WO2017133469A1

WO2017133469A1 - Uplink peak average power ratio reduction

Info

Publication number: WO2017133469A1
Application number: PCT/CN2017/071661
Authority: WO
Inventors: Guang Liu
Original assignee: Jrd Communication Inc.
Priority date: 2016-02-05
Filing date: 2017-01-19
Publication date: 2017-08-10
Also published as: GB2547041A; GB201602163D0

Abstract

Methods and apparatus are provided for efficient reduction in peak average power ratio (PAPR) for wireless communication unit transmitters when used in the UL of wireless communication systems over unlicensed radio spectrum, where, by way of example only but not limited to, Space DMA, CDMA, TDMA, FDMA such as L-FDMA, block-IFDMA and/or IFDMA based mappings may be used. PAPR may also be reduced for UL transmissions in which multiple sets of modulated data are scrambled or interleaved with different types of scrambling or interleaving, and selecting a set of scrambled or interleaved modulated data bits that minimise an estimated PAPR for use in the UL transmission.

Description

UPLINK PEAK AVERAGE POWER RATIO REDUCTION

TECHNICAL FIELD

Embodiments of the present invention generally relate wireless apparatus for wireless communication systems using unlicensed spectrum and in particular to methods and wireless apparatus for reducing peak average power ratio (PAPR) for uplink (UL) transmissions in such wireless communication systems.

BACKGROUND

Wireless communication systems and networks, such as the third-generation (3G) of mobile telephone standards and technology are well known. Such 3G standards and technology have been developed by the 3G Partnership Project (3GPP) . The 3rd generation of wireless communications has generally been developed to support macro-cell mobile phone communications. Such macro cells utilise high power base stations (NodeBs) to communicate with wireless communication units within a relatively large geographical coverage area.

Typically, wireless communication units, or User Equipment (UEs) as they are often referred to, communicate with a Core Network (CN) of the 3G wireless communication network via a Radio Network Subsystem (RNS) . A wireless communication network typically comprises a plurality of radio network subsystems, each radio network subsystem comprising one or more cells to which UEs may attach, and thereby connect to the network. Each macro-cellular RNS further comprises a controller, in a form of a Radio Network Controller (RNC) , operably coupled to the one or more NodeBs. Communications systems and networks have developed towards a broadband and mobile system. The 3rd Generation Partnership Project has developed a Long Term Evolution (LTE) solution, namely, an Evolved Universal Mobile Telecommunication System Territorial Radio Access Network, (E-UTRAN) , for a mobile access network, and a System Architecture Evolution (SAE) solution, namely, an Evolved Packet Core (EPC) , for a mobile core network. A macrocell in an LTE system is supported by a base station known as an eNodeB or eNB (evolved Node B) .

Current wireless communication networks operate using licensed radio spectrum in which multiple accesses to the communications resources of the licensed radio spectrum is strictly controlled. Each user of the network is essentially provided a “slice” of the spectrum using a variety of multiple access techniques such as, by way of example only but not limited to, frequency division multiplexing, time division multiplexing, code division multiplexing, and space division multiplexing or a combination of one or more of these techniques. Even with a combination of these techniques, with the popularity of mobile telecommunications, the capacity of current and future telecommunications networks is still very limited, especially when using licensed radio spectrum.

The use of unlicensed radio spectrum is being opened up for network operators in order to increase or supplement the capacity of their wireless communication networks. For example, a communication network based on the Long Term Evolution (LTE) /LTE advanced standards have been an enhanced downlink that uses a mechanism called Licensed-Assisted-Access (LAA) to operate on unlicensed spectrum such as, by way of example but is not limited to, the 5GHz Wi-Fi radio spectrum, which may increase the downlink capacity of current networks operating in the licensed radio spectrum. This enables the operation of a telecommunication network based on LTE in the 5GHz unlicensed spectrum for low power secondary cells based on regional regulatory power limits using carrier aggregation.

Nevertheless, network operators are not allowed to have unfettered access or use of unlicensed spectrum because they must share the unlicensed spectrum with other wireless devices such as, by way of example only but not limited to, Wi-Fi access points and terminals, medical devices, utilities meters, wireless machine-to-machine devices, Internet-of-things devices. Thus, a compromise has been struck between network operators and the governing bodies of the radio spectrum in relation to the use of unlicensed spectrum. Network operators must comply with various telecommunications regulations in order to make use of the unlicensed spectrum.

Currently there are two main regulations in sections 4.3 and 4.4 of the ETSI EN 301 893 V1.7.2 (2014-07) “Broadband Radio Access Networks (BRAN) ； 5 GHz high performance RLAN； Harmonized EN covering the essential requirements of article 3.2 of the R&TTE Directive” draft standard that each uplink (UL) wireless communication unit should comply with for the UL when using the unlicensed spectrum. The first regulation, in section 4.3 ETSI EN 301 893 V1.7.2 (2014-07) , the output signal of each wireless communication unit must be able to occupy at least 80％of the whole bandwidth. Even when only 2 RBs are allocated to one terminal, they must be located with enough distance in between, e.g., one RB at the left end and the other on the right end of the system bandwidth, while they could be located anywhere next to each other currently.

The second regulation, in section 4.4 ETSI EN 301 893 V1.7.2 (2014-07) , describes the power density per MHz is limited to a certain level measured in dBm (e.g., 10dBm) , this means even only one RB (180KHz) needs to be sent and the UE cannot use full power (e.g., 23dBm) . To explore more power, it is expected to distribute the subcarriers in frequency in a way that they are mapped into as many “MHz” as possible.

Although the following description describes, by way of example only but is not limited to, the use of Orthogonal Frequency-Division Multiple Access (OFDMA) , single-carrier and multi-carrier transmitters/receivers based on OFDM and other carrier formats, it is to be appreciated by the skilled person that the following description may be applied, not only to OFDMA or other related systems, but also to other communication systems, receivers and transmitters, such as, by way of example only but is not limited to, Code Division Multiple Access (CDMA) systems, time division multiple access (TDMA) systems, any other Frequency Division Multiple Access (FDMA) systems, or Space Division Multiple Access (SDMA) systems, or any other suitable communication system or combinations thereof.

Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user access method using an orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users or UEs. OFDMA is typically used in the downlink of LTE communication systems because the eNB (s) have control in granting multiple access to each UE served by that eNB. However, rather than using OFDMA for UL communications in LTE, single carrier-FDMA has certain advantages for UL communications. Most notably is the lower peak-to-average power ratio (PAPR) , which can greatly benefit the design of wireless communication units in terms of transmit power efficiency and reduced cost of the transmit power amplifier. It has been adopted as the UL multiple access scheme in 3GPP LTE or Evolved UTRA (E-UTRA) .

The peak-to-average power ratio (PAPR) is the peak amplitude squared (giving the peak power) divided by the average power. The PAPR for a signal X may be given as: PAPR＝|XPEAK|2 /E {X (n) . *conj (X (n) ) } , where X (n) are the samples of the signal X, conj (. ) is the conjugate function, and E {. } is the expectation function calculating the average. PAPR values are typically given in dB.

Typically, OFDMA has a high PAPR value and in theory, it is a linear function of the number of subcarriers. It is acceptable for downlink communications to have a high PAPR, because the transmit circuitry (e.g. linear amplifiers etc. ) of eNBs are robust and powerful enough to handle a high PAPR. However, high PAPR become problematic for UL communications because wireless communication units or UEs have severe design and power constraints such that their transmit circuitry (e.g. linear amplifiers etc. ) are more sensitive than eNB (s) in both cost and power consumption. For this reason, single carrier-FDMA is used on the LTE UL, where the terminal front end design is only capable of handling comparatively low PAPR values. This is achieved by mapping the subcarriers in the frequency domain such that they are equally separated.

The transmit power amplifier has a limited linear range and input signals exceed this range will experience more distortion. PAPR describes the power range of a signal and a high PAPR will force the amplifier to have a large backoff (reduce the output power) in order to ensure linear amplification of the signal. Additionally, high PAPR requires high resolution for the receiver analogue-to-digital (A/D) converter and places a complexity and power burden on a receiver front end at both eNB and UE. The receiver front-end of eNBs are required to be very sensitive to the considerably weaker UL signals transmitted by UEs.

There are several different subcarrier mapping methods or transmission techniques that are being used or are being proposed for use with the LTE UL, which currently uses SC-FDMA. Figure 1a illustrates three of the mappings for a block of contiguous subcarriers, where for each mapping a square in figure 1a represents a subcarrier. The first mapping is the so-called Localized Frequency Division Multiple Access (LFDMA) in which all subcarriers are allocated to each wireless communication device are continuously allocated in a contiguous sub-block of subcarriers. This is currently being used for LTE UL communications.

The second proposed mapping is the so-called Interleaved FDMA (IFDMA) in which each of the subcarriers allocated to a wireless communication device are separated by a predetermined number of subcarriers (e.g. equal separation) and each other wireless communication unit or UE is interleaved together on the unused subcarriers.

The third proposed mapping is a so-called block-IFDMA technique, which is a combination of LFDMA and IFDMA. In block-IFDMA, each wireless communication unit or UE is allocated a set of subcarriers in which each set contains two or more subsets (or groups) of subcarriers (also called subcarrier sets) that may have a size of X subcarriers, where X>＝2 and X is an integer. Each subset or group of subcarriers is a continuously allocated or contiguous block of X subcarriers. That is, there is no separation between the subcarriers. Each of the two or more groups of subcarriers are separated by a number of Y subcarriers, where Y>＝aX for a>＝1 and a is an integer. In some cases, a may be the number of users or UEs capable of using block-IFDMA.

Figure 1b shows a graph of the probability that the PAPR is greater than a reference PAPR (PAPR0) (e.g. Pr (PAPR>PAPR0) ) vs PAPR0 for a PAPR simulation of a communication system using LFDMA and block-IFDMA. As shown in figure 1b, the x-axis is PAPR0 is a reference PAPR value and the y-axis is the probability that the variable PAPRs are greater than the reference PAPR0 (e.g. Pr (PAPR>PAPR0) ) . The solid curve on left of figure 1b is when the communication system uses LFDMA over 20 resource blocks (RBs) . The dashed curve on the right of figure 1b is when the communication system uses block-IFDMA over 20 RBs, which are mapped with a frequency gap equal to 4 RB width between every 2 adjacent RBs as illustrated in figure 1a. A group of subcarriers continuously allocated or that are contiguous may also be called a cluster and obviously, in this case it can be said that there are 20 clusters. It has also been observed by simulation that the more clusters there are, the higher PAPR the output signals for transmission have.

As shown on the graph, for LFDMA (solid curve) the probability that a PAPR will be greater than 8dB is about 10^-4 for 1 cluster or group of 20RBs when continuously allocated i.e. when allocated as a contiguous block. As can be seen, for block-IFMDA, there are about a 2dB degradation (e.g. a 2dB increase in PAPR0) at the same 10^-4 probability. It is clear that block-IFDMA mapping does not have the property of single carrier FDMA (SC-FDMA) , which uses L-FDMA mapping, and the PAPR of the output signal is significantly increased, which can be problematic for UL communications.

Due to the above two regulation requirements being placed on the LAA UL i.e. each wireless communication unit is required to use 80％of the total frequency bandwidth for each block of 20MHz with power constraints per MHz bandwidth, LFDMA is being seen as an unattractive mapping technique when a small number of RBs are allocated to one UE. Given these regulations, the LAA UL is evolving into an enhanced LAA UL in which the UL subcarriers are expected to be mapped onto subcarriers unevenly separated apart due to these two regulation requirements, which it seems may be satisfied by the possible use of block-IFDMA or IFDMA or combinations thereof. Each frame of L RBs may have a large number of subcarriers (e.g. for L＝100, with each RB having 12 contiguous subcarrier, there will be 1200 subcarriers) . Thus, one wireless communication unit at a cell edge using block-IFDMA or IFDMA with non-identical gaps may inadvertently use a larger PAPR than a wireless communication unit closer to the cell center using LFDMA and thus overload its linear transmit amplifier. It is also a known problem that the PAPR for IFDMA and block-IFDMA are worse than for the current LFDMA techniques. There is a desire for a PAPR reduction scheme and UL control signalling for block-IFDMA and IFDMA mappings when used for the enhanced LAA UL that achieve the a reduced PAPR.

SUMMARY

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The invention relates to methods and apparatus for efficient reduction in peak average power ratio (PAPR) for wireless communication unit transmitters/receivers when used in the UL of wireless communication systems over unlicensed radio spectrum, where, by way of example only but not limited to, Space DMA, CDMA, TDMA, FDMA such as L-FDMA, block-IFDMA and/or IFDMA based mappings may be used. PAPR may also be reduced for UL transmissions in which multiple sets of modulated data are scrambled or interleaved with different types of scrambling or interleaving, and selecting a set of scrambled or interleaved modulated data bits that minimise an estimated PAPR for use in the UL transmission.

For example, PAPR may be reduced for UL transmissions using, by way of example only but is not limited to, a single carrier and/or multiple carrier type transmitter structures in which multiple sets of modulated data are scrambled or interleaved with different types of scrambling or interleaving, and selecting a set of scrambled or interleaved modulated data bits that minimise an estimated PAPR for transmitting from the SC or MC transmitter.

According to a first aspect of the invention, there is provided a transmitter apparatus for uplink peak average power ratio, PAPR, reduction in a wireless communications system, comprising: a plurality of signal processing branches coupled to a PAPR checker and a transmitter, wherein the PAPR checker is configured to: estimate the PAPR of baseband communication signals output from the corresponding signal processing branches； select the signal processing branch associated with an output baseband communication signal that has a reduced or minimal PAPR compared with other signal processing branches； and send the baseband communication signal output from the selected signal processing branch to the transmitter for uplink transmission.

Optionally, the PAPR checker is configured to select the signal processing branch in which the PAPR checker detects the estimated PAPR of the corresponding output baseband communication signal is minimised over all the output baseband communication signals on the remaining signal processing branches.

As an option, the PAPR checker is configured to select the signal processing branch in which the PAPR checker first detects the estimated PAPR of the corresponding output baseband communication signal to have reached a predetermined PAPR threshold.

As another option, when the PAPR checker detects that all of the estimated PAPRs of the corresponding output baseband communication signals are above the predetermined PAPR threshold, then the PAPR checker is configured to select the signal processing branch in which the PAPR checker detects the estimated PAPR of the corresponding output baseband communication signal is minimised over all the output baseband communication signals on the remaining signal processing branches.

Optionally, the signal processing branches are configured to receive a plurality of modulation symbols, wherein the plurality of modulation symbols are the same for each signal processing branch, and each signal processing branch further comprises: a scrambler or interleaving module coupled to an communication signal generator for outputting the baseband communication signal, wherein the scrambler or interleaving module is configured to scramble or interleave the modulation symbols prior to input to the communication signal generator.

As an option, the scrambler or interleaving module of each signal processing branch, uses a different scrambling scheme or a different interleaving scheme to the other signal processing branches.

Optionally, each signal processing branch is associated with an index value for identifying the scrambling scheme or interleaving scheme used to scramble or interleave the modulated symbols.

As an option, the PAPR checker is configured to use the index value to identify which signal processing branch has been selected and to send the baseband communication signal of the selected signalling branch to the transmitter for transmission based on the index value.

As another option, the transmitter further includes a selector with the selection inputs of the selector coupled to the output of the signal processing branches, an output of the selector coupled to the transmitter, and a control input of the selector coupled to a control output of PAPR checker, wherein the PAPR checker outputs the index value to the control input of the selector for sending the baseband communication signal output from the selected signal processing branch to the transmitter.

As an option, each output baseband communication signal comprises one or more baseband communication symbols, and the PAPR checker is configured to: select the signal processing branch for every one or more baseband communciation symbols that have a reduced or minimal PAPR compared with one or more baseband communication symbols associated with other signal processing branches.

As another option, the one or more baseband communication symbols for each output baseband communication signal comprises a subframe of a plurality of baseband communication symbols, and the PAPR checker is configured to: select the signal processing branch for every subframe of baseband communication symbols that have a reduced or minimal PAPR compared with the subframes of baseband communication symbols associated with other signal processing branches.

Optionally, the index value associated with the selected signal processing branch is transmitted to a receiver apparatus for use in descrambling or deinterleaving a received transmitted baseband communication signal output from the selected signal processing branch.

As an option, the transmitter includes a waveform generator is configured to generate a control signal waveform comprising data representative of the index value associated with the corresponding signal processing branch.

Optionally, the PAPR checker is further configured to: combine each output baseband communication signal with the control waveform associated with the corresponding signal processing branch； estimate the PAPR of each combined output baseband communication signal and corresponding control signal waveform； and select the signal processing branch associated with a combined output baseband communication signal and corresponding control signal waveform that has a reduced or minimal PAPR compared with other signal processing branches.

As an option, the baseband communication signal is an OFDM signal and the control signal waveform is a physical uplink control channel, PUCCH, waveform. Optionally, the PUCCH waveform is transmitted in a control channel bandwidth in the vicinity of the distal ends of carrier frequency or system bandwidth associated with the OFDM signal selected for transmission. As another option, the PUCCH waveform is transmitted in a control channel bandwidth within the carrier frequency or system bandwidth associated with the OFDM signal selected for transmission. Optionally, the PUCCH waveform is transmitted in a control channel bandwidth outside the carrier frequency or system bandwidth associated with the OFDM signal selected for transmission. As another option, the control channel bandwidth outside the carrier frequency or system bandwidth is one or more guard band (s) associated with the OFDM signal selected for transmission.

Optionally, the baseband communication signal is an OFDM signal, the communication signal generator is an OFDM signal generator within the signal processing branch associated with the index value, wherein the OFDM signal generator is further configured to: puncture one or more resource elements associated with data OFDM symbols； and insert the control signal waveform or data representative of the index value into the one or more resource elements, wherein a receiver apparatus receiving the punctured OFDM signal transmission retrieves the index value from the associated resource elements for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.

As an option, the baseband communication signal is an OFDM signal, the communication signal generator is an OFDM signal generator of the signal processing branch associated with the index value, and the OFDM signal comprises two or more resource blocks, wherein each resource block comprises a block of reference symbols, and the OFDM signal generator of the signal processing branch associated with the index value is further configured to: encode the index value within the reference symbols of two or more of the resource blocks, wherein a receiver apparatus receiving a selected OFDM signal transmission detects and decodes the index value from the associated reference symbols for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.

As an option, the transmitter apparatus is a multi-carrier, MC, transmitter apparatus associated with two or more center carrier, CC, frequency bandwidths, and the plurality of signal processing branches comprises two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to the PAPR checker and the transmitter, wherein the transmitter is a MC transmitter and wherein, each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal for input to the PAPR checker.

The PAPR checker may be further configured to: estimate the PAPR of each combined baseband communciation signal associated with each of the multiple combined signal processing branches； select a set of multiple combined signal processing branches in which the combined estimated PAPR of the corresponding baseband communication signals is reduced or minimised compared with the combined estimated PAPR for other sets of multiple combined signal processing branches, wherein each set of multiple combined signal processing branches includes signal processing branches associated with all of the CC frequency bandwidths； and send the baseband communication signal outputs associated with the signal processing branches of the selected set of multiple combined signal processing branches to the MC transmitter for uplink transmission.

As an option, each of the multiple combined signal processing branches is associated with an index value for identifying the scrambling schemes or interleaving schemes used to scramble or interleave the modulated symbols associated with the multiple combined signal processing branches. Optionally, the PAPR checker is configured to use the index values to identify which multiple combined signal processing branches have been selected and to send the baseband communication signals of the selected signalling branches to the transmitter for transmission based on the index values.

Optionally, the transmitter apparatus as claimed in any preceding claim wherein the transmitter apparatus is a multi-carrier (MC) transmitter apparatus associated with two or more center carrier (CC) frequency bandwidths, and the plurality of signal processing branches comprises two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to the PAPR checker and the transmitter, wherein the transmitter is a MC transmitter and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal for input to the PAPR checker.

As an option, the PAPR checker is further configured to: estimate the PAPR of each of the combined baseband communication signals associated with each of the multiple combined signal processing branches； select a combined signal processing branch associated with a combined baseband communciation signal that has an estimated PAPR that is reduced or minimised compared with the estimated PAPR of other combined baseband communciation signals output from other combined signal processing branches, wherein each combined signal processing branch includes signal processing branches that are each associated with a different CC frequency bandwidth and include signal processing branches from all of the CC frequency bandwidths； and send the baseband communication signal outputs associated with the signal processing branches of the selected combined signal processing branch to the MC transmitter for uplink transmission.

As an option, each of the combined signal processing branches is associated with an index value for identifying the scrambling schemes or interleaving schemes used to scramble or interleave the modulated symbols associated with the combined signal processing branch.

Optionally, the PAPR checker is configured to use the index values to identify which combined signal processing branch has been selected and to send the baseband communication signals associated with the selected combined signal processing branch to the transmitter for transmission based on the index values. Optionally, a waveform generator configured to generate a control signal waveform comprising data representative of the index value associated with the corresponding multiple combined of signal processing branches.

As an option, the PAPR checker is further configured to: combine each output baseband communication signals of the multiple combined signal processing branches with the control waveform associated with the corresponding multiple combined signal processing branches； estimate the PAPR of each combined output baseband communication signals and corresponding control signal waveform associated with each of the multiple combined signal processing branches； and select a combined signal processing branch in which the estimated PAPR of the corresponding combined baseband communication signals and control waveform is reduced or minimised compared with other combined signal processing branches.

As an option, a waveform generator configured to generate a control signal waveform comprising data representative of the index value associated with the corresponding multiple combined of signal processing branches. Optionally, the PAPR checker is further configured to: combine each output baseband communication signals of the multiple combined signal processing branches with the control waveform associated with the corresponding multiple combined signal processing branches； estimate the PAPR of each combined output baseband communication signals and corresponding control signal waveform associated with each of the multiple combined signal processing branches； and select a set of multiple combined signal processing branches in which the combined estimated PAPR of the corresponding combined baseband communication signals and control waveform is reduced or minimised compared with other sets of multiple combined signal processing branches, wherein each set of multiple combined signal processing branches includes signal processing branches associated with all of the CC frequency bandwidths.

According to a second aspect of the invention, there is provided a multi-carrier (MC) transmitter apparatus for uplink PAPR reduction in a wireless communications system, wherein the MC transmitter apparatus is associated with two or more center carrier (CC) frequency bandwidths, the MC transmitter apparatus comprising: a plurality of signal processing branches including two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to the PAPR checker and an MC transmitter, and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal for input to the PAPR checker.

The PAPR checker is further configured to: estimate the PAPR of each of the combined baseband communication signals associated with each of the multiple combined signal processing branches； select a combined signal processing branch associated with a combined baseband communciation signal that has an estimated PAPR that is reduced or minimised compared with the estimated PAPR of other combined baseband communciation signals output from other combined signal processing branches, wherein each combined signal processing branch includes signal processing branches that are each associated with a different CC frequency bandwidth and include signal processing branches from all of the CC frequency bandwidths； and send the baseband communication signal outputs associated with the signal processing branches of the selected combined signal processing branch to the MC transmitter for uplink transmission.

According to a third aspect of the invention, there is provided a receiver apparatus for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communciation signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols into a baseband communication signal for transmission with a reduced or minimised PAPR, and wherein the receiver apparatus has a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus, the receiver apparatus further comprising: a receiver unit for receiving the uplink communciation signal transmitted from a transmitter apparatus； a demodulator unit configured to demodulate the uplink communication signal into a scrambled or interleaved set of modulation symbols； a blind decoding unit configured to: select a candidate scrambling or interleaving scheme from the set of scrambling or interleaving schemes； decode the scrambled or interleaved set of modulation symbols； perform a cyclic redundancy check on the decoded modulation symbols, and when the cyclic redundancy check passes, output the decoded modulation symbols and proceed to decode any remaining scrambled or interleaved modulation symbols using the candidate scrambling or interleaving scheme whilst performing the CRC check, when the CRC check fails, select another candidate scrambling or interleaving scheme from the set of interleaving schemes to decode and perform the CRC check on the scrambled or interleaved modulation symbols using the other candidate scrambling or interleaving scheme.

According to a fourth aspect of the invention, there is provided a receiver apparatus for receiving an uplink communication signal from a transmitter apparatus in a wireless communication communications system, wherein the uplink communciation signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols into a baseband communication signal for transmission with a reduced or minimised PAPR, and wherein the uplink communication signal includes a control signal identifying the particular scrambling scheme or interleaving scheme, wherein the receiver apparatus has a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus, the receiver apparatus further comprising: a receiver unit for receiving the uplink communication signal transmitted from a transmitter apparatus； a control detection unit for detecting the control signal identifying the particular scrambling or interleaving scheme； a demodulator unit configured to demodulate the uplink communication signal into a scrambled or interleaved set of modulation symbols； and a decoding unit for decoding the scrambled or interleaved modulation symbols using the identified particular scrambling or interleaving scheme.

Optionally, wherein the uplink communication signal is an uplink OFDM signal and the control signal is a physical uplink control channel (PUCCH) waveform identifying the particular scrambling or interleaving scheme and the control detection unit detects the PUCCH waveform. As an option, the receiver and control unit are configured to detect the PUCCH waveform is located in a control channel bandwidth in the vicinity of the distal ends of carrier frequency or system bandwidth associated with the received OFDM signal. As another option, receiver and control unit are configured to detect the PUCCH waveform located in a control channel bandwidth outside the carrier frequency or system bandwidth associated with the OFDM signal. Optionally, the control channel bandwidth outside the carrier frequency or system bandwidth is one or more guard band (s) associated with the OFDM signal.

As an option, each signal processing branch of the transmitter apparatus is associated with an index value for identifying the particular scrambling scheme or interleaving scheme used to scramble or interleave the modulated symbols, wherein the control signal comprises data representative of the index value for use by the control detection unit in identifying the particular scrambling scheme or interleaving scheme.

Optionally, at the transmitter apparatus an OFDM signal generator of the signal processing branch associated with the index value is further configured to puncture one or more resource elements associated with data OFDM symbols and transmit the baseband communication signal at the output of the OFDM generator as an uplink OFDM signal transmission, and insert the control signal waveform or data representative of the index value into the one or more resource elements, wherein: the receiver unit is further configured to receive the punctured OFDM signal transmission； and the control detection unit is further configured to retrieve the index value from the associated resource elements for identifying the descrambling or deinterleaving scheme for retrieving the original modulation symbols.

As an option, the received uplink communication signal is a received OFDM signal that comprises two or more resource blocks, wherein each resource block comprises a block of reference symbols, and at the transmitter an OFDM signal generator of the signal processing branch associated with the index value encoded the index value within the reference symbols of two or more of the resource blocks and transmit the baseband communication signal at the output of the OFDM generator as an uplink OFDM signal transmission, wherein: the receiver unit is configured to receive the OFDM signal transmission； and the control detection unit is further configured to detect the encoded index value within the reference symbols； the decoding unit uses the index value from the associated reference symbols for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.

According to another aspect of the invention, there is provided a method for uplink PAPR reduction in a wireless communications system, the method, performed by a transmitter apparatus comprising a plurality of signal processing branches coupled a transmitter, the method comprising: estimating the PAPR of baseband communication signals output from the corresponding signal processing branches； selecting the signal processing branch associated with an output baseband communication signal that has a reduced or minimal PAPR compared with other signal processing branches； and sending the baseband communication signal output from the selected signal processing branch to the transmitter for uplink transmission.

According to a further aspect of the invention, there is provided a method for uplink PAPR reduction in a wireless communications system, the method performed by a multi-carrier (MC) transmitter apparatus associated with two or more center carrier (CC) frequency bandwidths, the MC transmitter apparatus comprising: a plurality of signal processing branches including two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to an MC transmitter, and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal, the method comprising: estimating the PAPR of each combined baseband communication signal associated with each of the multiple combined signal processing branches； selecting a set of multiple combined signal processing branches in which the combined estimated PAPR of the corresponding combined baseband communication signals is reduced or minimised compared with the combined estimated PAPR for other sets of multiple combined signal processing branches, wherein each set of multiple combined signal processing branches includes signal processing branches associated with all of the CC frequency bandwidths； and sending the baseband communication signal outputs associated with the signal processing branches of the selected set of multiple combined signal processing branches to the MC transmitter for uplink transmission.

According to a further aspect of the invention, there is provided a method for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communication signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols to output a baseband communication signal for transmission as the uplink communication signal with a reduced or minimised PAPR, the method comprising: receiving the uplink communication signal transmitted from a transmitter apparatus； demodulating the uplink communication signal into a scrambled or interleaved set of modulation symbols； blind decoding the scrambled or interleaved set of modulation symbols by: selecting a candidate scrambling or interleaving scheme from a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus； decoding the scrambled or interleaved set of modulation symbols； performing a cyclic redundancy check on the decoded modulation symbols； when the cyclic redundancy check passes, outputting the decoded modulation symbols, and proceeding to decode any remaining scrambled or interleaved modulation symbols using the candidate scrambling or interleaving scheme whilst performing the CRC check； when the CRC check fails, selecting another candidate scrambling or interleaving scheme from the set of interleaving schemes and performing the steps of decoding and performing the CRC check on the scrambled or interleaved modulation symbols using the other candidate scrambling or interleaving scheme.

According to another aspect of the invention, there is provided a method for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communication signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols as a baseband communication signal for transmission as an uplink communication signal with a reduced or minimised PAPR, and wherein the uplink communication signal includes a control signal identifying the particular scrambling scheme or interleaving scheme, the method further comprising: receiving the uplink communication signal transmitted from a transmitter apparatus； detecting the control signal identifying the particular scrambling or interleaving scheme from a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme； demodulating the uplink communication signal into a scrambled or interleaved set of modulation symbols； and decoding the scrambled or interleaved modulation symbols using the identified particular scrambling or interleaving scheme.

According to yet another aspect of the invention, there is provided a non-transitory computer-readable medium comprising program code stored thereon, which when executed on a processor, causes the processor to perform a method according to various aspects of the invention, and/or as described herein for transmitting a communication signal with reduced or minimised PAPR.

According to yet another aspect of the invention, there is provided a non-transitory computer readable medium comprising program code stored thereon, which when executed on a processor, causes the processor to perform a method according to various aspects of the invention, and/or as described herein for receiving a communication signal with reduced or minimised PAPR.

According to yet further aspects of the invention, there is provided a UE apparatus comprising a transmitter apparatus according to a first aspect of the invention, a second aspect of the invention, or other aspects of the invention as related to a transmitter apparatus and/or as described herein.

According to a further aspect of the invention, there is provided a UE apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the functions associated with the transmitter apparatus according to a first aspect of the invention, a second aspect of the invention, or other aspects of the invention as related to a transmitter apparatus and/or as described herein.

According to another aspect of the invention, there is provided a UE apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform a method according to a first aspect of the invention, a second aspect of the invention, or other aspects of the invention as related to a transmitter apparatus and/or as described herein.

According to an aspect of the invention, there is provided a base station apparatus comprising a receiver apparatus as described a third aspect of the invention, a fourth aspect of the invention, or other aspects of the invention related to a receiver apparatus and/or as described herein.

According to another aspect of the invention there is provided a base station apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, communications interface are configured to perform the functions associated with the receiver apparatus according to a third aspect of the invention, a fourth aspect of the invention, or other aspects of the invention related to a receiver apparatus and/or as described herein.

According to yet further aspects of the invention, there is provided a base station apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, communications interface are configured to perform the method according to a third aspect of the invention, a fourth aspect of the invention, or other aspects of the invention related to methods, functions of a receiver apparatus for performing the invention and/or as described herein.

According to a further aspect of the invention, there is provided a telecommunications network comprising a plurality of UEs, a plurality of base stations, each base station including an apparatus according to the second aspect of the invention or as described herein, wherein each base station serves one or more of the plurality of UE.

These and other aspects, features and advantages of the invention will be apparent from, and elucidated with reference to, the examples and/or embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described, by way of example, with reference to the following drawings, in which:

Figure 1a is a schematic diagram of subcarrier arrangements for L-FDMA, IFDMA and block-IFDMA mappings in accordance with embodiment (s) of the invention；

Figure 1b is a graph for a simulation comparing PAPR performance for LFDMA and block-IFDMA mappings as described in figure 1a；

Figure 1c is a schematic diagram of a wireless communication system in accordance with embodiment (s) of the invention； and

Figure 2 is a communication resource structure for use with embodiment (s) of the invention.

Figure 3a is a schematic diagram of an OFDM transmitter structure for wireless communication units；

Figure 3b is a schematic diagram of a single-carrier OFDM transmitter structure for wireless communication units in accordance with embodiment (s) of the invention；

Figure 3c is a graph illustrating the peak power to average power performance when using symbol branch selection and scrambling in the transmitter structure of figure 3b in accordance with embodiments of the invention；

Figure 3d is a graph illustrating the peak power to average power performance when using subframe branch selection and scrambling in the transmitter structure of figure 3b in accordance with embodiments of the invention；

Figure 3e is a graph illustrating the peak power to average power performance when using subframe branch selection and interleaving in the transmitter structure of figure 3b in accordance with embodiments of the invention；

Figure 4a is a schematic diagram of a multiple-carrier OFDM transmitter structure for wireless communication units

Figure 4b is a schematic diagram of a multiple-carrier OFDM transmitter structure for wireless communication units based on figure 4a in accordance with embodiment (s) of the invention；

Figure 5 is a flow diagram illustrating process performed at a base station for blind decoding of transmission signals from the transmitters based on figures 3b and 4b in accordance with embodiments of the invention；

Figure 6a is a graph illustrating the performance of instant power to average power for transmitters according to embodiments of the invention；

Figure 6b is a schematic diagram of a single carrier OFDMA transmitter with control signalling according to embodiments of the invention；

Claims

A transmitter apparatus for uplink peak average power ratio, PAPR, reduction in a wireless communications system, comprising: a plurality of signal processing branches coupled to a PAPR checker and a transmitter, wherein the PAPR checker is configured to:

estimate the PAPR of baseband communication signals output from the corresponding signal processing branches；

select the signal processing branch associated with an output baseband communication signal that has a reduced or minimal PAPR compared with other signal processing branches； and

send the baseband communication signal output from the selected signal processing branch to the transmitter for uplink transmission.
The transmitter apparatus as claimed in claim 1, wherein the PAPR checker is configured to select the signal processing branch in which the PAPR checker detects the estimated PAPR of the corresponding output baseband communication signal is minimised over all the output baseband communication signals on the remaining signal processing branches.
The transmitter apparatus as claimed in claim 1, wherein the PAPR checker is configured to select the signal processing branch in which the PAPR checker first detects the estimated PAPR of the corresponding output baseband communication signal to have reached a predetermined PAPR threshold.
The transmitter apparatus as claimed in claim 3, wherein when the PAPR checker detects that all of the estimated PAPRs of the corresponding output baseband communication signals are above the predetermined PAPR threshold, then the PAPR checker is configured to select the signal processing branch in which the PAPR checker detects the estimated PAPR of the corresponding output baseband communication signal is minimised over all the output baseband communication signals on the remaining signal processing branches.
The transmitter apparatus as claimed in any of claims 1-4, wherein the signal processing branches are configured to receive a plurality of modulation symbols, wherein the plurality of modulation symbols are the same for each signal processing branch, and each signal processing branch further comprises:

a scrambler or interleaving module coupled to an communication signal generator for outputting the baseband communication signal, wherein the scrambler or interleaving module is configured to scramble or interleave the modulation symbols prior to input to the communication signal generator.
The transmitter apparatus as claimed in claim 5, wherein the scrambler or interleaving module of each signal processing branch, uses a different scrambling scheme or a different interleaving scheme to the other signal processing branches.
The transmitter apparatus as claimed in claim 6, wherein each signal processing branch is associated with an index value for identifying the scrambling scheme or interleaving scheme used to scramble or interleave the modulated symbols.
The transmitter apparatus as claimed in claim 7, wherein the PAPR checker is configured to use the index value to identify which signal processing branch has been selected and to send the baseband communication signal of the selected signalling branch to the transmitter for transmission based on the index value.
The transmitter apparatus as claimed in claim 8, further comprising a selector with the selection inputs of the selector coupled to the output of the signal processing branches, an output of the selector coupled to the transmitter, and a control input of the selector coupled to a control output of PAPR checker, wherein the PAPR checker outputs the index value to the control input of the selector for sending the baseband communication signal output from the selected signal processing branch to the transmitter.
The transmitter apparatus as claimed in claims 7 to 9, wherein each output baseband communication signal comprises one or more baseband communication symbols, and the PAPR checker is configured to: select the signal processing branch for every one or more baseband communciation symbols that have a reduced or minimal PAPR compared with one or more baseband communication symbols associated with other signal processing branches.
The transmitter apparatus as claimed in claims 7 to 10, wherein the one or more baseband communication symbols for each output baseband communication signal comprises a subframe of a plurality of baseband communication symbols, and the PAPR checker is configured to: select the signal processing branch for every subframe of baseband communication symbols that have a reduced or minimal PAPR compared with the subframes of baseband communication symbols associated with other signal processing branches.
The transmitter apparatus as claimed in claims 7 to 11, wherein the index value associated with the selected signal processing branch is transmitted to a receiver apparatus for use in descrambling or deinterleaving a received transmitted baseband communication signal output from the selected signal processing branch.
The transmitter apparatus as claimed in claim 12, further comprising a waveform generator configured to generate a control signal waveform comprising data representative of the index value associated with the corresponding signal processing branch.
The transmitter apparatus as claimed in claim 13, wherein the PAPR checker is further configured to:

combine each output baseband communication signal with the control waveform associated with the corresponding signal processing branch；

estimate the PAPR of each combined output baseband communication signal and corresponding control signal waveform； and

select the signal processing branch associated with a combined output baseband communication signal and corresponding control signal waveform that has a reduced or minimal PAPR compared with other signal processing branches.
The transmitter apparatus as claimed in claim 14, wherein the baseband communication signal is an OFDM signal and the control signal waveform is a physical uplink control channel, PUCCH, waveform.
The transmitter apparatus as claimed in claim 15, wherein the PUCCH waveform is transmitted in a control channel bandwidth in the vicinity of the distal ends of carrier frequency or system bandwidth associated with the OFDM signal selected for transmission.
The transmitter apparatus as claimed in claim 16, wherein the PUCCH waveform is transmitted in a control channel bandwidth within the carrier frequency or system bandwidth associated with the OFDM signal selected for transmission.
The transmitter apparatus as claimed in claim 15, wherein the PUCCH waveform is transmitted in a control channel bandwidth outside the carrier frequency or system bandwidth associated with the OFDM signal selected for transmission.
The transmitter apparatus as claimed in claims 15 to 18, wherein the control channel bandwidth outside the carrier frequency or system bandwidth is one or more guard band (s) associated with the OFDM signal selected for transmission.
The transmitter apparatus as claimed in claim 13, wherein the baseband communication signal is an OFDM signal, the communication signal generator is an OFDM signal generator within the signal processing branch associated with the index value, wherein the OFDM signal generator is further configured to: puncture one or more resource elements associated with data OFDM symbols； and insert the control signal waveform or data representative of the index value into the one or more resource elements, wherein a receiver apparatus receiving the punctured OFDM signal transmission retrieves the index value from the associated resource elements for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.
The transmitter apparatus as claimed in claim 13, wherein the baseband communication signal is an OFDM signal, the communication signal generator is an OFDM signal generator of the signal processing branch associated with the index value, and the OFDM signal comprises two or more resource blocks, wherein each resource block comprises a block of reference symbols, and the OFDM signal generator of the signal processing branch associated with the index value is further configured to: encode the index value within the reference symbols of two or more of the resource blocks, wherein a receiver apparatus receiving a selected OFDM signal transmission detects and decodes the index value from the associated reference symbols for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.
The transmitter apparatus as claimed in any preceding claim wherein the transmitter apparatus is a multi-carrier, MC, transmitter apparatus associated with two or more center carrier, CC, frequency bandwidths, and the plurality of signal processing branches comprises two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to the PAPR checker and the transmitter, wherein the transmitter is a MC transmitter and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal for input to the PAPR checker, wherein the PAPR checker is further configured to:

estimate the PAPR of each of the combined baseband communication signals associated with each of the multiple combined signal processing branches；

select a combined signal processing branch associated with a combined baseband communciation signal that has an estimated PAPR that is reduced or minimised compared with the estimated PAPR of other combined baseband communciation signals output from other combined signal processing branches, wherein each combined signal processing branch includes signal processing branches that are each associated with a different CC frequency bandwidth and include signal processing branches from all of the CC frequency bandwidths； and

send the baseband communication signal outputs associated with the signal processing branches of the selected combined signal processing branch to the MC transmitter for uplink transmission.
The transmitter apparatus as claimed in claim 22, wherein each of the combined signal processing branches is associated with an index value for identifying the scrambling schemes or interleaving schemes used to scramble or interleave the modulated symbols associated with the combined signal processing branch.
The transmitter apparatus as claimed in claim 23, wherein the PAPR checker is configured to use the index values to identify which combined signal processing branch has been selected and to send the baseband communication signals associated with the selected combined signal processing branch to the transmitter for transmission based on the index values.
The transmitter apparatus as claimed in claim 24, further comprising a waveform generator configured to generate a control signal waveform comprising data representative of the index value associated with the corresponding multiple combined of signal processing branches.
The transmitter apparatus as claimed in claim 25, wherein the PAPR checker is further configured to:

combine each output baseband communication signals of the multiple combined signal processing branches with the control waveform associated with the corresponding multiple combined signal processing branches；

estimate the PAPR of each combined output baseband communication signals and corresponding control signal waveform associated with each of the multiple combined signal processing branches； and

select a combined signal processing branch in which the estimated PAPR of the corresponding combined baseband communication signals and control waveform is reduced or minimised compared with other combined signal processing branches.
A multi-carrier, MC, transmitter apparatus for uplink peak average power ratio, PAPR, reduction in a wireless communications system, wherein the MC transmitter apparatus is associated with two or more center carrier, CC, frequency bandwidths, the MC transmitter apparatus comprising: a plurality of signal processing branches including two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to the PAPR checker and an MC transmitter, and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal for input to the PAPR checker, wherein the PAPR checker is further configured to:

estimate the PAPR of each of the combined baseband communication signals associated with each of the multiple combined signal processing branches；

select a combined signal processing branch associated with a combined baseband communciation signal that has an estimated PAPR that is reduced or minimised compared with the estimated PAPR of other combined baseband communciation signals output from other combined signal processing branches, wherein each combined signal processing branch includes signal processing branches that are each associated with a different CC frequency bandwidth and include signal processing branches from all of the CC frequency bandwidths； and

send the baseband communication signal outputs associated with the signal processing branches of the selected combined signal processing branch to the MC transmitter for uplink transmission.
A receiver apparatus for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communciation signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols into a baseband communication signal for transmission with a reduced or minimised PAPR, and wherein the receiver apparatus has a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus, the receiver apparatus further comprising:

a receiver unit for receiving the uplink communciation signal transmitted from a transmitter apparatus；

a demodulator unit configured to demodulate the uplink communication signal into a scrambled or interleaved set of modulation symbols；

a blind decoding unit configured to:

select a candidate scrambling or interleaving scheme from the set of scrambling or interleaving schemes；

decode the scrambled or interleaved set of modulation symbols；

perform a cyclic redundancy check on the decoded modulation symbols, and when the cyclic redundancy check passes, output the decoded modulation symbols and proceed to decode any remaining scrambled or interleaved modulation symbols using the candidate scrambling or interleaving scheme whilst performing the CRC check, when the CRC check fails, select another candidate scrambling or interleaving scheme from the set of interleaving schemes to decode and perform the CRC check on the scrambled or interleaved modulation symbols using the other candidate scrambling or interleaving scheme.
A receiver apparatus for receiving an uplink communication signal from a transmitter apparatus in a wireless communication communications system, wherein the uplink communciation signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols into a baseband communication signal for transmission with a reduced or minimised PAPR, and wherein the uplink communication signal includes a control signal identifying the particular scrambling scheme or interleaving scheme, wherein the receiver apparatus has a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus, the receiver apparatus further comprising:

a receiver unit for receiving the uplink communication signal transmitted from a transmitter apparatus；

a control detection unit for detecting the control signal identifying the particular scrambling or interleaving scheme；

a demodulator unit configured to demodulate the uplink communication signal into a scrambled or interleaved set of modulation symbols； and

a decoding unit for decoding the scrambled or interleaved modulation symbols using the identified particular scrambling or interleaving scheme.
The receiver apparatus as claimed in claim 29, wherein wherein the uplink communication signal is an uplink OFDM signal and the control signal is a physical uplink control channel, PUCCH, waveform identifying the particular scrambling or interleaving scheme and the control detection unit detects the PUCCH waveform.
The receiver apparatus as claimed in claim 30, wherein receiver and control unit are configured to detect the PUCCH waveform is located in a control channel bandwidth in the vicinity of the distal ends of carrier frequency or system bandwidth associated with the received OFDM signal.
The receiver apparatus as claimed in claim 30, wherein receiver and control unit are configured to detect the PUCCH waveform located in a control channel bandwidth outside the carrier frequency or system bandwidth associated with the OFDM signal.
The receiver apparatus as claimed in claim 32, wherein the control channel bandwidth outside the carrier frequency or system bandwidth is one or more guard band (s) associated with the OFDM signal.
The receiver apparatus as claimed in any of claims 29 to 33, wherein each signal processing branch of the transmitter apparatus is associated with an index value for identifying the particular scrambling scheme or interleaving scheme used to scramble or interleave the modulated symbols, wherein the control signal comprises data representative of the index value for use by the control detection unit in identifying the particular scrambling scheme or interleaving scheme.
The receiver apparatus as claimed in claim 34, wherein, at the transmitter apparatus an OFDM signal generator of the signal processing branch associated with the index value is further configured to puncture one or more resource elements associated with data OFDM symbols and transmit the baseband communication signal at the output of the OFDM generator as an uplink OFDM signal transmission, and insert the control signal waveform or data representative of the index value into the one or more resource elements, wherein:

the receiver unit is further configured to receive the punctured OFDM signal transmission； and

the control detection unit is further configured to retrieve the index value from the associated resource elements for identifying the descrambling or deinterleaving scheme for retrieving the original modulation symbols.
The receiver apparatus as claimed in claim 33, wherein the received uplink communication signal is a received OFDM signal that comprises two or more resource blocks, wherein each resource block comprises a block of reference symbols, and at the transmitter an OFDM signal generator of the signal processing branch associated with the index value encoded the index value within the reference symbols of two or more of the resource blocks and transmit the baseband communication signal at the output of the OFDM generator as an uplink OFDM signal transmission, wherein:

the receiver unit is configured to receive the OFDM signal transmission； and

the control detection unit is further configured to detect the encoded index value within the reference symbols；

the decoding unit uses the index value from the associated reference symbols for identifying the descrambling or deinterleaving scheme to retrieve the original modulation symbols.
A method for uplink peak average power ratio, PAPR, reduction in a wireless communications system, the method, performed by a transmitter apparatus comprising a plurality of signal processing branches coupled a transmitter, the method comprising:

estimating the PAPR of baseband communication signals output from the corresponding signal processing branches；

selecting the signal processing branch associated with an output baseband communication signal that has a reduced or minimal PAPR compared with other signal processing branches； and

sending the baseband communication signal output from the selected signal processing branch to the transmitter for uplink transmission.
A method for uplink peak average power ratio, PAPR, reduction in a wireless communications system, the method performed by a multi-carrier, MC, transmitter apparatus associated with two or more center carrier, CC, frequency bandwidths, the MC transmitter apparatus comprising: a plurality of signal processing branches including two or more subsets of signal processing branches, wherein each signal processing branch outputs a baseband communication signal, and each subset of signal processing branches associated with each of the CC frequency bandwidths, in which each subset of signal processing branches is coupled to an MC transmitter, and wherein each signal processing branch from each subset of signal processing branches is combined with signal processing branches from different other subsets of signal processing branches to form multiple combined signal processing branches, wherein each combined signal processing branch outputs a combined baseband communication signal, the method comprising:

estimating the PAPR of each combined baseband communication signal associated with each of the multiple combined signal processing branches；

selecting a set of multiple combined signal processing branches in which the combined estimated PAPR of the corresponding combined baseband communication signals is reduced or minimised compared with the combined estimated PAPR for other sets of multiple combined signal processing branches, wherein each set of multiple combined signal processing branches includes signal processing branches associated with all of the CC frequency bandwidths； and

sending the baseband communication signal outputs associated with the signal processing branches of the selected set of multiple combined signal processing branches to the MC transmitter for uplink transmission.
A method for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communication signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols to output a baseband communication signal for transmission as the uplink communication signal with a reduced or minimised PAPR, the method comprising:

receiving the uplink communication signal transmitted from a transmitter apparatus；

demodulating the uplink communication signal into a scrambled or interleaved set of modulation symbols；

blind decoding the scrambled or interleaved set of modulation symbols by:

selecting a candidate scrambling or interleaving scheme from a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme used by the transmitter apparatus；

decoding the scrambled or interleaved set of modulation symbols；

performing a cyclic redundancy check on the decoded modulation symbols；

when the cyclic redundancy check passes, outputting the decoded modulation symbols, and proceeding to decode any remaining scrambled or interleaved modulation symbols using the candidate scrambling or interleaving scheme whilst performing the CRC check；

when the CRC check fails, selecting another candidate scrambling or interleaving scheme from the set of interleaving schemes and performing the steps of decoding and performing the CRC check on the scrambled or interleaved modulation symbols using the other candidate scrambling or interleaving scheme.
A method for receiving an uplink communication signal from a transmitter apparatus in a wireless communications system, wherein the uplink communication signal is associated with a particular signal processing branch of the transmitter apparatus that uses a particular scrambling scheme or interleaving scheme for scrambling or interleaving modulation symbols prior to processing the scrambled or interleaved modulation symbols as a baseband communication signal for transmission as an uplink communication signal with a reduced or minimised PAPR, and wherein the uplink communication signal includes a control signal identifying the particular scrambling scheme or interleaving scheme, the method further comprising:

receiving the uplink communication signal transmitted from a transmitter apparatus；

detecting the control signal identifying the particular scrambling or interleaving scheme from a set of scrambling or interleaving schemes including the particular scrambling or interleaving scheme；

demodulating the uplink communication signal into a scrambled or interleaved set of modulation symbols； and

decoding the scrambled or interleaved modulation symbols using the identified particular scrambling or interleaving scheme.
Computer readable medium comprising program code stored thereon, which when executed on a processor, causes the processor to perform a method according to claims 37 or 38.
Computer readable medium comprising program code stored thereon, which when executed on a processor, causes the processor to perform a method according to any of claims 39 or 40.
A UE apparatus comprising a transmitter apparatus as claimed in any one of claims 1 to 27
A UE apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the functions associated with the transmitter apparatus as claimed in any one of claims 1 to 27.
A UE apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, and communications interface are configured to perform the method as claimed in any of claims 37 or 38.
A base station apparatus comprising a receiver apparatus as claimed in any one of claims 28 to 36.
A base station apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, communications interface are configured to perform the functions associated with the receiver apparatus as claimed in any one of claims 28 to 36.
A base station apparatus comprising a processor, a storage unit and a communications interface, wherein the processor unit, storage unit, communications interface are configured to perform the method as claimed in any one of claims 39 or 40.
A telecommunications network comprising a plurality of UEs, each UE configured according to any of claims 43 to 45, a plurality of base stations, each base station configured according to any of claims 46 to 48, wherein each base station serves one or more of the plurality of UEs.