Multimode Communication and Radar System Resource Allocation

Abstract

A multimode communication and radar system resource allocation is disclosed. A wireless multimode system includes: an array of N antenna elements, the array comprising a first portion of M antenna elements and a second portion of L antenna elements; M transmit amplifiers configured to transmit frames of transmit data via the M antenna elements, wherein the frames of transmit data include transmit radar signals and transmit communication signals; M receive amplifiers configured to receive frames of receive data via the M antenna elements, wherein the frames of receive data include receive communication signals; and L receive amplifiers configured to receive receive radar signals via the L antenna elements; and a resource scheduler configured to allocate bandwidth for transmit radar signals and transmit communication signals within the frames of transmit data based on one or more predetermined parameters.

Description

Technical Field

[0001] The present disclosure relates generally to electronic systems and methods, and in particular embodiments, to multimode communications and radar system resource allocation. Background Art

[0002] Applications in the millimeter-wave (mmWave) frequency range have attracted widespread interest over the past few years due to the rapid development of low-cost semiconductor technologies such as silicon-germanium (SiGe) and fine-geometry complementary metal-oxide-semiconductor (CMOS) processes. The availability of high-speed bipolar and metal-oxide-semiconductor (MOS) transistors has led to increasing demand for integrated circuits for mmWave applications operating at 24 GHz, 60 GHz, 77 GHz, and 80 GHz, as well as beyond 100 GHz. Examples of such applications include automotive radar systems and multi-gigabit communication systems.

[0003] In some radar systems, the distance between the radar and the target is determined by transmitting a frequency modulated signal, receiving the reflection of the frequency modulated signal (also called an echo), and determining the distance based on the time delay and / or frequency difference between the transmission and reception of the frequency modulated signal. Therefore, some radar systems include a transmit antenna that transmits a radio frequency (RF) signal and a receive antenna that receives the reflected RF signal, as well as associated RF circuits for generating the transmit signal and receiving the RF signal. In some cases, multiple antennas can be used to implement directional beams using phased array technology. Multiple-input multiple-output (MIMO) configurations with multiple chipsets can also be used to perform coherent and non-coherent signal processing. Summary of the Invention

[0004] According to one embodiment, a wireless multimode system includes: an array of N antenna elements, the array including a first portion of M antenna elements and a second portion of L antenna elements, the second portion being different from the first portion, wherein N, M, and L are positive integers greater than zero, and wherein M plus L is less than or equal to N; M transmit amplifiers coupled to respective antenna elements of the first portion of the M antenna elements, the M transmit amplifiers configured to transmit a frame of transmit data via the M antenna elements, wherein the frame of transmit data includes a transmit radar signal and a transmit communication signal; M receive amplifiers coupled to respective antenna elements of the first portion of the M antenna elements, the M receive amplifiers configured to receive a frame of receive data via the M antenna elements, wherein the frame of receive data includes a receive communication signal, wherein the transmit communication signal and the receive communication signal form a communication link; and L receive amplifiers coupled to respective antenna elements of the second portion of the L antenna elements, the L receive amplifiers configured to receive a radar signal via the L antenna elements, wherein the receive radar signal corresponds to the transmit radar signal; and a resource scheduler configured to allocate bandwidth to the transmit radar signal and the transmit communication signal within the frame of transmit data based on one or more predetermined parameters.

[0005] According to an embodiment, a millimeter wave system includes: an array of N antenna elements, where N is a positive integer greater than zero; N transmit amplifiers; N receive amplifiers; N circulator circuits coupled between respective antenna elements of the N antenna element array, respective transmit amplifiers of the N transmit amplifiers, and respective receive amplifiers of the N receive amplifiers, wherein each of the N circulator circuits is configured to sequentially allow a signal to flow from a corresponding transmit amplifier to a corresponding antenna element while preventing a signal from flowing from the corresponding transmit amplifier to the corresponding receive amplifier, and allow a signal to flow from a corresponding antenna element to the corresponding receive amplifier while preventing a signal from flowing from the corresponding antenna element to the corresponding transmit amplifier; and a controller configured to divide the array into a first portion of M antenna elements and a second portion of L antenna elements. The second part is different from the first part, wherein M and L are positive integers greater than zero, wherein M plus L is less than or equal to N, wherein: the M transmission amplifiers of the first part are configured to transmit frames of transmission data via M corresponding antenna elements, wherein the frames of transmission data include transmission radar signals and transmission communication signals, the M reception amplifiers of the first part are configured to receive frames of reception data via M corresponding antenna elements, wherein the frames of reception data include reception communication signals, wherein the transmission communication signals and the reception communication signals form a communication link, and the L reception amplifiers of the second part are configured to receive reception radar signals via L corresponding antenna elements, wherein the reception radar signals correspond to the transmission radar signals, wherein the resource scheduler is configured to allocate bandwidth to the transmission radar signals and the transmission communication signals within the frames of transmission data according to the status of the communication link.

[0006] According to an embodiment, a method for operating a wireless multimode system includes: receiving data to be transmitted, the data including user communication data and a radar waveform; receiving information about a communication link associated with a first portion of an antenna array of the wireless multimode system; allocating a bandwidth of a frame transmitted by the first portion of the antenna array between the user communication data and the radar waveform based on the received information about the communication link; transmitting a frame via the first portion of the antenna array; receiving a reflected frame via a second portion of the antenna array, the second portion being different from the first portion, the reflected frame corresponding to the transmitted frame; retrieving a reflected radar waveform from the received reflected frame; and determining a position of a target based on the retrieved reflected radar waveform. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, in which:

[0008] Figure 1 A wireless multimode system operating as a radar according to an embodiment of the present invention is shown;

[0009] Figure 2 A schematic diagram of a wireless multi-mode system according to an embodiment of the present invention is shown;

[0010] Figure 3 Schematic diagram showing the arrangement of the RFIC of the wireless multi-mode system according to an embodiment of the present invention;

[0011] Figure 4 and Figure 5 A possible method of dividing an antenna array according to an embodiment of the present invention is shown;

[0012] Figure 6 A schematic diagram showing two front-end RF circuits of a wireless multi-mode system according to an embodiment of the present invention;

[0013] Figure 7 A schematic diagram of a wireless multi-mode system with a configurable front-end RF circuit according to an embodiment of the present invention is shown;

[0014] Figure 8 A schematic diagram showing two front-end RF circuits of a wireless multi-mode system according to an embodiment of the present invention;

[0015] Figure 9 A schematic diagram of a wireless multi-mode system with a configurable front-end RF circuit according to an embodiment of the present invention is shown;

[0016] Figures 10 to 12 shows a frame transmitted by a millimeter wave multimode system according to an embodiment of the present invention;

[0017] Figure 13 The embodiment of the present invention is shown Figures 1 to 12 A schematic diagram of a portion of a controller of any millimeter wave system;

[0018] Figure 14 shows a block diagram of an OFDM transceiver according to an embodiment of the present invention;

[0019] Figure 15 A base station with a millimeter wave multimode system according to an embodiment of the present invention is shown;

[0020] Figure 16 A flow chart illustrating an embodiment method for operating a wireless multimode system in a base station according to an embodiment of the present invention is shown; and

[0021] Figure 17 A flow chart of an embodiment method for operating a wireless multi-mode system in a base station according to an embodiment of the present invention is shown.

[0022] Corresponding numerals and symbols in different figures generally refer to corresponding parts unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the preferred embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0023] The making and using of the disclosed embodiments are discussed in detail below. However, it should be understood that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention and do not limit the scope of the invention.

[0024] The following description shows various specific details to provide a deeper understanding of several example embodiments according to the description. The embodiments may be obtained without one or more of the specific details, or by other methods, components, materials, etc. In other cases, known structures, materials, or operations are not shown or described in detail so as not to obscure different aspects of the embodiments. References to "embodiments" in this specification indicate that the specific configuration, structure, or feature described with respect to that embodiment is included in at least one embodiment. Therefore, phrases such as "in one embodiment" that may appear at different points in this specification do not necessarily refer to the same embodiment in their entirety. In addition, specific configurations, structures, or features may be combined in any appropriate manner in one or more embodiments.

[0025] Embodiments of the present invention will be described in a specific context, namely a wireless multimode system that works as a radar and communication system. Embodiments of the present invention can operate in a frequency range such as the millimeter wave band (30 GHz to 300 GHz) or the centimeter wave band (3 GHz to 30 GHz). Other frequencies, such as frequencies above 300 GHz or below 3 GHz, may also be used. Embodiments of the present invention can be implemented using a 5G communication system or an LTE communication system. Implementation using other communication systems including any orthogonal frequency division multiplexing access (OFDMA) communication system, WiFi, and WiGiG (also known as 60 GHz WiFi) is also possible.

[0026] In an embodiment of the present invention, a millimeter wave multimode system is used to implement a multimode communication and radar system. The millimeter wave multimode system uses a first portion of an antenna array to transmit a frame. The frame includes communication user data and a radar waveform. The second portion of the antenna array is used to receive a reflected frame corresponding to the transmitted frame. The reflected radar waveform is extracted from the received reflected frame and processed to detect and / or determine target information, such as the location of the target. The location of the target can be used to optimize the communication performance of the millimeter wave multimode system. A resource scheduler allocates the bandwidth of the frame between the communication user data and the radar waveform based on the status of the communication link associated with the first portion of the antenna array.

[0027] Figure 11 shows a wireless multimode system 100 operating as a radar according to an embodiment of the present invention. The wireless multimode system 100 includes a radar 102, which may utilize, for example, a millimeter wave radar for transmitting radar signals and a communication system ( Figure 1 is implemented by

[0028] For operation of the wireless multimode system 100 in radar mode, the wireless multimode system 100 transmits a radar signal 106 toward a scene 108 using, for example, a beam. The radar signal may include a radar waveform modulated using phase shift keying (PSK), quadrature amplitude modulation (QAM), amplitude PSK (APSK), amplitude shift keying (ASK), and frequency shift keying (FSK). Other radar waveforms, such as those based on pseudo-random binary sequences (PRBS), multi-frequency continuous waves (MFCW), and COSTAS codes, may also be used. In some embodiments, the radar waveform includes frequency modulation, such as linear chirps. In some embodiments, the wireless multimode system 100 transmits frames of equally spaced linear chirps, such as 256 equally spaced linear chirps. A different number of linear chirps (e.g., 16, 32) may also be used.

[0029] Objects in scene 108 reflect transmitted radar signal 106. Reflected radar signal ( Figure 1 The radar 102 (not shown) is also referred to as a return signal and is detected and processed by, for example, the radar 102 (or, for example, an associated processor) to determine the angle of arrival of the return signal, the location of moving and / or stationary objects in the field of view of the beam (i.e., range, azimuth, and elevation components), the velocity and / or direction of motion of the object within the field of view of the beam, identification of the type of object detected (e.g., using micro-Doppler and / or macro-Doppler signals), etc. To perform these and other radar functions, the radar 102 may perform one or more of a fast Fourier transform (FFT), a short-time fast Fourier transform (STFFT), a fractional Fourier transform (FrFT), a short-time fractional Fourier transform (STFrFT), a time-of-flight (ToF) calculation, and other radar processing techniques known in the art, slowly and / or rapidly.

[0030] Objects in scene 108 may include stationary people, such as lying down; people exhibiting low or infrequent motion, such as standing; moving people, such as running or walking; stationary or moving animals, such as dogs or cats; stationary or moving equipment, such as cars, trucks, drones, motorcycles, industrial equipment, furniture; equipment that moves periodically, such as a rotating fan, etc. Other objects may also be present in scene 108.

[0031] Radar 102 may operate as an FMCW radar comprising one or more transmit antennas and one or more receive antennas. In some embodiments, the same antenna may be used to transmit and receive radar signals.

[0032] Radar 102 may be implemented as a millimeter wave radar that transmits and receives signals in the range of 20 GHz to 122 GHz. Alternatively, frequencies outside this range, such as frequencies between 1 GHz and 20 GHz, or frequencies between 122 GHz and 300 GHz, may also be used.

[0033] The wireless multi-mode system 100 is implemented by hardware that also performs communication functions. For example, Figure 2 Schematic diagram of a wireless multimode system 200 according to an embodiment of the present invention is shown. The wireless multimode system 200 includes one or more modulators / demodulators (modems) 202, one or more frequency converters 204, one or more beamformer circuits 210, and an antenna array 218. The antenna array 218 includes a first portion and a second portion of an antenna. Figure 2 As shown, modem 202, frequency converter 204, and beamformer circuit 210 are bidirectional circuits (eg, I / O stands for input / output).

[0034] Wireless multimode system 200 is capable of performing radar operations (e.g., as described with respect to radar 102) as well as communication operations. Wireless multimode system 200 operates as a communication system, such as an OFDM communication system, that transmits and / or receives information by transmitting and receiving signals via a first portion of antenna array 218. Wireless multimode system 200 operates as a radar system (such as a millimeter wave radar system) by transmitting radar signals via a first portion of antenna array 218 and receiving radar signals via a second portion of antenna array 218. In some embodiments, the communication signals and the radar signals are embedded in frames transmitted via the first portion of antenna array 218 and the corresponding beamformer circuit 210.

[0035] To transmit OFDM communication signals, wireless multimode system 200 receives information to be transmitted via an I / O port, for example, from controller 220 or from another circuit or device. Modem 202 modulates the information to be transmitted to generate an intermediate frequency (IF) signal. Frequency converter 204 up-converts the IF signal to an RF signal, for example, in the millimeter wave range. The RF signal is then fed through beamformer circuitry 210 and transmitted through a first portion of antenna array 218.

[0036] To transmit radar signals, wireless multimode system 200 uses modem 202 to modulate a radar waveform (e.g., from controller 220 or another circuit or device) to operate as a radar to generate an IF signal. Frequency converter 204 is used to up-convert the IF signal to an RF signal, e.g., in the millimeter wave range. The RF signal is then fed through a first portion of antenna array 218 via corresponding beamformer circuitry 210.

[0037] In some embodiments, the information to be transmitted (e.g., information corresponding to an OFDM communication signal and / or a radar signal) received via the I / O terminal is digital. In these embodiments, the baseband to IF conversion can be performed digitally, and a digital-to-analog converter (DAC) can be used to generate the IF signal. In other embodiments, the information to be transmitted received via the I / O terminal is analog. In these embodiments, the analog baseband signal is modulated by modem 202 using a quadrature (IQ) modulator / demodulator.

[0038] The OFDM signal may include a 5G communication signal, such as described in a 5G standard or pre-standard, such as 5G standard Release 15 (5G NR standard), 5GTF, and 5G-SIG, as well as future releases scheduled for release in December 2019, such as 5G standard Release 16. In some embodiments, wireless multimode system 200 may also be used with other OFDM communication signals, such as, for example, signals used for LTE eNBs after Release 13. Those skilled in the art will recognize that the teachings disclosed herein are also applicable to wireless communication protocols other than the standards and pre-standards explicitly mentioned in this disclosure. The radar signal may include, for example, the radar waveform described with respect to radar 102.

[0039] During normal operation, wireless multimode system 200 may receive OFDM communication signals via a first portion of antenna array 218 and radar signals via a second portion of antenna array 218. In some embodiments, wireless multimode system 200 simultaneously receives communication signals via the first portion of antenna array 218 and radar signals via the second portion of antenna array 218.

[0040] For receiving communication signals, wireless multimode system 200 receives RF signals via a first portion of antenna array 218 and corresponding beamformer circuitry 210. The received RF signals are down-converted to IF signals using frequency converter 204. The IF signals are then demodulated using modem 202 and sent, for example, to controller 220 or another circuit or device for further communication processing.

[0041] In some embodiments, further communication processing includes unpacking (e.g., extracting information from one or more communication frames), processing control frames, determining communication link quality and strength, and other known communication processing. In some embodiments, communication processing also includes determining the location of a user equipment (UE) using known techniques, such as by using, for example, power strength (commonly referred to as received signal strength or RSS), time of flight (ToF), and angle of arrival (AoA). In some embodiments, communication processing also includes switching communication links from beam to beam and from base station to base station, for example, as the UE moves, in a manner known in the art. In some embodiments, the configurable wireless multimode system 100 can adjust the beamformer circuit 210, for example, to modify the shape and direction of the beam based on information received via the received packets.

[0042] To receive radar signals, wireless multimode system 200 receives an RF signal via the second portion of antenna array 218 and corresponding beamformer circuitry 210. The received RF signal corresponds to the radar signal transmitted via the first portion of antenna array 218, which was reflected by an object (e.g., an object in scene 108) within the field of view (FoV) of the first portion of antenna array 218. The received RF signal is down-converted to an IF signal using frequency converter 204. The IF signal is then demodulated using modem 202 and sent, for example, to controller 220 or to another circuit or device for further radar processing.

[0043] In some embodiments, further radar processing includes performing range FFTs, determining angle of arrival using, for example, a single-pulse algorithm, identifying static and moving objects in the field of view of one or more beams, determining the velocity of moving objects, detecting the pose of detected objects, tracking identified static or moving objects, performing radar imaging, and other known radar processing.

[0044] In some embodiments, each modem 202 includes a modulator circuit for modulating a baseband signal into an IF signal and a demodulator circuit for demodulating the IF signal into a baseband signal. The modulator circuit and the demodulator circuit can be implemented in any manner known in the art. Depending on whether the signal flowing through the I / O terminal is a digital signal or an analog signal, the implementation may vary. In some embodiments, the modulation circuit may include a DAC, digital and / or analog filters, and a digital signal processing (DSP) engine. The demodulator may include an analog-to-digital converter (ADC), digital and / or analog filters, and a digital signal processing (DSP) engine. In some embodiments, the same DSP engine can be used for the modulator circuit and the demodulator circuit. The DSP engine can be implemented, for example, in the modem 202 or the controller 220. Some embodiments may implement the DSP engine independently of the controller 220 and the modem 202.

[0045] Modem 202 can use any known modulation / demodulation method and technique to insert radar and communication signals into the OFDM waveform grid. For example, each communication or radar subcarrier in the OFDM grid can be modulated using PSK, QAM, ASK, FSK, or Amplitude PSK (APSK). Frequency Modulated Continuous Waveform (FMCW) for radar signals is also possible. In some embodiments, controller 220 can dynamically change the specific modulation / demodulation scheme used. For example, the modulation scheme used for radar operation can be different from the modulation scheme used for communication operation.

[0046] In some embodiments, each frequency converter 204 includes one or more mixing circuits (not shown) and one or more variable gain amplifiers (VGAs) (not shown), for example, to generate an RF signal based on an input IF signal and to generate an IF signal based on an input RF signal. In some embodiments, for example, the IF signal may be in the frequency range of 3 GHz to 9 GHz, while the RF signal may be in the millimeter wave range, such as between 24.25 GHz and 52.6 GHz. Other frequencies in other frequency ranges may also be used.

[0047] In some embodiments, each beamformer circuit 210 includes M beamforming channels (not shown), each of which includes a phase shifter circuit (not shown) and a VGA (not shown). The beamforming function can be performed, for example, by analog control of the channel power level via the VGA, and by controlling the phase shift of the phase shifter circuit via a digital interface control (e.g., a serial peripheral interface (SPI)), for example, via programming of corresponding registers. In some embodiments, each beamformer circuit 210 has a corresponding and independent modem 202, where the beamforming function is performed in part by analog control of the channel power level via the VGA and phase shifter, and in part by controlling the phase shift and level between the various digital streams in each modem 202 in the digital domain. In some embodiments, the beamforming function is performed only during the first period by analog control, only during the second period by digital control, and during the third period by mixed analog / digital control. In some embodiments, the first beamformer is controlled solely by analog control, while the second beamformer is simultaneously controlled solely by digital control. Other implementations are also possible.

[0048] In some embodiments, the beams are fixed. In other words, no dynamic beamforming is performed. In such embodiments, the dynamic beamforming capability may be omitted.

[0049] In some embodiments, the controller 220 may configure the beamformer circuit 210 corresponding to the first portion of the antenna array 218 to direct a beam in a target direction using, for example, analog beamforming. This beam may be used to transmit 5G communication signals and / or radar signals and / or to receive OFDM communication signals. In some embodiments, the beam associated with the first portion of the antenna array 218 may be directed in a direction that optimizes communication quality (e.g., by maximizing signal strength), such as the direction of arrival (DoA) of the communication signal. In some embodiments, the beam associated with the first portion of the antenna array 218 may be directed toward the spatial location to be scanned, such as a moving object or a static object. In some embodiments, the beam directions for the communication signal and the radar signal are independent, which may be achieved by using different gain / phase programming for the channels in the beamformer, for example, in a time division multiplexing (TDM) manner. In some embodiments, the beam direction is the same for both the communication signal and the radar signal.

[0050] In some embodiments, controller 220 may configure beamformer circuitry 210 corresponding to the second portion of antenna array 218 to direct a beam in the direction of a target using, for example, analog beamforming. For example, in some embodiments, the beam may be directed in the direction of an object to be monitored. In some embodiments, controller 220 may use the beamforming configuration (e.g., the state of the phase shifter circuitry and the VGA) to determine radar parameters such as angle of arrival (AoA) and range.

[0051] In some embodiments, controller 220 may dynamically modify the direction and / or shape of the beam to optimize the operation of wireless multimode system 200 .

[0052] In some embodiments, the frequency used for the OFDM communication signal is the same as the frequency used for the radar signal.

[0053] In some embodiments, the frequencies used for OFDM communication signals are different from the frequencies used for radar signals. For example, in some embodiments, the frequencies used for radar signals are within a frequency range adjacent to the frequency range used for 5G communications. For example, in some embodiments, the frequencies used for OFDM communication signals are in 5G communication band n258 (from 24.25 GHz to 27.5 GHz), and the frequencies used for radar operation are in the adjacent industrial, scientific, and medical (ISM) band from 24 GHz to 24.25 GHz. In some embodiments, the frequencies used for 5G communication are near the upper end of the FR2 band (52.6 GHz), as outlined in 5G standard Release 15, and the frequencies used for radar signals are in the adjacent ISM band from 61 GHz to 61.5 GHz. Other frequency ranges may also be used, such as 5G communication frequencies in the E-band (60 to 90 GHz) and radar operating frequencies in the range of 61 GHz to 61.5 GHz.

[0054] In some embodiments, wireless multimode system 200 includes L modems 202, L frequency converters 204, and L beamformer circuits 210, where each beamformer circuit 210 includes M beamforming channels and feeds N antennas, where L can be 1 or more, M can be 1 or more, and N can be L times M.

[0055] In some embodiments, antenna array 218 includes dozens of antennas. In some embodiments, antenna array 218 may include more than 100 antennas, such as 256 or more antennas. The antennas of antenna array 218 may be arranged in rows and columns, for example, in a manner known in the art. For example, the antennas of antenna array 218 may be spaced a first distance apart, where the first distance is based on the wavelength of the RF signal. In some embodiments, antenna array 218 includes multiple antenna subarrays or sections, where each antenna subarray corresponds to a modem 202.

[0056] In some embodiments, the first distance may be equal to or less than 0.6 times the wavelength of the RF signal used for 5G communications. Using adjacent frequency bands for 5G communications and radar operations advantageously allows the same antenna array to be used for both 5G communications and radar operations without significantly degrading radar or communications performance (because the first distance between antennas of antenna array 218 may be small compared to the wavelength of the RF signal, e.g., less than 1 times the wavelength of the radio frequency used for 5G communications or radar operations).

[0057] The controller 220 may configure one or more of the circuits 202, 204, and 210 using a wired or wireless protocol. For example, in some embodiments, the controller 220 configures the modem 202, the frequency converter 204, and / or the beamformer circuit 210 using SPI, for example, by writing to corresponding registers. Other embodiments may use an integrated circuit bus (I2C), a universal asynchronous receiver / transmitter (UART), or other protocols. Still other embodiments may use dedicated digital or analog signals to configure one or more aspects of the modem 202, the frequency converter 204, and / or the beamformer circuit 210.

[0058] Controller 220 can be implemented as a general-purpose processor, a controller, or a digital signal processor (DSP), and the general-purpose processor, controller, or digital signal processor (DSP) includes, for example, a combination circuit coupled to a memory. In some embodiments, the DSP can be implemented using, for example, an ARM or x86 architecture. In some embodiments, the controller 220 can be implemented as a custom application-specific integrated circuit (ASIC). In some embodiments, the controller 220 includes a plurality of processors, each of which has one or more processing cores. In other embodiments, the controller 220 includes a single processor with one or more processing cores. Other implementations are also possible. Some embodiments can implement the controller 220 as a combination of a hardware accelerator and software running on a DSP or a general-purpose microcontroller.

[0059] Wireless multimode system 200 can be implemented in a single semiconductor substrate within an integrated circuit (IC). In some embodiments, wireless multimode system 200 can be implemented in multiple semiconductor substrates, which are packaged in a single package or a module, such as several ICs. In other embodiments, wireless multimode system 200 can be implemented in multiple packages. For example, in some embodiments, frequency converter 204 is integrated into a first package, beamformer circuit 210 is in a second package, and antennas of antenna array 218 are external to both the first and second packages. In other embodiments, frequency converter 204 and beamformer circuit 210 are located in the first package, while antennas of antenna array 218 are external to the first package. Controller 220 can be implemented in a separate package from frequency converter 204 and beamformer circuit 210. In some embodiments, modem 202 and controller 220 are implemented together in the same package. In other embodiments, modem 202 and controller 220 are implemented separately. Other implementations are also possible.

[0060] In some embodiments, the wireless multimode system 200 can be implemented using L RFICs, where L is the number of modems 202, and each RFIC includes modem circuitry 202, a frequency converter 204, a beamformer circuit 210 having M channels, and M antennas arranged in an array of rows and columns, wherein each RFIC is packaged in a single package. In other embodiments, the wireless multimode system 200 can be implemented using N RFICs, each of which includes a phase shifter (or delay element), a VGA, and a corresponding antenna. In these embodiments, the modem(s) 202 and frequency converter(s) 204 can be external to the RFIC. In some embodiments, the DAC and ADC are integrated with the modem 202 in the same IC, within the same monolithic semiconductor substrate. In some embodiments, each RFIC includes M channels. In some embodiments, each RFIC includes more than one phase shifter and / or more than one VGA. Other integrated implementations are also possible.

[0061] Figure 3 FIG. 3 shows the arrangement of the RFIC 302 of the wireless multi-mode system 300 according to an embodiment of the present invention. Figure 3 As shown, the wireless multimode system 300 is arranged as a tile-based planar phased array. Other arrangements, such as a slate phased array or a brick phased array, are also possible.

[0062] Wireless multimode system 300 is a possible implementation of wireless multimode system 200 that includes 16 RFICs 302 , where each RFIC 302 includes beamformer circuitry 210 and a corresponding antenna. Figure 3 The arrangement of RFIC302 shown can be implemented in a printed circuit board (PCB). In some embodiments, Figure 3 The arrangement of RFIC 302 shown can be packaged in a module. Figure 3 3. Although shown as including only 16 RFICs, the wireless multi-mode system 300 may include a different number of RFICs, such as 4, 8, or 32 RFICs.

[0063] like Figure 3 As shown, each RFIC 302 controls four antennas 316. In some embodiments, each RFIC 302 can control a different number of antennas, such as 1, 2, 8, 16, or 32 antennas.

[0064] like Figure 3 As shown, each RFIC 302 is coupled to at least one antenna 316. In some embodiments, the RFIC 302 may include one or more antennas 316.

[0065] During normal operation, a first set of RFICs 302 corresponding to a first portion of antenna array 218 may be used to transmit OFDM communication signals and radar signals and to receive OFDM communication signals, and a second set of RFICs 302 corresponding to a second portion of antenna array 218 may be used to receive radar signals. Figure 4 and Figure 5 A possible method of partitioning the antenna array 218 according to an embodiment of the present invention is shown. Other methods of partitioning the antenna array 218, such as other partitioning into sub-arrays of adjacent elements, are also possible.

[0066] like Figure 4As shown, first section 402 of antenna array 218 and second section 404 of antenna array 218 have the same number of antennas (in this example, each section has 32 antennas 316). First section 402 can be used to transmit OFDM communication signals and radar signals and to receive OFDM communication signals. Second section 404 can be used to receive radar signals.

[0067] In some embodiments, the first and second parts may have different numbers of antennas. Figure 5 As shown, first portion 502 has fewer antennas than second portion 504 (in this example, first portion 502 has 16 antennas and second portion 504 has 48 antennas). First portion 502 can be used to transmit OFDM communication signals and radar signals and to receive OFDM communication signals. Second portion 504 can be used to receive radar signals. Other implementations are also possible. For example, in some embodiments, the second portion of antennas (e.g., for receiving radar signals) can have more antennas than the first portion of antennas (e.g., for transmitting OFDM communication signals and radar signals and for receiving OFDM communication signals). In some embodiments, antenna array 218 can be divided into more than two portions. For example, in some embodiments, antenna array 218 can include portions of unused antennas. In some embodiments, antenna array 218 can include portions of antennas used for other purposes.

[0068] Each antenna element 316 of antenna array 218 is coupled to front-end RF circuitry. In some embodiments, the front-end RF circuitry is implemented within beamformer circuitry 210. In other embodiments, the front-end RF circuitry is implemented between beamformer circuitry 210 and a corresponding antenna 316 of antenna array 218.

[0069] In some embodiments, the front-end RF circuitry may be different for transmitting OFDM communication signals and radar signals and for receiving OFDM communication signals (e.g., via a first portion of antenna array 218) and receiving radar signals (e.g., via a second portion of antenna array 218). For example, Figure 6 A schematic diagram of front-end RF circuitry 602 and front-end RF circuitry 612 of a wireless multimode system 600 according to an embodiment of the present invention is shown. Wireless multimode system 600 includes an antenna array having a first portion including a plurality of antennas 610 and a second portion including a plurality of antennas 616. The first and second portions of the antenna array of wireless multimode system 600 can be implemented, for example, in a manner similar to first portion 402 and second portion 404 or first portion 502 and second portion 504. In some embodiments, wireless multimode system 600 can operate as a time division duplex (TDD) system.

[0070] like Figure 6As shown, front-end RF circuitry 602 includes a power amplifier (PA) 604 for transmitting OFDM communication signals and radar signals via corresponding antennas 610 of antenna array 218. A low-noise amplifier (LNA) 608 is configured to receive OFDM communication signals. When switch 606 is in a first state, switch 606 connects power amplifier 604 to antenna 610, allowing power amplifier 604 to transmit OFDM communication signals and radar signals via antenna 610. When switch 606 is in a second state, switch 606 connects antenna 610 to LNA 608, allowing LNA 608 to receive OFDM communication signals. Switch 606 alternates between the first and second states to enable, for example, TDD operation. In some embodiments, a controller, such as controller 220, may control switch 606.

[0071] The front-end RF circuit 612 includes an LNA 614 for receiving radar signals. Figure 6 As shown, LNA 614 is directly connected to antenna 616 to allow for continuous reception of radar signals.

[0072] The wireless multimode system 600 may be implemented using non-configurable front-end RF circuits 602 and 612. In these embodiments, the partitioning of the antenna array (e.g., between the first portion and the second portion) is fixed by hardware. In some embodiments, the wireless multimode system 600 may be implemented using configurable front-end RF circuits. For example, Figure 7 FIG. 7 is a schematic diagram showing a wireless multimode system 700 with a configurable front-end RF circuit according to an embodiment of the present invention. Figure 7 As shown, the front-end RF circuitry of the first and second portions of the antenna array of wireless multimode system 700 uses the same hardware design. A controller, such as controller 220, can control switch 606 of front-end RF circuitry 602 to alternate between a first state and a second state in a manner similar to that of wireless multimode system 600, while controlling switch 606 of front-end RF circuitry 712 to continuously connect antenna 612 to LNA 608 to allow for continuous reception of radar signals.

[0073] The first and second parts of the antenna array of the wireless multimode system 700 having the same hardware design advantageously allows the partitioning of the antenna array to be modified (e.g., from Figure 3 The arrangement shown to Figure 4 arrangement shown) to optimize operation.

[0074] Figure 8A schematic diagram of front-end RF circuitry 802 and front-end RF circuitry 814 of wireless multimode system 800 according to an embodiment of the present invention is shown. Wireless multimode system 800 includes an antenna array having a first portion including a plurality of antennas 812 and a second portion including a plurality of antennas 820. The first and second portions of the antenna array of wireless multimode system 800 can be implemented, for example, in a manner similar to first portion 402 and second portion 404 or first portion 502 and second portion 504. In some embodiments, wireless multimode system 600 can operate as a frequency division duplex (FDD) system.

[0075] like Figure 8 As shown, front-end RF circuitry 802 includes a power amplifier (PA) 804 for transmitting OFDM communication signals and radar signals in a first frequency range f1 via corresponding antennas 812 of antenna array 218. A low-noise amplifier (LNA) 810 is configured to receive OFDM communication signals in a second frequency range f2. Filters 806 and 808 are bandpass filters having passbands in the first frequency range f1 and the second frequency range f2, respectively.

[0076] The front-end RF circuit 814 includes an LNA 816 for receiving radar signals. Figure 8 As shown, LNA 816 is connected to antenna 820 via filter 818 to allow continuous reception of radar signals in a first frequency range f1.

[0077] Figure 9 A schematic diagram of a wireless multimode system 900 with configurable front-end RF circuitry 902 according to an embodiment of the present invention is shown. Each antenna of the antenna array 218 of the wireless multimode system 900 is coupled to a corresponding front-end RF circuitry 902. The front-end RF circuitry 902 includes a power amplifier 904, an LNA 912, a circulator 908, and switches 906 and 910.

[0078] During normal operation, circulator 908 directs the RF signal from power amplifier 904 to antenna 914 instead of LNA 912. Circulator 908 directs the RF signal from antenna 914 to LNA 912 but not to power amplifier 904. Switches 906 and 910 are optional, for example, to provide additional isolation.

[0079] Similar to wireless multimode system 700, wireless multimode system 900 may be configured (e.g., by controller 220) to modify the assignment of antenna 316 to the first and second portions of antenna array 218 (e.g., in Figure 4 and Figure 5 ), respectively used for transmitting OFDM communication signals and radar signals and receiving OFDM communication signals, and for receiving radar signals.

[0080] In some embodiments, wireless multimode system 900 may configure a portion of antenna array 218 to transmit and receive OFDM signals and another portion of antenna array 218 to transmit and receive radar signals. For communication operation, switches 906 and 910 are switched in a TDD manner. For radar operation, switches 906 and 910 are closed.

[0081] In some embodiments, wireless multimode system 900 can be used for simultaneous communication and radar operations. For example, during transmission of OFDM communication signals and radar signals, switch 906 is closed and switch 910 is open. For reception of radar signals occurring shortly after the radar signal is transmitted, switches 906 and 910 are closed. For reception of OFDM communication signals occurring after the radar signal is received, switch 906 is open to improve the isolation of circulator 908.

[0082] In some embodiments, the wireless multimode system transmits frames including a communication signal and a radar signal. Figures 10 to 12 Frames transmitted by millimeter wave multimode system 1000 according to an embodiment of the present invention are shown. Millimeter wave multimode system 1000 is a wireless multimode system operating in the millimeter wave frequency band and can be implemented as wireless multimode systems 100, 200, 300, 400, 500, 600, 700, 800, and 900, for example.

[0083] Figure 10 FIG. 1 shows a frame structure such as the 5GNR standard. Figure 10 As shown, radio frame 902 includes multiple subframes. Each subframe (e.g., 1004, 1006, or 1008) includes multiple time slots. Each time slot contains an OFDM symbol including a resource block. Each resource block (depicted as a box within each subframe) includes an OFDM symbol, wherein each OFDM symbol has a cyclic prefix (CP). In LTE, a resource block has 12 subcarriers and 1 time slot (14 symbols). In 5G, a resource block has 12 subcarriers and 1 symbol. In some embodiments, radio frame 902 can be a 10ms frame and can include 10 subframes of 1ms each. Frames of different durations and including different numbers of subframes are also possible.

[0084] The number of slots in each subframe depends on the selected subcarrier spacing (SCS). For example, subframe 1004 operates at a 60kHz SCS and has 4 slots. Subframe 1006 operates at a 120kHz SCS and has 8 SCSs. Subframe 1008 operates at a 240kHz SCS and has 16 slots.

[0085] like Figure 11As shown, each subframe, such as subframe 1102, includes a resource grid 1106 including n times m resource blocks 1104, where m is the number of frequency channels (freq1 to freq m ), n is the number of resource blocks in each frequency channel. In some embodiments, m and n depend on the bandwidth of the signal and can be configurable. For example, in some embodiments, n can be 28 and m can be 7. In some embodiments, n can be lower than 28, such as 16 or 14 or lower, or higher than 28, such as 32, 56 or higher. In some embodiments, m can be lower than 7, such as 6 or 4 or lower, or higher than 7, such as 8, 12, 16, 24 or higher.

[0086] Resource blocks 1104 may be allocated to one or more 5G communication users and for radar signals. Figure 12 A non-limiting example of a resource grid 1202 is shown showing a possible allocation of resource blocks 1104 to 5G communication users U1, U2, U3, and U4 and to radar signals. Figure 12 As shown, in some embodiments, the full frequency bandwidth (ie, all frequency channels freq1 to freq m All subcarriers in the time slot are allocated to the radar signal. One or more consecutive time slots can be allocated to the radar signal. In some embodiments, more than one non-consecutive time slot can be allocated to the radar signal.

[0087] In some embodiments, the time / frequency allocation of resource blocks between communication users and radar signals is controlled by a resource scheduler and resource block mapper, such as implemented in controller 220 . Figure 13 A schematic diagram illustrating a portion of the controller 220 according to an embodiment of the present invention is shown.

[0088] During normal operation, the resource scheduler 1302 receives wireless channel quality information, quality of service (QoS) parameters (e.g., user priority), and configuration parameters and performs time / frequency allocation for 5G communication signals and radar signals. The resource block mapper allocates resources (e.g., resource blocks) in a resource grid (e.g., 1106) for radar waveforms, 5G communication user data, and control plane information based on the time / frequency allocation output from the resource scheduler 1302.

[0089] The resource scheduler 1302 allocates bandwidth (e.g., resource blocks) based on received wireless channel quality information and / or quality of service (QoS) parameters and / or configuration parameters. In some embodiments, QoS refers to throughput, delay, jitter, reliability, and / or packet error rate and / or other parameters. For example, in some embodiments, when the throughput allocated to a user is high, more resource blocks may be allocated to the user per unit time. Conversely, when the throughput allocated to a user is low, fewer resource blocks may be allocated to the user per unit time. For example, a video call may have a higher priority than TCP / IP communication. In some embodiments, a medium QoS priority (not the highest, nor the lowest) may be assigned to a radar signal. In some embodiments, the resource scheduler 1302 schedules the radar signal according to the assigned priority.

[0090] In some embodiments, when the 5G communication traffic condition is high, the resource scheduler 1302 may allocate more resource blocks to the 5G communication than when the 5G communication traffic condition is low.

[0091] Configuration parameters may include, for example, a minimum frequency (maximum period) for transmitting radar signals. In some embodiments, the maximum period may be, for example, 5 ms. Longer periods, such as 6 ms, 10 ms, or longer, or shorter periods, such as 4 ms, 3.5 ms, or shorter, may also be used.

[0092] In some embodiments, resource scheduler 1302 ensures that radar signals are transmitted at least at a minimum frequency specified by configuration parameters. In some embodiments, configuration parameters are static (i.e., do not change during operation). In other embodiments, configuration parameters can be modified dynamically.

[0093] After allocating the bandwidth of resource grid 1106 between the 5G communication signal and the radar signal, the resource block mapper allocates the 5G communication user data to the resource blocks of resource grid 1106 allocated to the 5G communication, and allocates the radar waveform to the resource blocks of resource grid 1106 allocated to the radar signal. In some embodiments, resource block mapper 1310 also allocates resource blocks to control plane information.

[0094] In some embodiments, the resource scheduler 1302 and the resource block mapper 1310 are implemented as software engines in the controller 220. For example, the controller 220 may be configured to execute software instructions stored in a memory associated with the controller 220 to perform the functions of the resource scheduler 1302 and the resource block mapper 1310. In other embodiments, the resource scheduler 1302 and the resource block mapper 1310 may be implemented using hard-coded digital hardware (e.g., using logic circuits), which in some embodiments may be configurable (e.g., via registers).

[0095] In some embodiments, controller 220 may also generate a radar waveform that is allocated in resource grid 1106. In some embodiments, the radar waveform may be any of PRBS, FSK / MFCW, and / or COSTAS codes. Other types of radar waveforms may also be used.

[0096] In some embodiments, the millimeter wave multimode system uses a single type of radar waveform. In other embodiments, the controller 220 can dynamically select the type of radar waveform to use, for example, based on available computing resources and / or the performance of a particular radar waveform.

[0097] Figure 14 FIG. 1 is a block diagram of an OFDM transceiver 1400 according to an embodiment of the present invention. The OFDM transceiver 1400 may be implemented, for example, by the wireless multimode systems 100 , 200 , 300 , 400 , 500 , 600 , 700 , 800 , 900 , and 1000 .

[0098] Waveform generator block 1402 generates a radar waveform. The radar waveform may be, for example, PRBS, FSK / MFCW, and / or COSTAS code. Other types of radar waveforms may also be used. In some embodiments, radar waveform generation is performed by controller 220. In other embodiments, the radar waveform is not generated within the millimeter wave multimode system. Instead, in these embodiments, the radar waveform may be stored, for example, in a memory associated with the millimeter wave multimode system.

[0099] Radar waveform generation can be performed in a manner known in the art. For example, if a PRBS radar waveform is used, the autocorrelation between the transmitted and received radar waveforms can be used to determine the distance to the target. For example, the peak of the autocorrelation function corresponds to the delay of the received signal, which indicates the round-trip delay and thus the range of the target from the antenna array 217. The PRBS sequence can be generated using a linear feedback shift register. For a signal with a frequency modulation period T c The maximum length code of the PRBS sequence with length M, autocorrelation R p (t) can be expressed by the following equations 1 and 2.

[0100]

[0101]

[0102] Where p(t) represents the period T c and amplitude a n = ±1, c(t) is a series of periodic pulses with a duration of T c and a single amplitude basic pulse.

[0103] As another example, if MFCW / FSK is used, when a sine wave is transmitted at a constant frequency sin(2πf0t) through, for example, the antenna array 218, the reflected signal seconds later, it arrives at the antenna array 218, where c is the speed of light and R is the distance between the antenna array 218 and the object that reflected the sine wave. The received signal can be sin(2πf0(tT)) and is 2πf0T out of phase with the transmitted sine wave. By measuring the phase difference Δφ, we can get Determine R.

[0104] MFCW radar uses parallel sinusoidal signals with two or more different frequencies f3 and f4 to increase the unambiguous range.

[0105]

[0106] The reflected signals r1 and r2 are given.

[0107] where f d is the Doppler frequency shift, and R is the distance from the reflected signal to the target (object). After mixing the reflected signal with the corresponding transmitted signal, we can get

[0108]

[0109] Gives the output signal.

[0110] Where d1 is the first down-conversion waveform and d2 is the second down-conversion waveform. Waveforms d1 and d2 are the waveforms that can be used to solve R and f. d Two equations with two unknowns. One way to solve the equations is to determine the phase difference Δφ (for example, by measuring the phase difference).

[0111] Determine the distance R.

[0112] Where Δf = f4 - f3.

[0113] The subcarrier mapping block 1404 maps the radar waveform to subcarrier frequencies. The IFFT block 1406 performs an inverse FFT (IFFT) on the mapped subcarrier frequency radar waveform. The CP entry block 1408 prepends a cyclic prefix (CP) to encapsulate the radar waveform for transmission.

[0114] Vector modulation block 1410 performs vector modulation (modulating a carrier signal with a baseband signal) on the packaged radar waveform. In some embodiments, vector modulation block 1410 also performs frequency conversion (converting the frequency of the modulated signal). Front-end RF circuitry 1412 associated with the first portion of antenna array 218 (such as front-end RF circuitry 602, 802, or 902) is used to transmit the packaged radar waveform through a channel (e.g., air) via the first portion of antenna array 218, for example, using resource blocks allocated to radar signals in resource grid 1106.

[0115] Front-end RF circuitry 1414 associated with the second portion of antenna array 218, such as front-end RF circuitry 612, 712, 814, or 902, receives the radar waveform reflected from the channel via the second portion of antenna array 218. Vector demodulation block 1416 performs vector demodulation of the encapsulated radar waveform. In some embodiments, vector demodulation block 1416 also performs frequency conversion. CP deblocking block 1418 removes the CP d from the received radar waveform. FFT block 1420 performs an FFT on the received radar waveform.

[0116] Subcarrier demapping block 1422 demaps the FFT-transformed radar waveform. Radar processing block 1424 performs radar processing on the demapped radar waveform, for example, to determine the angle of arrival of the return signal, the location of moving and / or stationary objects in the beam field of view (FoV) (i.e., range, azimuth, and elevation components), the speed and / or direction of movement of objects within the beam field of view, identification of the type of detected object (e.g., using micro-Doppler and / or macro-Doppler signals), etc. In some embodiments, blocks 1402, 1404, 1406, 1408, 1418, 1420, 1422, and 1424 are performed by modem 202.

[0117] In some embodiments, wireless multimode systems (e.g., 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000) may be implemented in a logical base station. Figure 15 A base station 1502 with a wireless multimode system 1504 according to an embodiment of the present invention is shown. Base station 1502 can be, for example, an eNB base station (also known as an evolved Node B or eNodeB) or a gNB base station. Other logical base stations can also implement wireless multimode systems, such as 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000.

[0118] Advantages of some embodiments include adding radar functionality to a base station, such as an eNB or gNB, by reusing base station hardware. Reusing the base station's hardware to implement the radar functionality advantageously allows the radar functionality to be performed without increasing the form factor and keeping costs low.

[0119] Incorporating radar functionality into the base station advantageously allows for monitoring the presence of people near the base station and turning sections of the base station on and off based on presence detection. By turning off sections of the base station based on the presence of people near the base station, power consumption can be reduced without impacting 5G communication performance. Figure 16 A flow chart of an embodiment method 1600 for operating a wireless multimode system in a base station according to an embodiment of the present invention is shown. The method 1600 can be implemented, for example, by any of the wireless multimode systems 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000, which can be located, for example, in the base station 1502.

[0120] In step 1602, a wireless multimode system receives data to be transmitted. The wireless multimode system includes an array of N antenna elements, such as antenna array 218. The antenna array includes a first portion having M antenna elements, such as first portion 402 or 502, and a second portion having L antenna elements, such as second portion 404 or 504. In some embodiments, M is equal to L. In other embodiments, M is different from L (e.g., M may be higher or lower than L).

[0121] In some embodiments, the wireless multimode system further includes M transmit amplifiers, such as 604, 804, and 904, coupled to respective antenna elements of the first portion of the M antenna elements. The M transmit amplifiers are configured to transmit a frame of transmission data, such as frame 902, via the M antenna elements.

[0122] In some embodiments, each frame includes P subframes, such as 10. Figure 10 Each subframe (eg, 1004, 1006, 1008, 1102) may include Q time slots (eg, Symbol 1 to Symbol 2). n Each time slot may include R frequency bands (eg, freq1 to freq m ).

[0123] In some embodiments, the wireless multimode system further includes M receive amplifiers, such as 608, 810, and 912, coupled to respective antenna elements of a first portion of the M antenna elements. The M receive amplifiers are configured to receive frames of receive data via the M antenna elements, wherein a communication link is formed by transmitting and receiving frames of communication signals.

[0124] In some embodiments, the wireless multimode system further includes L receive amplifiers coupled to corresponding antenna elements of the second portion of the L antenna elements, such as 614, 608, 816, and 912. The L receive amplifiers are configured to receive radar signals (e.g., reflected radar signals) corresponding to the transmitted radar signals via the L antenna elements.

[0125] Step 1602 includes step 1606 and step 1604. In step 1606, a radar waveform is received, for example, by controller 220 (e.g., resource block mapper 1310) and / or modem 202. The radar waveform may be of the PRBS, FSK / MFCW, and / or COSTAS type. The radar waveform may be generated by controller 220 or another portion of the wireless multimode system (e.g., 1402). In some embodiments, the radar waveform is generated external to the wireless multimode system. In these embodiments, the radar waveform may be received by the wireless multimode system during normal operation and / or may be stored in memory associated with the wireless multimode system.

[0126] During step 1604, user data to be transmitted via the communication link is received, for example, by the controller 220 (e.g., resource block mapper 1310) and / or the modem 202. During step 1608, parameters related to the communication link, such as QoS parameters, wireless channel quality information (e.g., signal-to-noise ratio), and communication link traffic (e.g., how much communication link bandwidth is requested / used by the communication user), are received, for example, by the controller 220 (e.g., resource scheduler 1302). It should be understood that steps 1602 and 1608 can be performed simultaneously or sequentially.

[0127] During step 1608, parameters unrelated to the communication link may also be received. For example, in some embodiments, configuration parameters may also be received. Configuration parameters may include, for example, a minimum frequency at which radar signals will be transmitted. In some embodiments, configuration parameters are static (i.e., do not change during normal operation of the wireless multimode system). In other embodiments, configuration parameters change dynamically during normal operation of the wireless multimode system.

[0128] During step 1616, bandwidth of the transmission portion of the communication link (e.g., the number and / or location of resource blocks 1104 of resource grid 1106) may be allocated to the communication signal and the radar signal, for example, by resource scheduler 1302, based on one or more parameters determined / received during step 1608. In some embodiments, when allocating bandwidth to the radar signal in a time slot, all frequency bands of the time slot are allocated to the radar signal. In some embodiments, more than one consecutive time slot is allocated to the radar signal, wherein all frequency bands in all allocated time slots are allocated to the radar signal.

[0129] During step 1618, the radar waveform and communication data are encapsulated into frames (e.g., 902) according to the bandwidth allocation (e.g., resource grid 1202) determined during step 1616. Encapsulation of the radar waveform may include, for example, steps 1404, 1406, 1408, and 1410.

[0130] During step 1620 , a frame including a communication signal (user data) and a radar signal (radar waveform) is transmitted via a first portion of the antenna array using M transmission amplifiers. Step 1620 may include, for example, step 1412 .

[0131] During step 1622 , the L receiving amplifiers receive, via the second portion of the antenna array, a reflected frame including a reflected radar signal corresponding to the transmitted radar signal. Step 1622 includes, for example, step 1414 .

[0132] During step 1624, the reflected radar waveform is retrieved (eg, unpacked) from the received reflection frame. Step 1624 includes, for example, steps 1416, 1418, 1420, and 1422.

[0133] During step 1626, the received reflected radar waveform is processed, for example, to determine information about the target. Step 1626 may include, for example, step 1424. During step 1626, the location of the target within the field of view of the wireless multimode system may be determined. Other parameters may also be identified, such as whether the target is moving or stationary, its speed, its size, the material of the target, and other parameters.

[0134] Determining the location of a target using the radar functionality of the base station advantageously allows for optimization of communication operations based on the radar operation results. For example, in some embodiments, the wireless multimode system can optimize the beam steering of the antenna array to avoid shadowing and reduce network entry time by reducing the number of initial beams. Figure 17 A flow chart of an embodiment method 1700 for operating a wireless multimode system in a base station according to an embodiment of the present invention is shown. The method 1700 can be implemented, for example, by any of the wireless multimode systems 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000, which can be located, for example, in the base station 1502.

[0135] During step 1702, the wireless multimode system monitors communication traffic, which may include, for example, bandwidth usage for communication operations (e.g., performed by a first portion of the antenna array). During step 1704, the wireless multimode system compares the traffic level (e.g., communication bandwidth usage) to a predetermined threshold. If the bandwidth usage is below the threshold (e.g., 50% of the available bandwidth), the wireless multimode system may shut down a portion of the wireless multimode system. For example, during step 1710, the second portion may be shut down, e.g., to reduce power consumption. In some embodiments, when the second portion of the antenna array is shut down, the resource scheduler may stop allocating bandwidth to the radar waveform.

[0136] If it is determined during step 1704 that the communication traffic is greater than or equal to the threshold, the wireless multimode system begins or continues to perform radar operations during step 1706. For example, if the second portion of the antenna array is off, the second portion is turned on during step 1706. Similarly, if the radar waveform is not being transmitted via the first portion of the antenna array, transmission of the radar waveform begins via the first portion of the antenna array during step 1706.

[0137] In step 1708, communication operations (e.g., transmitting communication data via the first portion of the antenna array) are optimized based on the radar results (e.g., based on the results obtained in step 1626). For example, if it is determined (e.g., by controller 220) by performing radar operations on reflected signals received via the second portion of the antenna array that a truck is obstructing the beam of the first portion of the antenna array, the beam may be redirected to avoid such an obstruction.

[0138] In some embodiments, millimeter wave base stations (e.g., small cells) can supplement macro base stations. For example, when traffic in a millimeter wave base station is low, the millimeter wave base station can disable its communication function while keeping its radar function enabled. If an object is detected by the millimeter wave base station's radar function, the millimeter wave base station's communication function can be enabled. By disabling communication functions as much as possible, power consumption can be advantageously reduced.

[0139] Example embodiments of the present invention are summarized here. Other embodiments are also apparent from the overall description and claims filed herewith.

[0140] Example 1. A wireless multimode system comprising: an array of N antenna elements, the array comprising a first portion of M antenna elements and a second portion of L antenna elements, the second portion being different from the first portion, wherein N, M, and L are positive integers greater than zero, and wherein M plus L is less than or equal to N; M transmit amplifiers coupled to corresponding antenna elements of the first portion of the M antenna elements, the M transmit amplifiers configured to transmit a frame of transmit data via the M antenna elements, wherein the frame of transmit data comprises a transmit radar signal and a transmit communication signal; M receive amplifiers coupled to corresponding antenna elements of the first portion of the M antenna elements, the M receive amplifiers configured to receive a frame of receive data via the M antenna elements, wherein the frame of receive data comprises a receive communication signal, wherein the transmit communication signal and the receive communication signal form a communication link; and L receive amplifiers coupled to corresponding antenna elements of the second portion of the L antenna elements, the L receive amplifiers configured to receive a radar signal via the L antenna elements, wherein the receive radar signal corresponds to the transmit radar signal; and a resource scheduler configured to allocate bandwidth to the transmit radar signal and the transmit communication signal within the frame of transmit data based on one or more predetermined parameters.

[0141] Example 2. A wireless multimode system according to Example 1, wherein each frame includes P subframes, each subframe includes Q time slots, each time slot includes R frequency bands, and the resource scheduler is configured to allocate R frequency bands of the first time slot to the radar signal when allocating the first time slot to the radar signal, wherein P, Q, and R are positive integers greater than zero.

[0142] Example 3. A wireless multimode system according to one of Examples 1 or 2, wherein each frame for transmitting data includes P subframes, each subframe includes Q time slots, each time slot includes R frequency bands, and wherein the resource scheduler is configured to allocate more than one consecutive time slot to the radar signal when allocating time slots to transmit the radar signal, wherein P, Q, and R are positive integers greater than zero.

[0143] Example 4. The wireless multimode system of any one of Examples 1 to 3, wherein the R frequency bands correspond to 12 orthogonal frequency division multiplexing (OFDM) subcarriers.

[0144] Example 5. A wireless multimode system according to any one of Examples 1 to 4, wherein the one or more predetermined parameters include a traffic volume in the communication link, a priority queue associated with the communication link, or a signal-to-noise ratio of the communication link.

[0145] Example 6. The wireless multimode system of any one of Examples 1 to 5, wherein the one or more predetermined parameters include a quality of service (QoS) parameter or a wireless channel quality.

[0146] Example 7. The wireless multimode system of any one of Examples 1 to 6, wherein the one or more predetermined parameters include a maximum period for transmitting the radar signal.

[0147] Example 8. The wireless multimode system of any one of Examples 1 to 7, wherein a maximum period for transmitting the radar signal is approximately 5 ms.

[0148] Example 9. A wireless multimode system according to one of Examples 1 to 8, wherein the M antenna elements of the first portion are configured to transmit and receive signals in a first frequency band, and the L antenna elements of the second portion are configured to receive signals in a second frequency band different from the first frequency band.

[0149] Example 10. The wireless multimode system of any one of Examples 1 to 9, wherein the transmitted radar signal comprises a PRBS, FSK, or COSTAS waveform.

[0150] Example 11. The wireless multimode system of one of Examples 1 to 10 further includes a controller configured to select a waveform type from a radar waveform set to be used as the radar signal when allocating the first time slot to the radar signal, wherein the radar waveform set includes an FSK radar signal, and wherein the controller includes a resource scheduler.

[0151] Example 12. The wireless multimode system of any one of Examples 1 to 11, wherein the radar waveform set further includes a PRBS radar signal and a COSTAS radar signal.

[0152] Example 13. The wireless multimode system of any one of Examples 1 to 12, wherein M is equal to L.

[0153] Example 14. The wireless multimode system of any one of Examples 1 to 13, wherein M plus L equals N.

[0154] Example 15. A millimeter wave system comprising: an array of N antenna elements, where N is a positive integer greater than zero; N transmit amplifiers; N receive amplifiers; N circulator circuits coupled between respective antenna elements of the N antenna element array, respective transmit amplifiers of the N transmit amplifiers, and respective receive amplifiers of the N receive amplifiers, wherein each of the N circulator circuits is configured to, in sequence, allow signals to flow from a respective transmit amplifier to a respective antenna element while preventing signals from flowing from the respective transmit amplifier to the respective receive amplifier, and allow signals to flow from a respective antenna element to the respective receive amplifier while preventing signals from flowing from the respective antenna element to the respective transmit amplifier; and a controller configured to divide the array into a first portion of M antenna elements and a second portion of L antenna elements, the first portion of which is configured to divide the array into a first portion of M antenna elements and a second portion of L antenna elements, the second ... The second part is different from the first part, wherein M and L are positive integers greater than zero, wherein M plus L is less than or equal to N, wherein: the M transmission amplifiers of the first part are configured to transmit frames of transmission data via M corresponding antenna elements, wherein the frames of transmission data include transmission radar signals and transmission communication signals, the M reception amplifiers of the first part are configured to receive frames of reception data via M corresponding antenna elements, wherein the frames of reception data include reception communication signals, wherein the transmission communication signals and the reception communication signals form a communication link, and the L reception amplifiers of the second part are configured to receive reception radar signals via L corresponding antenna elements, wherein the reception radar signals correspond to the transmission radar signals, wherein the resource scheduler is configured to allocate bandwidth to the transmission radar signals and the transmission communication signals within the frames of transmission data based on the status of the communication link.

[0155] Example 16. The millimeter wave system according to Example 15 further includes: N first switches coupled between each transmission amplifier of the N transmission amplifiers and each circulator circuit of the N circulator circuits; and N second switches coupled between each reception amplifier of the N reception amplifiers and each circulator circuit of the N circulator circuits.

[0156] Example 17. A method of operating a wireless multimode system, the method comprising: receiving data to be transmitted, the data comprising user communication data and a radar waveform; receiving information of a communication link associated with a first portion of an antenna array of the wireless multimode system; allocating a bandwidth of a frame transmitted by the first portion of the antenna array between the user communication data and the radar waveform based on the received information of the communication link; transmitting a frame via the first portion of the antenna array; receiving a reflected frame via a second portion of the antenna array, the second portion being different from the first portion, the reflected frame corresponding to the transmitted frame; retrieving a reflected radar waveform from the received reflected frame; and determining a position of a target based on the retrieved reflected radar waveform.

[0157] Example 18. The method of Example 17, further comprising: monitoring communication traffic of the communication link; and when a level of the communication traffic is below a threshold, shutting down a second portion of the second portion of the antenna array.

[0158] Example 19. The method according to one of Examples 17 or 18 further includes: monitoring the communication service of the communication link, and when the communication service level is lower than a threshold, stopping allocating bandwidth for frames to be transmitted to the radar waveform, while continuing to allocate bandwidth for frames to be transmitted to user communication data.

[0159] Example 20. The method of one of Examples 17 to 19, further comprising performing beam steering on a first portion of the antenna array based on the determined target location.

[0160] Although the present invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments, will be apparent to those skilled in the art upon reference to the specification. It is therefore intended that the appended claims include any such modifications or embodiments.

Claims

1. A wireless multimode system, comprising: an array of N antenna elements, the array comprising a first portion of M antenna elements and a second portion of L antenna elements, the second portion being different from the first portion, wherein N, M, and L are positive integers greater than zero, wherein M plus L is less than or equal to N; M transmit amplifiers coupled to respective antenna elements of a first portion of the M antenna elements, the M transmit amplifiers configured to transmit a frame of transmit data via the M antenna elements, wherein the frame of transmit data includes a transmit radar signal and a transmit communication signal; M receive amplifiers coupled to respective antenna elements of a first portion of the M antenna elements, the M receive amplifiers configured to receive a frame of receive data via the M antenna elements, wherein the frame of receive data comprises a receive communication signal, wherein the transmit communication signal and the receive communication signal form a communication link; as well as L receive amplifiers coupled to respective antenna elements of a second portion of the L antenna elements, the L receive amplifiers configured to receive a receive radar signal via the L antenna elements, wherein the receive radar signal corresponds to the transmit radar signal; as well as A resource scheduler is configured to allocate bandwidth for transmitting radar signals and transmitting communication signals within the frame of the transmission data based on one or more predetermined parameters and the status of the communication link.

2. The wireless multimode system according to claim 1, wherein each frame includes P subframes, each subframe includes Q time slots, and each time slot includes R frequency bands, wherein the resource scheduler is configured to allocate the R frequency bands of the first time slot to the radar signal when allocating the first time slot to the radar signal, wherein P, Q, and R are positive integers greater than zero.

3. The wireless multimode system according to claim 2, wherein each frame for transmitting data includes P subframes, each subframe includes Q time slots, and each time slot includes R frequency bands, wherein the resource scheduler is configured to allocate more than one consecutive time slot to the radar signal when allocating time slots to transmit the radar signal, wherein P, Q and R are positive integers greater than zero.

4. The wireless multimode system of claim 2, wherein the R frequency bands correspond to 12 Orthogonal Frequency Division Multiplexing (OFDM) subcarriers. 5 . The wireless multimode system according to claim 1 , wherein the one or more predetermined parameters include a traffic volume in the communication link, a priority queue associated with the communication link, or a signal-to-noise ratio of the communication link. 6 . The wireless multi-mode system according to claim 1 , wherein the one or more predetermined parameters include a Quality of Service (QoS) parameter or a wireless channel quality. 7 . The wireless multi-mode system of claim 1 , wherein the one or more predetermined parameters include a maximum period for transmitting the radar signal.

8. The wireless multi-mode system according to claim 7, wherein the maximum period for transmitting the radar signal is approximately 5 ms.

9. The wireless multimode system of claim 1 , wherein the M antenna elements of the first portion are configured to transmit and receive signals in a first frequency band, and the L antenna elements of the second portion are configured to receive signals in a second frequency band different from the first frequency band.

10. The wireless multi-mode system of claim 1, wherein the transmitted radar signal comprises a PRBS, FSK, or COSTAS waveform.

11. The wireless multimode system of claim 1 , further comprising a controller configured to select a waveform type from a radar waveform set to be used as the radar signal when allocating the first time slot to the radar signal, wherein the radar waveform set includes an FSK radar signal, and wherein the controller includes the resource scheduler.

12. The wireless multi-mode system according to claim 11, wherein the radar waveform set further comprises a PRBS radar signal and a COSTAS radar signal.

13. The wireless multi-mode system of claim 1, wherein M is equal to L. The wireless multi-mode system of claim 1 , wherein M plus L equals N.

15. A millimeter wave system comprising: an array of N antenna elements, where N is a positive integer greater than zero; N transmission amplifiers; N receiving amplifiers; N circulator circuits coupled between corresponding antenna elements in the array of N antenna elements, corresponding transmission amplifiers in the N transmission amplifiers, and corresponding reception amplifiers in the N reception amplifiers, wherein each of the N circulator circuits is configured to, in sequence, while preventing signals from flowing from the corresponding transmission amplifier to the corresponding reception amplifier, allowing signals to flow from the corresponding transmission amplifier to the corresponding antenna element, and allowing signals to flow from the corresponding antenna element to the corresponding receive amplifier while preventing signals from flowing from the corresponding antenna element to the corresponding transmit amplifier; as well as a controller configured to divide the array into a first portion of M antenna elements and a second portion of L antenna elements, the second portion being different from the first portion, wherein M and L are positive integers greater than zero, and wherein M plus L is less than or equal to N, wherein: The M transmission amplifiers of the first portion are configured to transmit frames of transmission data via the M corresponding antenna elements, wherein the frames of transmission data include transmission radar signals and transmission communication signals, The M receive amplifiers of the first portion are configured to receive a frame of receive data via the M corresponding antenna elements, wherein the frame of receive data comprises a receive communication signal, wherein the transmit communication signal and the receive communication signal form a communication link, and The L receive amplifiers of the second portion are configured to receive receive radar signals via the L corresponding antenna elements, wherein the receive radar signal corresponds to the transmit radar signal, wherein a resource scheduler is configured to allocate bandwidth for the transmit radar signal and the transmit communication signal within a frame of the transmit data based on a status of the communication link.

16. The millimeter wave system according to claim 15, further comprising: N first switches coupled between corresponding ones of the N transmission amplifiers and corresponding ones of the N circulator circuits; as well as N second switches are coupled between corresponding receive amplifiers among the N receive amplifiers and corresponding circulator circuits among the N circulator circuits.

17. A method for operating the wireless multi-mode system of claim 1, the method comprising: receiving data to be transmitted, the data comprising user communication data and radar waveform; receiving information of a communication link associated with a first portion of an antenna array of the wireless multimode system; allocating bandwidth of frames to be transmitted by a first portion of the antenna array between the user communication data and the radar waveform based on the received communication link information; transmitting the frame via a first portion of the antenna array; receiving a reflected frame via a second portion of the antenna array, the second portion being different from the first portion, the reflected frame corresponding to the transmitted frame; retrieving a reflected radar waveform from the received reflection frame; and The position of the target is determined based on the retrieved reflected radar waveform.

18. The method according to claim 17, further comprising: monitoring communication traffic of the communication link; and When the communication traffic level is below a threshold, the second portion of the antenna array is turned off.

19. The method according to claim 17, further comprising: monitoring communication traffic of the communication link; and When the communication traffic level is below a threshold, allocating bandwidth to the frames to be transmitted to the radar waveform is stopped while continuing to allocate bandwidth to the frames to be transmitted to the user communication data.

20. The method of claim 17, further comprising performing beam steering on a first portion of the antenna array based on the determined location of the target.

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