Method and an apparatus for physical uplink control channel (PUCCH) discontinuous transmission (DTX) determination in a wireless communication system

Abstract

Described is a method and apparatus for processing an uplink (UL) signal at a Physical Uplink Control Channel (PUCCH) in a wireless communication system to determine a discontinuous transmission (DTX) state. The method comprises receiving a UL channel signal at a PUCCH receiver apparatus and, after resource element (RE) demapping of said received UL channel signal in said PUCCH receiver apparatus, normalizing a signal power of at least one signal element or resource. The normalized power is compared to a selected, calculated or predetermined threshold and, based on said comparison, a determination is made on whether or not a DTX state has occurred.

Claims

1. A method of processing an uplink (UL) channel signal in a wireless communication system to determine a discontinuous transmission (DTX) state, the method comprising the steps of: receiving a UL channel signal at a Physical Uplink Control Channel (PUCCH) receiver apparatus; after resource element (RE) demapping of said received UL channel signal in said PUCCH receiver apparatus, normalizing a signal power of at least one signal element or resource; comparing said normalized signal power of said at least one signal element or resource to a selected, calculated or predetermined threshold; and, based on said comparison, determining whether or not a DTX state has occurred; wherein, if, based on a comparison of said normalized signal power of said at least one signal element or resource to said selected, calculated or predetermined threshold, it is determined that a DTX state has occurred then terminating processing of said received UL channel signal to obtain any uplink control information (UCI); wherein the step of terminating processing of said received UL channel signal to obtain any UCI data is implemented before equalization of the received UL channel signal in the PUCCH receiver apparatus.

2. The method of claim 1, wherein the signal power of said at least one signal element or resource is normalized to a constant level.

3. The method of claim 1, wherein the step of normalizing signal power of at least one signal element or resource is implemented before equalization or channel decoding of the received UL channel signal in the PUCCH receiver apparatus.

4. The method of claim 1, wherein the step of normalizing signal power of at least one signal element or resource is implemented before UCI data detection processing of the received UL channel signal in the PUCCH receiver apparatus.

5. The method of claim 1, comprising the steps of: where present, de-spreading a data signal, a reference signal (RS) and/or a spreading sequence for each HARQ/SR value in the RE demapped UL channel signal to provide de-spreading outputs for the data signal, the RS and/or the spreading sequence for each HARQ/SR value; and calculating a normalized power for one or more of the de-spreading outputs.

6. The method of claim 5, comprising the steps of: calculating a normalized power for a plurality of the de-spreading outputs; combining the normalized powers for at least some of said plurality of the de-spreading outputs; comparing the combined normalized power for at least some of said plurality of the de-spreading outputs to said selected, calculated or predetermined threshold; and, based on said comparison, determining whether or not a DTX state has occurred.

7. The method of claim 6, wherein combining the normalized power of some or all of the de-spreading outputs is given by the following equation and some or all of the normalized powers are selected for combining: $\tilde{P}=\underset{i\in S_{\mathrm{rx}}}{.Math.}\underset{t\in S_{\mathrm{trsc}}}{.Math.}\underset{f\in S_{\mathrm{fh}}}{.Math.}\underset{\mathrm{.Math.}\in S_{\mathrm{sig}}}{.Math.}\underset{n\in S_{\mathrm{op}}}{.Math.}{\stackrel{\_}{P}}_{i,t,f}^{\mathrm{.Math.}}\left(n\right)$ where i comprises a receive antenna index; t comprises a transmission resource index, where present; f comprises a frequency hop index; ε comprises a signal type; n comprises a signal index for a selected signal type; S.sub.rx.Math.U.sub.rx, U.sub.rx={0, 1, . . . , N.sub.rx−1} comprises a set of receive antennas; N.sub.rx is the number of receive antennas; S.sub.trsc.Math.U.sub.trsc, U.sub.trsc comprises a set of transmission resources, if present; S.sub.fh.Math.U.sub.fh, U.sub.fh comprises a set of frequency hops; S.sub.sig.Math.U.sub.sig, U.sub.sig={data signal, DMRS signal, spreading sequence, if present} comprises a set of signal types for de-spreading output signals; S.sub.op.Math.U.sub.op, U.sub.op={0, 1, . . . , N.sub.i,t,f.sup.ε1} comprises a set of de-spreading outputs of signal type ε for receive antenna i, transmission resource t, frequency hop f, and N.sub.i,t,f.sup.ε is the total number of signal elements in a specific resource comprising any of a receive antenna i. transmission resource t, frequency hop f, and/or signal type ε.

8. The method of claim 7, comprising selecting a combination of available signal elements or resources dependent on a level of computational complexity.

9. The method of claim 5, wherein, for 5G NR PUCCH Format 0, a maximum normalized power amongst normalized powers for all candidate HARQ/SR values is compared to said selected, calculated or predetermined threshold; and, based on said comparison, determining whether or not a DTX state has occurred.

10. The method of claim 5, wherein the normalized power for one or more of the de-spreading outputs is calculated based on a corresponding noise variance and a spreading factor for selected resources.

11. The method of claim 5, wherein the normalized power for the de-spreading outputs is given by the equation: $\overline{P}=\frac{{.Math.x.Math.}^2}{\frac{{\sigma }^2}{\alpha }}=\frac{\alpha .Math.{.Math.x.Math.}^2}{{\sigma }^2}$ where x is the de-spreading output for a data signal, an RS signal or a spreading sequence in a selected BS receive antenna, frequency hop and transmit resource, if present; σ.sup.2 is the noise variance in the corresponding radio bearer of said receive antenna; and α is the spreading factor.

12. The method of claim 11, wherein the noise variance σ.sup.2 is obtained from a long-term evaluation of other UL channel blocks.

13. The method of claim 5, wherein obtaining the pre-determined threshold δ for DTX detection is defined by the equation: $\delta =\beta .Math.{\gamma }^{-1}\left(N_e,{\left(1-P_{\mathrm{DTX}}\right)}^{\frac{1}{N_{s\mathrm{rc}}}}\right)$ where γ.sup.−1(.Math.) comprises an inverse lower incomplete gamma function; P.sub.DTX comprises one of: Pr(FA) where FA=“false alarm”, 2Pr(DTX.fwdarw.ACK) or Pr(DTX.fwdarw.TX); N.sub.e comprises a number of combined signal elements or resources; β comprises the adjust factor; N.sub.src is given by: (1) for NR PUCCH Format 0, it comprises a number of candidate HARQ-ACK/SR values: (i) N.sub.src=1, where only SR is reported; (ii) N.sub.src=2, where 1 bit ACK/NACK is reported; (iii) N.sub.src=4, where 2 bit ACK/NACK or 1 bit ACK/NACK plus SR is reported; (iv) N.sub.src=8, where 2 bit ACK/NACK plus SR is reported; or (2) for all LTE PUCCH Formats and NR PUCCH Formats 1, 2, 3 and 4: N.sub.src=1.

14. The method of claim 13, wherein a determination of DTX is made when: {tilde over (P)}≤δ for all PUCCH Formats except 5G NR PUCCH Format 0; max{tilde over (P)}≤δ for NR PUCCH Format 0, where maxP comprises a maximum normalized power amongst normalized powers for all candidate HARWSR values; otherwise normal transmission is determined.

15. A Physical Uplink Control Channel (PUCCH) receiver apparatus in a wireless communication system, the PUCCH receiver apparatus comprising: a memory storing machine-readable instructions; and a processor for executing the machine-readable instructions such that, when the processor executes the machine-readable instructions, it configures the PUCCH receiver apparatus to determine a discontinuous transmission (DTX) state by implementing the steps of: receiving a UL channel signal at said PUCCH receiver apparatus; after resource element (RE) demapping of said received UL channel signal in said PUCCH receiver apparatus, normalizing a signal power of at least one signal element or resource; comparing said normalized signal power of said at least one signal element or resource to a selected, calculated or predetermined threshold; and, based on said comparison, determining whether or not a DTX state has occurred; wherein, if, based on a comparison of said normalized signal power of said at least one signal element or resource to said selected, calculated or predetermined threshold, it is determined that a DTX state has occurred then terminating processing of said received UL channel signal to obtain any uplink control information (UCI); wherein the step of terminating processing of said received UL channel signal to obtain any UCI data is implemented before equalization of the received UL channel signal in the PUCCH receiver apparatus.

16. A non-transitory computer-readable medium storing machine-readable instructions, wherein, when the machine-readable instructions are executed by a processor, they configure a Physical Uplink Control Channel (PUCCH) receiver apparatus in a wireless communications system to determine a discontinuous transmission (DTX) state in an uplink (UL) channel by implementing the steps of: receiving a UL channel signal at said PUCCH receiver apparatus; after resource element (RE) demapping of said received UL channel signal in said PUCCH receiver apparatus, normalizing a signal power of at least one signal element or resource; comparing said normalized signal power of said at least one signal element or resource to a selected, calculated or predetermined threshold; and, based on said comparison, determining whether or not a DTX state has occurred; wherein, if, based on a comparison of said normalized signal power of said at least one signal element or resource to said selected, calculated or predetermined threshold, it is determined that a DTX state has occurred then terminating processing of said received UL channel signal to obtain any uplink control information (UCI); wherein the step of terminating processing of said received UL channel signal to obtain any UCI data is implemented before equalization of the received UL channel signal in the PUCCH receiver apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figures, of which:

(2) FIG. 1 is a signal diagram illustrating message exchanges between a BS and a UE for retransmission of control data and payload data;

(3) FIG. 2 is a signal diagram illustrating errant transmission of control data and payload data from a BS to a UE when a PUCCH receiver apparatus at the BS determines a false ACK message;

(4) FIG. 3 identifies LTE and 5G NR PUCCH Formats relevant to the present invention and UCI information associated with said signal formats;

(5) FIG. 4 is a schematic diagram showing a conventional PUCCH receiver apparatus for a wireless communications system;

(6) FIG. 5 is a block schematic diagram of an embodiment of a PUCCH receiver apparatus in accordance with the invention;

(7) FIG. 6 is a block schematic diagram of the PUCCH receiver apparatus of FIG. 5 comprising a combination of connected functional modules;

(8) FIG. 7 illustrates the probability density function for the normalization of the noise power from different elements or resources to a standard normal distribution;

(9) FIG. 8 illustrates spreading of the UL channel signal for LTE PUCCH Format 1 in a UE transmitter to derive the spreading factor; and

(10) FIG. 9 is the cumulative distribution function for determination of the theoretical threshold δ.

DESCRIPTION OF PREFERRED EMBODIMENTS

(11) The following description is of preferred embodiments by way of example only and without limitation to the combination of features necessary for carrying the invention into effect.

(12) Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments, but not other embodiments.

(13) It should be understood that the elements shown in the FIGS, may be implemented in various forms of hardware, software or combinations thereof. These elements may be implemented in a combination of hardware and software on one or more appropriately programmed general-purpose devices, which may include a processor, memory and input/output interfaces.

(14) The present description illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope.

(15) Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

(16) Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of systems and devices embodying the principles of the invention.

(17) The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (“DSP”) hardware, read-only memory (“ROM”) for storing software, random access memory (“RAM”), and non-volatile storage.

(18) In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements that performs that function or b) software in any form, including, therefore, firmware, microcode or the like, combined with appropriate circuitry for executing that software to perform the function. The invention as defined by such claims resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein.

(19) The invention relates to a generic DTX detection or determination method for different PUCCH Formats for both of at least LTE and 5G NR communications systems in which the BS can make early and efficient DTX detection without needing to implement the whole conventional DTX detection process or complete the UCI data acquisition process. The BS needs to have a DTX determination capability to be able to distinguish DTX from normal transmission.

(20) FIG. 5 shows an exemplary embodiment of an improved PUCCH receiver apparatus 100 for a BS in accordance with concepts of the present invention. In the illustrated embodiment, the PUCCH receiver apparatus 100 may comprise communication equipment such as a network node, a network card, or a network circuit communicatively connected to or forming part of a BS 105 (denoted by dashed-line box in FIG. 5), etc. operating in any of an LTE or 5G NR communications system environment 115 or a communications system environment exhibiting similar UL channel characteristics to an LTE or 5G NR communications system. The BS 105 communicates with one or more UEs 125 located within its cell area.

(21) The PUCCH receiver apparatus 100 may comprise a plurality of functional blocks for performing various functions thereof. For example, the PUCCH receiver apparatus 100 includes PUCCH receiver module 110 providing received signal processing and configured to provide received signals and/or information extracted therefrom to functional block module(s) 120 such as may comprise various data sink, control element(s), user interface(s), etc. Although PUCCH receiver module 110 is described as providing received signal processing, it will be appreciated that this functional block may be implemented as a transceiver providing both transmitted and received signal processing. Irrespective of the particular configuration of PUCCH receiver module 110, embodiments include signal detection module 130 disposed in association with the PUCCH receiver module 110 for facilitating accurate processing and/or decoding of a received channel signal in accordance with the invention. Channel signals may be received via an antenna module 103.

(22) Although the signal detection module 130 is shown as being deployed as part of the PUCCH receiver module 110 (e.g. comprising a portion of the PUCCH receiver module control and logic circuits), there is no limitation to such a deployment configuration according to the concepts of the invention. For example, the signal detection module 130 may be deployed as a functional block of PUCCH receiver apparatus 100 that is distinct from, but connected to, PUCCH receiver module 110. The signal detection module 130 may, for example, be implemented using logic circuits and/or executable code/machine readable instructions stored in a memory 140 of the PUCCH receiver apparatus 100 for execution by a processor 150 to thereby perform functions as described herein. For example, the executable code/machine readable instructions may be stored in one or more memories 140 (e.g. random access memory (RAM), read only memory (ROM), flash memory, magnetic memory, optical memory or the like) suitable for storing one or more instruction sets (e.g. application software, firmware, operating system, applets, and/or the like), data (e.g. configuration parameters, operating parameters and/or thresholds, collected data, processed data, and/or the like), etc. The one or more memories 140 may comprise processor-readable memories for use with respect to one or more processors 150 operable to execute code segments of signal detection module 130 and/or utilize data provided thereby to perform functions of the signal detection module 130 as described herein. Additionally, or alternatively, the signal detection module 130 may comprise one or more special purpose processors (e.g. application specific integrated circuit (ASIC), field programmable gate array (FPGA), graphics processing unit (GPU), and/or the like) configured to perform functions of the signal detection module 130 as described herein.

(23) FIG. 6 schematically illustrates the improved PUCCH receiver apparatus 100 implemented as a combination of connected functional modules of the kind comprising the conventional PUCCH receiver apparatus 10 of FIG. 4 where like modules in FIG. 6 to those of the conventional PUCCH receiver apparatus 10 of FIG. 4 are denoted by the same numerals but preceded by the numeral ‘2’. It will be understood that the functional modules of FIG. 6 could be implemented by any one or any combination of the PUCCH receiver module 110, signal detection module 130 and/or the functional block modules 120 of the apparatus 100 of FIG. 5.

(24) The improved PUCCH receiver apparatus 100 of FIG. 6 comprises a CP removal and fast Fourier transform (FFT) module 215, an RE demapper module 220, an IDFT module 225 but only if required for some specified LTE and 5G NR PUCCH Formats, a signal de-spreading module 230 but also only if required for some specified LTE and 5G NR PUCCH Formats, a channel estimation module 235, a noise estimation module 240, an equalizer module 245, a demodulation and descrambling module 250 and a UCI channel decoding stage or module 255. The channel estimation module 235, the noise estimation module 240, the equalizer module 245, the demodulation and descrambling module 250 and the UCI channel decoding stage or module 255 comprise the UCI data detection modules 260 of the PUCCH receiver apparatus 100.

(25) In contrast to the conventional PUCCH receiver apparatus 10 of FIG. 4, the PUCCH receiver apparatus 100 in accordance with the invention extracts, as shown in FIG. 6, the UL channel signal after it has been processed in the RE demapper module 220 but prior to UCI data detection in the UCI data detection modules 260 and, more specifically, prior to equalization in the equalizer module 245. The PUCCH receiver apparatus 100 is configured to firstly normalize a signal power of at least one signal element or resource of the RE demapped UL channel signal. A DTX determination module 265 comprising a power calculation and normalization module 270, a power combination module 275 (for some but not embodiments), and a DTX comparison and decision module 280 is provided to process the RE demapped UL channel signal. A power calculation and normalization module 270 is provided for calculating the power of the at least one signal element or resource and normalizing the power of said at least one signal element or resource. As such, the RE demapped UL channel signal is diverted to an input of this module 270. The normalized signal power of said at least one signal element or resource is compared to a selected, calculated or predetermined threshold δ in the DTX comparison and decision module 280 and, based on said comparison, the DTX comparison and decision module 280 makes a determination of whether or not a DTX state has occurred on the UL between the UE 125 and BS 105 or whether the UL can be considered as operating under normal transmission.

(26) One significant advantage of the improved DTX determination method and apparatus in accordance with the invention is that, if, based on said comparison of the normalized signal power of said at least one signal element or resource to said selected, calculated or predetermined threshold δ, it is determined that a DTX state has indeed occurred then processing of said received UL channel signal to obtain any uplink control information (UCI) can be terminated. Advantageous results include that: a DTX determination is made with low latency of processing of the received UL channel signal even if said channel signal only comprises noise—this is especially useful in 5G NR URLLC applications; DTX determination is more efficient; and processing resources of the UCI data detection modules 260 are not needlessly wasted. Furthermore, the improved DTX determination method in accordance with the invention is generic to multiple LTE and 5G NR PUCCH Formats as will be more fully described hereinbelow.

(27) The signal power of the at least one signal element or resource is preferably normalized to a standard normal distribution. Furthermore, in some embodiments, the signal powers of selected combinations of signal elements or resources are normalized and their normalized powers then combined in the optional power combination module 275 to provide a combined normalized power value which is passed to the DTX comparison and decision module 280 to compare said combined normalized power value to the selected, calculated or predetermined threshold δ from which a DTX determination is then made. The selected combinations of signal elements or resources may be selected from some or all of signal types, BS receive antennas, transmission resources (for LTE-A only) and frequency hops. The power of the a signal element or resource may be normalized with respect to noise variance of different BS receive antennas and/or the spreading factor for different signal types only where the UL channel signal is subject to de-spreading in the PUCCH receiver apparatus 100. The noise variance σ.sup.2 may be obtained from a long-term evaluation of UL channel blocks but it will be understood that any suitable method of obtaining noise variance values may be implemented.

(28) Taking the case where the received UL channel signal is subject to de-spreading by the de-spreading module 230, FIG. 7 illustrates the probability density function for the normalization of the signal power from different elements or resources to a standard normal distribution. The normalized power for any resulting de-spreading outputs from the de-spreading module 230 is given by the equation:

(29) $\overline{P}=\frac{{.Math.x.Math.}^2}{\frac{{\sigma }^2}{\alpha }}=\frac{\alpha .Math.{.Math.x.Math.}^2}{{\sigma }^2}$
where x is the de-spreading output for any of, as appropriate, a data signal, an RS signal or a spreading sequence (only for 5G NR PUCCH Format 0) for a selected or specified BS receive antenna, frequency hop and transmit resource (only for LTE-A). σ.sup.2 is the noise variance in the corresponding radio bearer of said receive antenna and a is the spreading factor in the current frequency hop. The final spreading factor α should take into account both the frequency and the time domain as illustrated in FIG. 8 for, by way of example only, LTE PUCCH Format 1. FIG. 8 illustrates spreading of the UL channel signal for LTE PUCCH Format 1 in a UE transmitter and, based on the transmitter scheme, to derive the spreading factor. Consequently, the method includes, where necessary, de-spreading a data signal, a reference signal (RS) and/or a spreading sequence for each HARQ/SR value in the RE demapped UL channel signal to provide de-spreading outputs for the data signal, the RS and/or the spreading sequence for each HARQ/SR value. Normalized powers for one or more of the de-spreading outputs from the de-spreading module 230 are provided by the power calculation and normalization module 270.

(30) In some embodiments therefore, the method may include calculating normalized powers for a plurality of the de-spreading outputs in module 270 and then combining said normalized powers for at least some of said plurality of the de-spreading outputs in the power combination module 275. This provides a single combined normalization value which can be compared to the threshold δ in the DTX comparison and decision module 280 in order to make a DTX determination.

(31) Combining the normalized power of some or all of the de-spreading outputs is given by the following equation and some or all of the normalized powers are selected for combining:

(32) $\tilde{P}=\underset{i\in S_{\mathrm{rx}}}{.Math.}\underset{t\in S_{\mathrm{trsc}}}{.Math.}\underset{f\in S_{\mathrm{fh}}}{.Math.}\underset{\mathrm{.Math.}\in S_{\mathrm{sig}}}{.Math.}\underset{n\in S_{\mathrm{op}}}{.Math.}{\stackrel{\_}{P}}_{i,t,f}^{\mathrm{.Math.}}\left(n\right)$

(33) where i comprises a receive antenna index;

(34) t comprises a transmission resource index, where present;

(35) f comprises a frequency hop index;

(36) ε comprises a signal type;

(37) n comprises a signal index for a selected signal type;

(38) S.sub.rx.Math.U.sub.rx, U.sub.rx={0, 1, . . . , N.sub.rx−1} comprises a set of receive antennas;

(39) N.sub.rx is the number of receive antennas;

(40) S.sub.trsc.Math.U.sub.trsc, U.sub.trsc comprises a set of transmission resources, if present;

(41) S.sub.fh.Math.U.sub.fh, U.sub.fh comprises a set of frequency hops;

(42) U.sub.sig.Math.U.sub.sig, U.sub.sig={data signal, DMRS signal, spreading sequence, if present} comprises a set of signal types for de-spreading output signals;

(43) S.sub.op.Math.U.sub.op, U.sub.op={0, 1, . . . , N.sub.i,t,f.sup.s−1} comprises a set of de-spreading outputs of signal type ε for receive antenna i, transmission resource t, frequency hop f, and

(44) N.sub.i,t,f.sup.s is the total number of signal elements in the specific resource.

(45) Resources refer to receive antenna i. transmission resource t, frequency hop f, and signal type ε.

(46) A selection of a combination of available signal elements or resources may be based on a degree of computational complexity in processing said selected combination, it being desirable to maintain an efficient level of computational complexity.

(47) In the case of 5G NR PUCCH Format 0, it is preferred not to combine normalization powers to obtain a single combined normalization power but instead top use a maximum normalized power amongst normalized powers for some or all candidate HARQ/SR values. The maximum normalized power then passed to the DTX comparison and decision module 280 to be compared to the threshold δ and, based on the comparison result, making a determination of whether or not a DTX state has occurred.

(48) Preferably, the pre-determined threshold δ for DTX detection comprises a theoretical threshold δ defined by the equation:

(49) $\delta =\beta .Math.{\gamma }^{-1}\left(N_e,{\left(1-P_{\mathrm{DTX}}\right)}^{\frac{1}{N_{s\mathrm{rc}}}}\right)$

(50) where γ.sup.−1(.Math.) comprises an inverse lower incomplete gamma function; and

(51) P.sub.DTX is a probability that DTX has occurred and comprises one of: Pr(FA) where FA=“false alarm”, 2Pr(DTX.fwdarw.ACK) or Pr(DTX.fwdarw.TX);

(52) N.sub.e comprises a number of combined signal elements or resources;

(53) β comprises the adjust factor;

(54) N.sub.src is given by:

(55) (1) for NR PUCCH Format 0, it comprises a number of candidate HARQ-ACK/SR values: (i) N.sub.src=1, where only SR is reported;

(56) (ii) N.sub.src=2, where 1 bit ACK/NACK is reported; (iii) N.sub.src=4, where 2 bit ACK/NACK or 1 bit ACK/NACK plus SR is reported; (iv) N.sub.src=8, where 2 bit ACK/NACK plus SR is reported; or
(2) for all LTE PUCCH Formats and NR PUCCH Formats 1, 2, 3 and 4: N.sub.src=1.

(57) The foregoing leads to a probability of DTX defined by:
P.sub.DTX=1−[Pr({tilde over (P)}≤δ)].sup.N.sup.src

(58) where Pr({tilde over (P)}≤δ)] denotes the probability of {tilde over (P)}≤δ.

(59) Consequently, a determination of DTX can be made when: {tilde over (P)}≤δ for all PUCCH Formats except 5G NR PUCCH Format 0; and max{tilde over (P)}=δ for NR PUCCH Format 0, where maxP comprises a maximum normalized power amongst normalized powers for all candidate HARQ/SR values; otherwise normal transmission is determined.

(60) For foregoing example of FIG. 8, the measure of theoretical threshold δ is illustrated by FIG. 9 which comprises a Chi-squared distribution:
{tilde over (P)}˜X.sup.2(N.sub.e)

(61) The present invention enables a selection of any combinations of available elements or resources based on computational complexity for both LTE and 5G NR.

(62) The following scenarios apply to specified LTE and 5G NR PUCCH Formats.

(63) For LTE Normal PUCCH Format 1/1a/1b for normal CP, calculating the normalized power for the de-spreading outputs can be applied to LTE Normal PUCCH Format 1/1a/1b for normal CP with α=48 in the first and second frequency hop when x is the de-spreading output of the data signal, and α=36 in the first and second frequency hop when x is the de-spreading output of the RS signal.

(64) For LTE Normal PUCCH Format 1/1a/1b for extended CP, calculating the normalized power for the de-spreading output can be applied to LTE Normal PUCCH Format 1/1a/1b for extended CP with α=48 in the first and second frequency hop when x is the de-spreading output of data, and α=24 in the first and second frequency hop when x is the de-spreading output of the RS signal.

(65) For LTE Shortened PUCCH Format 1/1a/1b for normal CP, calculating the normalized power for the de-spreading output can be applied to LTE Shortened PUCCH Format 1/1a/1b for normal CP with α=48 in the first frequency hop and α=36 in the second frequency hop when x is the de-spreading output of the data signal, and α=36 in the first and second frequency hop when x is the de-spreading output of the RS signal.

(66) For LTE Shortened PUCCH Format 1/1a/1b for extended CP, calculating the normalized power for the de-spreading output can be applied to LTE Shortened PUCCH Format 1/1a/1b for extended CP with α=48 in the first frequency hop and α=36 in the second frequency hop when x is the de-spreading output of the data signal, and α=24 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(67) For LTE PUCCH Format 2/2a/2b for normal CP, calculating the normalized power for the de-spreading output can be applied to LTE PUCCH Format 2/2a/2b for normal CP with α=12 in the first and second frequency hops when x is the de-spreading output of the data signal, and α=24 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(68) For LTE PUCCH Format 2 for extended CP, calculating the normalized power for the de-spreading output can be applied to LTE PUCCH Format 2 for extended CP with α=12 in the first and second frequency hops when x is the de-spreading output of the data signal, and α=12 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(69) For LTE Normal PUCCH Format 3 for normal CP, calculating the normalized power for the de-spreading output can be applied to LTE Normal PUCCH Format 3 for normal CP with α=5 in the first and second frequency hops when x is the de-spreading output of the data signal, and α=24 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(70) For LTE Normal PUCCH Format 3 for extended CP, calculating the normalized power for the de-spreading output can be applied to LTE Normal PUCCH Format 3 for extended CP with α=5 in the first and second frequency hops when x is the de-spreading output of the data signal, and α=12 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(71) For LTE Shortened PUCCH Format 3 for normal CP, calculating the normalized power for the de-spreading output can be applied to LTE Shortened PUCCH Format 3 for normal CP with α=5 in the first frequency hop and α=4 in second frequency hop when x is the de-spreading output of the data signal, and α=24 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(72) For LTE Shortened PUCCH Format 3 for extended CP, calculating the normalized power for the de-spreading output can be applied to LTE Shortened PUCCH Format 3 for extended CP with α=5 in the first frequency hop and α=4 in the second frequency hop when x is the de-spreading output of the data signal, and α=12 in the first and second frequency hops when x is the de-spreading output of the RS signal.

(73) For 5G NR PUCCH Format 0, calculating the normalized power for the de-spreading output can be applied for NR PUCCH Format 0 with a according to Table 1 below:

(74) TABLE-US-00001 TABLE 1 Spreading factor α Number of symbols No hopping Hopping (α.sub.1, α.sub.2) 1 12 Invalid in Standard 2 12 12, 12

(75) For 5G NR PUCCH Format 1, calculating the normalized power for the de-spreading output can be applied for NR PUCCH Format 1 with α. The spreading factor α for the data signal and the RS signal is according to Table 2 below:

(76) TABLE-US-00002 TABLE 2 Spreading Spreading Number factor α for data signal factor α for RS signal of symbols No hopping Hopping (α.sub.1, α.sub.2) No hopping Hopping (α.sub.1, α.sub.2) 4 24 12, 12 24 12, 12 5 24 12, 12 36 12, 24 6 36 12, 24 36 24, 12 7 36 12, 24 48 24, 24 8 48 24, 24 48 24, 24 9 48 24, 24 60 24, 36 10 60 24, 36 60 36, 24 11 60 24, 36 72 36, 36 12 72 36, 36 72 36, 36 13 72 36, 36 84 36, 48 14 84 36, 48 84 48, 36

(77) For 5G NR PUCCH Format 2, calculating the normalized power for the de-spreading output can be applied for NR PUCCH Format 2 with α. The spreading factor α is according to Table 3 below:

(78) TABLE-US-00003 TABLE 3 Number Spreading Spreading of factor α for data signal factor α for RS signal symbols No hopping Hopping (α.sub.1, α.sub.2) No hopping Hopping (α.sub.1, α.sub.2) 1 1 Invalid in 1 Invalid in Standard Standard 2 1 1, 1 1 1, 1

(79) For 5G NR PUCCH Format 3, calculating the normalized power for the de-spreading output can be applied for NR PUCCH Format 3 with α=1 when x is the de-spreading output of the data signal, and α=1 when x is the de-spreading output of the RS signal.

(80) For 5G NR PUCCH Format 4, calculating the normalized power for the de-spreading output can be applied for NR PUCCH Format 4 with α=N.sub.SF.sup.PUCCH,4 when x is the de-spreading output of the data signal, and α=12 when x is the de-spreading output of the RS signal and in which N.sub.SF.sup.PUCCH,4 is the length of an orthogonal cover code used in NR PUCCH Format 4.

(81) The present invention also provides a PUCCH receiver apparatus comprising a memory storing machine-readable instructions and a processor for executing the machine-readable instructions such that, when the processor executes the machine-readable instructions, it configures the PUCCH receiver apparatus to implement the method in accordance with the invention.

(82) The present invention also provides a non-transitory computer-readable medium storing machine-readable instructions, wherein, when the machine-readable instructions are executed by a processor, they configure a PUCCH receiver apparatus to implement the method in accordance with the invention.

(83) The apparatus described above may be implemented at least in part in software. Those skilled in the art will appreciate that the apparatus described above may be implemented at least in part using general purpose computer equipment or using bespoke equipment.

(84) Here, aspects of the methods and apparatuses described herein can be executed on any apparatus comprising the communication system. Program aspects of the technology can be thought of as “products” or “articles of manufacture” typically in the form of executable code and/or associated data that is carried on or embodied in a type of machine readable medium. “Storage” type media include any or all of the memory of the mobile stations, computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives, and the like, which may provide storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunications networks. Such communications, for example, may enable loading of the software from one computer or processor into another computer or processor. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links or the like, also may be considered as media bearing the software. As used herein, unless restricted to tangible non-transitory “storage” media, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution.

(85) While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.

(86) In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

(87) It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art.