WO2010068160A1 - Réglage de puissance adaptatif en mode tdd - Google Patents

Réglage de puissance adaptatif en mode tdd Download PDF

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Publication number
WO2010068160A1
WO2010068160A1 PCT/SE2009/050522 SE2009050522W WO2010068160A1 WO 2010068160 A1 WO2010068160 A1 WO 2010068160A1 SE 2009050522 W SE2009050522 W SE 2009050522W WO 2010068160 A1 WO2010068160 A1 WO 2010068160A1
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Prior art keywords
power control
power
fast fading
frequency bands
indicator
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PCT/SE2009/050522
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English (en)
Inventor
Per BURSTRÖM
Jessica ÖSTERGAARD
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Telefonaktiebolaget L M Ericsson (Publ)
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Publication of WO2010068160A1 publication Critical patent/WO2010068160A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/28—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
    • H04W52/285—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission taking into account the mobility of the user
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
    • H04W52/241—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
    • H04W52/242—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account path loss
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04—TPC
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/28—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
    • H04W52/282—TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission taking into account the speed of the mobile

Definitions

  • TITLE Adaptive power control in TDD mode
  • the present invention relates to a device and a method for adaptive power control in a time division duplex (TDD) communication system.
  • TDD time division duplex
  • a communication system such as a wireless communication system
  • devices communicate with one another while managing various parameters associated with a communication link.
  • a wireless station and user equipment may communicate with one another while managing various parameters, such as power control, that are associated with a communication link.
  • the same frequency band may be used in both uplink and downlink such that channel reciprocity exists. In this regard, the requirement of providing continuous feedback of channel estimates may be unnecessary.
  • Long Term Evolution (LTE) is one of many communication platforms that support TDD.
  • LTE Long-Term Evolution
  • PUCCH Physical Uplink Control Channel
  • the channel may be assumed to be reciprocal during a non- infinitesimal time span, path loss as measured in this way will be very much more representative for the upcoming transmission than a value averaged over the entire bandwidth (which is what traditional power control uses) .
  • the performance gains on system level come from less interference being induced to other users, which is especially important for the PUCCH since it is based on code-division multiplexing access. This, in its turn, leads to lower bit error rate (BER) .
  • BER bit error rate
  • fast fading capturing power control may increase the multiplexing capacity of the PUCCH by as much as a factor of two as compared to regular open loop power control for slow moving users .
  • the physical uplink control channel is part of band edges in a frequency spectrum. For example, in a 10 MHz frequency spectrum, only the two outer resource blocks (e.g., 180 kHz frequency bands) are allocated to the PUCCH.
  • One PUCCH message e.g., ACK/NACK or channel quality indicator (CQI)
  • CQI channel quality indicator
  • power control consists of a closed loop around an open loop point of operation according to the following expression:
  • PpuccH(J) min ⁇ PMAX, PO _ PUCCH + PL + AF __ PUCCH(F) + g(i)[dBm] Eq . 1 , where PPUCCH is the total power, PMAX is the maximum allowed power that depends on the UE power class, Po PUCCH is a parameter composed of the sum of a 5-bit cell specific parameter Po_NOMINAL_PUCCH provided by higher layers with 1 db resolution in the range of [-127, -96] dBm and a UE specific component Po_UE_PUCCH configured by Radio Resource Control (RRC) in the range of [-8, 7] dB with 1 dB resolution, PL is the downlink path loss estimate calculated in the UE, AF _PUCCH(F) corresponds to table entries for each PUCCH transport format (TF) given by the RRC (i.e., an offset for the modulation and coding scheme employed) , and g(i) corresponds the current PUCCH
  • Equation 1 The path loss (PL) in Equation 1 is based on the measured path gain of downlink reference symbols. This measurement is typically done over the entire downlink frequency spectrum and is time-filtered, resulting in a slow- fading, frequency averaged gain of which the power control is based.
  • PUSCH Physical Uplink Shared Channel
  • Fig. 1 is a diagram illustrating TDD open loop ACK/NACK error rates.
  • the UE may, for example, perform measurements on the downlink, determine the fading environment, and manage its power output. For example, the UE may manage its output power so that it reaches a certain signal-to-noise ratio.
  • the technique of using output power based on path loss measured from fast-fading gain on a narrow frequency band works well only if the measurement is accurate and reciprocally or semi-reciprocally reflects the channel for the upcoming uplink transmission. For instance, the fading can change too rapidly to be tracked if the UE moves at high speed.
  • the described embodiments of the invention is directed towards reducing interference on a system level, lowering the bit error rate (BER) and increasing the multiplexing capacity of the UE.
  • BER bit error rate
  • the wireless network comprises a User Equipment and an evolved Node B that are communicatively coupled to each other so that channel reciprocity exists.
  • a first fast fading indicator is continuously monitored.
  • the power control modes are changed, and the User Equipment is being run in a first power control mode.
  • a second fast fading indicator is being monitored.
  • this second indicator fulfills a second condition, power control modes are changed again, and the UE is being run in a second power control mode.
  • the User Equipment is configured to monitor a first fading indicator continuously.
  • a first fast fading indicator fulfills a first condition
  • the UE changes into a first power control.
  • the User Equipment continuously monitors a second fast fading indicator.
  • this second indicator fulfills a second condition
  • the power control modes change again, and the User Equipment now runs in a second power control mode.
  • a UE in TDD mode selectively switches between two or more distinct power control modes for the open loop part of the power control.
  • Either the UE or the serving evolved Node B (eNB) keeps a measure that indicates how fast the frequency-selective fast fading varies for the channel (s) .
  • this measure indicates that control of the PUCCH no longer gains from using frequency-selective path loss estimates, the UE switches (or is directed to switch) over to, and runs in another power control mode to improve system performance. This may or may not occur in conjunction with re-initialization of fast closed loop power control .
  • Fig. 1 is a diagram illustrating simulation results for slow fading versus fast fading compensation within an open loop power control mode
  • Fig. 2A is a diagram illustrating devices communicating with one another via an intermediate device
  • Fig. 233 is a diagram illustrating an exemplary implementation of the devices depicted in Fig. 2A;
  • Fig. 3A is a diagram illustrating exemplary components of the User Equipment (UE) depicted in Fig. 2B;
  • UE User Equipment
  • Fig. 3B is a diagram illustrating functional components of the UE that may monitor fast fading variation, switch power control modes, calculate output power and perform power allocation
  • Fig. 3C is a diagram illustrating an exemplary implementation of the UE that includes a wireless telephone
  • Fig. 4A is a flow chart illustrating the method of the present invention
  • Fig. 4B is a flow diagram related to an exemplary process for calculating and allocating power consistent with concepts describe herein
  • Fig. 5 is a diagram illustrating an exemplary scenario in which the process described herein may be implemented
  • Fig. 6 is a diagram illustrating how frequency bands correspond to resource blocks within spectrum allocations
  • Fig. 7 is a diagram illustrating the relation between resource blocks, symbols, sub-carriers illustrated as a physical resource grid where each column corresponds to one OFDM symbol and each row to one OFDM subcarrier;
  • Fig. 8 is a diagram illustrating the LTE TDD frame structure
  • the UE measures the Reference Symbol Received Power (RSRP) on the downlink frequency bands that correspond to PUCCH transmissions in the upcoming uplink frames and transposes this to path loss. As long as some quality measure of the channel - an indicator (as described more fully below) exceeds a threshold value, the PUCCH transmission power is set using this fast-fading power control mode. If/when a predetermined threshold value is reached, the UE changes its measurement process. For instance, in some embodiments the UE changes into a power control mode based on average path loss over more frames.
  • RSRP Reference Symbol Received Power
  • the UE may fall back onto a power control mode based on traditional path loss measurement, such as a broadband path loss measurement.
  • the UE runs in a power control mode that combines the results of the fast-fading path loss measurements and either the measurement filter output or the traditional path loss measurement to get a more reliable path loss estimate when the threshold has been reached.
  • the instantaneous channel variations are continually monitored via an indicator. Thus, a return of the indicator to a level above a predetermined threshold triggers a return to fast fading power control and to using the fast-fading path loss measurements once more.
  • Embodiments described herein may provide a power control mode applicable to a TDD communication system.
  • the power control mode may measure path loss with respect to frequency bands to which the UE intends to transmit.
  • the frequency bands may correspond to scheduled frequency bands (e.g., an uplink data channel) or on an allocated channel (e.g., an uplink control and/or signaling channel) .
  • the path loss measurements may also include path loss measurements corresponding to individual frequency bands . The individual path loss measurements may be utilized for power allocation.
  • the power control mode may provide a higher PUCCH capacity in TDD mode for messages transmitted thereon
  • the power control mode may provide for improved signaling, as well as other advantages that necessarily flow therefrom.
  • TDD communication systems such as Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN) .
  • Fig. 2A is a diagram illustrating an exemplary communication system 200 in which the concepts described herein may be implemented.
  • communication system 200 may include a device 205, an intermediate device 210, and a device 215.
  • a device may include, for example, a UE, a gateway, a base station, a relay, a repeater, a combination thereof, or another type of device (e.g., a satellite) .
  • the device may operate at layer 1, layer 2, and/or at a higher layer.
  • the devices may be communicatively coupled.
  • the devices may be communicatively coupled via wireless communication links (e.g., radio, microwave, etc.) .
  • Communication system 200 may include a TDD communication system (e.g., a LTE TDD communication system) in which channel reciprocity exists. Since the concepts described herein are applicable to a variety of devices in communication system 200, communication system 200 will be described based on the exemplary devices illustrated in Fig. 2B.
  • Fig. 2B illustrates an exemplary implementation in which device 205 includes a UE, intermediate device 210 includes a base station (e.g., an enhanced Node B (eNodeB) ) , and device 215 includes a UE.
  • Fig. 2B illustrates UE 205, eNodeB 210 and UE 215 as communicatively coupled to form a multi-hop network.
  • UE 205 and 215 may each include a device having communication capability.
  • a UE may include a telephone, a computer, a personal digital assistant (PDA) , a gaming device, a music playing device, a video playing device, a web browser, a personal communication system (PCS) terminal, a pervasive computing device, and/or some other type of communication device.
  • PDA personal digital assistant
  • gaming device a gaming device
  • music playing device a music playing device
  • video playing device a web browser
  • PCS personal communication system
  • pervasive computing device a pervasive computing device, and/or some other type of communication device.
  • ENodeB 210 may include a device having communication capability.
  • ENode B 210 may operate in a LTE communication system (not illustrated) .
  • the LTE communication system may include access gateways (AGWs) connected to various types of networks (e.g., Internet Protocol (IP) networks, etc) .
  • AGWs access gateways
  • IP Internet Protocol
  • power control may be implemented between the devices in communication system 200, as illustrated in Fig. 2B.
  • Fig. 2B illustrates an exemplary communication system 200, in other implementations, fewer, different, and/or additional devices, arrangements, etc., may be utilized in accordance with the concepts described herein.
  • Fig. 3A is a diagram illustrating exemplary components of UE 205.
  • UE 215 may be similarly configured.
  • the term component is intended to be broadly interpreted to include, for example, hardware, software and hardware, firmware, software, a combination thereof, and/or some other type of component.
  • UE 205 may include a processing system 300, transceiver 305, antenna 310, a memory 315, an input device 320, and an output device 325.
  • Processing system 300 may include a component capable of interpreting and/or executing instructions.
  • processing system 300 may include a general- purpose processor, a microprocessor, a data processor, a co-processor, a network processor, an application specific integrated circuit (ASIC) , a controller, a programmable logic device, a chipset, and/or a field programmable gate array (FPGA) .
  • ASIC application specific integrated circuit
  • Processing system 300 may control one or more other components of UE 205.
  • Processing system 300 may be capable of performing various communication-related processing (e.g., signal processing, channel estimation, power control, timing control, etc.), as well as other operations associated with the operation and use of UE 205.
  • various communication-related processing e.g., signal processing, channel estimation, power control, timing control, etc.
  • Transceiver 305 may include a component capable of transmitting and/or receiving information over wireless channels via antennas 310.
  • transceiver 305 may include a transmitter and a receiver.
  • Transceiver 305 may be capable of performing various communication-related processing (e.g., filtering, de/coding, de/modulation, signal measuring, etc.) .
  • Antenna 310 may include a component capable of receiving information and transmitting information via wireless channels.
  • antenna 310 may include a multi-antenna system (e.g., a MIMO antenna system) .
  • Antenna 310 may provide one or more forms of diversity (e.g., spatial, pattern, or polarization) .
  • Memory 315 may include a component capable of storing information (e.g., data and/or instructions) .
  • memory 315 may include a random access memory (RAM) , a dynamic random access memory (DRAM) , a static random access memory (SRAM) , a synchronous dynamic random access memory (SDRAM) , a ferroelectric random access memory (FRAM) , a read only memory (ROM) , a programmable read only memory (PROM) , an erasable programmable read only memory (EPROM) , an electrically erasable programmable read only memory (EEPROM) , and/or a flash memory.
  • Input device 320 may include a component capable of receiving an input from a user and/or another device.
  • input device 320 may include a keyboard, a keypad, a touchpad, a mouse, a button, a switch, a microphone, a display, and/or voice recognition logic.
  • Output device 325 may include a component capable of outputting information to a user and/or another device.
  • output device 325 may include a display, a speaker, one or more light emitting diodes (LEDs), a vibrator, and/or some other type of visual, auditory, and/or tactile output device.
  • LEDs light emitting diodes
  • UE 205 may include fewer, additional, and/or different components than those depicted in Fig. 3A.
  • UE 205 may include a hard disk or some other type of computer-readable medium along with a corresponding drive.
  • the term "computer-readable medium,” as used herein, is intended to be broadly interpreted to include, for example, a physical or a logical storing device. It will be appreciated that one or more components of UE 205 may be capable of performing one or more other tasks associated with one or more other components of UE 205.
  • Fig. 3B is a diagram illustrating exemplary functional components capable of performing one or more operations associated with the concepts described herein.
  • the exemplary functional component may be implemented in processing system 300 of UE 205.
  • this functional component may be implemented in connection with, for example, other components (e.g., transceiver 305) of UE 205, in combination with two or more components (e.g., processing system 300, transceiver 305, memory 315) of UE 205, and/or as an additional component (s) to those previously described in Fig. 3A.
  • the functional components may include a power calculator 325 and a power allocator 330.
  • Power calculator 325 may include a component capable of determining one or more power values and/or power- related values in accordance with the power mode described herein. For example, power calculator 325 may determine one or more power values that may influence the output power of a transmission by UE 205. As will be described in greater detail below, power calculator 325 may determine a power value based on path loss estimates corresponding to frequency bands in which UE 205 intends to transmit. The path loss estimates may include individual path loss estimates that correspond to individual frequency bands .
  • Power allocator 330 may include a component capable of assigning power output to a transmission based on the power values and/or power-related values determined by power calculator 325. For example, power allocator 330 may assign power values to addressable units (e.g., resource blocks, och carrier frequencies) of a transmission. Power allocator 330 may allocate output power based on the individual path loss estimates.
  • addressable units e.g., resource blocks, och carrier frequencies
  • UE 205 may include fewer, additional, and/or different functional components than those depicted in Fig. 3B. It will be appreciated that one or more functional components of UE 205 may be capable of performing one or more other tasks associated with one or more other functional components of UE 205.
  • Fig. 3C is a diagram illustrating an exemplary implementation of UE 205, where UE 205 includes a wireless telephone.
  • UE 205 may include a microphone 335 (e.g., of input device 320) for entering audio information, a speaker 340 (e.g., of output device 325) for outputting audio information, a keypad 345 (e.g., of input device 320) for entering information or selecting functions, and a display 350 (e.g., of input device 320 and/or output device 325) for outputting visual information and/or inputting information, selecting functions, etc.
  • a microphone 335 e.g., of input device 320
  • speaker 340 e.g., of output device 325
  • a keypad 345 e.g., of input device 320
  • a display 350 e.g., of input device 320 and/or output device 325) for outputting visual information and/or inputting information, selecting functions, etc.
  • UE 205 may include fewer, additional, or different exemplary components than those depicted in Fig. 3C.
  • step 600 the UE is in a traditional power control mode, i.e. the UE is using some version of wideband path loss measurements to calculate an appropriate output power level .
  • step 600 the UE is monitoring a reference signal's SNR variation.
  • the SNR variation is a good indicator of the behaviour of the fast fading.
  • the UE is waiting for the SNR variation to descend below a predetermined threshold.
  • the decision could here be based on a multitude of parameters indicative of fast fading variation, e.g., by measuring, or obtaining from an advanced eNodeB, the Doppler shift and determining the UE speed to be above a certain threshold, interference measurements, uplink channel variation autocorrelation (possible due to reciprocity) , rank adaptation information, processed channel information, such as DL transmission mode (e.g. closed or open loop spatial multiplexing or other mode that implies slow or fast channel variations), or a suitable combination of said methods .
  • DL transmission mode e.g. closed or open loop spatial multiplexing or other mode that implies slow or fast channel variations
  • a Doppler shift measurement will probably be available for other purposes in an advanced eNB and an advanced UE. This means that using the Doppler shift as an indicator of channel variations is just a reuse of an existing measurement.
  • step 606 the UE monitors the SNR variation again, i.e. in this particular embodiment the first and second fast fading indicator are identical. However, where appropriate, a second fast fading indicator, based on one or many parameters indicative of the fast fading variation, such as e.g. the ones above, could be monitored instead.
  • step 608 the UE waits for the SNR variation to exceed a predetermined threshold. This will typically happen when the UE increases its speed. This threshold is slightly above the threshold used in step 602, so as to achieve hysteresis in order to avoid flickering between power control modes .
  • the same predetermined threshold is used in steps 602 and 608. It is to be noted though, that the conditions for switching in steps 602 and 608 are different also in this alternative embodiment, since the first condition is to descend below the threshold and the second condition is to exceed the same threshold.
  • the threshold is set at a level where fast-fading path loss measurements no longer give path loss predictions that are both accurate and timely. This may occur, e.g., if the measurement inaccuracies become too large, or if the power setting cannot be done quickly enough to utilize the measurements, Typically the threshold is exceeded while the UE is increasing its speed. It can also occur due to increased occurrence of moving surrounding objects, such as e.g. cars or buses.
  • the threshold is exceeded, using one (or more) of several possible decision mechanism, the UE changes its measurement process when switching power control modes in step 610, so that the method of measurement is changed to traditional wideband path loss.
  • the decision mechanism can be one of several options, such as : a) The UE recognizing by itself that it cannot track the fast fading and thus autonomously adjusts its method of measurement . b) A response to the UE being configured for a specific antenna selection scheme. c) The serving eNB instructing the UE to adjust the measurement to any of the alternative measurements mentioned above.
  • the instruction can be explicit or implicit, through the signaling or another parameter with which the pathloss measurement instruction is coupled.
  • the total system performance improves through the reduction of interference on PUCCH transmissions. Meanwhile, fast fading is being monitored, in order to facilitate a quick return back to narrowband measurements .
  • the UE changes its measurement filter to average path loss over more frames.
  • the method of measurement is changed to traditional wideband path loss.
  • fast-fading measurements can be combined with longer-term, frequency-selective measurements or with traditional wideband path loss measurements.
  • two or more of these approaches may be selectively used, depending on the channel conditions .
  • the monitoring of the fast fading indicators and the decision mechanisms used in steps 602 and 608 reside in the eNB .
  • At least one fast fading indicator is a mathematical function of several parameters, and at least one of the parameters is measured in the UE and at least one is measured in the eNB.
  • At least one fast fading indicator is a mathematical function of several parameters all of which are measured in the eNB.
  • the power control method used during the fast fading power control mode in a preferred embodiment is described below.
  • An exemplary process is described below, in connection with Fig. 4B, in which UE 205 may perform a power control mode.
  • the exemplary process will be described based on communication system 200 depicted in Fig. 2B. However, it will be appreciated that the exemplary process may be performed in communication system 200 depicted in Fig. 2A, in which different devices may be present.
  • Fig. 4B is a flow diagram illustrating an exemplary process 400 for calculating and allocating power.
  • the exemplary process 400 of FIG. 4B may be performed by UE 205 for controlling power with respect to a transmission.
  • process 400 will be described in connection with previous figures, as well as Fig. 5.
  • Process 400 may begin with receiving signals in a downlink frequency domain to enable channel estimation (block) .
  • eNodeB 210 may transmit a downlink signal 505.
  • the received signal may include, for example, a pilot signal or some other reference signal.
  • Frequency bands in the downlink frequency domain that correspond to uplink frequency bands associated with a channel allocation or a scheduling grant may be selected (block 410) .
  • transceiver 305 may select the frequency bands in downlink signal 505 that correspond to uplink frequency bands associated with the PUCCH or the PUSCH.
  • the frequency bands selected may correspond to the frequency bands in which UE 205 intends to transmit based on its uplink power control 510.
  • the frequency bands may correspond to the outer frequency bands in a uplink frequency spectrum.
  • the frequency bands may correspond to the frequency bands (e.g., resource blocks) in which UE 205 received a scheduled grant in the uplink frequency spectrum.
  • the frequency band may correspond to carrier frequencies .
  • the selected frequency bands may be measured (block 415) .
  • transceiver 305 may perform channel measurements on the selected frequency bands.
  • the channel measurements may include fast fading even though this is typically (according to LTE standard) filtered away. Further, if the measurements are performed expediently, such measurements may well match the expected channel of the upcoming PUCCH transmission or PUSCH transmission in TDD.
  • the PUCCH for example, downlink pilots in the two corresponding PUCCH frequency bands (typically 18OkHz on the bandwidth edges) may be measured.
  • the PUSCH for example, all PUSCH resource blocks may be measured individually.
  • the carrier frequencies may be measured individually and also the PUSCH resource blocks within each carrier frequency.
  • Path losses based on the measured selected frequency bands may be estimated (block 420) .
  • power calculator 325 of UE 205 may estimate path losses (PL) based on the pilots in the frequency bands in which UE 205 intends to transmit.
  • PL path loss value
  • power calculator 325 may estimate two individual path loss values, , corresponding to both slots.
  • a path loss value (PL) may be estimated by power calculator 325 based on the PUSCH measurements.
  • power calculator 325 may estimate individual path loss values, PL ⁇ ,P ⁇ 2,...,PLx based on the PUSCH measurements.
  • power calculator 325 may not estimate individual path loss values for the PUSCH.
  • a total power based on the estimated path losses may be calculated (block 425) .
  • power calculator 325 may calculate a total power based on equations 1 and 2, as previously described above.
  • the path loss value (PL) relates to a path loss corresponding to frequency bands on which UE 205 intends to transmit versus the entire downlink frequency spectrum.
  • power calculator 325 may calculate an average power budget with respect to the resource blocks in the PUSCH. In such instances, individual power values may be estimated.
  • the power values PPUCCHI and PPUCCH2 may be calculated according to the standard formula Eq.1 using individual PL values.
  • a power allocation based on the calculated total power may be determined (block 430) .
  • a number of different power allocation schemes associated with the slots may be implemented by power allocator 330 of UE 205.
  • all of the power e.g., 2 * PPUCCH_AVG
  • the criterion for determining the best slot may be based on the slot that has the minimum path loss.
  • all of the power may be allocated to the best slot if the absolute value of the difference in path losses, PLi,PLi , is larger than a specified threshold. In the event that the difference in path losses is less than the threshold, the total power may be distributed between both slots.
  • the threshold may be any value (e.g., one to infinity) .
  • all of the power may be allocated in a manner that provides that both PUCCH slots are received by eNodeB 210 at equal strength. For example, the power allocation of each slot may be determined based on the following expression:
  • the variable A is a parameter that is used to tune the water filling algorithm.
  • the power allocation may be different for ACK/NACK and CQI transmissions. For example, for ACK/NACK transmissions, all of the power may be allocated to the slot that has the minimum path loss since the same information is transmitted on both slots. On the other hand, for example, for CQI transmissions, all of the power may be allocated in a manner that provides that both slots are received by eNodeB 210 at equal strength since different information may be transmitted in each slot.
  • the total power may be allocated to the frequency bands associated with the uplink grant.
  • power allocator 330 may a power allocation scheme based on the schemes described for the PUCCH .
  • An uplink transmission based on the determined power allocation may be transmitted (block 435) .
  • UE 205 may transmit an uplink transmission 515 based on the determined power allocation.
  • a device such as UE 205, may employ a power scheme that includes calculating power values and/or power-related values based on path losses that correspond to frequency bands in which UE 205 intends to transmit. In the case of a LTE communication system, application of these concepts has been described in connection with the PUCCH and the PUSCH. The device, such as UE 205, may also manage power allocation based on individual path losses. Power allocation schemes may be tailored to the particular information being transmitted. For example, as previously described, different power allocation schemes may be used between ACK/NACK and CQI transmissions.
  • the utilization of channel reciprocity is an important way to improve PUCCH capacity, which can be further improved by fast-fading power control.
  • the controllability described herein is vital if the fast- fading tracking becomes infeasible, since trying to track fast fading in that case will cause a performance loss when compared to using traditional path loss estimates.

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  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention concerne un procédé permettant de réduire les parasites dans un réseau sans fil grâce au passage d’un mode de réglage de puissance à un autre. Ledit réseau sans fil comprend un Equipement Utilisateur et un Nœud B évolué couplés de manière communicante, de sorte qu’il existe une réciprocité entre les canaux. Selon ce procédé, un premier indicateur d’évanouissement rapide est surveillé en continu. Lorsque ce premier indicateur d’évanouissement rapide remplit une première condition, les modes de réglage de puissance sont changés, et l’Equipement Utilisateur se met à fonctionner selon un premier mode de réglage de puissance. Dans ce premier mode de réglage de puissance, un second indicateur d’évanouissement rapide est surveillé en continu. Lorsque ce second indicateur remplit une seconde condition, les modes de réglage de puissance sont changés à nouveau, et l’UE se met à fonctionner selon un second mode de réglage de puissance. Grâce au passage d’un mode de réglage de puissance à un autre, le niveau de parasites du système se trouve réduit.
PCT/SE2009/050522 2008-12-08 2009-05-11 Réglage de puissance adaptatif en mode tdd WO2010068160A1 (fr)

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US61/120,601 2008-12-08

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WO2011014435A1 (fr) * 2009-07-30 2011-02-03 Qualcomm Incorporated Procédé et appareil de détection d'un état de canal pour dispositif de communication sans fil
WO2012000340A1 (fr) * 2010-07-02 2012-01-05 中兴通讯股份有限公司 Procédé et appareil de mappage d'affaiblissement de trajet de cellule voisine
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CN111787623A (zh) * 2020-06-28 2020-10-16 重庆邮电大学 一种联合功率控制、上下行信道分配和模式选择的d2d通信资源分配方法

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8979349B2 (en) 2009-05-29 2015-03-17 Qualcomm Mems Technologies, Inc. Illumination devices and methods of fabrication thereof
US9121979B2 (en) 2009-05-29 2015-09-01 Qualcomm Mems Technologies, Inc. Illumination devices and methods of fabrication thereof
WO2011014435A1 (fr) * 2009-07-30 2011-02-03 Qualcomm Incorporated Procédé et appareil de détection d'un état de canal pour dispositif de communication sans fil
WO2012000340A1 (fr) * 2010-07-02 2012-01-05 中兴通讯股份有限公司 Procédé et appareil de mappage d'affaiblissement de trajet de cellule voisine
CN102333369A (zh) * 2011-10-19 2012-01-25 中兴通讯股份有限公司 一种对数据调度进行控制的方法和系统
CN102333369B (zh) * 2011-10-19 2018-07-24 南京中兴新软件有限责任公司 一种对数据调度进行控制的方法和系统
US10098181B2 (en) 2014-03-19 2018-10-09 Apple Inc. Selecting a radio access technology mode based on current conditions
JP2019041174A (ja) * 2017-08-23 2019-03-14 日本電気株式会社 通信システム
CN111787623A (zh) * 2020-06-28 2020-10-16 重庆邮电大学 一种联合功率控制、上下行信道分配和模式选择的d2d通信资源分配方法
CN111787623B (zh) * 2020-06-28 2022-04-26 重庆邮电大学 一种复用上下行信道的d2d通信资源分配方法

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