Arbitrary Noise Shaping Transmitter with Receive Band Notching

Abstract

This disclosure discusses techniques for generating signals using arbitrary noise shaping. An example apparatus configured for use within a transmitter may include a noise shaper configured to: receive an input signal x q ; and applying noise shaping to the input signal x q To generate the noise shaped output signal y q , where the noise shaping output signal y q The in-band noise of the signal is below the in-band noise threshold of the spectrum mask associated with the noise shaper, where the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and the output signal y q Noise in each of the plurality of passband regions is below an associated noise threshold for the passband region in the spectral mask.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application serial number 15 / 671,888, filed on August 8, 2017, the specification of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to wireless technologies and, more particularly, to techniques for arbitrary noise shaping in a transmitter to fit a spectral mask, for example, a spectral mask including one or more receive band notches. Background Art

[0004] A transmitter in a wireless communication device (e.g., user equipment (UE), base station (BS)) generates a transmit signal within a transmit band and may potentially generate significant noise outside the transmit band. This noise may exceed a target noise level for one or more reasons, such as exceeding a target adjacent channel leakage rate (ACLR), exceeding a target noise in a receive (Rx) band (s), exceeding a target noise for out-of-band transmissions, etc. In order to meet these target noise levels, noise shaping may be employed to ensure that the transmitter design meets or exceeds a spectrum mask that encompasses these targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is a block diagram illustrating an example user equipment (UE) that can be used in conjunction with various aspects described herein.

[0006] Figure 2 is a block diagram illustrating example components of a base station (BS) device (e.g., eNB, gNB, etc.) that may be employed in conjunction with various aspects discussed herein.

[0007] Figure 3 is a diagram illustrating an example of an arbitrary noise shape spectrum that may be satisfied via the noise shaping techniques discussed herein.

[0008] Figure 4 is a pair of graphs showing a comparison between a (idealized) conventional noise shaping technique based on a noise floor with a flat quantization noise and the quantization noise from the noise shaping technique discussed herein.

[0009] Figure 5 is an example graph illustrating the results of applying noise shaping according to aspects discussed herein to a three-carrier signal.

[0010] Figure 6 is a block diagram of a first example noise shaper that can be used to shape noise to satisfy an arbitrary spectral mask in accordance with various aspects discussed herein.

[0011] Figure 7 A pair of block diagrams are shown according to various aspects discussed herein, illustrating a first exemplary two-stage noise shaper and a second exemplary two-stage noise shaper, each of which can be used as a noise shaping filter in a communication device (e.g., a UE or a BS) of a wireless communication system.

[0012] Figure 8 A pair of example graphs depicting the results of applying DAC nonlinearity compensation techniques according to aspects discussed herein are shown.

[0013] Fig. 9 Three block diagrams are shown illustrating various implementations of pyramid encoders that may be used as noise shapers in accordance with various aspects discussed herein.

[0014] Fig.10 A flow chart illustrating an example method of generating a noise shaped signal in accordance with various aspects described herein. DETAILED DESCRIPTION

[0015] The present disclosure will now be described with reference to the accompanying drawings, wherein throughout the text, similar reference numerals are used to refer to similar elements, and the structures and devices shown therein need not be drawn to scale. As used herein, the terms "component", "system", "interface", etc. are intended to refer to entities, hardware, software (e.g., in execution) and / or firmware related to a computer. For example, a component can be a processor (e.g., a microprocessor, a controller, or other processing device), a process running on a processor, a controller, an object, an executable file, a program, a storage device, a computer, a tablet PC, and / or a user device (e.g., a mobile phone, etc.) with a processing device. As an example, an application running on a server and the server can also be a component. One or more components can reside in a process, and a component can be located on a computer and / or distributed between two or more computers. A group of elements or a group of other components can be described here, wherein the term "group" can be interpreted as "one or more".

[0016] In addition, for example, these components can be executed from various computer-readable storage media having various data structures stored thereon, such as using modules. Components can communicate via local and / or remote processes, such as according to signals having one or more data packets (e.g., data from one component interacting with another component in a local system, a distributed system, and / or across a network, such as the Internet, a local area network, a wide area network, or a similar network with other systems via signals).

[0017] As another example, a component may be a device having a specific functionality provided by mechanical parts operated by electrical or electronic circuits, where the electrical or electronic circuits may be operated by a software application or firmware application executed by one or more execution processors. The one or more processors may be internal or external to the device and may execute at least a portion of the software application or firmware application. As yet another example, a component may be a device that provides a specific functionality through electronic components without mechanical parts; the electronic components may include one or more processors therein to execute software and / or firmware that at least partially gives the electronic components functionality.

[0018] The exemplary use of words is intended to present concepts in a concrete way. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X uses A or B" is intended to mean any natural inclusive arrangement. That is, if X uses A; X uses B; or X uses both A and B, then "X uses A or B" is satisfied in any of the foregoing cases. In addition, the articles "a" and "an" used in this application and the appended claims should generally be interpreted to mean "one or more" unless otherwise specified or clear from the context to point to a singular form. Moreover, to the extent the terms "include", "comprise", "have", "contain", "with" or variations thereof are used in the detailed description and claims, these terms are intended to be included in a manner similar to the term "comprising".

[0019] As used herein, the term "circuit" may refer to, be a part of, or include an application specific integrated circuit (ASIC), electronic circuit, processor (shared, dedicated, or grouped), and / or memory (shared, dedicated, or grouped) that executes one or more software or firmware programs, combinational logic circuits, and / or other suitable hardware components that provide the described functionality. In some embodiments, the circuit may be implemented with one or more software or firmware modules, or functions associated with the circuit may be implemented with one or more software or firmware modules. In some embodiments, the circuit may include logic that is at least partially operable in hardware.

[0020] The embodiments described herein may be implemented as a system using any suitably configured hardware and / or software. Figure 1Example components of a user equipment (UE) device 100 are illustrated according to an embodiment. In some embodiments, the UE device 100 may include application circuitry 102, baseband circuitry 104, radio frequency (RF) circuitry 106, front-end module (FEM) circuitry 108, and one or more antennas 110 coupled together at least as shown.

[0021] The application circuitry 102 may include one or more application processors. For example, the application circuitry 102 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to or may include a memory / storage device and may be configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0022] The baseband circuit 104 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The baseband circuit 104 may include one or more baseband processors and / or control logic to process baseband signals received from the receive signal path of the RF circuit 106 and generate baseband signals for the transmit signal path of the RF circuit 106. The baseband processing circuit 104 may interface with the application circuit 102 to generate and process baseband signals and control the operation of the RF circuit 106. For example, in some embodiments, the baseband circuit 104 may include a second generation (2G) baseband processor 104a, a third generation (3G) baseband processor 104b, a fourth generation (4G) baseband processor 104c, and / or other (one or more) baseband processors 104d for other existing generations, generations under development, or generations to be developed in the future (e.g., fifth generation (5G), sixth generation (6G), etc.). The baseband circuit 104 (e.g., one or more of the baseband processors 104a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuit 106. The radio control functions may include, but are not limited to, signal modulation / demodulation, encoding / decoding, radio frequency shifting, and the like. In some embodiments, the modulation / demodulation circuitry of the baseband circuitry 104 may include Fast Fourier Transform (FFT), precoding, and / or constellation mapping / demapping functions. In some embodiments, the encoding / decoding circuitry of the baseband circuitry 104 may include convolution, tail-biting convolution, turbo, Viterbi, and / or Low Density Parity Check (LDPC) encoder / decoder functions. The embodiments of the modulation / demodulation and encoder / decoder functions are not limited to these examples, and may include other suitable functions in other embodiments.

[0023] In some embodiments, the baseband circuit 104 may include elements of a protocol stack, such as elements of an Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and / or radio resource control (RRC) elements. A central processing unit (CPU) 104e of the baseband circuit 104 may be configured to run elements of the protocol stack for signaling at the PHY, MAC, RLC, PDCP, and / or RRC layers. In some embodiments, the baseband circuit 104 may include one or more audio digital signal processors (DSPs) 104f. (One or more) audio DSPs 104f may include elements for compression / decompression and echo cancellation, and may include other appropriate processing elements in other embodiments. The components of the baseband circuit may be appropriately combined in a single chip, in a single chipset, or arranged on the same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuit 104 and the application circuit 102 may be implemented together, for example, on a system on a chip (SOC).

[0024] In some embodiments, the baseband circuit 104 may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuit 104 may support communications with an evolved universal terrestrial radio access network (E-UTRAN) and / or other wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), and wireless personal area networks (WPANs). An embodiment in which the baseband circuit 104 is configured to support radio communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit.

[0025] The RF circuit 106 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuit 106 may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. The RF circuit 106 may include a receive signal path that may include circuitry to down-convert RF signals received from the FEM circuit 108 and provide a baseband signal to the baseband circuit 104. The RF circuit 106 may include a transmit signal path that may include circuitry to up-convert baseband signals provided by the baseband circuit 104 and provide an RF output signal to the FEM circuit 108 for transmission.

[0026] In some embodiments, the RF circuit 106 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuit 106 may include a mixer circuit 106a (used for multiplication of the signal or for sampling the signal), an amplifier circuit 106b, and a filter circuit 106c. The transmit signal path of the RF circuit 106 may include a filter circuit 106c and a mixer circuit 106a. The RF circuit 106 may also include a synthesizer circuit 106d for synthesizing frequencies for use by the mixer circuits 106a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 106a of the receive signal path may be configured to down-convert the RF signal received from the FEM circuit 108 based on the synthesized frequency provided by the synthesizer circuit 106d. The amplifier circuit 106b may be configured to amplify the down-converted signal and the filter circuit 106c may be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the down-converted signal to generate an output baseband signal. The output baseband signal may be provided to the baseband circuit 104 for further processing. In some embodiments, the output baseband signal may be a zero-frequency baseband signal, although this is not a necessary requirement. In some embodiments, the mixer circuit 106a of the receive signal path may include a passive mixer, although the scope of the embodiments is not limited thereto.

[0027] In some embodiments, mixer circuit 106a of the transmit signal path may be configured to up-convert an input baseband signal based on a synthesized frequency provided by synthesizer circuit 106d to generate an RF output signal for FEM circuit 108. The baseband signal may be provided by baseband circuit 104 and may be filtered by filter circuit 106c. Filter circuit 106c may include a low pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0028] In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and / or up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may be arranged for direct down-conversion and / or direct up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may be configured for superheterodyne operation.

[0029] In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited thereto. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuit 106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits, and the baseband circuit 104 may include a digital baseband interface to communicate with the RF circuit 106.

[0030] In some dual-mode embodiments, separate radio IC circuits may be provided to process signals for each spectrum, although the scope of the embodiments is not limited in this regard.

[0031] In some embodiments, synthesizer circuit 106d may be a fractional-N synthesizer or a fractional-N / N+1 synthesizer, although the scope of the embodiments is not limited in this regard, as other types of frequency synthesizers may be appropriate. For example, synthesizer circuit 106d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider.

[0032] Synthesizer circuit 106d may be configured to synthesize an output frequency based on the frequency input and the divider control input for use by mixer circuit 106a of RF circuit 106. In some embodiments, synthesizer circuit 106d may be a fractional-N / N+1 synthesizer.

[0033] In some embodiments, the frequency input may be provided by a voltage controlled oscillator (VCO), although this is not a requirement. Depending on the desired output frequency, the divider control input may be provided by the baseband circuit 104 or the application processor 102. In some embodiments, the divider control input (e.g., N) may be determined from a lookup table based on the channel indicated by the application processor 102.

[0034] The synthesizer circuit 106d of the RF circuit 106 may include a frequency divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N+1 (e.g., based on a carry output) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay element may be configured to decompose the VCO cycle into Nd equal phase packets, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0035] In some embodiments, the synthesizer circuit 106d may be configured to generate a carrier frequency as an output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and divider circuit to generate multiple signals at the carrier frequency with multiple different phases relative to each other. In some embodiments, the output frequency may be an LO frequency (fLO). In some embodiments, the RF circuit 106 may include an IQ / polar converter.

[0036] FEM circuitry 108 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas 110, amplify the received signals, and provide an amplified version of the received signals to RF circuitry 106 for further processing. FEM circuitry 108 may also include a transmit signal path that may include circuitry configured to amplify signals provided for transmission by RF circuitry 106 for transmission by one or more of one or more antennas 110.

[0037] In some embodiments, the FEM circuit 108 may include a TX / RX switch to switch between transmit mode and receive mode operation. The FEM circuit 108 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit 108 may include a low-noise amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., provided to the RF circuit 106). The transmit signal path of the FEM circuit 108 may include a power amplifier (PA) to amplify the input RF signal (e.g., provided by the RF circuit 106), and include one or more filters to generate an RF signal for subsequent transmission (e.g., transmitted by one or more of the one or more antennas 110).

[0038] In some embodiments, the UE device 100 may include additional elements such as memory / storage, displays, cameras, sensors, and / or input / output (I / O) interfaces.

[0039] Reference Figure 2 , illustrates example components of a base station (BS) device (e.g., eNB, gNB, etc.) 200 that can be used in conjunction with various aspects discussed herein. In some embodiments, the BS device 200 may include a digital unit 210 and one or more radio units 220, each of which may be connected to one or more antennas 230. i .

[0040] The digital unit 210 may include a switch 211, a layer 1 (L1) signal processing circuit 212, a layer 2+ (L2+) packet processing circuit 213, and a control and timing circuit 214. The digital unit 210 may perform at least the following functions: (a) switching between various radio units (on a cell tower or roof top) and various baseband cards in the digital unit (e.g., via the switch 211); (b) layer 1 signal processing (e.g., via the L1 signal processing circuit 212), performing modulation / demodulation and forward error correction functions on the actual waveform to be transmitted on different RF carriers and frequency bands; (c) layer 2 scheduling for users (e.g., via the L2+ packet processing circuit 213); (d) layer 2 / layer 3 packet processing (e.g., via the L2+ packet processing circuit 213); (e) control plane processing and timing / synchronization (e.g., via the control and timing circuit 214); and (f) encrypting packets entering the backhaul (e.g., via the control and timing circuit 214).

[0041] Each radio unit 220 may include a digital front end (DFE) signal processing circuit 221, one or more digital-to-analog converters (DAC) 222 associated with (one or more) transmit chains, one or more analog-to-digital converters (ADC) 223 associated with (one or more) receive chains, optional radio frequency (RF) transmit circuits 224 associated with (one or more) transmit chains, optional radio frequency (RF) receive circuits 225 associated with (one or more) receive chains, and RF front end (RF FE) circuits 226. The digital unit 210 may perform at least the following functions: (a) digital front end (DFE) signal processing (performing digital IF carrier combination, crest factor reduction, digital pre-distortion of the power amplifier) ​​(e.g., via DFE signal processing circuit 221); (b) digital-to-analog conversion and analog-to-digital conversion (e.g., via DAC 222 and ADC 223); (c) RF mixing (i.e., modulation) and RF frequency synthesizer; (d) RF front end functions: power amplifier (PA), low noise amplifier (LNA), variable gain amplifier (VGA), filter, switch (TDD) or duplexer (FDD) (e.g., via RF front end circuit 226). In the aspect where the RF transmit circuit 224 and / or the RF receive circuit 225 are omitted, the DAC 222 and / or the ADC 223 may operate at the RF sampling rate, thereby making analog / RF modulation / demodulation unnecessary.

[0042] RF signals may be fed from the radio unit(s) 220 to the antenna 230 i In current radio base stations, the antennas are external, and the industry is working to develop active antenna systems (AAS) with integrated RF and antenna arrays, such as for 5G.

[0043] Various embodiments disclosed herein can generate arbitrary noise shapes that can fit a given spectral mask. Based on the techniques discussed herein, a DAC (digital-to-analog converter) with lower resolution than based on conventional techniques can be used to fit the spectral template. In various aspects, the noise shaper described herein can be used to generate a spectral mask that meets one or more noise thresholds. These noise thresholds can be associated with one or more ACLRs, one or more Rx bands, out-of-band emission targets (e.g., based on legal / regulatory guidance), etc.

[0044] Transmit noise due to DAC quantization causes interference to Rx bands. These Rx bands can be used for receivers with the same radio technology or other technologies (e.g., cellular transmitters with noise entering their own receive bands, global positioning system (GPS) receivers, WiFi receive signals, etc.). Conventionally, this has been mitigated by using expensive front-end filters in both mobile phone (e.g., UE) and base station (e.g., eNB (Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B, evolved Node B, or eNodeB), gNB (Next Generation NodeB, g NodeB, etc.) applications.

[0045] In various embodiments, the techniques discussed herein can be used to perform arbitrary noise shaping of a transmit signal. By introducing arbitrary out-of-band noise shaping, this can allow the use of a coarser DAC than conventional methods for achieving performance similar to that of a high-resolution DAC. In various examples, the arbitrary out-of-band noise shaping can include several Rx notches (e.g., one or more Rx notches (e.g., 2, etc.) for carrier aggregation or for receive bands of other systems). These notches can be designed to have precise shapes, which can include arbitrary bandwidths (BW). In various aspects, noise shaping according to the embodiments discussed herein can be performed in a manner that keeps the Rx noise level the same for various DAC resolutions (e.g., from 8b to 10b). In various aspects discussed herein, arbitrary spectrum masks can be met with less stringent front-end filtering than conventional systems and / or a transmit DAC with a lower resolution than conventional systems, either (or both) of which can reduce complexity and cost.

[0046] In aspects discussed herein, a digital implementation (e.g., may be multiplier-free and may use a lookup table (LUT)) may be employed that may shape the noise into any arbitrary shape. In various aspects, filter taps for noise shaping filters used in various aspects may be pre-computed in the frequency domain to design the inverse of a target shape for filter synthesis from which an impulse response may be derived, which may allow for highly controlled responses in both the Tx band and the Rx band(s). The filter tap values ​​may then be computed in the time domain based on the pre-computed frequency domain shape.

[0047] In various embodiments, the techniques discussed herein may be used in a transmitter that may be designed to meet a spectrum mask that meets various conditions in terms of one or more ACLRs, noise in (one or more) Rx bands, out-of-band emissions, etc. Figure 3, shows an example of an arbitrary noise shape spectrum that can be satisfied via the noise shaping techniques discussed herein (e.g., where the noise shaping filter according to aspects discussed herein can be the inverse of the spectrum). Figure 3 Specific noise spectrum shapes are shown as examples, but in various aspects discussed herein, the relative attenuation of different frequency bands, their location in the frequency domain, width, and transition sharpness may be chosen arbitrarily.

[0048] Figure 3 An example of a spectral mask is shown, illustrating various conditions that may be satisfied by the noise shaping techniques discussed herein. Figure 3 The spectrum mask of shows an example dynamic range (DR, the difference between signal and noise power spectrum levels) defined in various bandwidths (BW) around a specific frequency and in the system BW near the baseband signal and other out-of-band locations. Figure 3 A specific spectral mask is shown for illustration purposes, but the techniques discussed herein can be used for noise shaping to satisfy any spectral mask.

[0049] Reference Figure 4 , shows a comparison between a conventional noise shaping technique based on an (idealized) noise floor with a flat quantization noise at 400 and the quantization noise from the noise shaping technique discussed herein at 410. Both techniques can satisfy Figure 3 spectral mask, but the techniques discussed in this article can satisfy Figure 3 or any spectral mask for a system with less complexity and lower cost (e.g. via a lower resolution DAC and / or less stringent front-end filtering).

[0050] As in Figure 4 As can be seen in FIG. 1 , in various aspects, the noise shaping techniques discussed herein can be used to perform noise shaping of the noise of a Tx (transmit) signal to satisfy various spectral shape characteristics of a spectrum mask. As a first example, the bandwidth (BW) for the Tx signal signal ) may have a frequency region outside of the band below a first noise threshold for out-of-band noise (e.g., Figure 4 The DR shown in OOB ) of the noise (e.g., in dB, etc.), so that the out-of-band noise is below the first noise threshold and within the system bandwidth (BW system ) but in BW signalThe noise other than the first noise threshold may also be equal to or lower than the first noise threshold. In addition, in various aspects, one or more frequency regions may have noise below one or more additional noise thresholds, the one or more additional noise thresholds being lower than the first noise threshold, while other frequency regions may have noise above the one or more additional noise thresholds (but lower than the first noise threshold). As a second example, the system bandwidth (BW system ) may have a noise level lower than a second noise threshold (eg, S system ) to keep ACLR at an acceptable level. As a third example, one or more passband regions may be defined (e.g., the passband regions shown may have the same or different bandwidths, such as Figure 3 and Figure 4 As shown in the figure) (e.g., the passband regions shown may be associated with Rx frequency bands at a BS or UE using aspects discussed herein), each passband region may have an associated threshold value (e.g., the threshold values ​​may be the same or different, e.g., as Figure 3 and 4 As shown), so that the Tx noise in one or more Rx bands (e.g., the Rx bands used by the UE or BS to generate the Tx signal) can have noise equal to or below the relevant threshold. In various aspects, the difference between the first threshold (for out-of-band noise) and the (one or more) associated thresholds (for the Rx band notch or one or more bandpass regions) can be any of the various attenuation values ​​discussed herein or shown in the accompanying drawings (e.g., 40 dB, or less or greater, for example Figure 3 values ​​shown).

[0051] Reference Figure 5 , an example graph showing the results of applying noise shaping according to aspects discussed herein to a three-carrier signal. Figure 5 The signals shown in are 20 MHz LTE carriers centered at 805, 1840, and 2655 MHz (within LTE downlink bands B20, B3, and B7, respectively). Graph 502 shows the power spectrum based on a 6-bit DAC with noise shaping applied in accordance with various aspects discussed herein, graph 504 shows the power spectrum of a 6-bit ideal DAC, and graph 506 shows the power spectrum of a 10-bit ideal DAC. Figure 5 As can be seen, the techniques discussed herein can facilitate noise shaping to meet a given spectral mask using a DAC with lower resolution than conventional techniques.

[0052] In various aspects, the spectral shape characteristics may be met via noise shaping employing the techniques discussed herein, which may be used with a coarser DAC than conventional systems, which may be easier to design than very high resolution DACs. Figure 6 , a first example noise shaper 610 is shown that can be used to shape noise to satisfy an arbitrary spectral mask in accordance with various aspects discussed herein. In various aspects, the noise shaper 610 can be any of a variety of types of noise shapers, such as, for example, delta-sigma, pyramid encoders, etc. as described herein. In various aspects, the filter taps of the noise shaper 610 can be pre-computed in the frequency domain to design the inverse of a target shape for filter synthesis, where an impulse response can be derived from the filter synthesis, which can allow for a highly controlled response in both the Tx band and (one or more) Rx bands. The filter tap values ​​can then be calculated in the time domain based on the pre-computed frequency domain shape. Based on the design of the noise shaper 610, the noise shaper 610 can obtain a desired response from a given input signal x. q (eg, a transmit signal to be transmitted by a transmitter employing the noise shaper 610) to generate a noise shaped output signal y q (For example, a noise-shaped transmit signal to be transmitted by a transmitter employing the noise shaper 610, the noise-shaped output signal y q The spectral mask associated with the design of the noise shaper 610 is satisfied.

[0053] In various aspects, the noise shaper 610 can be a single-stage noise shaper, while in other aspects, the noise shaper 610 can be multiple stages (e.g., two or more stages, such as the following combined Figure 7 The two-stage noise shaper discussed).

[0054] In some aspects, to reduce the complexity of the noise shaper, the B y (For example, B c +B p ) bit quantized B p The least significant bits (LSBs) perform noise shaping, where B c and B p The value of (which may be a positive integer) may vary between embodiments. Figure 7 , a pair of block diagrams of a first example two-stage noise shaper 700 and a second example two-stage noise shaper 750 are shown, each of which can be used as a noise shaping filter in a communication device (e.g., a UE or a BS) of a wireless communication system in accordance with various aspects discussed herein. The example device 700 may include a quantizer 710 (e.g., which may be a conventional or proprietary quantizer, etc.), a noise shaper (e.g., a single stage) 720 (e.g., which may be any type such as delta-sigma or pyramid as described in more detail herein), and an adder 730 i , adder 730i The noise shaped input may be provided to a saturation circuit 740, which may provide an output signal y to the DAC via a saturation algorithm. q .

[0055] It can be shown that the number of bits B of the quantizer 710 c and the number of bits after noise shaping B p can be given by equations (1) and (2), respectively, which are approximate values ​​for low noise:

[0056]

[0057]

[0058] Where P s is the sampling noise power, f s is the sampling noise frequency, DR is the dynamic range (e.g., OOB (out-of-band), etc.), BW is the bandwidth (e.g., system, notch 1, notch 2, signal, etc.), and A is the attenuation caused by noise shaping (e.g., system, notch 1, notch 2, etc.). It can be seen that B p ≤B c , which can take advantage of the attenuation effect in the system and the notch band. Although B p The specific forms include Figure 3-5 A two-notch spectral mask is shown, but similar results can be shown for other spectral masks.

[0059] Quantizer 710 can be used in c q The output is x q B y B c The most significant bit (MSB) (e.g., a floating point signal, or B x bit signal, where B x Can ≥ B y ). Adder 7301 can be used from the transmitted signal x q The output signal c of the quantizer 710 is subtracted from q , to convert the input signal e q (can include signal x q B y B p LSB) is provided to a noise shaper 720 (eg, a delta-sigma, pyramid encoder, etc.). The noise shaper 720 may q Noise shaping is performed to generate a noise shaped output signal p q , the noise-shaped output signal p q can be combined by adder 7302 to generate output signal y qAs the signal x q B y bit version, with B p Noise shaping of 1 LSB.

[0060] B of quantizer 710 c B of the bit and noise shaper 720 p The bit division can depend on the filter properties. p This may allow for lower complexity and may therefore be advantageous (particularly in UE embodiments). As can be seen from Table 1 below, for moderate attenuation (eg 40 dB), a 3-level noise shaper quantization may be performed:

[0061] Table 1: B with different attenuation c and B p Example value of

[0062] NSF Attenuation <![CDATA[Number of bits of DAC (B c + B p )]]> <![CDATA[B c ]]> <![CDATA[B p ]]> 40dB 10 9 1.6 (Level 3) 50dB 9 7 2.3 (Level 5) 60dB 8 5 3, 2 (9 levels)

[0063] Some overlap between the encoding of the quantizer 710 and the noise shaper 720 may be included, which may ensure stability on the part of the noise shaper 720. In one example, the dynamic ranges of the quantizer 710 and the noise shaper 720 may overlap by at least one bit (e.g., n LSBs of the quantizer 710 and n MSBs of the noise shaper 720, where n ≥ 1). Thus, the noise shaper 720 may have a dynamic range of 2 Bp +1 level. The noise added by this overlap can be removed by saturation circuit 740. In the first specific example, B c Can be equal to B v , and the dynamic ranges of the quantizer 710 and the noise shaper 720 may overlap B p A second specific example is shown in Table 2 below, where B x =16, B c =4, B p =3, B y =7:

[0064] Table 2: x q 、c q 、e q 、p q 、c q +p q and q Example place value of

[0065]

[0066]

[0067] The example apparatus 750 may include the components discussed in conjunction with the example apparatus 700, and the example apparatus 750 may additionally include a digital-to-analog converter (DAC) model 712. One feature of the noise shaping technique using a two-stage noise shaper is that the nonlinearity of the DAC may be compensated. By including a DAC response model such as the DAC model 712 (e.g., in the form of a lookup table) at the output of the quantizer 710, the DAC response model 712 may be used to compensate for the nonlinearity of the DAC. c The nonlinear error associated with each MSB can be noise shaped in a manner similar to the quantization noise shaped by the noise shaper 720. c >>B p This method is effective when .

[0068] Reference Figure 8 , shows a pair of example graphs 800 and 810 depicting the results of applying DAC nonlinearity compensation techniques according to aspects discussed herein. Graph 800 shows a signal without DAC compensation, and graph 810 shows a signal based on a signal of the form y=x+0.05x 3 A signal with DAC nonlinearity compensation for a static DAC nonlinearity response. In various aspects, similar techniques can be used in the presence of dynamic nonlinearities.

[0069] Reference Fig. 9 , showing three example implementations of pyramid encoders that may be used as the noise shaper 720, example encoders 900, 902, and 904 according to various aspects discussed herein.

[0070] Each example encoder 902, 904, and 906 may be, for example, at an initial delay element 940 of a set of delay elements. N Receive signal at 940 N The output may be provided to the initial adder 930 of a horizontal, filter-like adder chain N-1 .

[0071] Adder 930 i The associated first received signal (eg, input e, which is the signal from the previous delay element 940) may be i+1 signal) and an associated second received signal (eg, a noise shaping filter tap signal h i ) are combined and can output associated combined signals. All adders 930 except the final adder 9301 i The associated combined signal may be output to the next delay element 940 i .

[0072] The final adder 9301 may output its associated combined signal to a component that may vary depending on the embodiment. For example, in embodiments 900 and 902, the final adder 9301 may output its associated combined signal to a rounding circuit 910. In embodiment 900, the rounding circuit 910 may provide an output signal s as an output of the noise shaper 720, which may be received as an input to a register file (regfile) 922i, which may be used to generate a signal. i The tap signal h can be generated based on the received signal s i In embodiment 902, rounding circuit 910 may provide an output signal i to a lookup table (LUT) 920. LUT , the LUT 920 may correspond to a register file 922 i Or implement positive register file 922 i , and the tap signal h can be generated i and output signal s. In both embodiments 900 and 902, the bit number B p The corresponding register stack 922 i The number of entries in is determined as N, which can be The nearest integer (for example, B p =9 corresponds to the corresponding register file 922 i Embodiment 904 provides a simplified alternative in which the final adder 9301 can output its associated combined signal to M-level (e.g., where M=3 is shown in embodiment 904) quantizers 924. Based on the output of quantizer 924, each tap signal circuit 926 i The corresponding tap signal h i Generates one of M outputs.

[0073] In various aspects, the noise shaper 720 (in various embodiments) can operate a decimated rate while producing noise shaped digital symbols s(k) at an oversampled rate (which can reduce the operating clock frequency of the encoder). The coefficients of the prototype noise shaping filter (e.g., hi, etc.) can be pre-calculated, and the inner products of the codewords of these filter taps can be stored in a lookup table. In the case where decimation is not used in the encoder (e.g., decimation ratio D=1), as shown at 904 in the example with a three-level quantizer, an implementation using delta-sigma modulation can be obtained.

[0074] from Fig. 9As can be seen in , each pyramid encoder embodiment of the noise shaper 720 can be multiplier-less. In the case of delta-sigma modulation, the modulator can operate at full rate.

[0075] To generate arbitrary noise shapes, the response of the filter can be created in the frequency domain. In various aspects, the implementation complexity can be proportional to the number of taps in the noise shaping filter, depending on the selectivity and sharpness of the filter. Using an inverse Fourier transform, the coefficients h(k) of the noise shaping filter can be calculated. To reduce the number of taps (e.g., in UE embodiments where cost and power issues are more relevant), for example in Figure 5 You can create smoother transitions in

[0076] Based on extensive simulations performed in conjunction with various embodiments, it was demonstrated that arbitrary shapes can be achieved and the number, shape and location of the Rx notches (or other spectrum mask characteristics) can be very flexible.

[0077] Reference Fig.10 , a flow chart of an example method 1000 for generating a noise shaping signal according to various aspects described herein is shown. In some aspects, the method 1000 can be performed at a transmitter of a transmitter (e.g., a mobile device such as a UE or an access point such as an eNB or gNB, etc.). In other aspects, a machine-readable medium can store instructions associated with the method 1000, which when executed can cause the transmitter to perform the actions of the method 1000.

[0078] At 1002, a filter input signal x may be received. q (For example, floating point or high resolution (B x bit, etc.)).

[0079] At 1004, noise shaping may be applied to the input signal x q , to generate a noise-shaped output signal y that conforms to a given spectral mask q .

[0080] Additionally or alternatively, method 1000 may include one or more other actions described herein in conjunction with the noise shaping techniques discussed herein.

[0081] Examples herein may include subject matter, such as methods, apparatus for performing actions or blocks of a method, and at least one machine-readable medium including executable instructions that, when executed by a machine (e.g., a processor with memory, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc.), cause the machine to perform actions of a method or apparatus or system for concurrent communication using multiple communication technologies according to the described embodiments and examples.

[0082] Example 1 is an apparatus configured for use in a transmitter, comprising: a noise shaper configured to: receive an input signal x q ; and applying noise shaping to the input signal x q To generate the noise shaped output signal y q , where the noise shaping output signal y q The in-band noise of the noise shaper is lower than the in-band noise threshold of the spectrum mask associated with the noise shaper, wherein the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and wherein the output signal y q Noise in each of the plurality of passband regions is below an associated noise threshold for that passband region in the spectral mask.

[0083] Example 2 includes the subject matter of any variation of any of Example(s) 1, wherein the noise shaper is configured to compensate the input signal x q The nonlinearity of the digital-to-analog converter (DAC) in the

[0084] Example 3 includes the subject matter of any variation of any of Example(s) 1-2, wherein the noise shaper is further configured to apply noise shaping to the input signal x using delta-sigma modulation. q .

[0085] Example 4 includes the subject matter of any variation of any of Example(s) 1-2, wherein the noise shaper is further configured to apply noise shaping to the input signal x using pyramid coding. q .

[0086] Example 5 includes the subject matter of any variation of any of Example 4(s), wherein the noise shaper comprises: a pyramid encoder configured to receive an input signal x comprising the input signal x q B p The least significant bit (LSB) of the signal q , and based on the signal e q and multiple filter taps of the pyramid encoder to generate a Bp bit noise shaping signal p q ; and an adder configured to convert the B p The noise-shaped signal p q With B c Bit signal c q Add together to generate the combined signal c q +p q , the B c Bit signal cq B including the transmitted signal c The noise shaper is configured to generate a noise signal based on the combined signal c q +p q To generate the noise shaped output signal y q .

[0087] Example 6 includes the subject matter of any variation of any of Example 5(s), wherein the noise shaper further comprises a saturation circuit configured to provide a saturation signal to the combined signal c q +p q Apply a saturation algorithm to generate the noise shaped output signal y q .

[0088] Example 7 includes the subject matter of any variation of any of Example(s) 5, wherein B p The noise-shaped signal p q and the B c Bit signal c q Overlap at least one bit.

[0089] Example 8 includes the subject matter of any variation of any of Example(s) 1-2, wherein the noise shaped output signal y q The out-of-band noise of at least a portion of the out-of-band region is above a noise threshold associated with each passband region of the spectral mask.

[0090] Example 9 includes the subject matter of any variation of any of Example(s) 1-2, wherein the noise shaper is configured to apply noise shaping to the input signal x via a plurality of filter taps. q .

[0091] Example 10 includes the subject matter of any variation of any of Example(s) 9, wherein the noise shaper is configured to generate the filter taps based on a lookup table of pre-computed values ​​for the plurality of filter taps.

[0092] Example 11 includes the subject matter of any variation of any of (one or more) Example 9, wherein the noise shaper is configured to generate the filter taps based on an M-level quantizer, wherein M is greater than or equal to 3.

[0093] Example 12 includes the subject matter of any variation of any of Example(s) 5-6, wherein B p The noise-shaped signal p q and B c Bit signal c q Overlap at least one bit.

[0094] Example 13 includes the subject matter of any variation of any of Example(s) 1-6 and 12, wherein the noise shaped output signal y q The out-of-band noise of at least a portion of the out-of-band region is above a noise threshold associated with each passband region of the spectral mask.

[0095] Example 14 includes the subject matter of any variation of any of Example(s) 1-6 or 12-13, wherein the noise shaper is configured to apply noise shaping to the input signal x via a plurality of filter taps. q .

[0096] Example 15 is an apparatus configured for use in a transmitter, comprising: a quantizer configured to receive a signal x q And generate B c Bit signal c q , where B c is a positive integer; the first adder is configured to obtain the signal x from q Subtract the B c Bit signal c q To generate the difference signal e q ; A noise shaper configured to receive the difference signal e q And generate noise shaping B p bit signal p q , where B p is smaller than B c A positive number; and a second adder configured to add the B c Bit signal c q and the noise shaping B p bit signal p q Combined to produce noise shaping B y Bit signal c q +p q , where B y is greater than B c A positive integer.

[0097] Example 16 includes the subject matter of any variation of any of Example(s) 15, further comprising a saturation circuit configured to receive the noise shaping B y Bit signal c q +p q And generate saturated noise shaping B y bit signal y q .

[0098] Example 17 includes the subject matter of any variation of any of Example(s) 15, further comprising a digital-to-analog converter (DAC) model configured to compensate for the input signal x q DAC nonlinearity in .

[0099] Example 18 includes the subject matter of any variation of any of Example(s) 15-17, wherein the noise shaper is further configured to apply noise shaping to the input signal x using delta-sigma modulation. q .

[0100] Example 19 includes the subject matter of any variation of any of Example(s) 15-17, wherein the noise shaper is further configured to apply noise shaping to the input signal x using pyramid coding. q .

[0101] Example 20 includes the subject matter of any variation of any of Example(s) 15-16, further comprising a digital-to-analog converter (DAC) model configured to compensate for the input signal x q DAC nonlinearity in .

[0102] Example 21 includes the subject matter of any variation of any of Example(s) 15-16 or 20, wherein the noise shaper is further configured to apply noise shaping to the input signal x using delta-sigma modulation. q .

[0103] Example 22 includes the subject matter of any variation of any of Example(s) 15-16 or 20, wherein the noise shaper is further configured to apply noise shaping to the input signal x using pyramid coding. q .

[0104] Example 23 is a machine-readable medium comprising instructions that, when executed, cause a transmitter to: receive an input signal x q ; and applying noise shaping to the input signal x q To generate the noise shaped output signal y q , where the noise shaping output signal y q The in-band noise of the noise shaper is lower than the in-band noise threshold of the spectrum mask associated with the noise shaper, wherein the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and wherein the output signal y qNoise in each of the plurality of passband regions is below an associated noise threshold for that passband region in the spectral mask.

[0105] Example 24 includes the subject matter of any variation of any of Example(s) 23, wherein the instructions, when executed, further cause the transmitter to: compensate the input signal x q The nonlinearity of the digital-to-analog converter (DAC) in the

[0106] Example 25 includes the subject matter of any variation of any of Example(s) 23-24, wherein the instructions, when executed, further cause the transmitter to: apply noise shaping to the input signal x using delta-sigma modulation q .

[0107] Example 26 includes the subject matter of any variation of any of Example(s) 23-24, wherein the instructions, when executed, further cause the transmitter to: apply noise shaping to the input signal x using pyramid coding q .

[0108] Example 27 is an apparatus configured for use in a transmitter, comprising: a device for receiving an input signal x q and a device for applying noise shaping to the input signal x q To generate the noise shaped output signal y q The device, wherein the noise shaping output signal y q The in-band noise of the noise shaper is lower than the in-band noise threshold of the spectrum mask associated with the noise shaper, wherein the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and wherein the output signal y q Noise in each of the plurality of passband regions is below an associated noise threshold for that passband region in the spectral mask.

[0109] Example 28 includes the subject matter of any variation of any of Example 27(s), further comprising: compensating the input signal x q A nonlinear device in a digital-to-analog converter (DAC).

[0110] Example 29 includes the subject matter of any variation of any of Example(s) 27-28, wherein the means for applying noise shaping is configured to: apply noise shaping to the input signal x using delta-sigma modulation q .

[0111] Example 30 includes the subject matter of any variation of any of Example(s) 27-28, wherein the means for applying noise shaping is configured to: apply noise shaping to the input signal x using pyramid coding. q .

[0112] The above description of exemplary embodiments of the present disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the disclosed embodiments to the precise forms disclosed. Although specific embodiments and examples are described herein for illustrative purposes, various modifications are contemplated within the scope of these embodiments and examples as those skilled in the relevant art can recognize.

[0113] In this regard, although the disclosed subject matter has been described in conjunction with various embodiments and corresponding drawings, it should be understood that other similar embodiments may be used, or modifications and additions may be made to the described embodiments to perform the same, similar, alternative, or substitute functions as the disclosed subject matter, where applicable, without departing from the subject matter of the present disclosure. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but should be interpreted in accordance with the breadth and scope of the appended claims.

[0114] In particular, with respect to the various functions performed by the above-mentioned components or structures (members, devices, circuits, systems, etc.), the terms used to describe these components (including references to "means for...") correspond to any component or structure that performs the specified function of the described component (e.g., functionally equivalent), unless otherwise specified, even if not structurally equivalent to the disclosed structure that performs the function in the exemplary embodiments shown herein. In addition, although a particular feature may have been disclosed for only one of several embodiments, the feature may be combined with one or more other features of other embodiments, depending on the possible expectations and benefits of any given or particular application.

Claims

1. An apparatus configured for use in a transmitter, comprising: Noise shaper, configured as: Receive input signal x q ; as well as Apply noise shaping to the input signal x q To generate the noise shaped output signal y q , where the noise shaping output signal y q The in-band noise of the noise shaper is lower than the in-band noise threshold of the spectrum mask associated with the noise shaper, wherein the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and wherein the output signal y q noise in each of the plurality of passband regions is below an associated noise threshold for that passband region in the spectral mask, Wherein, the noise shaper comprises: The pyramid encoder is configured to receive an input signal x comprising the q B p The signal of the least significant bit (LSB) q , and based on the signal e q and multiple filter taps of the pyramid encoder to generate B p The noise-shaped signal p q ;and adder, configured to convert the B p The noise-shaped signal p q With B c Bit signal c q Add together to generate the combined signal c q +p q , the B c Bit signal c q Including B that sends the signal c The most significant bit (MSB), The noise shaper is configured to be based on the combined signal c q +p q To generate the noise shaped output signal y q .

2. The apparatus according to claim 1, wherein the noise shaper is configured to compensate the input signal x q The nonlinearity of the digital-to-analog converter (DAC) in the 3. The apparatus of claim 1 , wherein the noise shaper further comprises a saturation circuit configured to provide a saturation signal to the combined signal c q +p q Apply a saturation algorithm to generate the noise shaped output signal y q .

4. The device according to claim 1, wherein the B p The noise-shaped signal p q and the B c Bit signal c q Overlap at least one bit.

5. The device according to any one of claims 1 to 2, wherein: The noise shaped output signal y q The out-of-band noise of at least a portion of the out-of-band regions is above a noise threshold associated with each passband region of the spectrum mask.

6. The device according to any one of claims 1 to 2, wherein: The noise shaper is configured to apply noise shaping to the input signal x via a plurality of filter taps. q .

7. The device according to claim 6, wherein: The noise shaper is configured to generate the filter taps based on a look-up table of pre-computed values ​​for the plurality of filter taps.

8. The device according to claim 6, wherein: The noise shaper is configured to generate the filter taps based on an M-level quantizer, where M is greater than or equal to three.

9. An apparatus configured for use in a transmitter, comprising: Quantizer, configured to receive a signal x q And generate B c Bit signal c q , where B c is a positive integer; The first adder is configured to receive the signal x q Subtract the B c Bit signal c q To generate the difference signal e q ; A noise shaper is configured to receive the difference signal e q And generate noise shaping B p bit signal p q , where B p is smaller than B c A positive number; The second adder is configured to add the B c Bit signal c q and the noise shaping B p bit signal p q Combined to generate noise-shaped B y Bit signal c q +p q , where B y is greater than B c A positive integer of ; and saturation circuit, configured to receive the noise shaping B y Bit signal c q +p q And generate saturated noise shaping B y bit signal y q .

10. The apparatus of claim 9, further comprising a digital-to-analog converter (DAC) model configured to compensate for the signal x q DAC nonlinearity in .

11. The device according to claim 9 or 10, wherein: The noise shaper is further configured to apply noise shaping to the signal x using delta-sigma modulation. q .

12. The device according to claim 9 or 10, wherein: The noise shaper is further configured to apply noise shaping to the signal x using pyramid coding. q .

13. An apparatus configured for use in a transmitter, comprising: To receive the input signal x q Components; For applying noise shaping to the input signal x q To generate the noise shaped output signal y q components, wherein the noise shaping output signal y q The in-band noise of the noise shaper is lower than the in-band noise threshold of the spectrum mask associated with the noise shaper, wherein the noise shaped output signal y q The out-of-band noise is lower than the out-of-band noise threshold of the spectrum mask, and wherein the output signal y q noise in each of the plurality of passband regions is below an associated noise threshold for that passband region in the spectral mask; For receiving an input signal x comprising q B p The signal of the least significant bit (LSB) q , and based on the signal e q and multiple filter taps to generate B p The noise-shaped signal p q Components; For the B p The noise-shaped signal p q With B c Bit signal c q Add together to generate the combined signal c q +p q The components of B c Bit signal c q Including B that sends the signal c Most Significant Bits (MSBs); and For based on the combined signal c q +p q To generate the noise shaped output signal y q components.

14. The apparatus according to claim 13, further comprising: To compensate the input signal x q Nonlinear components in the digital-to-analog converter (DAC).

15. The apparatus according to claim 13 or 14, wherein the component for applying noise shaping is configured to apply noise shaping to the input signal x using delta-sigma modulation. q .

16. The apparatus according to claim 13 or 14, wherein the component for applying noise shaping is configured to apply noise shaping to the input signal x using pyramid coding. q .

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