utilize more bits than layer 1 , which itself may utilize more bits than layer 0) and may do so in accordance with SNR that may increase with progress through the layers.

[0043] In some examples, a configuration or arrangement of the combining cells 318 across the multiple DSP layers may be variable or configurable. For example, depending on the quantity of analog tiles 310, subtiles 312, or both, a communications bandwidth (e.g., an instantaneous bandwidth, such as a maximum instantaneous bandwidth or minimum instantaneous bandwidth), a scan angle (e.g., a maximum scan angle, a minimum scan angle, or both), SNR (e.g., at one or more layers, combining cells 318, or ADCs 316), one or more other factors or characteristics described herein, or any combination thereof, some or all of the combining cells 318 may be instantiated in a single hardware unit (e.g., programmable logic hardware, such as a field programmable gate array (FPGA)).

[0044] For example, an amount of processing resources may be available to a device, and these processing resources may be assigned or allocated (e.g., through configuration, activation, or deactivation of combining cells 318, ADCs 316, one or more other elements described herein, or any combination thereof) based on one or more factors or communication characteristics. For example, processing resources may be assigned or allocated to one or more layers based on a quantity of processing resources consumed by one or more TTDUs 322, combiners 320, MBUs 324, one or more other entities described herein, or any combination thereof. Additionally, or alternatively, processing resources may be assigned or allocated to one or more layers based on an SNR associated with one or more layers. For example, TTD operations may be employed at layers that are under low SNR conditions (e.g., that fail to satisfy an SNR threshold) because the bit depth may be lower, and other processing (e.g., combiners 320 without TTD operations) may be employed at layers that are under high SNR conditions (e.g., that satisfy an SNR threshold).

[0045] Additionally, or alternatively, multiple hardware units may be interconnected through suitable interfaces (e.g., a serializer / deserializer (SERDES) interface) in a tree shape (e.g., as depicted, in which layer closer to the tiles 310 may include more combining cells 318 and the quantity of combining cells 318 per layer may decrease as the signals move away from the tiles 310.

[0046] Various configurations of combining cells 318 may be employed (e.g., either statically configured or dynamically configured with programmable logic or other hardware, for instance). For example, a combining cell 318 may include a combiner 320, a TTDU 322, and an MBU 324, or any subset or element thereof. In some examples, a buffering unit may be used as an alternative to the TTDU 322 in one or more combining cells 318. Such a buffering unit may offer a delaying mechanism that may be less costly (e.g., in terms ofpower consumption, processing or storage resources, or any combination thereof) than a TTDU 322, but may not be appropriate for all situations (e.g., buffering may be less precise or otherwise suffer in performance as compared to a TTDU 322, but may offer savings (e.g., in terms of power consumption, processing or storage resources, or any combination thereof).

[0047] In some examples, processing operations may be different for different layers. In some examples of processing, a TTD may be employed, and in other examples phase shifts may be employed. In some examples, a phase shift (e.g., involving complex multiplication of signals) may be cheaper (e.g., in terms of power consumption, processing or storage resources, or any combination thereof) as opposed to TTD, (e.g., which may include, for example, up to 20 times the amount of multiplication operations performed) In some examples, the effect of a delay may be more effective at some frequencies and less effective at other frequences (e.g., as desired).

[0048] In some examples, each combining cell 318 in all of the layers may include a combiner 320, a TTDU 322, and an MBU 324. In some cases, varying the quantity of layers may modify a fan-in of each combining cell 318. For example, where the quantity of layers N is equal to log_2(QuantityOfAnalogTiles), the fan-in of each combining cell 318 may be equal to 2, where if the quantity of layers N is less than log _2 Quantity 0 fAnalogT lie s'), the fan-in for at least some combining cells (e.g., combining cells at a given layer) may be more than 2.

[0049] Additionally, or alternatively, each combining cell 318 in a given layer may be configured similarly. For example, combining cells 318 in layer 0 may each include a combiner 320, a TTDU 322, and an MBU 324, combining cells 318 in layer 1 may each include a combiner 320 and a TTDU 322 (e.g., and may not include an MBU 324), and combining cells 318 in layer 2 may each include a combiner 320 (e.g., and may not include a TTDU 322 and an MBU 324).

[0050] Additionally, or alternatively, a quantity of TTDUs 322 employed in a given layer may depend on the position of the layer in the hierarchy of DSP layers. For example, layers closer to the tiles 310 may include combining cells 318 that may perform phase adjustments (e.g., where a greater quantity of combining cells 318 are employed) which may be less taxing (e.g., in terms of power consumption, processing or storage resources, or any combination thereof). Correspondingly, layers farther from the tiles 310 may include combining cells 318 with a TTDU 322, an MBU 324, or other processing that may be morecostly (e.g., in terms of power consumption, processing or storage resources, or any combination thereof) than phase adjustments, but due to the smaller quantity of combining cells 318 included, the overall cost may be reduced (e.g., as compared to employing such processing through a greater quantity of DSP layers). It is worth noting that if multi-beam processing is desired, MBUs 324 may exist for DSP layers that are above the first layer in which multi-beam processing is employed. For example, DSP layers at or above a DSP layer n may employ MBUs 324, where n is a lowest (e.g., closest to the antenna elements) DSP layer using multi-beam processing.

[0051] In some examples, it may be desirable to determine at which layers more costly TTD processing is to be performed and at which layers other processing that is less costly (e.g., phase shifts, combining, weighting, or other operations) may be performed. For example, from a computational standpoint, it may be desirable to have TTDUs 322 at layers farther away from the tiles 310, as fewer TTDUs 322 may be employed, resulting in power and computational savings. In some examples, such an analysis be performed on a layer-by- layer basis, based on communication characteristics (e.g., bandwidth, scan angle, a quantity of tiles 310 or subtiles 312, any other characteristics described herein, or any combination thereof) to determine whether a given layer is to include or operate a TTDU 322 in one or more combining cells 318 or whether other operations (e.g., employing the combiner 320 without the TTDU 322) are to be performed. In some examples, a phase shift may approximate or may be equivalent to the use of TTD for a single frequency and / or for a small bandwidth. However, at some larger bandwidths, the effects of a phase shift may not be equal to or approximate the effects of a TTD operation and different content at different frequencies may have different time delays. In some examples, a determination of whether or not to perform TTD operations at a given layer may be based on a determined amount of error resulting from non- TTD operations and whether such error satisfies an error threshold.

[0052] In some examples, at layers closer to the analog tiles, TTDUs 322 may have high resolution and small range (e.g., in accordance with a distance between blocks in those layers), whereas other TTDUs 322 of other layers have a coarser resolution and longer delays at deeper layers (e.g., where the equivalent beamformed subarray is larger).

[0053] In some examples, TTDUs 322 may be implemented or configured based on their hierarchical position in the processing chain. For instance, a TTDU 322 may be based on one or more buffering operations (e.g., a delay equal to an integer multiple of the sample rate), one or more coordinate rotation digital computer (CORDIC) operations, one or morefractional delay finite impulse response (FIR) filters, or any combination thereof. For example, in some cases it may be more efficient for a combining cell 318 to implement digital filtering and combining at multiple different frequencies than to implement TTD operations across a range of frequencies. This may be the case where frequencies of interest within a range of frequencies associated with a beam are separated from each other by unused frequency spectrum. Thus, filtering and combining may be used with an MBU 324 to generate multiple beam signals for different frequencies within a frequency range associated with a beam. In this case, the MBU 324 is used to generate multiple beam signals associated with a same beam (e.g., not spatially separated) for different frequencies.

[0054] In some examples, a delay accumulated due to TTD operations may be made incrementally across multiple layers. For example, least significant bits (e.g., a resolution associated with the least significant bits) may be delayed at layers closer to the analog tiles 310 and most significant bits (e.g., a resolution associated with the most significant bits) may be delayed at layers farther from the analog tiles 310. In some examples, if a variable sampling rate is used along the data-path, both least significant bit delays and most significant bit delays may be achieved by buffering.

[0055] In some examples, the hardware may be dynamically reconfigurable (e.g., an FPGA or other programmable logic) based on specific use cases. For example, each combining cell 318 may be configured accordingly to achieve the targeted performance with reduced complexity and power consumption. For example, if programmable logic is used, the reconfiguration can be achieved by reprogramming the hardware (e.g., an FPGA). However, if the hardware is not programmable but implemented in a modular fashion, the building blocks assigned to some operations that are not used can be switched off. For instance, parallel layers employing TTDUs 322 may be designed for different scenarios (e.g., different scan ranges or instantaneous bandwidth), and the most suitable chain can be activated on demand.

[0056] In some examples, the hardware (e.g., an FPGA, other programmable logic, modular hardware, or any other hardware) may be configured based on one or more conditions. For example, if the SNR at a given layer satisfies an SNR threshold (e.g., is higher than or equal to a threshold), the combining cells 318 at that layer may be configured to employ one or more processing operations (e.g., TTD, multi-beam, combining / weighting, one or more other operations, or any combination thereof). Similarly, if the SNR at the given layer does not satisfy an SNR threshold (e.g., is lower than the threshold), then the hardware at thatlayer may be configured to employ one or more processing operations (e.g., TTD, multibeam, combining / weighting, one or more other operations, or any combination thereof). In another example, if the SNR at one or more layers closer to the tiles 310 fails to satisfy an SNR threshold, combining cells 318 at such layers may be configured to use TTDUs 322, as a smaller bit depth may be employed at such layers and TTDUs 322 configured for such bit depths may be less costly (e.g., in terms of power consumption, processing or storage resources, or any combination thereof). However, if the SNR at such layers satisfies an SNR threshold (e.g., is greater than or equal to the threshold), combining cells 318 at such layers may be configured to use combiners 320 (e.g., to perform less costly operations in terms of power consumption, processing or storage resources, or any combination thereof) and TTDUs 322 may be used at layers further away from the tiles 310, where fewer combining cells 318 (and therefore fewer TTDUs 322) may be employed, reducing costs of operation (e.g., in terms of power consumption, processing or storage resources, or any combination thereof).

[0057] In some examples, different subtiles 312 can be allocated and processed independently, so that clusters potentially fulfilling different concepts of operations or other considerations (e.g., low earth orbits, geo-stationary orbits, situations with or without handover, or any other considerations) may be defined dynamically (e.g., across a full physical aperture or one or more portions thereof).

[0058] In some examples, the combiners 320 may be employed in one or more combining cells 318 (e.g., without employing the TTDUs 322) based on a scan angle being less than an angle threshold. Additionally, or alternatively, the TTDUs 322 may be employed in cases in which the scan angle is greater than the angle threshold. Such configurations (or any other configuration of combining cells 318, including combiners 320, TTDUs 322, and MBUs 324) may be made on a layer-by-layer basis, or the configurations may be made on subsets of combining cells 318 within a single layer or across multiple layers. For example, some combining cells 318 associated with layer 0 may perform TTD operations, but other combining cells 318 associated with layer 0 may not perform TTD operations.

[0059] In some examples, TTDUs 322 may be employed on alternating layers. For example, even-numbered layers (e.g., layer 0 and layer 2) may employ TTDUs 322 in one or more combining cells 318 and odd-numbered layers (e.g., layer 1) may employ combiners 320 (e.g., may not employ TTDUs 322) in one or more combining cells 318. Additionally, or alternatively, any other pattern of layers that employ TTDUs 322 and those that do not may be employed.

[0060] In some examples, TTDUs 322 may be employed on layers associated with an SNR that satisfies an SNR threshold. For example, if an SNR associated with layer 0 is less than an SNR threshold, then combiners 320 may be employed (e.g., one or more TTDUs 322 may not be employed) for combining cells 318 of that layer. Further, if an SNR associated with layer 2 is greater than an SNR threshold, then one or more TTDUs 322 may be employed for combining cells 318 of that layer.

[0061] In some examples, division of combining cells 318 that employ TTDUs 322 and those that do not may be configured vertically (e.g., for some tiles 310 or subtiles 12 and not for others, as opposed to divisions by layers, as described herein). For example, some signal paths across multiple layers (e.g., those associated with a first group of one or more tiles 310) may be associated with or may include TTD processing, while other signal paths across the same multiple layers (e.g., those not associated with the first group of one or more tiles 310) may not be associated with or may not include TTD processing. For example, a signal path from a first tile 310 may include TTDUs 322 at one or more points along the signal path, but a signal path from a second tile 310 may not include such TTDUs 322. In some examples, a signal path not associated with or including TTDUs 322 may be combined with a signal path that is associated with or includes TTDUs 322, in which case the combined signal path may be associated with or include TTDUs 322.

[0062] In some examples, no TTDUs 322 may be employed in one or more layers or in all of the layers, and combiners 320 may be used in some or all layers. Additionally, or alternatively, other operations, such as buffering, fractional delay, resample and delay, or digital filtering, may be performed.

[0063] Any combination of combiners 320, TTDUs 322, MBUs 324, one or more other processing blocks corresponding to any operations described herein, or any combination thereof, may be employed across combining cells 318 or DSP layers.

[0064] FIG. 4 shows an example of a beamforming architecture 400 that supports variable depth hybrid beamforming in accordance with examples as disclosed herein. In particular, the beamforming architecture 400 may be an example of a transmission signal path that employed variable depth hybrid beamforming.

[0065] The beamforming architecture 400 may include multiple antenna elements. For example, the beamforming architecture 400 may include multiple tiles 410 of antenna elements, which may include subtiles 412. The tiles 410 may be in a plane, and a scan anglefor the array of tiles 410 may be measured from a line that is orthogonal from the plane. For example, lower scan angles may be closer to the line that is orthogonal from the plane, while higher scan angles may be further from the line (e.g., closer to parallel with the plane). In some examples, each subtile 412 may include or be associated with a single antenna element or with multiple antenna elements. In some examples, each subtile 412 may be coupled with an analog beamformer 414, which may perform one or more analog beamforming operations on the signal received from the subtile 412. In some examples, each analog beamformer 414 may include a variable phase shifter, a variable gain amplifier, one or more other processing elements, or any combination thereof, to perform analog beamforming operations on the signals received from the subtiles 412.

[0066] The DACs 416 may convert digital signals (e.g., received from dividing cells 418 in layer 0)) to analog signals and pass the analog signals to the analog beamformers 414, so that following processing may be performed in the analog domain. Such processing may include analog beamforming, weighting, division, gain adjustment, or other operations. In some examples, because the overall beamforming for the transmit chain results from both analog and digital functional blocks, processing may be referred to as “hybrid.”

[0067] In some examples, one or more elements of the digital portion of the beamforming architecture 400 may include multiple dividing cells that perform one or more DSP operations, such as linear division and / or weighting, TTD operations, or both, which may be performed on a single beam or on multiple beams (e.g., using the MBU 424, for example). In some examples, such processing may be carried out via one or more elements of the dividing cell 418, which may include a divider 420 that divides signals into multiple signals (optionally applying one or more phase and / or amplitude weights to one or more of the signals to be divided), a TTDU, such as the TTDU 422, that applies TTD operations to one or more signals, an MBU, such as the MBU 424 that may aid in processing multiple beams (e.g., via the divider 420, the TTDU 422, or both).

[0068] For example, the divider 420 may divide input signals (e.g., according to beam weights) and forward them to multiple following DSP stages (e.g., other dividing cells 418) or to DACs 416. In some examples, a divider 420 may be used and other processing may not be used, such as in situations in which the antenna array (e.g., the collection of tiles 410) is relatively orthogonal to a scan direction or the device that employs the antenna array is scanning at relatively low angles for a given instantaneous handwidth. In such cases, whenthe instantaneous bandwidth increases, the maximum scan angle at which a beam squint stays negligible (or below a beam squint threshold) may decrease.

[0069] The TTDU 422 may be employed to perform TTD operations after which the delayed signals may be divided, weighted, or otherwise processed (e.g., by the divider 420) and passed on to the next stage. Such an approach may be used in cases in which an instantaneous bandwidth at a given scan angle is such that the analog phase rotation (e.g., that which may be performed by the analog beamformers 414) or digital combining according to beam weights is not enough to prevent significant beam squint (e.g., beam squint exceeding a beam squint threshold) or excessive side lobes in a communication pattern of the antenna array. It is worth noting that the phase rotation applied by analog beamformers or digital combining is intrinsically a frequency dependent operation. As such, it may not be desirable for use in connection with a wideband signal, whereas the TTDU 422 may apply a constant delay across different frequencies.

[0070] The MBU 424 may be employed to aid the dividing cell 418 in managing multiple beams. For example, in a case in which a dividing cell 418 is to process multiple beams, the transmit streams may be digitally combined to generate and process M different beams (e.g., combine the M multiple beams into a single beam) in the same dividing cell 418 or in another dividing cell 418 (e.g., via a divider 420, a TTDU 422, or both). In some cases, a subtile 412 may include a single antenna element and the digital path may be duplicated (e.g., multiple beams combined) in a dividing cell 418 of layer 0 (e.g., soon after the DAC 416) to process M independent beams. It is worth noting that the same would apply if the analog subtile 412 had multiple elements, but the digital scan range may be reduced due to high directivity of the analog tile and grating lobes.

[0071] The dividing cells 418 may be arranged in multiple DSP layers. For example, Figure 3 depicts layer 0, layer 1, and layer 2, though additional or alternative layers may also be employed. For example, the DSP layers may begin at layer N, (e.g., a first digital layer that is the first DSP layer to process signals after the DACs 416) and progress to Layer 0, whereiV < log _2(QuantityO fAnalogT ies) . At Layer 0, the signal may be fully beamformed as a result of operations performed at the analog beamformers 414, the one or more DSP layers, or any combination thereof. As the signals pass through the various stages of manipulation towards layer 0, the associated SNR decreases.

[0072] In some examples, a configuration or arrangement of the dividing cells 418 across the multiple DSP layers may be variable or configurable. For example, depending on the quantity of analog tiles 410, subtiles 412, or both, a communications bandwidth (e.g., an instantaneous bandwidth, such as a maximum instantaneous bandwidth or minimum instantaneous bandwidth), a scan angle (e.g., a maximum scan angle, a minimum scan angle, or both), SNR (e.g., at one or more layers, dividing cells 418, or DACs 416), one or more other factors or characteristics described herein, or any combination thereof, some or all of the dividing cells 418 may be instantiated in a single hardware unit (e.g., programmable logic hardware, such as a field programmable gate array (FPGA)).

[0073] For example, an amount of processing resources may be available to a device, and these processing resources may be assigned or allocated (e.g., through configuration, activation, or deactivation of dividing cells 418, DACs 416, one or more other elements described herein, or any combination thereof) based on one or more factors or communication characteristics. For example, processing resources may be assigned or allocated to one or more layers based on a quantity of processing resources consumed by one or more TTDUs 422, dividers 420, MBUs 424, one or more other entities described herein, or any combination thereof. Additionally, or alternatively, processing resources may be assigned or allocated to one or more layers based on an SNR associated with one or more layers.

[0074] Additionally, or alternatively, multiple hardware units may be interconnected through suitable interfaces (e.g., a serializer / deserializer (SERDES) interface) in a tree shape (e.g., as depicted, in which layer closer to the tiles 410 may include more dividing cells 418 and the quantity of dividing cells 418 per layer may decrease as the signals move away from the tiles 410.

[0075] Various configurations of dividing cells 418 may be employed (e.g., either statically configured or dynamically configured with programmable logic or other hardware, for instance). For example, a dividing cell 418 may include a divider 420, a TTDU 422, and an MBU 424, or any subset or element thereof. In some examples, a buffering unit may be used as an alternative to the TTDU 422 in one or more dividing cells 418. Such a buffering unit may offer a delaying mechanism that may be less costly (e.g., in terms of power consumption, processing or storage resources, or any combination thereof) than a TTDU 422, but may not be appropriate for all situations (e.g., buffering may be less precise or otherwise suffer in performance as compared to a TTDU 422, but may offer savings (e.g., in terms of power consumption, processing or storage resources, or any combination thereof).

[0076] In some examples, processing operations may be different for different layers. In some examples of processing, a TTD may be employed, and in other examples phase shifts may be employed. In some examples, a phase shift (e.g., involving complex multiplication of signals) may be cheaper (e.g., in terms of power consumption, processing or storage resources, or any combination thereof) as opposed to TTD, (e.g., which may include, for example, up to 20 times the amount of multiplication operations performed) In some examples, the effect of a delay may be more effective at some frequencies and less effective at other frequences (e.g., as desired).

[0077] In some examples, each dividing cell 418 in all of the layers may include a divider 420, a TTDU 422, and an MBU 424.

[0078] Additionally, or alternatively, each dividing cell 418 in a given layer may be configured similarly. For example, dividing cells 418 in layer 0 may each include a divider 420, a TTDU 422, and an MBU 424, dividing cells 418 in layer 1 may each include a divider 420 and a TTDU 422 (e.g., and may not include an MBU 424), and dividing cells 418 in layer 2 may each include a divider 420 (e.g., and may not include a TTDU 422 and an MBU 424).

[0079] Additionally, or alternatively, a quantity of TTDUs 422 employed in a given layer may depend on the position of the layer in the hierarchy of DSP layers. For example, layers closer to the tiles 410 may include dividing cells 418 that may perform phase adjustments (e.g., where a greater quantity of dividing cells 418 are employed) which may be less taxing (e.g., in terms of power consumption, processing or storage resources, or any combination thereof). Correspondingly, layers farther from the tiles 410 may include dividing cells 418 with a TTDU 422, an MBU 424, or other processing that may be more costly (e.g., in terms of power consumption, processing or storage resources, or any combination thereof) than phase adjustments, but due to the smaller quantity of dividing cells 418 included, the overall cost may be reduced (e.g., as compared to employing such processing through a greater quantity of DSP layers). It is worth noting that if multi-beam processing is desired, MBUs 424 may be present in dividing cells 418 for all DSP layers.

[0080] In some examples, it may be desirable to determine at which layers more costly TTD processing is to be performed and at which layers other processing that is less costly (e.g., phase shifts, combining, weighting, or other operations) may be performed. For example, from a computational standpoint, it may be desirable to have TTDUs 422 at layers farther away from the tiles 410, as fewer TTDUs 422 may be employed, resulting in powerand computational savings. In some examples, such an analysis be performed on a layer-by- layer basis, based on communication characteristics (e.g., bandwidth, scan angle, a quantity of tiles 410 or subtiles 412, any other characteristics described herein, or any combination thereof) to determine whether a given layer is to include or operate a TTDU 422 in one or more dividing cells 418 or whether other operations (e.g., employing the divider 420 without the TTDU 422) are to be performed. In some examples, a phase shift may approximate or may be equivalent to the use of TTD for a single frequency and / or for a small bandwidth. However, at some larger bandwidths, the effects of a phase shift may not be equal to or approximate the effects of a TTD operation and different content at different frequencies may have different time delays. In some examples, a determination of whether or not to perform TTD operations at a given layer may be based on a determined amount of error resulting from non- TTD operations and whether such error satisfies an error threshold.

[0081] In some examples, at layers closer to the analog tiles, TTDUs 422 may have high resolution and small range (e.g., in accordance with a distance between blocks in those layers), whereas other TTDUs 422 of other layers have a coarser resolution and longer delays at deeper layers (e.g., where the equivalent beamformed subarray is larger).

[0082] In some examples, TTDUs 422 may be implemented or configured based on their hierarchical position in the processing chain. For instance, a TTDU 422 may be based on one or more buffering operations (e.g., a delay equal to an integer multiple of the sample rate), one or more coordinate rotation digital computer (CORDIC) operations, one or more fractional delay finite impulse response (FIR) filters, or any combination thereof.

[0083] In some examples, a delay accumulated due to TTD operations may be made incrementally across multiple layers. For example, least significant bits (e.g., a resolution corresponding to the least significant bits) may be delayed at layers closer to the analog tiles 410 and most significant bits (e.g., a resolution corresponding to the most significant bits) may be delayed at layers farther from the analog tiles 410. In some examples, if a variable sampling rate is used along the data-path, both least significant bit delays and most significant bit delays may be achieved by buffering.

[0084] In some examples, the hardware may be dynamically reconfigurable (e.g., an FPGA or other programmable logic) based on specific use cases. For example, each dividing cell 418 may be configured accordingly to achieve the targeted performance with reduced complexity and power consumption. For example, if programmable logic is used, thereconfiguration can be achieved by reprogramming the hardware (e.g., an FPGA). However, if the hardware is not programmable but implemented in a modular fashion, the building blocks assigned to some operations that are not used can be switched off. For instance, parallel layers employing TTDUs 422 may be designed for different scenarios (e.g., different scan ranges or instantaneous bandwidth), and the most suitable chain can be activated on demand.

[0085] In some examples, the hardware (e.g., an FPGA, other programmable logic, modular hardware, or any other hardware) may be configured based on one or more conditions.

[0086] In some examples, different subtiles 412 can be allocated and processed independently, so that clusters potentially fulfilling different concepts of operations or other considerations (e.g., low earth orbits, geo-stationary orbits, situations with or without handover, or any other considerations) may be defined dynamically (e.g., across a full physical aperture or one or more portions thereof).

[0087] In some examples, the dividers 420 may be employed in one or more dividing cells 418 (e.g., without employing the TTDUs 422) based on a scan angle being less than an angle threshold. Additionally, or alternatively, the TTDUs 422 may be employed in cases in which the scan angle is greater than the angle threshold. Such configurations (or any other configuration of dividing cells 418, including dividers 420, TTDUs 422, and MBUs 424) may be made on a layer-by-layer basis, or the configurations may be made on subsets of dividing cells 418 within a single layer or across multiple layers. For example, some dividing cells 418 associated with layer 0 may perform TTD operations, but other dividing cells 418 associated with layer 0 may not perform TTD operations. In some cases, a quantity of layers N may depend on the scan angle or frequency range supported.

[0088] In some examples, TTDUs 422 may be employed on alternating layers. For example, even-numbered layers (e.g., layer 0 and layer 2) may employ TTDUs 422 in one or more dividing cells 418 and odd-numbered layers (e.g., layer 1) may employ dividers 420 (e.g., may not employ TTDUs 422) in one or more dividing cells 418. Additionally, or alternatively, any other pattern of layers that employ TTDUs 422 and those that employ dividers 420 (e.g., do not employ TTDUs 422) may be used.

[0089] In some examples, division of dividing cells 418 that employ TTDUs 422 and those that do not may be configured vertically (e.g., for some tiles 410 or subtiles 412 and notfor others, as opposed to divisions by layers, as described herein). For example, some signal paths across multiple layers (e.g., those associated with a first group of one or more tiles 410) may be associated with or may include TTD processing, while other signal paths across the same multiple layers (e.g., those not associated with the first group of one or more tiles 410) may not be associated with or may not include TTD processing. For example, a signal path from a first tile 410 may include TTDUs 422 at one or more points along the signal path, but a signal path from a second tile 410 may not include such TTDUs 422. In some examples, a signal path not associated with or including TTDUs 422 may be combined with a signal path that is associated with or includes TTDUs 422, in which case the combined signal path may be associated with or include TTDUs 422.

[0090] In some examples, no TTDUs 422 may be employed in one or more layers or in all of the layers, and dividers 420 may be used in some or all layers. Additionally, or alternatively, other operations, such as buffering, fractional delay, resample and delay, or digital filtering, may be performed.

[0091] Any combination of dividers 420, TTDUs 422, MBUs 424, one or more other processing blocks corresponding to any operations described herein, or any combination thereof, may be employed across dividing cells 418 or DSP layers.

[0092] FIG. 5 shows an example of system 500 including a device 505 that supports variable depth hybrid beamforming in accordance with examples as disclosed herein. The device 505 may include multiple tiles 510, which may be examples of tiles 310 described herein. The device may include programmable logic 515 (e.g., one or more FPGAs or other programmable logic hardware), which may implement one or more combining cells 520, which may be examples of combining cells 318. The programmable logic 515 may be addressable by the processor 540, the signal processing manager 525, or both, to perform one or more operations described herein. Additionally, or alternatively, the combining cells 520 may be implemented using modular hardware, which may allow for individual, subgroup, or group addressing of the combining cells (e.g., by the processor 540, the signal processing manager 525, or both, to perform one or more operations described herein). In both cases (e.g., combining cells 318 implemented in programmable logic 515 or in modular hardware) or any combination thereof, the combining cells 318 may be organized into one or more DSP layers as described herein to perform operations described herein.

[0093] In some examples, the signal processing manager 525 may configure the combining cells 520 (e.g., as implemented in the programmable logic 515, in modular hardware, other hardware, or any combination thereof) to configured processing operations at the combining cells 520. For example, as described herein, one or more combining cells 520 may be organized into a layer 0, one or more combining cells 520 may be organized into a layer 1 , one or more combining cells 520 may be organized into a layer 2, and so on, for as many DSP layers as desired. The signal processing manager 525 may transmit signaling to configure the combining cells 520 to implement processing blocks (e.g., the combiners 320, TTDUs 322, MBUs 324, one or more other processing blocks or operations, or any combination thereof). As described herein, various configurations of processing blocks, combining cells 520, DSP layers, any other elements or entities described herein, or any combination thereof, may be configured by the signal processing manager 525 in accordance with one or more desired arrangements of the device 505 to produce a beamforming architecture as described herein.

[0094] Although the signal processing manager 525 is illustrated to configure combining cells 520 for reception operations, the signal processing manager 525 may, additionally or alternatively, configure dividing cells, such as the dividing cells 418 to support transmission operations. In some examples, the signal processing manager 525 may include multiple processing managers (e.g., for reception and transmission operations).

[0095] Although the signal processing manager 525 is illustrated as a separate component, in some examples, one or more functions described with reference to the signal processing manager 525 may be supported by or performed by the at least one processor 540, the at least one memory 530, the code 535, or any combination thereof. For example, the code 535 may include instructions executable by the at least one processor 540 to cause the device 505 to perform various aspects of data burst handling as described herein, or the at least one processor 540 and the at least one memory 530 may be otherwise configured to, individually or collectively, perform or support such operations.

[0096] The at least one memory 530 may include random access memory (RAM) and read-only memory (ROM). The at least one memory 530 may store computer-readable, computer-executable, or processor-executable code, such as the code 535. The code 535 may include instructions that, when executed by the at least one processor 540, cause the device 505 to perform various functions described herein. The code 535 may be stored in a non- transitory computer-readable medium such as system memory or another type of memory. Insome cases, the code 535 may not be directly executable by the at least one processor 540 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 530 may include, among other things, a basic I / O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0097] The at least one processor 540 may include one or more intelligent hardware devices (e.g., one or more general-purpose processors, one or more DSPs, one or more CPUs, one or more graphics processing units (GPUs), one or more neural processing units (NPUs) (also referred to as neural network processors or deep learning processors (DLPs)), one or more microcontrollers, one or more ASICs, one or more FPGAs, one or more programmable logic devices, discrete gate or transistor logic, one or more discrete hardware components, or any combination thereof). In some cases, the at least one processor 540 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the at least one processor 540. The at least one processor 540 may be configured to execute computer-readable instructions stored in a memory (e.g., the at least one memory 530) to cause the device 505 to perform various functions (e.g., functions or tasks supporting data burst handling). For example, the device 505 or a component of the device 505 may include at least one processor 540 and at least one memory 530 coupled with or to the at least one processor 540, the at least one processor 540 and the at least one memory 530 configured to perform various functions described herein.

[0098] In some examples, the at least one processor 540 may include multiple processors and the at least one memory 530 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions described herein. In some examples, the at least one processor 540 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 540) and memory circuitry (which may include the at least one memory 530)), or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. For example, the at least one processor 540 or a processing system including the at least one processor 540 may be configured to, configurable to, or operable to cause the device 505 to perform one or more of the functions described herein. Further, asdescribed herein, being “configured to,” being “configurable to,” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code 535 (e.g., processor-executable code) stored in the at least one memory 530 or otherwise, to perform one or more of the functions described herein.

[0099] It should be noted that these methods describe examples of implementations, and that the operations and the steps may be rearranged or otherwise modified such that other implementations are possible. In some examples, aspects from two or more of the methods may be combined. For example, aspects of each of the methods may include steps or aspects of the other methods, or other steps or techniques described herein.

[0100] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0101] The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0102] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

[0103] Computer readable media includes both non transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer readable media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory, compact disk read-only memory (CDROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor. Also, any connection is properly termed a computer readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer readable media.

[0104] As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of’ or “one or more of’) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.”

[0105] In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the descriptionis applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

[0106] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0107] The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

CLAIMSWhat is claimed is:

1. An apparatus, comprising: a plurality of antenna elements arranged in a plurality of tiles (310), each tile of the plurality of tiles (310) comprising a subset of the plurality of antenna elements, wherein the plurality of antenna elements are configured to receive a radio frequency beam; a plurality of analog beamforming elements (314) coupled with the plurality of antenna elements; a plurality of analog to digital converters (ADCs) (316) coupled with the plurality of analog beamforming elements (314); a plurality of digital signal processing (DSP) layers coupled with the plurality of ADCs (316), wherein a first layer of the plurality of DSP layers comprises a first plurality of combining cells (318) configurable for combining respective subsets of signals from the plurality of ADCs (318), wherein a second layer of the plurality of DSP layers comprises a second plurality of combining cells (318) configurable for combining signals from the first plurality of combining cells (318), and wherein each of the first plurality of combining cells (318) and the second plurality of combining cells (318) are configurable for linearly weighting signals input to the combining cells (318) or applying a true time delay function (322) to the signals input to the combining cells; and a signal processing manager (525) coupled with the plurality of DSP layers, wherein the signal processing manager (525) is configured to determine one or more of the plurality of DSP layers to implement the true time delay function based at least in part on one or more characteristics of the radio frequency beam.

2. The apparatus of claim 1, wherein: one or more first combining cells (318) of the first plurality of combining cells (318), the second plurality of combining cells (318), or any combination thereof, are configured for linearly weighting the signals input to the one or more first combining cells (318) based at least in part on a scan angle of the radio frequency beam being less than an angle threshold associated with a communications bandwidth of the radio frequency beam.

3. The apparatus of any one of claims 1 or 2, wherein: one or more first combining cells (318) of the first plurality of combining cells (318) or the second plurality of combining cells (318) are configured for applying the true time delay function (322) to the signals input to the one or more first combining cells (318) based at least in part on a scan angle of the radio frequency beam being greater than or equal to an angle threshold associated with a communications bandwidth of the radio frequency beam.

4. The apparatus of claim 3, wherein: at least a subset of the plurality of analog beamforming elements (314) apply respective analog phase rotations to respective analog signals obtained from at least a subset of the plurality of antenna elements.

5. The apparatus of claim 3, wherein one or more second combining cells (318) of the first plurality of combining cells (318) or the second plurality of combining cells (318) are configured for linearly weighting the signals input to the one or more second combining cells (318).

6. The apparatus of any one of claims 1 through 5, wherein: each of the first plurality of combining cells (318) output a plurality of beam signals and each of the second plurality of combining cells (318) are configured for processing the plurality of beam signals output from two or more of the first plurality of combining cells (318).

7. The apparatus of claim 6, wherein: each subtile (312) of the plurality of tiles (310) comprises a single antenna element of the plurality of antenna elements; and each of the first plurality of combining cells (318) output a plurality of beam signals.

8. The apparatus of any one of claims 1 through 7, wherein: one or more first combining cells (318) of the first plurality of combining cells (318) are configured for applying the true time delay function (322) in accordance with first true time delay parameters based at least in part on the one or more first combining cells (318) being comprised in the first plurality of combining cells (318); andone or more second combining cells (318) of the second plurality of combining cells (318) are configured for applying the true time delay function in accordance with second true time delay parameters based at least in part on the one or more second combining cells (318) being comprised in the second plurality of combining cells (318).

9. The apparatus of claim 8, wherein: the first true time delay parameters are associated with a first resolution that is higher than a second resolution associated with the second true time delay parameters; and the first true time delay parameters are associated with a first range that is less than a second range associated with the second true time delay parameters.

10. The apparatus of claim 8, wherein: the first true time delay parameters, the second true time delay parameters, or any combination thereof, indicate buffering operations, coordinate rotation digital computer (CORDIC) operations, fractional delay finite impulse response (FIR) filter operations, or any combination thereof.

11. The apparatus of any one of claims 1 through 10, wherein: a first portion of a total delay applied across the plurality of DSP layers is applied in the first layer of the plurality of DSP layers; and a second portion of the total delay applied across the plurality of DSP layers is applied in the second layer of the plurality of DSP layers.

12. The apparatus of any one of claims 1 through 11, further comprising: one or more programmable logic elements that implement the plurality of DSP layers; wherein configuration of the first plurality of combining cells (318), the second plurality of combining cells (318), or any combination thereof, is performed through configuration of the one or more programmable logic elements by the signal processing manager (525).

13. The apparatus of any one of claims 1 through 12, further comprising: a plurality of modular processing elements that implement at least a portion of the plurality of DSP layers; wherein configuration of the first plurality of combining cells (318), the second plurality of combining cells (318), or any combination thereof, is performed through selective activation of at least a portion of the plurality of modular processing elements by the signal processing manager (525).

14. The apparatus of any one of claims 1 through 13, wherein: a first configuration associated with a first portion of the plurality of tiles (310) differs from a second configuration associated with a second portion of the plurality of tiles (310); the first configuration is applied to a first portion of the first plurality of combining cells (318) and a first portion of the second plurality of combining cells (318); and the second configuration is applied to a second portion of the first plurality of combining cells (318) and a second portion of the second plurality of combining cells (318).

15. The apparatus of any one of claims 1 through 15, further comprising: a plurality of transmit antenna elements arranged in a plurality of transmit tiles (410), each transmit tile (410) of the plurality of transmit tiles comprising a subset of the plurality of transmit antenna elements, wherein the plurality of transmit antenna elements are configured to transmit another radio frequency beam; a plurality of transmit analog beamforming elements (414) coupled with the plurality of transmit antenna elements; a plurality of digital to analog converters (DACs) (416) coupled with the plurality of transmit analog beamforming elements (414); a plurality of transmit digital signal processing (DSP) layers coupled with the plurality of DACs (416), wherein a first transmit layer of the plurality of transmit DSP layers comprises a first plurality of dividing cells (418) configurable for dividing respective subsets of transmit signals to be provided to the plurality of DACs(416), wherein a second transmit layer of the plurality of transmit DSP layers comprises a second plurality of dividing cells (418) configurable for dividing signals that are to be provided to the first plurality of dividing cells (418), and wherein each of the first plurality of dividing cells (418) and the second plurality of dividing cells (418) are configurable for linearly weighting signals input to the dividing cells (418) or applying a transmit true time delay function (422) to the signals input to the dividing cells (418); and a transmit signal processing manager (525) coupled with the plurality of transmit DSP layers, wherein the transmit signal processing manager is configured to determine one or more of the plurality of transmit DSP layers to implement the transmit true time delay (422) based at least in part on one or more characteristics of the transmit radio frequency beam.

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