Low bandwidth listening for wireless communications

Abstract

The invention provides a method, a device and a system for wireless communication. The present implementations more particularly relate to reducing power consumption of a radio frequency (RF) receiver when listening for a wireless channel. In some aspects, a wireless communication device may receive an RF signal over a wireless channel, down-convert the RF signal to a baseband, and converting the baseband signal to a digital domain via an analog-to-digital converter (ADC) configured to sample the baseband signal at one of a plurality of sampling rates based at least in part on whether adjacent channel interference (ACI) is determined to be present in the received signal. For example, a wireless communication device may configure an ADC to sample at a lower rate when an ACI is determined to be absent and to sample at a higher rate when an ACI is determined to be present or when a packet is detected in a received signal.

Description

Technical Field

[0001] The present implementations relate generally to wireless communications and, more particularly, to low-bandwidth listening techniques for wireless communications. Background Art

[0002] Wireless communication devices rely on radio frequency (RF) transmitters and receivers (also known as "radios") to communicate with other devices over wireless communication channels. The RF transmitter modulates data or other information onto a carrier wave and upconverts the modulated waveform to a radio frequency (such as 2.4 GHz) by, for example, mixing the modulated waveform with a local oscillator (LO) signal oscillating at the radio frequency. The resulting RF signal is further amplified by a power amplifier for transmission over a wireless channel via one or more antennas. The RF receiver receives the RF signal via one or more antennas and amplifies the received signal via a low-noise amplifier (LNA). The RF receiver mixes the received signal with another LO signal oscillating at the radio frequency to recover the modulated waveform (also known as the "baseband signal") and further converts the baseband signal from the analog domain to the digital domain using an analog-to-digital converter (ADC) for further processing.

[0003] RF receivers typically spend a significant amount of time operating in "listen mode," where the receiver listens to a wireless channel for wireless communications from other wireless communication devices. When operating in listen mode, the RF receiver continues to draw current and power from the wireless communication device even when no incoming communications are being received. Because many wireless communication devices are battery-operated devices with limited power budgets, there is a need to reduce the power consumption of the RF receiver when operating in listen mode. Summary of the Invention

[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0005] One innovative aspect of the disclosed subject matter can be implemented as a method performed by a wireless communication device. The method includes: receiving a first signal via a wireless communication channel; determining whether adjacent channel interference (ACI) is present in the first signal based on one or more signals previously received by the wireless communication device via the wireless communication channel; and configuring an analog-to-digital converter (ADC) to sample the first signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the first signal, wherein the ADC generates a digital signal based on the sampling of the first signal.

[0006] Another innovative aspect of the disclosed subject matter can be implemented in a wireless communication device comprising a processing system and a memory storing instructions that, when executed by the processing system, cause the wireless communication device to: receive a first signal via a wireless communication channel; determine whether ACI is present in the first signal based on one or more signals previously received by the wireless communication device via the wireless communication channel; and configure an ADC to sample the first signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the first signal, wherein the ADC generates a digital signal based on the sampling of the first signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present implementations are illustrated by way of example and are not intended to be limited by the figures of the accompanying drawings.

[0008] Figure 1 An example wireless communication system is shown.

[0009] Figure 2 A block diagram of an example radio frequency (RF) receiver is shown in accordance with some implementations.

[0010] Figure 3 A block diagram illustrating an example controller for an RF receiver according to some implementations is shown.

[0011] Figure 4 Shown is a timing diagram depicting example wireless communications between a transmitting device and a receiving device, according to some implementations.

[0012] Figure 5 A block diagram of an example wireless communication apparatus is shown in accordance with some implementations.

[0013] Figure 6 An illustrative flow diagram depicting example operations for wireless communications is shown in accordance with some implementations. DETAILED DESCRIPTION

[0014] In the following description, many specific details (such as examples of specific components, circuits and processes) are set forth to provide a thorough understanding of the present disclosure. As used herein, the term "coupling" means being directly connected to one or more intermediate components or circuits or being connected through one or more intermediate components or circuits. The terms "electronic system" and "electronic device" can be used interchangeably to refer to any system capable of electronically processing information. Moreover, in the following description, and for the purpose of explanation, specific terms are set forth to provide a thorough understanding of aspects of the present disclosure. However, it will be apparent to those skilled in the art that these specific details may not be required to practice the example embodiments. In other examples, well-known circuits and devices are shown in block diagram form to avoid making the present disclosure difficult to understand. Some parts of the subsequent detailed description are presented based on other symbolic representations of procedures, logic blocks, processing and the operation of data bits in computer memory.

[0015] These descriptions and representations are the means by which those skilled in the art of data processing are used to most effectively convey the essence of their work to other skilled in the art. In the present disclosure, procedures, logic blocks, processes, etc. are considered to be the self-consistent sequences of steps or instructions that lead to a desired result. The steps are those steps that require the physical manipulation of physical quantities. Usually, although not necessarily, these quantities take the form of electrical or magnetic signals that can be stored, transferred, combined, compared, and otherwise manipulated in a computer system. However, it should be remembered that all terms in these and similar terms are associated with appropriate physical quantities and are merely convenient labels that are applied to these quantities.

[0016] Unless specifically stated otherwise, as will be apparent from the following discussion, it is appreciated that throughout this application, discussions utilizing terms such as "access," "receive," "send," "use," "select," "determine," "normalize," "multiply," "average," "monitor," "compare," "apply," "update," "measure," "derive," etc., relate to the actions and processes of a computer system or similar electronic computing device that manipulates and transforms data represented as physical (electronic) quantities within a computer system's registers and memories into other data similarly represented as physical quantities within the computer system's memories or registers or other such information storage, transmission, or display devices.

[0017] In the figures, a single block may be described as performing one or more functions; however, in actual practice, the one or more functions performed by the block may be performed in a single component or across multiple components, and / or may be performed using hardware, using software, or using a combination of hardware and software. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described below generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Technicians may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of this disclosure. Moreover, the example system or device may include components other than those shown, including well-known components such as processors, memories, etc.

[0018] The techniques described herein, unless specifically described as being implemented in a particular manner, may be implemented in hardware, software, firmware, or any combination thereof. Any features described as modules or components may also be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques may be implemented at least in part by a non-transitory processor-readable storage medium comprising instructions that, when executed, perform one or more of the methods described above. The non-transitory processor-readable data storage medium may form part of a computer program product, which may include packaging materials.

[0019] Non-transitory processor-readable storage media may include random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, other known storage media, etc. Additionally or alternatively, the technology may be implemented at least in part by a processor-readable communication medium that carries or communicates code in the form of instructions or data structures and can be accessed, read, and / or executed by a computer or other processor.

[0020] The various illustrative logical blocks, modules, circuits, and instructions described in connection with the embodiments disclosed herein may be executed by one or more processors (or processing systems). As used herein, the term "processor" may refer to any general-purpose processor, special-purpose processor, conventional processor, controller, microcontroller, and / or state machine capable of executing scripts or instructions of one or more software programs stored in memory.

[0021] Aspects of the present disclosure can be implemented by a device capable of receiving radio frequency (RF) signals, such as those in accordance with one or more Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, IEEE 802.15 standards, as defined by the Bluetooth Special Interest Group (SIG), or the like. The present invention may be implemented by any device, system, or network that is capable of receiving RF signals based on one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), single user (SU) multiple input multiple output (MIMO), and multi-user (MU) MIMO. The present invention may also be implemented using other wireless communication protocols or RF signals suitable for use with one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), or an Internet of Things (IoT) network.

[0022] As described above, wireless communication devices rely on radio frequency (RF) transmitters and receivers (also referred to as "radios") to communicate with other devices over wireless communication channels. The RF transmitter modulates data or other information onto a carrier wave and up-converts the modulated waveform to a radio frequency, for example, by mixing the modulated waveform with a local oscillator (LO) signal oscillating at the radio frequency. The resulting RF signal is further amplified by a power amplifier for transmission over a wireless channel via one or more antennas. The RF receiver receives the RF signal via one or more antennas and amplifies the received signal via a low-noise amplifier (LNA). The RF receiver mixes the received signal with another LO signal oscillating at the radio frequency to recover the modulated waveform (also referred to as the "baseband signal") and further converts the baseband signal from the analog domain to the digital domain using an analog-to-digital converter (ADC) for further processing.

[0023] Many RF receivers include a low-pass filter (LPF) that filters or suppresses noise and interference (including adjacent channel interference (ACI)) in analog baseband signals. However, due to various factors (such as die size and power requirements), a significant portion of ACI is typically filtered out in the digital domain (using a digital filter). To support digital filtering of ACI, the ADC must sample the baseband signal at a sampling rate greater than or equal to twice the Nyquist frequency (such as to prevent ACI from folding back into the baseband). Aspects of the present disclosure recognize that the current or power consumed by an ADC is proportional to its sampling rate. In other words, the ADC draws more current when sampling at a higher sampling rate than when sampling at a lower sampling rate. Therefore, aspects of the present disclosure further recognize that when no incoming communications are being received (such as in "listen mode"), the power consumption of the RF receiver can be reduced by reducing the sampling rate of the ADC.

[0024] Various aspects relate generally to wireless communications, and more particularly to reducing power consumption of an RF receiver when monitoring a wireless communication channel. In some aspects, a wireless communication device (or RF receiver) may receive an RF signal via a wireless communication channel, downconvert the RF signal to baseband, and convert the baseband signal to a digital domain via an ADC configured to sample the baseband signal at one of a plurality of sampling rates based at least in part on whether ACI is determined (or expected) to be present in the received signal. For example, the wireless communication device may configure the ADC to sample at a lower rate when ACI is expected to be absent and to sample at a higher rate when ACI is expected to be present or when a packet is detected in the received signal. In some implementations, the wireless communication device may further include a digital ACI filter configured to suppress ACI in the digital signal when the ADC samples at the higher rate and to be bypassed when the ADC samples at the lower rate.

[0025] Specific implementations of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages. By dynamically adjusting the sampling rate of the ADC based on whether ACI is determined or expected to be present in the received signal, aspects of the present disclosure can optimize the power consumption of an RF receiver operating in listening mode. For example, when ACI is expected not to be present in the received signal, the wireless communication device can bypass the digital ACI filter with little or no risk of losing any information carried on the received signal. In such instances, the wireless communication device can also reduce the sampling rate of the ADC (such as below twice the Nyquist frequency) to reduce the power consumption of the RF receiver. On the other hand, when ACI is expected to be present in the received signal (or a packet is detected), the wireless communication device can increase the sampling rate of the ADC to enable the digital ACI filter to suppress ACI in the digital signal.

[0026] Figure 1 An example wireless communication system 100 is shown. The system 100 is shown to include a wireless access point (AP) 110 and four wireless stations STA1-STA4. Although one AP and four wireless stations (STA) are Figure 1 Although shown in the example of , the wireless communication system 100 may include any number of APs and any number of STAs.

[0027] Wireless stations STA1-STA4 may include any suitable wireless communication device, including, among other examples, a mobile phone, a personal digital assistant (PDA), a desktop device, or other personal computing device. STAs may also be referred to as user equipment (UE), subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, or some other suitable terminology. Each of wireless stations STA1-STA4 may include one or more radio frequency (RF) transceivers, one or more processing resources (such as processors or ASICs), one or more memory resources, and a power source (such as a battery).

[0028] The AP 110 may be any suitable device that allows one or more wireless communication devices to connect to a wireless network 120 (such as a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), or the Internet, among other examples) using Wi-Fi, Bluetooth, or any other suitable wireless communication standard. In some aspects, the wireless network 120 may be a WLAN, such as a Wi-Fi network. For example, the wireless network 120 may implement at least one of the IEEE 802.11 family of wireless communication protocol standards. In some implementations, the AP 110 may be any suitable wireless communication device (such as a STA) that acts as a software-implemented access point (SoftAP). The AP 110 may include one or more RF transceivers, one or more processing resources (such as a processor or ASIC), one or more memory resources, and a power source (such as a battery).

[0029] For stations STA1-STA4 and AP 110, one or more transceivers may include Wi-Fi transceivers, Bluetooth transceivers, cellular transceivers, and any other suitable RF transmitters or receivers that transmit or receive wireless communication signals. Each transceiver can communicate with other wireless devices in different operating bands, using different communication protocols, or both. For example, a Wi-Fi transceiver can communicate in the 900 MHz band, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, and the 60 MHz band according to the IEEE 802.11 standard. A Bluetooth transceiver can communicate in the 2.4 GHz band according to the standards provided by the Bluetooth Special Interest Group (SIG), according to the IEEE 802.15 standard, or both. A cellular transceiver can communicate in various RF bands according to any suitable cellular communication standard.

[0030] In some aspects, according to the IEEE 802.11 standard, access to the shared wireless medium may be governed by a distributed coordination function (DCF), such as carrier sense multiple access with collision avoidance (CSMA / CA). With CSMA / CA, there is generally no centralized master device that allocates the time and frequency resources of the shared wireless medium. Instead, any wireless communication device (including an AP or a STA) attempting to transmit data must wait for a random backoff (RBO) duration and compete for access to the wireless medium. More specifically, after the RBO duration expires, the wireless communication device must perform a clear channel assessment (CCA) and determine that the desired wireless channel is idle before it can transmit communication packets, such as physical layer convergence protocol (PLCP) protocol data units (PPDUs), on that channel.

[0031] When a wireless communication device is not actively transmitting or receiving on a wireless channel, the device is typically "listening" to the channel for communications from other wireless communication devices (such as to detect incoming communications or to contend for medium access). When operating in listening mode, the RF receiver draws current or power from the wireless communication device even when the channel is idle. Aspects of the present disclosure recognize that a significant portion of power is consumed by the analog-to-digital converter (ADC) that converts the received signal into the digital domain. Aspects of the present disclosure further recognize that the current or power consumed by the ADC is proportional to its sampling rate. In other words, the ADC draws more current when sampling at a higher sampling rate than when sampling at a lower sampling rate. In some aspects, a wireless communication device (such as an AP or STA) may dynamically adjust the sampling rate of one or more ADCs implemented by its RF receiver based at least in part on whether the receiver is operating in listening mode.

[0032] Figure 21 is a block diagram of an example RF receiver 200 according to some implementations. The RF receiver 200 is configured to receive an RF signal 201 on behalf of a wireless communication device via a wireless communication channel. In some implementations, the wireless communication device may be an AP or a STA (such as a Figure 1 AP 110 or any wireless station among wireless stations STA1-STA4).

[0033] The RF receiver 200 includes a low noise amplifier (LNA) 220, an RF mixer 230, a low pass filter (LPF) 240, an ADC 250, an adjacent channel interference (ACI) filter 260, a packet detection component 270, and a low bandwidth listening (LBL) controller 280. The LNA 220 amplifies an RF signal 201 received via one or more antennas 210, and the RF mixer 230 downconverts the RF signal 201 to a baseband (RX) signal 203. For example, the RF mixer 230 may demodulate the RX signal 203 based on a local oscillator (LO) signal 202 oscillating at a carrier frequency (or RF).

[0034] LPF 240 is configured to remove or suppress noise and interference in RX signal 203 by passing a subset of the frequencies of RX signal 203 to ADC 250 as filtered RX signal 203′. For example, LPF 240 may attenuate frequencies of RX signal 203 that are above (or below) a cutoff frequency. The range of frequencies passed by LPF 240 (such as the subset of frequencies associated with filtered RX signal 203′) may represent the “bandwidth” of LPF 240. In other words, the bandwidth of LPF 240 may be defined by its upper (and lower) cutoff frequencies.

[0035] ADC 250 converts filtered RX signal 203′ into a series of discrete time-domain samples representing digital signal 204 that can be processed in the digital domain. The resolution or granularity of the digital samples depends on the sampling rate of ADC 250. ACI filter 260 is a digital filter configured to filter or remove residual ACI (such as any ACI not removed by LPF 240) from digital signal 204. To support ACI filtering in the digital domain, ADC 250 must sample filtered RX signal 203′ at a sampling rate greater than or equal to the Nyquist frequency (such as to prevent ACI from folding back into baseband).

[0036] As reference Figure 1As described above, the current or power consumed by ADC 250 is proportional to its sampling rate. In other words, ADC 250 draws more current when sampling at a higher sampling rate than when sampling at a lower sampling rate. However, in existing wireless communication devices (as well as existing RF receivers and transceivers), the ADC has a relatively high sampling rate that is preconfigured to support ACI filtering in the digital domain even when ACI is not present or when no incoming communications are being received (such as when operating in listen mode).

[0037] In some aspects, the LBL controller 280 can dynamically control the sampling rate (SR) 208 of the ADC 250 based at least in part on whether ACI is present (or absent) in the RF signal 201. More specifically, the LBL controller 280 can receive or monitor one or more ACI parameters 206 associated with a previously received RF signal to determine whether ACI is expected to be present in the RF signal 201. Example suitable ACI parameters include, among other examples, a received signal strength indication (RSSI) associated with the RF signal (or other measure of total signal power) and the amount of power in the digital signal resulting from the analog-to-digital conversion (or other measure of in-band signal power).

[0038] In some implementations, the LBL controller 280 can reduce the sampling rate 208 of the ADC 250 in response to determining that ACI is not present in the RF signal 201 (for at least a threshold duration). For example, the LBL controller 280 can reduce the sampling rate 208 from a sampling rate greater than or equal to two times the Nyquist frequency to a sampling rate less than two times the Nyquist frequency in response to determining that ACI is not present in the RF signal 201. In such implementations, the LBL controller 280 can further disable (or bypass) the ACI filter 260 via an enable (EN) signal 209, such that the ACI filter 260 passes the digital signal 204 unchanged as the digital output 204′. For example, the LBL controller 280 can deassert the EN signal 209, which causes the ACI filter 260 to refrain from filtering the digital signal 204.

[0039] As used herein, the term "low bandwidth listening" (LBL) mode refers to a state of the RF receiver 200 in which the ADC 250 operates at a reduced sampling rate 208 and the ACI filter 260 is bypassed or disabled. Aspects of the present disclosure recognize that the presence of ACI may hinder the ability of a wireless communication device to demodulate or recover any information carried in the digital signal 204'. In some implementations, the LBL controller 280 may further deactivate the LBL mode in response to determining that ACI is present in the RF signal 201, such as by increasing or restoring the sampling rate 208 of the ADC 250 and re-enabling the ACI filter 260. When the ACI filter 260 is enabled (such as by asserting the EN signal 209), the ACI filter 260 may filter or remove the ACI from the digital output 204'.

[0040] Aspects of the present disclosure further recognize that the ACI parameter 206 associated with a previously received RF signal may not accurately reflect the amount of ACI in the current RF signal 201 (which may be higher than the estimated amount). In some implementations, the LBL controller 280 may also deactivate the LBL mode in response to detecting a packet carried on the digital output 204'. For example, the packet detection component 270 may be configured to detect communication packets that comply with one or more wireless communication standards (such as PPDU). In some implementations, the packet detection component 270 may output a packet detection (PD) signal 205 indicating whether a packet was detected in the digital output 204'. If the PD signal 205 indicates that a packet was detected when the RF receiver 200 was operating in the LBL mode, the LBL controller 280 may deactivate the LBL mode even if the ACI parameter 206 indicates that ACI is not present.

[0041] In some implementations, the LBL controller can also control the bandwidth (BW) 207 of the LPF 240 based on whether the RF receiver 200 is operating in the LBL mode. More specifically, the LBL controller 280 can reduce the bandwidth 207 of the LPF 240 in response to activating the LBL mode (such as when ACI is determined not to be present in the RF signal 201 while no packets are detected in the digital output 204'). Reducing the bandwidth 207 of the LPF 240 can improve the signal-to-noise ratio (SNR) of the filtered RX signal 203', which improves the accuracy of packet detection performed by the packet detection component 270. The LBL controller 280 can subsequently increase or restore the bandwidth 207 of the LPF 240 in response to deactivating the LBL mode (such as when ACI is determined to be present in the RF signal 201 or a packet is detected in the digital output 204').

[0042] Figure 3A block diagram of an example controller 300 for an RF receiver according to some implementations is shown. In some implementations, the controller 300 may be Figure 2 More specifically, the controller 300 is configured to control the bandwidth (BW) 356 of the LPF and the sampling rate (SR) 366 of the ADC and to selectively enable (or disable) the ACI filter via an enable (EN) signal 346. Figure 2 , the LPF, ADC, and ACI filters may be examples of LPF 240, ADC 250, and ACI filter 260, respectively. Thus, the signals BW 356, SR 366, and EN 346 may be respectively Figure 2 Examples of signals BW 207, SR 208 and EN 209.

[0043] The controller 300 includes an ACI calculator 310, an accumulator 320, and a comparator 330. The ACI calculator 310 is configured to calculate the ACI based on the RSSI 301 of the RF signal previously received by the RF receiver and the RF signal after conversion to the digital domain (such as Figure 2 The RSSI 301 and the digital power 302 can be measured or estimated by wireless communication using any known system or technology. Figure 2 , RSSI 301 and digital power 302 may be examples of ACI parameters 206. In some implementations, ACI value 303 may be a ratio of the total power of the RF signal (as a function of RSSI 301) to the in-band power of the RF signal (as a function of digital power 302).

[0044] The accumulator 320 stores or accumulates the ACI value 303 (such as a plurality (N) of the most recent ACI values ​​303) for a threshold duration. In some implementations, the accumulator 320 may further calculate or maintain a running average (avg) 304 of the N most recent ACI values ​​303. The comparator 330 compares the running average 304 with a threshold 305 and generates an ACI detection (AD) signal 306 based on the comparison. In some implementations, the AD signal 306 may indicate whether ACI is determined to be present in the RF signal currently being received by the RF receiver. For example, if the running average 304 exceeds the threshold 305 (indicating the presence of ACI), the comparator 330 may assert the AD signal 306 to a logic high state, and if the running average 304 is below the threshold 305 (indicating the absence of ACI), the comparator 330 may deassert the AD signal 306 to a logic low state.

[0045] The AD signal 306 is provided as input to the logic gate 340 along with a packet detect (PD) signal 307. The PD signal 307 indicates whether a packet has been detected in the RF signal currently being received by the RF receiver. Figure 2 , PD signal 307 can be an example of PD signal 205 output by packet detection component 270. For example, when a packet is detected in the current RF signal, PD signal 307 can be asserted to a logic high state, and when no packet is detected in the current RF signal, PD signal 307 can be deasserted to a logic low state. Logic gate 340 generates EN signal 346 based on a logical combination of AD signal 306 and PD signal 307. Figure 3 In the example of FIG, logic gate 340 is shown as implementing OR logic.

[0046] More specifically, logic gate 340 deasserts EN signal 346 to a logic low state only when AD signal 306 and PD signal 307 are both deasserted (indicating that ACI is not present and no packet is detected in the current RF signal). However, if AD signal 306 or PD signal 307 is asserted (indicating that ACI is present or a packet is detected in the current RF signal), logic gate 340 also asserts EN signal 346, such as to a logic high state. Figure 2 As described, the controller 300 may enable or otherwise cause the ACI filter 260 to remove ACI from the digital signal 204 by asserting the EN signal 346 (to a logic high state), and may disable or otherwise cause the digital signal 204 to bypass the ACI filter 260 by de-asserting the EN signal 346 (to a logic low state).

[0047] The EN signal 346 is also used to control the outputs of a set of multiplexers 350 and 360. The first multiplexer 350 receives as its inputs a high BW signal 352 and a low BW signal 354 and selects one of the input signals 352 or 354 for output as a BW signal 356 based on the state of the EN signal 346. For example, referring to Figure 2 The high BW signal 352 can cause the LPF 240 to attenuate any frequencies in the RF signal 201 above a first cutoff frequency (such as 10 MHz), while the low BW signal 354 can cause the LPF 240 to attenuate any frequencies in the RX signal 203 above a second cutoff frequency (such as 6.5 MHz) that is lower than the first cutoff frequency. In some implementations, the first multiplexer 350 can output the high BW signal 352 as the BW signal 356 when the EN signal 346 is asserted (to a logic high state), and can output the low BW signal 354 as the BW signal 356 when the EN signal 346 is deasserted (to a logic low state).

[0048] The second multiplexer 360 receives the high SR signal 362 and the low SR signal 364 as its inputs and selects one of the input signals 362 or 364 for output as the SR signal 366 based on the state of the EN signal 346. Figure 2 The high SR signal 362 can cause the ADC 250 to sample the filtered RX signal 203′ at a sampling rate greater than or equal to twice the Nyquist frequency (such as 40 MHz), while the low SR signal 364 can cause the ADC 250 to sample the filtered RX signal 203′ at a lower sampling rate (such as 20 MHz) that can be less than twice the Nyquist frequency. In some implementations, the second multiplexer 360 can output the high SR signal 362 as the SR signal 366 when the EN signal 346 is asserted (to a logic high state), and can output the low SR signal 364 as the SR signal 366 when the EN signal 346 is deasserted (to a logic low state).

[0049] Figure 4 A timing diagram 400 depicting example wireless communications between a transmitting (TX) device 410 and a receiving (RX) device 420 is shown according to some implementations. In some implementations, the TX device 410 may be Figure 1 In some implementations, the RX device 420 may be an example of an AP 110 or any of the wireless stations STA1-STA4. Figure 1 An example of the AP 110 or any wireless station among the wireless stations STA1-STA4.

[0050] TX device 410 transmits PPDU 401 between time t0 and t2. PPDU is a communication packet that complies with the IEEE 802.11 standard. The PPDU format is a composite structure that includes a physical layer (PHY) preamble 402 and a payload 404 in the form of a PHY service data unit (PSDU). The information provided in the PHY preamble 402 can be used by a receiving device (such as RX device 420) to decode subsequent data in the PSDU. The PSDU can represent or "carry" one or more medium access control (MAC) protocol data unit (MPDU) frames. Each MPDU frame includes a MAC header followed by the data portion of the MPDU frame (also referred to as the "payload" or "frame body").

[0051] like Figure 4As shown in FIG, the PHY preamble 402 includes a legacy short training field (L-STF) 406, a legacy long training field (L-LTF) 408, and a legacy signaling field (L-SIG) 410. In some implementations, the PHY preamble 402 may also include a non-legacy portion (not shown for simplicity). The L-STF 406 may be used by the RX device 420 to perform automatic gain control (AGC) and coarse timing and frequency estimation. The L-LTF 408 may be used by the RX device 420 to perform fine timing and frequency estimation and also estimate the wireless channel. The L-SIG 410 may be used by the RX device 420 to determine the duration of the PPDU 401 and use the determined duration to avoid transmitting over the PPDU 401.

[0052] exist Figure 4 In the example of FIG, RX device 420 is configured to operate in LBL mode at (or before) time t0. Figure 2 , the LBL controller 280 may select a low bandwidth 207 for the LPF 240 and a low sampling rate 208 for the ADC 250, while also disabling or bypassing the ACI filter 260 (such as by deasserting the EN signal 209). The RX device 420 receives the RX signal carrying the PPDU 401 at time t0 and detects the L-STF 406 (and the PPDU 401) at time t1. For example, referring to Figure 2 , the packet detection component 270 can detect the L-STF in the digital output 204 ′ and assert the PD signal 205 .

[0053] In response to detecting the L-STF at time t1, the RX device 420 immediately disables the LBL mode. Figure 2 , the LBL controller 280 may select the high bandwidth 207 for the LPF 240 and the high sampling rate 208 for the ADC 250, while also enabling the ACI filter 260 (such as by asserting the EN signal 209) or otherwise causing the ACI filter 260 to remove ACI from the digital signal 204. As a result, the RX device 420 may receive the remainder of the PPDU 401 under normal operating conditions from time t1 to t2.

[0054] Figure 5 A block diagram of an example wireless communication device 500 is shown according to some implementations. The wireless communication device 500 can be a chip, a system on a chip (SoC), a chipset, a package, or a device including at least one processor and at least one modem. In some implementations, the wireless communication device 500 can be Figure 1In some other implementations, the wireless communication device 500 may be an LBL controller (such as an LBL controller, such as an LBL controller, a LBL controller, and a LBL controller). Figure 2 and 3 An example of an LBL controller 280 or controller 300 in FIG.

[0055] Wireless communication device 500 includes a network interface 510, a processing system 520, and a memory 530. Network interface 510 is configured to communicate with one or more other wireless communication devices. In some implementations, network interface 510 can receive wireless signals via a wireless communication channel.

[0056] The memory 530 may include a non-transitory computer-readable medium (including one or more non-volatile memory elements such as EPROM, EEPROM, flash memory, or a hard drive, among other examples) that may store at least the following software (SW) modules: ACI determination SW module 532 to determine whether ACI is present in a received signal based on one or more signals previously received by the wireless communication device via the wireless communication channel; and • An ADC configuration SW module 534 to configure the ADC to sample the received signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the received signal, wherein the ADC generates a digital signal based on the sampling of the received signal. Each software module includes instructions that, when executed by processing system 520 , cause wireless communication device 500 to perform a corresponding function.

[0057] The processing system 520 may include any suitable one or more processors capable of executing scripts or instructions of one or more software programs stored in the wireless communication device 500 (such as in the memory 530). For example, the processing system 520 may execute the ACI determination SW module 532 to determine whether ACI is present in the received signal based on one or more signals previously received by the wireless communication device via the wireless communication channel. The processing system 520 may also execute the ADC configuration SW module 534 to configure the ADC to sample the received signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the received signal, wherein the ADC generates a digital signal based on the sampling of the received signal.

[0058] Figure 6 An illustrative flow chart depicting example operations 600 for wireless communication is shown in accordance with some implementations. In some implementations, the example operations 600 may be performed by a wireless communication device such as Figure 1AP 110 or any wireless station among wireless stations STA1-STA4 or Figure 3 In some other implementations, the example operations 600 may be performed by an LBL controller, such as a controller 300, respectively. Figure 2 and 3 The LBL controller 280 or controller 300 in the embodiment is used for execution.

[0059] A wireless communication device receives a first signal via a wireless communication channel (610). The wireless communication device determines whether ACI is present in the first signal based on one or more signals previously received by the wireless communication device via the wireless communication channel (620). The wireless communication device further configures an ADC to sample the first signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the first signal, wherein the ADC generates a digital signal based on the sampling of the first signal (630).

[0060] In some aspects, configuring the ADC may include configuring the ADC to sample the first signal at a first sampling rate of a plurality of sampling rates in response to determining that ACI is present in the first signal, and configuring the ADC to sample the first signal at a second sampling rate of the plurality of sampling rates in response to determining that ACI is not present in the first signal, the second sampling rate being lower than the first sampling rate.

[0061] In some aspects, the wireless communication device may further selectively filter the digital signal via a digital filter based on whether the ADC is configured to sample the first signal at a first sampling rate or a second sampling rate, wherein the digital filter is configured to remove ACI from the digital signal. In some implementations, the selective filtering of the first digital signal may include filtering the digital signal via the digital filter in response to the ADC being configured to sample the first signal at the first sampling rate, and refraining from filtering the digital signal via the digital filter in response to the ADC being configured to sample the first signal at the second sampling rate.

[0062] In some aspects, the wireless communication device may further detect a packet carried on the first signal and adjust a sampling rate of the ADC in response to detecting the packet. In some implementations, adjusting the sampling rate of the ADC may include changing the sampling rate of the ADC from a second sampling rate to a first sampling rate. In some implementations, the packet may be a PPDU with an L-STF, and the sampling rate of the ADC may be adjusted in response to detecting the L-STF.

[0063] In some aspects, the first signal may be filtered via a low-pass filter. In some implementations, the wireless communication device may further configure a bandwidth of the low-pass filter based on whether ACI is determined to be present in the first signal. In some implementations, configuring the bandwidth of the low-pass filter may include configuring the low-pass filter to attenuate frequencies above a first cutoff frequency in response to determining that ACI is present in the first signal, and configuring the low-pass filter to attenuate frequencies above a second cutoff frequency in response to determining that ACI is not present in the first signal, wherein the second cutoff frequency is lower than the first cutoff frequency.

[0064] In some aspects, the wireless communication device may further determine an RSSI associated with the first signal, estimate the amount of power in the digital signal, and calculate an ACI value based on the RSSI and the estimated amount of power in the digital signal. In some implementations, the wireless communication device may further receive a second signal via the wireless communication channel; determine whether ACI is present in the second signal based at least in part on whether the ACI value exceeds a threshold; and configure the ADC to sample the second signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the second signal.

[0065] Those skilled in the art will appreciate that information and signals 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 above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0066] In addition, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithmic steps described in conjunction with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of this disclosure.

[0067] The methods, sequences, or algorithms described in conjunction with the aspects disclosed herein may be implemented directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative embodiment, the storage medium may be integrated with the processor.

[0068] In the foregoing description, the embodiments have been described with reference to specific examples thereof. However, it will be apparent that various modifications and changes may be made thereto without departing from the broader scope of the present disclosure as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims

1. A method for wireless communication via a wireless communication device, comprising: receiving a first signal via a wireless communication channel; determining whether adjacent channel interference (ACI) is present in the first signal based on one or more signals previously received by the wireless communication device via the wireless communication channel; as well as An analog-to-digital converter (ADC) is configured to sample the first signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the first signal, the ADC generating a digital signal based on the sampling of the first signal.

2. The method of claim 1 , wherein the configuring of the ADC comprises: In response to determining that ACI is present in the first signal, configuring the ADC to sample the first signal at a first sampling rate of the plurality of sampling rates; as well as In response to determining that ACI is not present in the first signal, the ADC is configured to sample the first signal at a second sampling rate of the plurality of sampling rates, the second sampling rate being lower than the first sampling rate.

3. The method of claim 2, further comprising: The digital signal is selectively filtered via a digital filter based on whether the ADC is configured to sample the first signal at the first sampling rate or the second sampling rate, the digital filter being configured to remove ACI from the digital signal.

4. The method of claim 3, wherein the selective filtering of the digital signal comprises: filtering the digital signal via the digital filter in response to configuring the ADC to sample the first signal at the first sampling rate; as well as In response to configuring the ADC to sample the first signal at the second sampling rate, filtering the digital signal via the digital filter is avoided.

5. The method of claim 2, further comprising: detecting a packet carried on the first signal; as well as A sampling rate of the ADC is adjusted in response to detecting the packet.

6. The method of claim 5 , wherein the adjusting of the sampling rate of the ADC comprises: The sampling rate of the ADC is changed from the second sampling rate to the first sampling rate.

7. The method of claim 5, wherein the packet comprises a physical layer convergence protocol (PLCP) protocol data unit (PPDU) having a legacy short training field (L-STF), and the sampling rate of the ADC is adjusted in response to detecting the L-STF.

8. The method of claim 1 , wherein the first signal is filtered via a low-pass filter, the method further comprising: A bandwidth of the low-pass filter is configured based on whether ACI is determined to be present in the first signal.

9. The method of claim 8, wherein the configuring of the bandwidth of the low-pass filter comprises: responsive to determining that ACI is present in the first signal, configuring the low-pass filter to attenuate frequencies above a first cutoff frequency; as well as In response to determining that ACI is not present in the first signal, the low-pass filter is configured to attenuate frequencies above a second cutoff frequency, the second cutoff frequency being lower than the first cutoff frequency.

10. The method of claim 1, further comprising: determining a received signal strength indication (RSSI) associated with the first signal; estimating an amount of power in the digital signal; as well as An ACI value is calculated based on the RSSI and the estimated amount of power in the digital signal.

11. The method of claim 10, further comprising: receiving a second signal via the wireless communication channel; determining whether ACI is present in the second signal based at least in part on whether the ACI value exceeds a threshold; as well as The ADC is configured to sample the second signal at one of the plurality of sampling rates based at least in part on whether ACI is determined to be present in the second signal.

12. A wireless communication device, comprising: processing systems; as well as a memory storing instructions that, when executed by the processing system, cause the wireless communication device to: receiving a first signal via a wireless communication channel; determining whether adjacent channel interference (ACI) is present in the first signal based on one or more signals previously received by the wireless communication device via the wireless communication channel; as well as An analog-to-digital converter (ADC) is configured to sample the first signal at one of a plurality of sampling rates based at least in part on whether ACI is determined to be present in the first signal, the ADC generating a digital signal based on the sampling of the first signal.

13. The wireless communication device of claim 12 , wherein the configuring of the ADC comprises: In response to determining that ACI is present in the first signal, configuring the ADC to sample the first signal at a first sampling rate of the plurality of sampling rates; as well as In response to determining that ACI is not present in the first signal, the ADC is configured to sample the first signal at a second sampling rate of the plurality of sampling rates, the second sampling rate being lower than the first sampling rate.

14. The wireless communication device of claim 13, wherein execution of the instructions further causes the wireless communication device to: The digital signal is selectively filtered via a digital filter based on whether the ADC is configured to sample the first signal at the first sampling rate or the second sampling rate, the digital filter being configured to remove ACI in the digital signal.

15. The wireless communication device of claim 13 , wherein execution of the instructions further causes the wireless communication device to: detecting a packet carried on the first signal; and A sampling rate of the ADC is adjusted in response to detecting the packet.

16. The wireless communication device of claim 15, wherein the adjusting of the sampling rate of the ADC comprises: The sampling rate of the ADC is changed from the second sampling rate to the first sampling rate.

17. The wireless communication apparatus of claim 15, wherein the packet comprises a physical layer convergence protocol (PLCP) protocol data unit (PPDU) having a legacy short training field (L-STF), and the sampling rate of the ADC is adjusted in response to detecting the L-STF.

18. The wireless communication device of claim 12, wherein the first signal is filtered via a low-pass filter, execution of the instructions further causing the wireless communication device to: A bandwidth of the low-pass filter is configured based on whether ACI is determined to be present in the first signal.

19. The wireless communication device of claim 12, wherein execution of the instructions further causes the wireless communication device to: determining a received signal strength indication (RSSI) associated with the first signal; estimating an amount of power in the digital signal; and An ACI value is calculated based on the RSSI and the estimated amount of power in the digital signal.

20. The wireless communication device of claim 19, wherein execution of the instructions further causes the wireless communication device to: receiving a second signal via the wireless communication channel; determining whether ACI is present in the second signal based at least in part on whether the ACI value exceeds a threshold; and The ADC is configured to sample the second signal at one of the plurality of sampling rates based at least in part on whether ACI is determined to be present in the second signal.

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