WO2020069131A1 - Non-linear-phase pulse-shape minimizing spurious emission at power amplifier 2nd harmonic for bpsk single-carrier modulated signal - Google Patents

Abstract

A mobile network device or a User Equipment (UE) including a power amplifier, processing circuitry, and a filter can receive a radio frequency (RF) signal and perform a modulation of the RF signal into a modulated RF signal with a pulse-shaping that reduces even harmonic spurs. The pulse-shaping includes a time-domain modulation that comprises a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM). The pulse-shaping further reduces one or more narrow-band spurs based on an even harmonic distortion.

Description

NON-LINEAR-PHASE PULSE-SHAPE MINIMIZING SPURIOUS EMISSION AT POWER AMPLIFIER 2ND HARMONIC FOR BPSK SINGLE-CARRIER

MODULATED SIGNAL

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/737,660 filed September 27, 2018, entitled“NON-LINEAR-PHASE PULSE-SHAPE MINIMIZING SPURIOUS EMISSION AT PA'S 2ND HARMONIC, FOR BPSK SINGLE CARRIER MODULATED SIGNAL”, the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

[0002] Single-Carrier Binary Phase Shift Keying (BPSK) transmission has low peak- to-average power ratio (PAPR) and easy error vector magnitude (EVM) requirements, enabling high power transmission by working in the non-linear region of the power amplifier. However, a second power amplifier (PA) harmonic of a BPSK-modulated signal contains an up-converted to double-carrier frequency periodical component. The first harmonic of that component can be observed as a spectral spur near the double carrier frequency, and can violate regulatory limitations.

[0003] Traditional solutions are to design the radio frequency (RF) hardware (HW) attenuating the second PA harmonic (and higher harmonics), or to reduce transmit (TX) power until reaching linear enough point of the PA. However, this does not take into account design issues such SI modeling or high insertion-loss at frequencies of 60GHz or greater, for example. Reducing TX power also deteriorates link-budget.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is exemplary architecture of mobile device, or communication equipment for various embodiments described.

[0005] FIG. 2 is an example symmetric and asymmetric filter simulation for various embodiments described.

[0006] FIG. 2 is an example symmetric and asymmetric filter simulation for various embodiments described.

[0007] FIG. 3 is an example spectral density of a signal about a second harmonic of a filter configured for various embodiments described. [0008] FIG. 4 is an example symmetric and asymmetric filter simulation for various embodiments described.

[0009] FIG. 5 is an example of filter bandwidths configured for various embodiments described.

[0010] FIG. 6 is an example of filter bandwidths configured for various embodiments described.

[0011] FIG. 7 is an example of filter responses for various embodiments described.

[0012] FIG. 8 is a flow diagram illustrating a process flow according to various embodiments described.

[0013] FIG. 9 is example architecture of a user (access) equipment or base station for implementing various embodiments described.

DETAILED DESCRIPTION

[0014] The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of various embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the various embodiments may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of the present document, the phrase“A or B” means (A), (B), or (A and B).

[0015] The present disclosure will now be described with reference to the attached drawing figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms“component,”“system,”“interface,” and the like are intended to refer to a computer-related entity, hardware, software (e.g., in execution), and/or firmware. For example, a component can be a processor, a process running on a processor, a controller, an object, an executable, a program, a storage device, a programmable processing circuit, a programmable array, electronic circuitry, or a computer with a processing device with circuitry (processing circuitry). [0016] In consideration of the various deficiencies or needs the embodiments herein comprises a device or system that uses time-domain (e.g. single-carrier, or DFT-s- OFDM), where a pulse-shaping is optimized to reduce narrow-band spurs due to even harmonic distortion. This system operates where the modulation is BPSK or pi/2-BPSK, and spurious emissions caused by second harmonic are minimized. The modulation is pi/2-BPSK and its pulse-shaping is designed such that a convolution of the frequency response of the pulse with itself is close to zero at ±1/(2^*Ts) (Ts is the symbol time).

The pulse-shape has non-linear phase response in frequency (or in other words it is not symmetric in time). The phase response in frequency is approximately piecewise-linear, with slope of +pi^*Ts (Ts is the symbol time) for negative frequencies, and slope of -pi^*Ts for positive frequencies.

[0017] Referring to FIG. 1 , illustrated is an exemplary communication or mobile device 100 comprising an inductor component in accordance with various aspects being described. The device 100 can comprise a mobile or wireless device, for example, and can further include a digital baseband processor 102, an RF frontend 104 and an antenna port 108 for connecting to an antenna 106. The device 100 can further comprise an exemplary driver / power amplifier 1 10 as a part of the digital baseband processor 102 or the RF frontend 104. The digital baseband processor 102 or the RF frontend 104 can further comprise a filter component 1 12 coupled to the power amplifier 1 10, the digital baseband processor 102, or the RF frontend 104, as an external device, or integrated within or as a part of any of the devices thereof (e.g., as in an RFIC, SoC, or the like). The RF frontend 104 can also be coupled to the digital baseband processor 102 and the antenna port 108, which is configurable with the antenna 106. The baseband processor 102 or the RF front end 104 can include processing circuitry and associated interface(s), which can comprise transmitter circuitry (e.g., associated with one or more transmit chains) or receiver circuitry (e.g., associated with one or more receive chains) that can employ common circuit elements, distinct circuit elements, or a combination thereof), and a memory (e.g., any of a variety of storage mediums and can store instructions or data associated with one or more of processor(s)).

[0018] In an example, the power amplifier 1 10 can operate to provide a power signal along a transmitter path for transmissions according to various operating bands. The power amplifier 1 10 can operate in multi-band or multi-mode operations to

simultaneously support multiple communication standards with various operating bands. Rapidly growing demands have posed challenges for future radio frequency (RF) transmitter development, especially power amplifiers.

[0019] The second PA harmonic of BSPSK-modulated signal contains an up- converted to double-carrier frequency periodical component. The first harmonic of that component is seen as a spectral spur near the double-carrier frequency, and can violate regulatory limitations. These issues in particular are found in wireless Gigabyte (WiGig) transmissions around 60GHz, and it is hard to design the RF filter for 120GHz (e.g., due to a lack of accurate Si modeling at this frequency range, high insertion-loss for every added component), and further, due to project timelines, sometimes it is too late to change the HW design (mainly Si design). Further as mentioned above, reducing TX power can deteriorate link-budget accordingly.

[0020] In embodiments, in order to preserve the magnitude of TX Frequency- Response (to avoid the increasing of "equalizer noise enhancement"), phase of the filter response FR can be modified (e.g., via filter component 1 12), in a way that minimizes the spur. This solution enables higher TX power without violating regulatory spurious emission limit near 120 GHz. Further the embodiments herein can be used when spurious emission at the 2^nd PA harmonic limits the TX power (and not other regulatory considerations like spectral-mask of maximal effective isotropic radiated power (EIRP), and not error vector magnitude (EVM)), this invention can enable better link-budget.

[0021] In an aspect, the filter component 1 12 can comprise one or more devices, electric circuits, circuit components, or the like communicatively coupled to, connected or coupled to, integrated with one or more components 1 12, as well as operate at operating frequencies in a GHz range (e.g., from one gigahertz to 120 GHz, such as 60 GHz, millimeter Wave (mmWave) frequencies, or higher).

[0022] The pi / 2-BPSK modulation as defined and referenced in WiGig (802.1 1 ad / 802.1 1 -2016). The following variables can be denoted for representation: s(t) - waveform of the symbol pulse at PA input; i(r) - its Fourier transform (equal to Tx FR); s₀{t) - the default waveform with s₀(f ) having good flatness, where s₀(f) = Fourier transform of s₀{t) .

[0023] In addition, b = (p_k ), b_k = { 0,l}, k = - ... -1,0,1... - infinite stochastic sequence of bits; T - signaling (symbol) interval where

[0024] s{t)

j^k (-l)^¾ s{t - kT) - p/2-BPSK signal modulated by b . The signal S details the transmitted signal in the time domain. [0025] Referring to FIG. 2, illustrated is an example filter curves 200. Linear phase filters can be either symmetric or asymmetric. Curve 202 demonstrates a linear curve for a real part, in which the filter operation is linear and symmetrical with no imaginary part. Curve 204 demonstrates a non-linear phase comprising a real part 206 and an imaginary part 208. The embodiments herein can be applied to nonlinear phase filters for reducing the spurs generated in the non-linear phases, for example. In this way, a pulse shape can be performed with the non-linear phase, as a non-linear-phase pulse shaping.

[0026] The following signal can be regarded as the time domain signal for modulation as squared.

[0027] length

of s{t) in T units.

[0028] Opening the inner sum above, obtains the following

[0029]

[0030] A(t) contains random components only, as the coefficients (- l)^{bl +b} ' are random. It can be proven, that spectrum of A{t) is continuous.

[0031] B(t) is deterministic, periodical with period 2 T the even harmonics = 0. The above A(t) and B(t) basically shows the parts that contribute to the spurious parts and what is done next in the design is pulse shaping S to reduce the spurious parts to be smaller than usual (e.g., about 8dB or another difference).

[0032] At frequencies of odd harmonics of fi(i) , "spurs" exists in power spectral density PSD of S²(z). To minimize the first harmonic of B(t ) while keeping the flatness, targeting a non-linear-phase filter s(t) is targeted such that s{f) = e^{i ip{f )} · ¾(/) and

[0033] Note: If roll-off factor of i(/)<1 .5, then out of / e frequency

interval s(f)® s(f ) is small. Hence,

,if |&| > 2 then (s(/)® s(/)) 0

/= 2 T

[0034] That is, for reasonable roll-off factors, B(t) harmonics of the third and higher orders are always small or smaller than the other orders.

[0035] A similar design method can be applied to BPSK signals without

rotation, for higher-order power amplifier (PA)-harmonics and higher order phase shift keying (PSK) modulations (e.g. the 4^th harmonic of Quadrature Phase Shift Keying (QPSK) modulation).

[0036] Referring to FIG. 3, illustrated is an example simulated spectral density of filter signal(s) around a second harmonic according to embodiments herein. A linear phase filter signal is simulated at curve 302 and an optimization as a non-linear phase filter for reduction of second harmonic spurs at curve 304. The example of a filter design simulation in curves 300 in accordance with the embodiments herein demonstrated that the spurious level was reduced by about 8 dB (and also confirmed in lab

measurements) between curves 302 and 304. Here, the spurs were not completely reduced on account of other parameters for a trade-off, but this does not mean the spurs at 306 and 308 could not be removed or mitigated based on embodiments herein. In this example, the spurs can be mitigated or reduced to be at 320, 322 and 310, 312, 314 as part of the curve 304 phase shaping.

[0037] In embodiments, a novel pulse-shaping criterion or parameters can be optimized to reduce 2^nd harmonic spurious emission of BPSK. The use of a pulse shaping filter as the filter 1 12 or a component thereof can be configured to reduce even harmonic spurs for one or more modulated signals. This could be utilized for second harmonic spurs of TT/2 BPSK and BPSK signals, in which pie (TT) can be in degrees or radians, for example. In addition, or alternatively, this could be utilized specifically for fourth harmonic spurs for QPSK signal(s) also.

[0038] Referring to FIG. 4, illustrated is an example poly-phase filter 400 that can be used to implement any one of embodiment(s) herein, and can be an example

configuration of filter 1 12 of FIG. 1 . As such, the embodiments herein can used with one or more various filter configurations or designs for the selection of any number of filter coefficients 404 (ho...hN-i), along with inverse Z transform operators 402, and adders 406 that enable an output y(n), for example. Any conventional Finite Impulse Response (FIR) filter can be utilized as long as it does not assume symmetry (or anti-symmetry) can be utilized.

[0039] The filter implementation 400 can be a poly-phase filter that includes x1 .5 interpolation, complex coefficients 404 for enabling pre-compensation for flatness improvement, variable bit-width of coefficients to reduce HW complexity, and many other details not specified necessarily.

[0040] One unique property (criterion or parameter) is the non-linear phase response of the filter (1 12 or 400). The FIR filter designs used in communication systems can be symmetric (or anti-symmetrical) and consequently can have linear phase response (as function of frequency). As such, the poly-phase filter 400 can be a non-linear FIR filter design used for communication or one or more variants on minimal-phase filters (aiming to have a sharper“start” of the signal or symbols). As such a non-linear filter design criterion can be the non-linear phase response. This exact property can be represented

(s(f) ® s(f)) _f ~ 0

as follows: ^2T . This property (non-linear phase response) can still leave a lot of freedom for different implementations. This property can be general, and never satisfied by a symmetric (or linear-phase) filter design.

[0041] In various embodiments, strong spurious emission due to a PA’s 2^nd harmonic occurs at frequencies of 2 F_c where F_c is the carrier frequency, and T_s is the symbol

duration of the pi/2-BPSK modulation (more generally they may appear also higher order terms, e.g. in frequency 2 F_c +— or 2 F -— but for reasonable band limited

signals they are expected to be much lower).

[0042] The modulation is pi/2-BPSK and its pulse-shaping is configured by the filter 1 12 such that a convolution of the frequency response of the pulse with itself can be close to zero at ±1 /(2^*Ts) (Ts is the symbol time).

[0043] For BPSK signal with no pi/2 rotation spurs are at: 2 F_c +— , for k e

Ts

(0, ±1, ±2 ... }, so an appropriate design criterion could be that s(f) * s(f) \_{f=0 «} 0 and maybe also that s(J) * s(/) | _j_ « 0. Treatment of 4^th harmonic of QPSK and BPSK can also be similar as implemented herein. The phase response in frequency can be approximately piecewise-linear, with alternating slopes of ±— , in the ranges of

4 -T_s

symbol of the transmission.

[0044] Thus, the designed the filter for pi/2-BPSK modulation can affect the filter design and also similar if BPSK signals without pi/2 rotation or higher-order PA- harmonics and higher order PSK modulations (e.g. the 4th harmonic of QPSK modulation) are used.

[0045] As such, various embodiments herein comprise a reduction in the second harmonic of S² that can achieve an 8 dB reduction, for example, or a different reduction at the point of frequency where spurs are seen based on the second harmonic of the modulated signal. As a part of filter design, there can be tradeoffs between the requirements, but an 8 dB reduction was found to suffice for certain cases, however other reduction amounts (e.g., 10 dB reduction, less or greater can also be generated). Other target reductions lower or higher can also be envisioned. The filter design criterion (properties or parameters) can include the following: 1 ) a hardware (HW) limitation - number of taps, fixed-point of coefficients; 2) flatness (in the in-band ripple) - actually targeting to meet Nyquist criterion that implies no inter-symbol interference or ISI after the receiver matched filter, and it includes pre-compensation for analog non flatness; 3) out of band rejection; 4) in-band noise due to replicas (e.g., a poly-phase filter with digital decimation that causes aliasing); 5) signal PAPR (or crest factor) in digital analog converter (DAC) and in PA - as a single-Carrier BPSK has inherent low PAPR, which is increased by one or more filters;“Peak-iness” or spurious emission of the filter impulse response - some receiver algorithms in WiGig implementation relies on correlation of received signal with the reference ideal symbols, i.e. no rake-receiver or frequency domain equalization (where they depend on having one tap of the filter significantly stronger than other taps); 7) reduction of 2^nd harmonic spurs (the current disclosure focused criterion). The optimization criterion for second harmonic spurs and targeting certain frequencies based on these does not necessarily directly conflict with most of the filter design criterions (with the exception of potentially #5 and #6 above).

[0046] In particular, the design criterion (#7) as part of embodiments herein does not conflict with the fundamental filter design requirements of flatness and rejection (as #2 and #3 in above listed criterion). So without existing (conventional) HW limitations, and without consideration of PAPR and Peak-iness (#5 and #6), it is possible to design filter that rejects spurs completely while meeting a desired (target) amplitude frequency response. [0047] In a WiGig case example, the 8 dB reduction can be good enough for passing the regulatory limit of spurious emissions. With regards to configuring a best comprise or trade-off among the criterion, various considerations can be accounted for and different trade-offs can be utilized to obtain different reductions of spurious emission levels.

[0048] In some aspects, longer filter lengths may be realized or more complex filters with additional taps, plus a lack of symmetry or doubling of multipliers for different given flatness requirements among the curves 300.

[0049] Embodiments may be applied to WiGig, 5G mm-wave transmissions, or other transmission types. 5G mm-wave UL modulation can either be OFDMA or DFT- precoded-OFDM (a.k.a SC-FDMA). DFT-precoded-OFDM with pi/2-BPSK and with QPSK, both are defined in 5G can readily take advantage of the embodiments herein.

[0050] However, these embodiments are related also the BW of the transmitted signal. In WiGig case (e.g., in FIG. 5) the channel BW can be 2.16 GHz, while the resolution BW for spurious emission testing is only 1 MHz. This means that unwanted emission(s) that are“smooth” and wide-band are ~x2,000 wider than the measurement, which means that if the total (unwanted) radiated power is X, the measured“spur” level would be -X-33 dB (10^*log10(2000)=33). In the pi/2-BPSK scenario, due to the periodicity of S²(t), spurs can be obtained that are about 30 dB higher than expected (all the energy is concentrated on two very narrow spurs, and thus is not smooth at all).

[0051] In 5G mmWave (e.g., in FIG. 6) the minimal channel BW would be 50 MHz (other options are 100MHz, 200MHz, 400 MHz and 800MHz), and resolution-BW for spurious emission is still 1 MHz. So when transmitting pi/2-BPSK on the entire channel, the potential spurious emission can be 17 dB (=10^*log 10(50/1 )) higher compared to signals with no periodicity of S²(t). But in 5G (like in LTE) the UE could transmit only on a small portion of the entire BW - as small as 1 physical resource block (PRB), which is 720 kHz (12 sub-carriers at SCS of 60 kHz), which is lower than the resolution-BW. In such cases the proposed method could offer little or small gain.

[0052] As such, in various embodiments herein can be applicable to a subset of 5G mm-Wave UL transmissions.

[0053] Some embodiments address the 5G problem of having spurious emissions around the 2^nd harmonic. For small RB allocations (a.k.a. small(er) BW), configurations can be allowed to reduce the transmit power (as extended to all power classes, esp. for pi/2 BPSK). In this case, there is a problem for the BPSK DFT-s-OFDM transmission for large BWs. For the standard implemented other modulations, when one increases the BW by a factor of 'Kthe worst case emissions (measured with a 1 MHz BW) around the 2^nd harmonic will decrease roughly by 10^*log10(V) [dB] This is something that is not true for the pi/2 BPSK, due to the spurs as illustrated in FIG. 5 in the curves 500.

[0054] Referring to FIG. 5, illustrated are examples curves 500 for the case of DFT- S-OFDM QPSK PSD of squared signal around 2 x carrier (for 50 MHz SCS = 60 kHz).

[0055] Referring to FIG. 6, illustrated are example curves 600 for the case of DFT-s- OFDM pi / 2 BPSK PSD of squared signal around 2 x carrier (for 50 MHz SCS=60kHz).

[0056] In these cases of curves 500, 600, there is a problem for the BPSK DFT-s- OFDM transmission for large BWs. For the standard’s other modulations, when one increases the BW by a factor of V the worst case emissions (measured with a 1 MHz BW) around the 2^nd harmonic will decrease roughly by 10^*log10(V) [dB] This is something that is not true for the pi/2 BPSK, due to the spurs as illustrated.

[0057] As mentioned before, a large part of the power is located in the two spurs, and attenuation is desired to reduce these spurs for the larger / wider BWs 502, 602. A modified pulse shaping filter can be utilized to attenuate the spurs in the 2^nd harmonics (in general even harmonics of the signal, as a result of the TT/2 BPSK modulation).

[0058] When the different curve lines are used as different options for bandwidth of the signal. RB stands for resource block, and one RB is 10 times the bandwidth, and the value 66 would be inside the maxima bandwidth for a specific scenario. If only one RB BPSK and QPSK relation which is approximately the same level, such as the value 68 minus 69 so up to one DB difference, thus it would very similar. However, for the wider bandwidth this peakiness (high spurious level) of the second harmonic in frequency domain makes it much higher level for the BPSK compared to the QPSK curves between FIGs. 5 and 6, and the embodiments herein can relieve / remove this peakiness of the square root of the signal to reduce the spur peaks. Peakiness is a frequency domain of the square of the time domain signal. For example, the second harmonic can be reduced somewhat by squaring the time domain signal in every instance, and then evaluating at the frequency domain of this squared signal. Those peaks or spurs in spectral may violate the regulation, and thus be mitigated by non- linear-phase pulse shaping at the PAs (e.g., 1 10) second harmonic for BPSK single carrier modulated signals. The phase response in frequency can be approximately piecewise-linear, with alternating slopes of ±— , in the ranges of

4 T_s

symbol of the transmission.

[0059] Referring to FIG. 7 illustrates curves 700 for showing how widening out the spurs in the ideal amplitude response 704 is being performed for the amplitude and phase. As such, the phase response 702 of the channel estimation in frequency can be examined to see if it significantly deviates from a linear-phase (or constant phase after time alignment) to observe the attenuation of spurs embodied herein.

[0060] The peaks or spurs in spectral may violate the regulation, and thus be mitigated by non-linear-phase pulse shaping at the PAs (e.g., 1 10) second harmonic for BPSK single-carrier modulated signals. The phase response in frequency can be approximately piecewise-linear, with alternating slopes of ±— , in the ranges of

4 -T_s

symbol of the transmission.

[0061] Referring to FIG. 8, illustrated is a process flow 800 for a non-linear phase pulse shaping to minimize spurs from the second harmonics of a power amplifier or PA 1 10 for BPSK single-carrier modulated signals as described herein.

[0062] At 802, the process flow 800 comprises modulating the one or more RF input signals using a time domain modulation comprising a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) modulation.

[0063] At 804, the process flow 800 includes reducing one or more narrow band spurs derived from an even harmonic distortion. A pulse shaping can be generated via the filter 1 12, for example, that reduces the narrower band spur(s) comprising even harmonic spurs for a modulated signal. The one or more spurs can be based on a second power amplifier PA harmonic of a Binary Pulse Shaped Keying (BPSK) modulated signal comprising an up-converted to double-carrier frequency periodical component. The processing circuitry coupled to the filter configured to reduce (e.g., about 8 dB or other amount) the one or more spurs (e.g., at about 60 GHz or 120 GHz) comprising narrow band spurs due to even harmonic distortion by targeting these spurs specifically in the pulse shaping. The RF signals can be modulated based on a pulse- shape that has a non-linear phase response in frequency or is asymmetric in time. The non-linear phase response in frequency is approximately piecewise-linear. The filter can be a pulse shaping filter, for example. [0064] To provide further context for various aspects of the disclosed subject matter, FIG. 9 illustrates a block diagram of an embodiment of access (user) equipment, a new radio (NR) NodeB or gNodeB (gNB), or eNodeB (eNB) related to access of a network (e.g., base station, wireless access point, femtocell access point, and so forth) that can enable and/or exploit features or aspects disclosed herein as related to embodiments herein for non-linear phase pulse shaping to minimize spurs or spurious emission at PA second harmonics for BPSK single-carrier modulated signals.

[0065] Access equipment, UE and/or software related to access of a network can receive and transmit signal(s) from and to wireless devices, wireless ports, wireless routers, etc. through segments 902I -902B (B is a positive integer). Segments 902I-902B can be internal and/or external to access equipment and/or software related to access of a network, and can be controlled by a monitor component 904 and an antenna component 906. Monitor component 904 and antenna component 906 can couple to communication platform 908, which can include electronic components and associated circuitry that provide for processing and manipulation of received signal(s) and other signal(s) to be transmitted.

[0066] In an aspect, communication platform 908 includes a receiver/transmitter 910 that can convert analog signals to digital signals upon reception of the analog signals, and can convert digital signals to analog signals upon transmission. In addition, receiver/transmitter 910 can divide a single data stream into multiple, parallel data streams, or perform the reciprocal operation. Coupled to receiver/transmitter 910 can be a multiplexer/demultiplexer 912 that can facilitate manipulation of signals in time and frequency space. Multiplexer/demultiplexer 912 can multiplex information (data/traffic and control/signaling) according to various multiplexing schemes such as time division multiplexing, frequency division multiplexing, orthogonal frequency division multiplexing, code division multiplexing, space division multiplexing. In addition,

multiplexer/demultiplexer component 912 can scramble and spread information (e.g., codes, according to substantially any code known in the art, such as Hadamard-Walsh codes, Baker codes, Kasami codes, polyphase codes, and so forth).

[0067] A modulator/demodulator 914 is also a part of communication platform 908, and can modulate information according to multiple modulation techniques, such as frequency modulation, amplitude modulation (e.g., M-ary quadrature amplitude modulation, with M a positive integer); phase-shift keying; and so forth). [0068] Access equipment and/or software related to access of a network also includes a processor 916 configured to confer, at least in part, functionality to substantially any electronic component in access equipment and/or software. In particular, processor 916 can facilitate configuration of access equipment and/or software through, for example, monitor component 904, antenna component 906, and one or more components therein. Additionally, access equipment and/or software can include display interface 918, which can display functions that control functionality of access equipment and/or software or reveal operation conditions thereof. In addition, display interface 918 can include a screen to convey information to an end user. In an aspect, display interface 918 can be a liquid crystal display, a plasma panel, a monolithic thin-film based electrochromic display, and so on. Moreover, display interface 918 can include a component (e.g., speaker) that facilitates communication of aural indicia, which can also be employed in connection with messages that convey operational instructions to an end user. Display interface 918 can also facilitate data entry (e.g., through a linked keypad or through touch gestures), which can cause access equipment and/or software to receive external commands (e.g., restart operation).

[0069] Broadband network interface 920 facilitates connection of access equipment and/or software to a service provider network (not shown) that can include one or more cellular technologies (e.g., third generation partnership project universal mobile telecommunication system, global system for mobile communication, and so on) through backhaul link(s) (not shown), which enable incoming and outgoing data flow. Broadband network interface 920 can be internal or external to access equipment and/or software and can utilize display interface 918 for end-user interaction and status information delivery.

[0070] Processor 916 can be functionally connected to communication platform 908 and can facilitate operations on data (e.g., symbols, bits, or chips) for

multiplexing/demultiplexing, such as effecting direct and inverse fast Fourier transforms, selection of modulation rates, selection of data packet formats, inter-packet times, and so on. Moreover, processor 916 can be functionally connected, through data, system, or an address bus 922, to display interface 918 and broadband network interface 920, to confer, at least in part, functionality to each of such components.

[0071] In access equipment and/or software memory 924 can retain location and/or coverage area (e.g., macro sector, identifier(s)) access list(s) that authorize access to wireless coverage through access equipment and/or software sector intelligence that can include ranking of coverage areas in the wireless environment of access equipment and/or software, radio link quality and strength associated therewith, or the like.

Memory 924 also can store data structures, code instructions and program modules, system or device information, code sequences for scrambling, spreading and pilot transmission, access point configuration, and so on. Processor 916 can be coupled (e.g., through a memory bus), to memory 924 in order to store and retrieve information used to operate and/or confer functionality to the components, platform, and interface that reside within access equipment and/or software.

[0072] As it employed in the subject specification, the term“processor” can refer to substantially any computing processing unit or device including, but not limited to including, single-core processors; single-processors with software multithread execution capability; multi-core processors; multi-core processors with software multithread execution capability; multi-core processors with hardware multithread technology;

parallel platforms; and parallel platforms with distributed shared memory. Additionally, a processor can refer to an integrated circuit, an application specific integrated circuit, a digital signal processor, a field programmable gate array, a programmable logic controller, a complex programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions and/or processes described herein. Processors can exploit nano-scale architectures such as, but not limited to, molecular and quantum-dot based transistors, switches and gates, in order to optimize space usage or enhance performance of mobile devices. A processor may also be implemented as a combination of computing processing units.

[0073] By way of illustration, and not limitation, nonvolatile memory, for example, can be included in a memory, non-volatile memory (see below), disk storage (see below), and memory storage (see below). Further, nonvolatile memory can be included in read only memory, programmable read only memory, electrically programmable read only memory, electrically erasable programmable read only memory, or flash memory.

Volatile memory can include random access memory, which acts as external cache memory. By way of illustration and not limitation, random access memory is available in many forms such as synchronous random access memory, dynamic random access memory, synchronous dynamic random access memory, double data rate synchronous dynamic random access memory, enhanced synchronous dynamic random access memory, Synchlink dynamic random access memory, and direct Rambus random access memory. Additionally, the disclosed memory components of systems or methods herein are intended to include, without being limited to including, these and any other suitable types of memory.

[0074] Examples can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described herein.

[0075] A first example is an apparatus configured to be employed in a mobile device or a User Equipment (UE). The apparatus comprises a power amplifier, and processing circuitry coupled to a filter configured to: generate a modulation of an RF signal into a modulated RF signal with a pulse-shaping that reduces even harmonic spurs; and perform a time-domain modulation that comprises a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) to the RF signal. A radio frequency (RF) interface is configured to provide, to RF circuitry, data for a transmission of the modulated RF signal.

[0076] A second example can include the first example, wherein the pulse-shaping further reduces one or more narrow-band spurs caused by an even harmonic distortion.

[0077] A third example can include the first or second example, wherein the pulse shaping comprises a BPSK or pi/2 BPSK signal modulation that minimizes a spur that is based on a second harmonic.

[0078] A fourth example can include any one of the first through third examples, wherein the pulse-shaping minimizes a spur that is based on a fourth harmonic for a Quadrature Phase Shift Keying signal.

[0079] A fifth example can include any one of the first through fourth examples, wherein the pulse-shaping comprises a pi/2 BPSK modulation.

[0080] A sixth example can include any one of the first through fifth examples, wherein a convolution of a frequency response of a pulse of the RF signal is about zero at plus/minus 1/(2^*Ts), where Ts comprises a symbol time.

[0081] A seventh example can include any one of the first through sixth examples, wherein the filter is configured to reduce a spurious level by about 8 dB at one or more spurious emissions. [0082] An eighth example can include any one of the first through seventh examples, wherein the pulse-shaping comprises a frequency- response that has a non-linear phase as a function of frequency and is not symmetrical and not anti-symmetrical.

[0083] A ninth example can include any one of the first through eighth examples, wherein the modulation comprises a phase response in frequency that is approximately piecewise-linear, with alternating slopes of ±— , in ranges of

4 'T_s

[0084] A tenth example is an apparatus configured to be employed in a network device, a user equipment (UE) or a next generation NodeB (gNB). The apparatus comprises a power amplifier; and processing circuitry coupled to a filter configured to: modulate RF signals in a non-linear phase based on a pulse shaping that reduces one or more spurs; and perform a time-domain modulation that comprises a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) to the RF signals. A radio frequency (RF) interface is configured to provide, to RF circuitry, data for a transmission of the modulated RF signal.

[0085] An eleventh example can include the tenth example, wherein the one or more spurs are based on a second power amplifier harmonic of a Binary Pulse Shaped Keying (BPSK) modulated signal comprising an up-converted to double-carrier frequency periodical component.

[0086] A twelfth example can include any one of the tenth through eleventh examples, wherein the processing circuitry coupled to the filter is further configured to reduce the one or more spurs comprising narrow band spurs caused by even harmonic distortion.

[0087] A thirteenth example can include any one of the tenth through twelfth examples, wherein the processing circuitry coupled to the filter is further configured to modulate the RF signals based on a pulse-shape that has a non-linear phase response in frequency or is asymmetric in time.

[0088] A fourteenth example can include any one of the tenth through thirteenth examples, wherein the non-linear phase response in the frequency is approximately piecewise-linear, with alternating slopes of ±— , in ranges of

4 -T_s

[0089] A fifteenth example can include any one of the tenth through fourteenth examples, wherein the one or more spurs are from a second harmonic and are reduced at about 60 GHz or 120 GHz.

[0090] A sixteenth example can include any one of the tenth through fifteenth examples, wherein the filter comprises a pulse shaping filter configured to reduce even harmonic spurs for a modulated signal.

[0091] A seventeenth example includes a computer readable storage device storing executable instructions that, in response to execution, cause one or more processors of a network device to perform operations. The operations comprises: modulating one or more RF input signals using a time domain modulation comprising a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) modulation; and reducing one or more narrow band spurs derived from an even harmonic distortion.

[0092] An eighteenth example includes the seventeenth example, wherein the operations further comprise: generating a pulse shaping that reduces the one or more narrow band spurs caused by even harmonic spurs for a modulated signal.

[0093] A nineteenth example includes any one of the seventeenth through eighteenth examples, wherein the operations further comprise: modulating the RF signals based on a pulse-shape that has a non-linear phase response in frequency.

[0094] A twentieth example includes any one of the seventeenth through nineteenth examples, wherein the one or more narrow band spurs are from a second harmonic and are reduced at about 60 GHz or 120 GHz.

[0095] It is to be understood that aspects described herein can be implemented by hardware, software, firmware, or any combination thereof. When implemented in software, functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media or a computer readable storage device can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD- ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or other tangible and/or non-transitory medium, that can be used to carry or store desired information or executable instructions. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

Combinations of the above should also be included within the scope of computer- readable media.

[0096] Various illustrative logics, logical blocks, modules, and circuits described in connection with aspects disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other

programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform functions described herein. A general-purpose processor can be a microprocessor, but, in the alternative, processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Additionally, at least one processor can comprise one or more modules operable to perform one or more of the s and/or actions described herein.

[0097] For a software implementation, techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform functions described herein. Software codes can be stored in memory units and executed by processors. Memory unit can be implemented within processor or external to processor, in which case memory unit can be communicatively coupled to processor through various means as is known in the art. Further, at least one processor can include one or more modules operable to perform functions described herein.

[0098] Single carrier frequency division multiple access (SC-FDMA), which utilizes single carrier modulation and frequency domain equalization is a technique that can be utilized with the disclosed aspects. SC-FDMA has similar performance and essentially a similar overall complexity as those of OFDMA system. SC-FDMA signal has lower peak-to-average power ratio (PAPR) because of its inherent single carrier structure. SC-FDMA can be utilized in uplink communications where lower PAPR can benefit a mobile terminal in terms of transmit power efficiency.

[0099] Moreover, various aspects or features described herein can be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks {e.g., compact disk (CD), digital versatile disk (DVD), etc.), smart cards, and flash memory devices {e.g., EPROM, card, stick, key drive, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term“machine-readable medium” can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data. Additionally, a computer program product can include a computer readable medium having one or more instructions or codes operable to cause a computer to perform functions described herein.

[00100] In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding Figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below.

[00101] In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component {e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims

CLAIMS What is claimed is:

1 . An apparatus configured to be employed in a mobile device or a User Equipment (UE), comprising:

a power amplifier; and

processing circuitry coupled to a filter configured to:

generate a modulation of an RF signal into a modulated RF signal with a pulse-shaping that reduces even harmonic spurs; and

perform a time-domain modulation that comprises a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) to the RF signal;

a radio frequency (RF) interface, configured to provide, to RF circuitry, data for a transmission of the modulated RF signal.

2. The apparatus of claim 1 , wherein the pulse-shaping further reduces one or more narrow-band spurs caused by an even harmonic distortion.

3. The apparatus of claim 1 , wherein the pulse-shaping comprises a BPSK or pi/2 BPSK signal modulation that minimizes a spur that is based on a second harmonic.

4. The apparatus of claim 1 , wherein the pulse-shaping minimizes a spur that is based on a fourth harmonic for a Quadrature Phase Shift Keying signal.

5. The apparatus of claim 1 , wherein the pulse-shaping comprises a pi/2 BPSK modulation.

6. The apparatus of claim 5, wherein a convolution of a frequency response of a pulse of the RF signal is about zero at plus/minus 1/(2^*Ts), where Ts comprises a symbol time.

7. The apparatus of claim 1 , wherein the filter is configured to reduce a spurious level by about 8 dB at one or more spurious emissions.

8. The apparatus of claim 1 , wherein the pulse-shaping comprises a frequency- response that has a non-linear phase as a function of frequency and is not symmetrical and not anti-symmetrical.

9. The apparatus of claim 1 , wherein the modulation comprises a phase response in frequency that is approximately piecewise-linear, with alternating slopes of ±— , in

⁴ -T_s ranges

10. An apparatus configured to be employed in a network device, a user equipment or a next generation NodeB (gNB), comprising:

a power amplifier; and

processing circuitry coupled to a filter configured to:

modulate RF signals in a non-linear phase based on a pulse shaping that reduces one or more spurs; and

perform a time-domain modulation that comprises a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) to the RF signals;

a radio frequency (RF) interface, configured to provide, to RF circuitry, data for a transmission of the modulated RF signal.

1 1 . The apparatus of claim 10, wherein the one or more spurs are based on a second power amplifier harmonic of a Binary Pulse Shaped Keying (BPSK) modulated signal comprising an up-converted to double-carrier frequency periodical component.

12. The apparatus of claim 10, wherein the processing circuitry coupled to the filter is further configured to reduce the one or more spurs comprising narrow band spurs caused by even harmonic distortion.

13. The apparatus of claim 10, wherein the processing circuitry coupled to the filter is further configured to modulate the RF signals based on a pulse-shape that has a non linear phase response in frequency or is asymmetric in time.

14. The apparatus of claim 13, wherein the non-linear phase response in the frequency is approximately piecewise-linear, with alternating slopes of ±— 4 7s , in ranges

15. The apparatus of claim 10, wherein the one or more spurs are from a second harmonic and are reduced at about 60 GHz or 120 GHz.

16. The apparatus of claim 10, wherein the filter comprises a pulse shaping filter configured to reduce even harmonic spurs for a modulated signal.

17. A computer readable storage device storing executable instructions that, in response to execution, cause one or more processors of a network device to perform operations, the operations comprising:

modulating one or more RF input signals using a time domain modulation comprising a single-carrier or a discrete Fourier transform (DFT) spread orthogonal frequency division multiplexing (DFT-s-OFDM) modulation; and

reducing one or more narrow band spurs derived from an even harmonic distortion.

18. The computer readable storage device of claim 17, wherein the operations further comprise:

generating a pulse shaping that reduces the one or more narrow band spurs caused by even harmonic spurs for a modulated signal.

19. The computer readable storage device of claim 17, wherein the operations further comprise:

modulating the RF signals based on a pulse-shape that has a non-linear phase response in frequency.

20. The computer readable storage device of claim 17, wherein the one or more narrow band spurs are from a second harmonic and are reduced at about 60 GHz or 120 GHz.