RU2479924C2 - Method and apparatus for adjustments for delta-based power control in wireless communication systems - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: systems and methods are described, which provide techniques for performing adjustments for delta-based power control and interference management in a wireless communication system. A terminal can utilise one or more delta-based power control techniques described herein during participation in a reverse link transmission after a predetermined period of silence or after receiving indications of interference from neighbouring access points. A delta value can be computed through open-loop projection, based on which transmission resources such as bandwidth and/or transmission power can be increased or decreased to manage interference caused by the terminal. A delta value, other feedback from the terminal and/or indications of interference caused by the terminal can also be communicated as feedback to a serving access point to allow the access point to assign transmission resources for the terminal.

EFFECT: mitigating interference effects in a wireless communication system.

20 cl, 15 dwg

Description

CROSS REFERENCE

This application claims the priority of provisional application US No. 60/843365, filed September 8, 2006, entitled "METHODS AND DEVICE FOR CORRECTIONS BASED ON DELTA VALUE OF POWER MANAGEMENT IN WIRELESS COMMUNICATION SYSTEMS" and provisional application US No. 60/862765 year entitled "METHODS AND DEVICE FOR CORRECTIONS ON THE BASIS OF DELTA VALUE OF POWER MANAGEMENT IN WIRELESS COMMUNICATION SYSTEMS", the contents of which are fully incorporated into this document by reference.

I. The technical field to which the invention relates.

The present disclosure generally relates to wireless communications and, more specifically, to technologies for power control and interference control in a wireless communications system.

II. State of the art

Wireless communication systems are widely used to provide a variety of communication services; for example, voice, video, packet data, broadcast and message services can be provided through such wireless communication systems. These systems may be multiple access systems that are capable of communicating with multiple terminals by sharing available system resources. Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems and orthogonal frequency division multiple access (OFDMA) systems.

A multiple access wireless communication system can simultaneously support communication for multiple wireless terminals. In such a system, each terminal can communicate with one or more sectors through transmissions on the forward and reverse links. A forward link (or downlink) refers to a communication channel from sectors to terminals, and a reverse link (or uplink) refers to a communication channel from terminals to sectors.

Many terminals can simultaneously transmit on the reverse link due to the multiplexing of their transmissions to ensure their orthogonality with respect to each other in the time, frequency and / or code domain. Upon achieving full orthogonality between transmissions, transmissions from each terminal will not interfere with transmissions from other terminals in the receiving sector. However, full orthogonality between transmissions from different terminals is often not realized due to channel conditions, imperfections in receivers, and other factors. As a result, terminals often generate some amount of interference to other terminals communicating with the same sector. Moreover, since transmissions from terminals communicating with different sectors are generally not orthogonal to each other, each terminal may also interfere with terminals communicating with nearby sectors. This interference leads to reduced performance at each terminal in the system. Accordingly, there is a need in the art for effective technologies to mitigate interference effects in a wireless communication system.

SUMMARY OF THE INVENTION

The following is a simplified summary of the disclosed embodiments in order to provide an overview of such embodiments. This disclosure is not a detailed overview of all the alleged embodiments and is not intended to identify key or critical elements, nor to determine the scope of such embodiments. Its sole purpose is to present some ideas of the disclosed embodiments in a simplified form as an introduction to the more detailed description that is presented below.

The described embodiments mitigate the above problems by providing technologies for managing reverse link transmission resources to control observed interference in a wireless communication system. More specifically, a terminal in a wireless communication system may adjust resources used to communicate with an access point on a reverse link using one or more delta-based (delta-based) power control technology. For example, a terminal may use one or more delta-based power control technology described herein when the terminal participates in reverse link transmission with a serving access point after a predetermined period of silence or after receiving interference metrics from neighboring access points. The terminal may first calculate the delta value by designing an open loop based on which transmission resources, such as bandwidth and / or transmit power, can be increased or decreased to control the interference caused by the terminal. In addition, the delta value, other feedback from the terminal, and / or interference metrics generated by the terminal can be reported as feedback to the serving access point to allow the access point to further assign transmission resources to the terminal.

According to one aspect, a method for power control in a wireless communication system is described herein. The method may comprise determining whether there has been a previous transmission of a previously predetermined threshold value. In addition, the method may include the step of calculating one or more of the open loop delta values, the open loop delta values based on the assigned bandwidth or the bandwidth based on the delta value. Additionally, the method may comprise adjusting one or more parameters for use in a future transmission, at least in part, based on the calculated values.

Another aspect relates to a wireless communication device, which may comprise a storage device that stores data regarding the time at which the previous transmission was conducted and the threshold value. The wireless communication device may further include a processor configured to determine whether a previous transmission of a previously threshold value has occurred and, if the determination is positive, calculating one or more of the open loop delta value, the open loop delta value based on the assigned bandwidth or bandwidth based on the delta value, and adjusting the parameter to be used for transmissions based on the calculated values.

Another aspect relates to a device that provides reverse link power control in a wireless communication system. The device may include means for performing transmission to the serving sector on the reverse link. In addition, the device may include means for determining whether transmission has occurred outside of the temporary threshold value. Additionally, the device may include means for calculating an open loop delta value, an open loop delta value, or a bandwidth based on a delta value, if the determination is positive. The device may also include means for adjusting a parameter used to transmit to the serving sector based on the calculated value.

An additional aspect relates to a computer-readable medium, which may contain code for causing the computer to transmit on the reverse link to the base station after a predetermined temporary threshold value. The computer-readable medium may further include code for causing a computer to calculate one or more open loop delta parameters. In addition, the computer-readable medium may include code for causing the computer to adjust the bandwidth and / or transmit power used for future transmissions to the base station, at least in part, based on the calculated open loop delta parameters.

According to another aspect, an integrated circuit is described herein that can execute computer-executable instructions for controlling power and controlling reverse link interference in a wireless communication system. These instructions may include performing reverse link transmission to the serving sector. Additionally, the instructions may comprise determining whether an OSI metric corresponding to reverse link transmission has been received. Additionally, the instructions may include adjusting one or more parameters to be used for future transmissions on the reverse link, based at least in part on whether an OSI metric has been received.

According to another aspect, a method for performing reverse link power control in a wireless communication system is described herein. The method may comprise receiving a communication request and / or power control feedback information from a terminal. In addition, the method may include receiving a report on the OSI activity generated by the terminal. Additionally, the method may include setting a parameter that is used to communicate with the terminal based on the received information and the received OSI activity report.

Another aspect relates to a wireless communication device, which may include a storage device that stores data regarding an OSI activity report generated by an access terminal and power control feedback information received from an access terminal. In addition, the wireless communication device may include a processor configured to generate an assignment for transmission resources based on at least one OSI activity report or power control feedback information and an assignment message to the access terminal.

Another aspect relates to an apparatus that provides power control and reverse link interference control in a wireless communication system. The device may comprise means for receiving power control information and OSI information corresponding to a wireless terminal. Additionally, the device may include means for assigning one or more of the transmission power and bandwidth to the wireless terminal, at least in part, based on the received information. The device may further include means for reporting the assigned transmit power or the assigned bandwidth to the wireless terminal.

An additional aspect relates to computer-readable media, which may include code for causing a computer to receive an OSI activity report generated by a terminal. Additionally, the computer-readable medium may include code for causing the computer to generate an assignment for one or more of the transmission power and bandwidth intended for use by the terminal, at least in part, based on the received report. In addition, the computer-readable medium may further include code for causing a computer to communicate an assignment to a terminal.

An additional aspect described herein relates to an integrated circuit that can execute computer-executable instructions for controlling power and controlling reverse link interference in a wireless communication system. These instructions may include receiving feedback information from the terminal, wherein the feedback information contains a report on OSI metrics received by the terminal. Additionally, the instructions may comprise assigning transmission resources to the terminal based on the received feedback information. In addition, instructions may include reporting to the terminal the assigned transmission resources.

In conclusion of the above and related results, one or more embodiments comprise features described in more detail below and specifically indicated in the claims. The following description and the annexed drawings in detail reflect some illustrative features of the disclosed embodiments. These features, however, testify only to some of the various ways of applying the principles of various embodiments. Additionally, the disclosed embodiments are intended to include all such features and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless multiple access communication system in accordance with various aspects set forth herein.

FIG. 2A-2B illustrate the operation of an illustrative system for delta-based power control in a wireless communication system in accordance with various aspects.

FIG. 3A-3B illustrate the operation of an exemplary system for power control and reverse link interference control in a wireless communication system in accordance with various aspects.

FIG. 4 shows an illustrative timing diagram of a reverse link transmission in accordance with various aspects.

FIG. 5 is a flowchart of a method for adjusting reverse link transmission resources in a wireless communication system.

FIG. 6 is a flowchart of a method for adjusting reverse link transmission resources to reduce interference in a wireless communication system.

FIG. 7 is a flowchart of a method for performing power control and reverse link interference control in a wireless communication system.

FIG. 8 is a block diagram illustrating an example wireless communication system in which one or more of the embodiments described herein may function.

FIG. 9 is a block diagram of a system that facilitates reverse link power control in accordance with various aspects.

FIG. 10 is a block diagram of a system that coordinates reverse link power control and interference control in accordance with various aspects.

FIG. 11 is a block diagram of an apparatus that facilitates initial adjustments to transmission resources in a wireless communication system.

FIG. 12 is a block diagram of an apparatus that facilitates adjusting reverse link transmission resources to control interference in a wireless communication system.

FIG. 13 is a block diagram of an apparatus that facilitates power control and reverse link interference control in a wireless communication system.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments will now be described with reference to the drawings, with the same reference numbers throughout being used to refer to the same elements. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects of the invention. However, it can be clearly seen that such embodiment (s) of implementation can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

As used in this application, the terms "component", "module", "system", etc. refers to a computer-related object, or hardware, or firmware, or a combination of hardware and software, software, or executable software. For example, a component may be, but is not limited to, a process running on a processor, an integrated circuit, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application executed on a computing device and a computing device may be a component. One or more components may belong to a process and / or thread of execution, and the component may be localized on one computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media storing various data structures. Components can exchange information through local and / or remote processes, for example, in accordance with a signal containing one or more data packets (for example, data from one component interacting with another component in a local system, distributed system, and / or over a network, such as the Internet, with other systems through a signal).

In addition, various embodiments are described herein with reference to a wireless terminal and / or base station. A wireless terminal may refer to a device that provides the ability to interact with the user through voice and / or data. The wireless terminal may be connected to a computing device, such as a laptop computer or desktop computer, or it may be a stand-alone device, such as a personal digital assistant (PDA). A wireless terminal may also be called a system, subscriber module, subscriber station, mobile station, mobile device, remote station, access point, remote terminal, access terminal, user terminal, user intermediary, user device or user equipment. A wireless terminal may be a subscriber station, a wireless device, a cellular telephone, a digital cellular telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless subscriber access station (WLL), a handheld personal computer (PDA), portable a device having the ability to wirelessly connect, or another processing device connected to a wireless modem. A base station (eg, an access point) may refer to a device in an access network that communicates over the air interface, through one or more sectors, with wireless terminals. The base station can act as a routing device between the wireless terminal and the rest of the access network, which can include an Internet Protocol (IP) network, converting frames received through the air interface into IP packets. In addition, the base station coordinates attribute management for the air interface.

Moreover, various aspects or features described herein may be implemented in the form of a method, device, or product using standard software and / or engineering technologies. The term “product,” as used herein, is intended to encompass a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to, magnetic storage devices (eg, hard disk, floppy disk, magnetic cards, ...), optical disks (eg, compact disc (CD), digital versatile disk (DVD) , ...), smart cards and flash memory devices (for example, a card, memory card, key drive, ...).

Various embodiments will be presented based on systems that may include a variety of devices, components, modules, and the like. You need to understand and take into account that various systems may include additional devices, components, modules, etc., and / or may not include all devices, components, modules, etc., considered in relation to the drawings . A combination of these approaches can also be used.

FIG. 1 is a depiction of a wireless multiple-access communication system 100 in accordance with various aspects. In one example, a wireless multiple-access communication system 100 includes a plurality of base stations 110 and a plurality of terminals 120. Additionally, one or more base stations 110 may communicate with one or more terminals 120. As a non-limiting example, the base station 110 may be access point, Node B and / or other suitable network entity. Each base station 110 provides a communication coverage area for a particular geographic area 102a-c. As used herein and generally in the art, the term “cell” may refer to base station 110 and / or its service area 102, depending on the context in which the term is used.

To increase system capacity, the service area 102a corresponding to base station 110 may be divided into multiple smaller areas (e.g., areas 104a, 104b, and 104c). Each of the smaller areas 104a, 104b, and 104c may be served by a respective base transceiver subsystem (BTS, not shown). As used herein and generally in the art, the term “sector” may refer to the BTS and / or its service area, depending on the context in which the term is used. In one example, sectors 104 in cell 102a may be formed by antenna groups (not shown) at base station 110, each antenna group being responsible for communicating with terminals 120 in a portion of cell 102. For example, base station 110 serving cell 102a may have a first antenna group corresponding to sector 104a, a second antenna group corresponding to sector 104b, and a third antenna group corresponding to sector 104c. It should be borne in mind that various aspects of the invention disclosed herein can be used in a system having sectorized and / or non-sectorial cells. Additionally, it should be borne in mind that all suitable wireless communication networks having any number of sectors divided into sectors and / or sectors not divided into sectors assume falling within the scope of the claims appended to this document. For simplicity, the term “base station,” as used herein, can refer to both a station that serves a sector and a station that serves a cell. As further used herein, a “serving” access point is an access point with which a given terminal is in communication, and a “neighboring” access point is an access point with which a given terminal is not in communication. While the following description, as a rule, relates to a system in which, for simplicity, each terminal communicates with one serving access point, it must be taken into account that the terminals can communicate with any number of serving access points.

In accordance with one aspect of the invention, terminals 120 may be dispersed throughout the system 100. Each terminal 120 may be stationary or mobile. By way of non-limiting example, terminal 120 may be an access terminal (AT), a mobile station, user equipment, a subscriber station, and / or another suitable network entity. Terminal 120 may be a wireless device, a cellular telephone, a personal digital assistant (PDA), a wireless modem, portable device, or other suitable device. Additionally, terminal 120 may communicate with any number of base stations 110 or with none of the base stations 110 at any given point in time.

In another example, system 100 may utilize a centralized architecture using a system controller 130 that can be connected to one or more base stations 110 and provide coordination and control for base stations 110. In accordance with another aspect, system controller 130 may be a separate network An object or set of network objects. Additionally, system 100 may utilize a distributed architecture to allow base stations 110 to communicate with each other if necessary. In one example, system controller 130 may further comprise one or more connections to multiple networks. These networks may include the Internet, other packet-switched networks and / or circuit-switched telephone networks that can deliver information to terminals 120 in communication with one or more base stations 110 in system 100, and / or from them. In another example, system controller 130 may include or be connected to a scheduler (not shown) that can schedule transmissions to and from terminals 120 and / or from them. Alternatively, the scheduler may be located in each individual cell 102, each sector 104, or a combination thereof.

In one example, system 100 may utilize one or more multiple access schemes, such as CDMA, TDMA, FDMA, OFDMA, Single Carrier FDMA (SC-FDMA), and / or other suitable multiple access schemes. TDMA utilizes time division multiplexing (TDM), with transmissions for various terminals 120 being orthogonalized due to transmission in different time intervals. FDMA uses frequency division multiplexing (FDM), with transmissions for various terminals 120 being orthogonalized due to transmission in different frequency subcarriers. In one example, TDMA and FDMA systems can also use code division multiplexing (CDM), while transmissions for multiple terminals can be orthogonalized by using different orthogonal codes (e.g., Walsh codes), even though they are sent in the same same time slot or frequency subcarrier. OFDMA uses orthogonal frequency division multiplexing (OFDM), and SC-FDMA uses single-carrier frequency division multiplexing (SC-FDM). OFDM and SC-FDM can split the system bandwidth into multiple orthogonal subcarriers (eg, tones, bins, ...), each of which can be modulated with data. Typically, modulation symbols are sent in the frequency domain using OFDM, and in the time domain using SC-FDM. Additionally and / or alternatively, the system bandwidth may be divided into one or more frequency carriers, each of which may contain one or more subcarriers. System 100 may also use a combination of multiple access schemes, such as OFDMA and CDMA. Although the power control technologies presented herein are generally described for an OFDMA system, it should be appreciated that the technologies described herein can similarly be applied to any wireless communication system.

In another example, base stations 110 and terminals 120 in system 100 may communicate using one or more data channels and signaling using one or more control channels. The data channels used by system 100 can be allocated to active terminals 120 so that each data channel is used by only one terminal at a given time. Alternatively, data channels may be allocated to a plurality of terminals 120, which may overlap or be distributed orthogonally over the data channel. To conserve system resources, control channels used by system 100 can also be shared by multiple terminals 120 using, for example, code division multiplexing. In one example, data channels orthogonally multiplexed only in frequency and time (for example, data channels not multiplexed using CDM) may be less susceptible to loss of orthogonality due to channel conditions and receiver imperfections than corresponding control channels.

In accordance with one aspect, system 100 may utilize central scheduling through one or more scheduling devices implemented, for example, in system controller 130 and / or in each base station 110. In a system using central scheduling, scheduler (s) may depend on feedback information from terminals 120 when making appropriate scheduling decisions. In one example, this feedback information may include power amplifier reserve (PA) feedback information to enable the scheduler to evaluate an acceptable peak reverse link rate for terminal 120 from which such feedback information is received, and accordingly allocate a width strip system.

In accordance with another aspect, base stations 110 may broadcast or otherwise transmit interference metrics to terminals 120. In one example, base station 110 may broadcast another sector interference (OSI) messages and / or other similar information corresponding to whether it is experiencing base station 110 excessive interference. This information may be broadcast via an OSI dedicated channel and / or other suitable channel. Once transmitted, OSI messages can then be used by terminals 120 to adjust resources used for reverse link transmission. As a typical example, these resources may include a power spectral density (PSD) parameter, which is based on the difference between the data channel PSD, the control channel PSD, and the difference in long-term average path loss between the serving base station 120 and one or the most powerful neighboring base stations 120. In another representative example, reverse link interference management can be used by system 100 to guarantee minimum system stability and quality of service (QoS) parameters for system. More specifically, decoding the error probability of an acknowledgment message transmitted on a reverse link (RL) can be used by system 100 as a minimum error level for all transmissions on a forward link. By applying interference management to the RL, system 100 can facilitate energy efficient transmission of control traffic and QoS and / or other traffic with strict error requirements.

FIG. 2A-2B are block diagrams that demonstrate the operation of an exemplary system 200 for delta-based power control in a wireless communication system. In one example, system 200 includes a terminal 210 that can communicate with a base station 220 on the forward and reverse links through one or more antennas 216 at the terminal 210 and one or more antennas 222 at the base station 220. that base station 220 may provide coverage for a cell (eg, cell 102) or an area within the cell (eg, sector 104). In addition, while for brevity, only one terminal 210 and base station 220 are displayed in system 200, system 200 may include any number of base stations and / or terminals. For example, system 200 may include one or more neighboring base stations that may provide coverage for respective geographic areas, which may include all, part, or none of the areas covered by base station 220.

In accordance with one aspect, terminal 210 and base station 220 may communicate to control the amount of transmit power or other resources used by terminal 210 to communicate with base station 220 through one or more power control technologies. In one example, terminal 210 may locally perform power control for communication with base station 220 using transmission adjustment component 212. Alternatively, power control technologies may be performed in a coordinated manner between terminal 210 and base station 220. Illustrative power control technologies that may be performed by terminal 210 and base station 220 are described in further detail below.

In accordance with another aspect, power control technologies used by entities in system 200 may further account for interference present in system 200. For example, in a multiple access wireless communication system, multiple terminals 210 can simultaneously transmit on the uplink, multiplexing their transmissions so so that they are orthogonal to each other in the time, frequency and / or code domain. However, complete orthogonality between transmissions from various terminals 210 is often not achieved due to channel conditions, receiver imperfections, and other factors. As a result, terminals 210 in system 200 will often interfere with other terminals 210 in communication with the common sector. In addition, since transmissions from terminals 210 communicating with different sectors are generally not orthogonal to each other, each terminal 210 may also interfere with terminals 210 communicating with neighboring sectors. As a result, the performance of terminals 210 in system 200 may be reduced by interference from other terminals 210 in system 200.

Accordingly, the amount of interference between cells created by this terminal 210 can be determined by the level of transmit power used by the terminal 210 and the location of the terminal 210 relative to neighboring sectors in the system 200. Based on this, power control can be performed in the system 200 so that each terminal 210 it is possible to transmit at a power level that is appropriate while keeping interference within a cell and between cells within acceptable levels. For example, a terminal 210 located close to its serving base station 220 may be allowed to transmit at a higher power level since this terminal is likely to cause less interference to other base stations in the system 200. Conversely, a terminal 210 located further from the base station 220 towards the boundary of the coverage area of the base station 220, may be limited by a lower transmit power level, since this terminal may cause more interference to neighboring base stations. By controlling the transmit power, system 200 can reduce the overall interference observed by base stations 220, while at the same time allowing “suitable” terminals 210 to achieve higher signal-to-noise ratios and, therefore, higher data rates.

Interference-based power control using various technologies may be performed in system 200 to increase the overall performance of its facilities. In one such technology, the Transmission Power Spectral Density (PSD) for a data channel, or other suitable channel with a power offset, based on another channel, may be expressed for a given terminal 210 as follows:

P _dch ( n ) = P _ref ( n ) + ΔP ( n ), (one)

where P _dch ( n ) is the transmission PSD for the data channel for the update interval n , P _ref ( n ) is the reference level PSD for the update interval n , and ΔP ( n ) is the transmission delta PSD for the update interval n . The PSD levels P _dch ( n ) and P _ref ( n ) and the transmit power delta ∆P ( n ) can be specified in decibels (e.g. dBm / Hz for P _dch ( n ) and P _ref ( n ), and dB for ∆P ( n )), although other units may be used. Additionally, it must be borne in mind that other calculations can also be used other than those specified by Equation (1). In one example, the reference level PSD P _ref ( n ) corresponds to the amount of PSD required to achieve the target signal-to-noise ratio (SNR) or erasure rate for the assigned transmission. The transmission may be provided through a fixed channel, such as, for example, a channel for transmitting feedback quality information or a channel for transmitting requests. If the reference power level allows the achievement of the corresponding target SNR or erasure coefficient, then the received SNR for another channel can be estimated as follows:

SNR _dch ( n ) = SNR _target + ΔP ( n ). (2)

In one example, the data channel and the corresponding control channel used by entities in system 200 may have similar interference statistics. This may occur, for example, when control and data channels from different sectors interfere with each other. In this case, the interference offset for the channels may be calculated at terminal 210. Alternatively, the interference offset between the control channels and the data channels may be broadcast in one or more base stations 220.

In another example, a transmission PSD for a data channel can be set based on factors such as the amount of interference between sectors that the terminal 210 theoretically creates for other terminals in neighboring sectors (e.g. sectors 104), the amount of interference within the sector that the terminal 210 theoretically creates for other terminals in the same sector, the maximum allowable transmit power level for terminal 210, the time period between transmissions of terminal 210, and / or other factors.

In FIG. 2A, reverse link (RL) transmission 230 is shown between terminal 210 and base station 220 in system 200. In one example, resources used by terminal 210 for reverse link transmission, such as power and / or bandwidth, may be adjusted by a component 212 transmit adjustment in the terminal 210. In another example, the transmission correction component 212 can adjust the resources used by the terminal 210 for transmission on the reverse link using one or more power control technologies that can take into account Pipeline interference observed objects in system 200, and / or other factors. One example of a power control technology that transmission correction component 212 can use is a delta-based power control technology in which the transmit power of terminal 210 can be adjusted based on a delta offset. As a specific non-limiting example, the delta bias value may correspond to the difference in transmit power between the pilot channel and the information channel used by terminal 210 and / or some other suitable quantitative indicator.

In accordance with one aspect, terminal 210 may further include feedback component 214 to report reverse power transmission control information to base station 220 to facilitate joint power control of terminal 210. For example, feedback component 214 may send the transmission PSD delta calculated by the transmission adjustment component 212 and the maximum number of subcarriers or subbands that the terminal 210 can support at the current PSD delta, N _{sb, max} ( n ), per ba call station 220. In addition, parameters of the desired quality of service (QoS) and buffer size can also be transmitted to base station 220 by feedback component 214. To reduce the amount of signaling required, the feedback component 214 may transmit ΔP ( n ) and N _{sb, max} ( n ) in a subset of the update intervals by means of in-band signaling on a data channel and / or in another way. It should be taken into account that the small transmit PSD delta corresponding to the terminal 210 does not mean that the terminal 210 does not use all the resources available to it. Instead, terminal 210 may be provided with more subcarriers or subbands for transmission in order to use all the transmit power available to it. Additionally, the feedback component 214 may deliver power control information to the base station 220 in different ways. For example, such information may be delivered to base station 220 via a MAC packet header, such as a control channel packet; on a separate physical channel, such as a channel for interference or for power control feedback; as part of feedback on channel status information (for example, as one or more bits of channel status information); and / or other suitable method.

In accordance with another aspect, while delta-based power control can be very effective for adjusting the transmit powers of terminal 210 and controlling the amount of interference created at base stations 220 in system 200 during continuous transmission, it cannot provide an initial setpoint for transmit power or PSD of terminal 210. Preferably, the initial setpoint may be a PSD value after a period of inactivity (or a “period of silence”). If the system 200 is partially loaded, so that the terminal 210 is the only source of impulse noise for the neighboring sector, the delta value for the terminal 210 may increase to a maximum delta value during any period of silence due to the fact that the neighboring sector does not experience any interference during this period, and does not transmit indicators of large interference from other sectors. In this case, the pulse transmissions of the terminal 210 can create a significant amount of interference for the neighboring sector at the beginning of each pulse before the delta-based power control can adjust the delta value of the terminal 210 to an appropriate level. This, in turn, can lead to errors in the packet or to lost acknowledgment messages on the feedback line in the neighboring sector. Therefore, in one example, the transmission adjustment component 212 may be configured to correct a delta value at the beginning of each pulse triggered by the terminal 210. By performing initial adjustments to the resources used by the terminal 210 for transmission, the transmission correction component 212 can serve to limit performance loss from due to a large increase in interference.

In one example, terminal 210 may begin transmitting after a period of silence with a minimum delta value and enable transmission adjustment component 212 to correct the delta value for subsequent transmissions. However, in some cases, for example, when the terminal 210 transmits an intermittent information stream with small packets to the base station 220, this can lead to unnecessarily low throughput for intermittent traffic. Alternatively, in order to limit the amount of interference at the beginning of each pulse, the transmission adjustment component 212 can make open loop corrections for the delta value and / or the maximum requested bandwidth W _max . As an example, transmission adjustment component 212 may determine whether a previous transmission by terminal 210 has taken place after a predetermined threshold value, the selection of which may be based on the number of frames, superframes, time period, number of destination messages, number of erasure measurements, and / or other quantitative indicators. If so, then the transmission correction component 212 can calculate the open loop delta value, the open loop delta value based on the bandwidth assigned for transmission, the bandwidth assigned for transmission based on the delta value, and / or other parameters. After computing the appropriate parameters, adjustments can be made for the bandwidth and / or transmit power used by the terminal 210 based on the calculation.

In one example, transmission adjustment component 212 may be limited to only making open loop corrections at the beginning of each pulse, for example, after it is determined that a threshold value has been passed. Alternatively, the transmission adjustment component 212 may provide open loop corrections at other times, for example, in frames or parts of frames corresponding to interlaces that the terminal 210 is not scheduled to provide maximum values for a fixed delta value to prevent too much high delta values due to low OSI activity.

Based on the feedback information provided to the base station 220 by the feedback component 214 in the terminal 210, as shown in FIG. 2A, and / or other information, base station 220 may generate a resource assignment 240 for terminal 210 and report resource assignment 240 to terminal 210, as shown in FIG. 2B. In one example, transmit power for terminal 210 may be assigned by power control component 224 in serving sector 220. Power control component 224 may receive feedback information from feedback component 214 in terminal 210, interference metrics from terminal 210 and / or other base stations in system 200 and / or other parameters for use in generating a resource assignment for terminal 210. The parameters used by power control component 224 may be received together in a common message or from Yelnia messages. Once the resource assignment 240 is determined by the power control component 224, the assignment can be communicated back to the terminal 210 by the base station 220, after which the transmission adjustment component 212 can adjust the transmission resources for the terminal 210 in accordance with the assignment.

In one specific example, the power control component 224 may calculate ΔP ( n ) and / or other parameters used to generate resource assignments 240 for terminal 210 based on the reference level PSD P _ref ( n ), the power of the signals received over the quality indication channel channel and / or request channel in the reverse link from terminal 210, and / or other coefficients. In this example, the offset of the carrier power to interference ratio can be determined along with the amount of interference minus the rise above the thermal noise power (IoT - RoT). These values can then be used to offset the power of signals received from the channel quality indication channel and / or request channel as part of the reverse link from terminal 210 and / or transmitted as power control commands back to terminal 210. In one example, the power ratio offset carrier to interference can be defined as a function of interference within the sector and other terminals 210 in the sector served by base station 220. Additionally, IoT values can be calculated for base station 220 and / or received from others these access points or sectors in system 200 through broadcast transmissions from said access points or sectors and / or via feedback. Additionally and / or alternatively, RoT values may be calculated by power control component 224, as is known. In another example, the offsets used by the power control component 224 may be incremental, otherwise varying, and / or may be system-dependent delta coefficients.

In another example, the total interference power received in the passband of system 200 may be used by power control component 224 as a quantitative measure of interference control. The total interference power can be used to determine the maximum planned interference value for each user, which can then be used to schedule terminal 210 for reverse link transmission depending on bandwidth, timing, and / or other parameters. Planned interference for each user can be set, for example, as a small fraction of the total interference power for systems with interference-sensitive applications. By way of non-limiting example, such a planned value can be used when deploying microcells, since a separate terminal at the cell boundary during such deployment can have sufficient power to overload the cell in a 5 or 10 MHz bandwidth. In addition, such a planned value can be used with respect to cells used to exchange information flow having a very short delay time, which is sensitive to large changes in IoT.

In accordance with another aspect, the resource assignment 240 determined by the power control component 224 and received by the terminal 210 may not meet the open loop requirements for the terminal 210 calculated by the transmission adjustment component 212. For example, the assigned bandwidth may be too large for use by the terminal 210 based on the maximum bandwidth corresponding to the minimum delta values calculated by the transmission adjustment component 212. In this case, the transmission adjustment component 212 may return to its original state in various ways due to a mismatch in the assignment. For example, transmission adjustment component 212 may instruct terminal 210 to pause transmission and skip an assignment received from base station 220. As another example, a minimum delta value may be used by transmission adjustment component 212 to determine a new maximum bandwidth and / or delta value which can then be communicated to base station 220 to receive a new destination. Additionally and / or alternatively, if terminal 210 is configured to reverse rate indication (RRI) and / or decode a multi-dimensional hypothesis, terminal 210 may change the packet format used to communicate with base station 220 to efficiently use the resource assignment. As a further example, the transmission adjustment component 212 may not take into account the resource assignment and instruct the terminal 210 or suspend the transmission or continue retransmission with the hybrid automatic request (HARQ) to take into account the unaccounted assignment.

FIG. 3A-3B are block diagrams that demonstrate the operation of an exemplary system 300 for power control and reverse link interference control in a wireless communication system. In one example, system 300 includes a terminal 310 that communicates with serving sector 320 via forward and reverse links through respective antennas 316 and 322. System 300 may also include one or more neighboring sectors 330 without direct communication with terminal 310 For example, neighboring sector 330 may provide coverage for a geographical area adjacent to an area for which coverage is provided by serving sector 320. Although system 300 depicts only one terminal 310 and two sectors 320 and 33 0, it should be appreciated that system 300 may include any number of terminals and / or sectors.

In accordance with one aspect, terminal 310 may use one or more delta-based power control algorithms to manage resources used by terminal 310 to communicate with serving sector 320 over a reverse link. Terminal 310 may apply such technologies independently, or, alternatively, terminal 310 may perform delta-based power control in conjunction with serving sector 320. In one example, power control technologies used by terminal 310 and serving sector 320 may be based on interference level generated by terminal 310 in serving sector 320 and / or other sectors, such as neighboring sector 330. Using interference as a factor in power control for terminal 310, such technologies can Gut facilitate more optimal overall performance characteristic in system 300 than similar techniques that do not account for interference.

FIG. 3A shows reverse link transmission 314 from terminal 310 to serving sector 320 and a subsequent other sector interference indicator (OSI) 318 from neighboring sector 330. In accordance with one aspect, if dominant interference sector 330 is interfered sequentially after transmission over the reverse link from terminal 310, the dominant interference sector 330 may transmit one or more OSI metrics 318 to the terminal 310 in a forward link through one or more antennas 332. Terminal 310 may use OSI metrics 318 received from a prevailing interference 330 to determine the amount of interference between sectors that the terminal 310 theoretically creates in various ways. In one example, the amount of interference between sectors created by the terminal 310 can be estimated directly at the prevailing interference sector 330 and / or other neighboring access points at system 300. These direct estimates can then be sent to terminal 310 to allow terminal 310 to adjust transmit power accordingly.

Alternatively, the amount of interference between sectors created by terminal 310 may be roughly estimated based on the total interference observed by prevailing interference sector 330 and / or neighboring access points; channel gains for serving sector 320, dominant interference sector 330, and / or neighboring access points; and / or the transmit power level used by terminal 310. In one example, corresponding access points in system 300 can estimate the total or average observed amount of interference and broadcast these interference measurements for use by terminals in other sectors. By way of non-limiting example, a single other sector interference bit (OSI) may be used by each access point to provide interference information. Accordingly, each access point can set its own OSI bit (OSIB) as follows:

(3)

where IOT _{meas, m} ( n ) is the measured value of interference above thermal noise (IOT) for the mth sector in the time interval n , and IOT _target is the desired operating mode for the sector. As used in Equation (3), the IOT is attributed to the ratio of the total interference power observed by the access point to the thermal noise power. On this basis, a specific operating mode can be selected for the system and designated as IOT _target . In one example, OSI can be divided into many layers and accordingly contain many bits. For example, an OSI metric can have two levels, such as IOT _MIN and IOT _MAX . The layers may be configured such that, for example, if the observed IOTs are between the IOT _MIN and IOT _MAX , then the terminal 310 may continue to use its current transmit power without adjustment. Alternatively, if the observed IOTs are above or below predetermined levels, then the transmit power can be adjusted up or down accordingly.

OSI indices 318 may be transmitted by the dominant interference sector in different ways. For example, OSI metrics 318 reported by the dominant interference sector 330 may be regular OSI metrics carried on physical forward link channels, such as a forward link OSI channel (F-OSICH). OSI regular metrics can be limited in transmission frequency, for example, by one transmission in a superframe, to account for power consumption and time-frequency resources of such metrics. As another example, the OSI metrics 318 reported by the dominant interference sector 330 may be fast OSI metrics carried over the forward link OSI speed channel (F-FOSICH) and / or another suitable channel. Such indicators can be used, for example, in scenarios where an intermittent information stream is transmitted by terminal 310 to enable more dynamic control of power levels. Additionally, OSI metrics 318 reported by the dominant interference sector 330 may include indicators of the excess of information interference over thermal noise power (IOT) and / or other interference bias parameters observed by the dominant interference sector 330 that may be carried on the forward link physical channel such as a forward link IOT (F-IOTCH).

In accordance with another aspect, terminal 310 may further estimate a channel gain or propagation path gain for access points that can receive reverse link transmission 314 from terminal 310. Channel gain for each of the access points can be estimated using pilot processing -signal received from access points in a forward link. In one example, the channel gain between the serving sector 320 and a neighboring access point, such as the dominant interference sector 330, can be used as a “relative distance” indicating the distance to the dominant interference sector 330 relative to the distance to the serving sector 320. You can see that the coefficient the channel gain for a neighboring access point will typically decrease as terminal 310 moves toward a sector boundary corresponding to serving sector 320, and typically it increases as terminal 310 moves closer to serving sector 320. In addition, information regarding the excess of the control carrier power over thermal noise power (pCoT) and / or other channel quality parameters can be communicated by sectors 320 and / or 330 to terminal 310 via the pilot indication channel forward link quality (F-PQICH) and / or other suitable physical forward link channel.

Based on the presence or absence of an OSI indicator from sector 330 of predominant interference, indicating interference caused by terminal 310 as a result of reverse link transmission to serving sector 320, as illustrated in FIG. 3A, terminal 310 may perform delta adjustments of resources used for reverse link transmission and retransmit using adjusted resources, as illustrated in FIG. 3B. In one example, terminal 310 may include transmission adjustment component 312 for adjusting transmission power, bandwidth, and / or resources used to establish reverse link communications with serving sector 320. Although transmission adjustment component 312 is depicted in FIG. 3B as a component of terminal 310, it should be appreciated that serving sector 320 and / or other appropriate network entity may also perform some or all of the calculations performed by transmission adjustment component 312, either independently of, or in conjunction with terminal 310.

In accordance with one aspect, terminal 310 may track broadcast of OSI bits by neighboring access points in system 300 and may be configured to respond only to the OSI bit of prevailing interference sector 330, which may have the smallest channel gain relative to neighboring access points. In one example, if the OSI bit of the dominant interference sector 330 is set to '1', due, for example, to the fact that the dominant interference sector 330 observes the interference between the sectors above acceptable, then the transmission adjustment component 312 may accordingly reduce the transmission resources accordingly on the reverse link used by terminal 310, and instruct serving sector 320 to retransmit the last transmission on the reverse link. Conversely, if the OSI bit of the prevailing interference sector 330 is set to '0', the transmission adjustment component 312 can adjust the uplink transmission resources of the terminal 310 upward. Alternatively, transmission adjustment component 312 may use OSI bits from more than one access point and may use various algorithms to adjust reverse link transmission resources of terminal 310 and initiate reverse link retransmissions 324 based on the multiple received OSI bits.

In accordance with another aspect, reverse link transmit power and / or other resources used by terminal 310 may be adjusted by transmission adjustment component 312 based on fast OSI metrics received from prevailing interference sector 330 using the power metric calculated by correction component 312 transmission. For example, if the transmission of a packet by the terminal 310 interferes with the dominant interference sector 330, the dominant interference sector 330 may indicate to the terminal 310 that it is advisable to reduce the transmit power used for retransmission of the packet. This can be done, for example, by interleaving the OSI metric for terminal 310, as illustrated in FIG. 3A, with the transmission of a packet associated with an OSI metric.

Transmissions, corrections, and subsequent retransmissions of packets on the reverse link by terminal 310 in system 300 based on OSI indicators from prevailing interference sector 330 can be performed, as illustrated by timing diagram 400 in FIG. 4. In accordance with one aspect, transmission adjustment component 312 may perform resource adjustments used by terminal 310 before retransmitting a packet that caused OSI after receiving an OSI metric. For example, as illustrated by a timing diagram 400, a first reverse link transmission may be performed at interlace 401, and an OSI metric corresponding to this transmission may be received at interlace 403. Based on an OSI metric, resource adjustment may be performed at interlace 404 to retransmit the first a packet in interlace 410. Similarly, a second reverse link transmission can be performed in interlace 402, and a second resource adjustment can be performed in interlace 408, based on the OSI metric, corresponding to the second gear received in alternation 405. The OSI metric can also be received in general alternation with reverse link transmission, as illustrated by the third reverse gear in alternation 405. The OSI metric for third gear can also be adopted as indicated in alternation 407 The retransmission for this packet may occur in the eighth interlace after the initial transmission, as illustrated by the interlaces 401 and 410 in the timing diagram 400, or, alternatively, the retransmission soap has may occur in any other suitable regular or irregular interval following the initial transmission.

In one example, the transmit power for retransmission of a packet may be determined by determining whether the initial transmission generated an OSI metric and whether adjustment is required. If so, terminal 310 may check other adjustments that have been made at a predetermined number of interlaces, select the smallest of the corrected power values that have been marked as an OSI measure, and lower the smallest power value by the delta offset value. Alternatively, if it is determined that the initial transmission did not generate an OSI metric, terminal 310 may check other adjustments that were made at a predetermined number of interlaces, select the largest of the corrected power values that were marked as not generating an OSI metric, and increase such highest power per delta offset value. In another example, the delta values and / or quantitative power metrics used to adjust transmission resources may be predefined or computed using one or more technologies, as described below.

In another example, a new assignment for transmission resources for terminal 310 may come from a serving sector 320 and / or another suitable entity in system 300 during any interlace in timing diagram 400. The new assignment may contain, for example, a delta value that provides the PSD based on adjustments to previous rotations. Based on the new assignment, terminal 310 can provide a report on the power metric used by terminal 310 to adjust transmission resources to serving sector 320 at the start of the next reverse link transmission to allow serving sector 320 to use the power metric in new assignments for the terminal 310. In one example, if the serving sector 320 determines that an OSI is present, based on a report from the terminal 310, the serving sector 320 may lower l transmit power used by terminal 310 for subsequent purposes.

In FIG. 5-7 demonstrate methods for delta-based power control and interference control in a wireless communication system. Although to simplify the explanation of the methods are depicted and described as a sequence of actions, you need to understand and take into account that the methods are not limited to this order of actions, so some actions, in accordance with one or more options for implementation, can occur in a different order and / or simultaneously by other actions, as opposed to that depicted and described herein. For example, those skilled in the art will understand and appreciate that the process execution procedure could alternatively be represented as a sequence of interrelated states or events, for example, in a state diagram. Moreover, not all illustrated acts may be required to implement a method in accordance with one or more embodiments.

FIG. 5 shows a procedure 500 for adjusting reverse link transmission resources in a wireless communication system (eg, system 200). It should be appreciated that procedure 500 may be performed, for example, by a terminal (eg, terminal 210) and / or any other suitable network entity. Procedure 500 begins at step 502, where a reverse link transmission is performed to the serving sector (e.g., base station 220). Then, at step 504, it is determined whether there has been a reverse link transmission carried out at step 502 after a predetermined threshold value. The threshold value may be based, for example, on the number of frames or superframes, the time period, the number of destination messages, the number of erasure measurements, and / or other quantitative indicators.

If it is determined in step 504 that the transmission in step 502 did not occur after the threshold value, the procedure 500 ends. Otherwise, the procedure 500 proceeds to step 506, in which one or more of the open loop delta values, the open loop delta values based on the assigned bandwidth, and the bandwidth based on the delta value are calculated. In one example, the open loop corrections made in step 506 may be limited to the start of the respective transmission pulses, for example, after the threshold value used in step 504 is passed. Alternatively, the open-loop design can be calculated in step 506 by interlaces in which the entity performing procedure 500 is not planned to determine the maximum value for the fast delta value so as not to allow the delta value to become too large due to low activity OSI score.

In accordance with one aspect, computing an open loop delta value, an open loop delta value based on a bandwidth assigned for transmission and / or a bandwidth assigned for transmission based on a delta value that can be performed at 506, may continue as described in the following non-limiting examples. In one example, to calculate the open loop delta value in step 506 to control the maximum rise in PSD, the delta value can be calculated so that

(IoT _avg + pCoT × Δ) / IoT _avg <IoTRise _max (four)

As used in Equation (2), IoT _avg is the interference bias value that can be provided as a system parameter; for example, it may be broadcast by a non-serving sector, for which open-loop correction is calculated in step 506, and / or from a sector having the smallest channel gain difference with the serving sector. In one example, IoT _avg can be set to a fixed value to simplify system design and / or to reduce the amount of feedback information requiring power control. In this example, IoT _avg can be set to a value taken with a margin (for example, 1, thus not assuming any other current interference other than thermal noise), a nominal value of IoT, such as IoT _target , and / or another suitable value. Additionally, pCoT corresponds to a measurement of the received signal power (e.g., excess of the received carrier PSD over thermal noise PSD) in a reference channel (e.g., reverse link pilot channel, channel quality indication channel and / or any other reference channel) in a non-serving sector. The pCoT value may be reported on a dedicated forward link channel, such as a forward link pilot quality channel (F-PQICH), communicated from a non-serving sector, output by appropriate correction of the corresponding parameters for the serving sector using the channel gain difference value, and / or otherwise. In addition, IoTRise _max denotes the maximum allowable increase in the amount of interference caused by any access terminal in a non-serving sector. The IoTRise _max value may be a value provided by the system configuration or service signals.

In another example, in the case where the delta value calculated using the aforementioned technology is less than the minimum delta value (Δ _min ), the maximum acceptable bandwidth, W _max , can be reduced by distribution by a predetermined value or by based on the following expression:

(IoT _avg + W _max / W _tot × pCoT × Δ _min ) / IoT _avg <IoTRise _max (5)

where W _tot is the total system bandwidth.

In a further example, an open loop delta can be calculated in step 506 to control the average rise of the PSD based on the assigned bandwidth W, as follows:

(IoT _avg + W / W _tot × pCoT × Δ) / IoT _avg <IoTRise _max (6)

Additionally, as additional information to assist the serving sector in designating W, the maximum acceptable bandwidth, W _max , can also be calculated from the minimum delta value (Δ _min ) so that

(IoT _avg + W _max / W _tot × pCoT × Δ _min ) / IoT _avg <IoTRise _max (7)

and communicate to the serving sector for assignment.

In a further example, the amount of interference at the beginning of each transmission pulse can also be controlled in step 506 by limiting the initial maximum acceptable bandwidth based on the current delta value and controlling the average rise of the PSD. In this case, the maximum value of the acceptable bandwidth (W _max ) can be calculated so that

(IoT _avg + W _max / W _tot × pCoT × Δ) / IoT _avg <IoTRise _max (8)

and communicate with the serving access point. The serving access point can then gradually increase the assigned bandwidth in successive assignments to provide enough time for fast OSI readings to adjust the delta value.

In accordance with another aspect, the serving sector may use a data carrier power to interference ratio (DataCtoI) value to allocate resources to an entity performing procedure 500, while at the same time, a corresponding delta value may be used by an entity performing procedure 500. In addition, each format a packet may have a DataCtoI _min and / or Δ _min value associated with it. In one example, a correspondence table may be supported that includes the DataCtoI _min values used. Additionally, at step 506, an index in the correspondence table for each packet format may be provided to enable the entity performing the procedure 500 and / or the serving sector to match the DataCtoI _min and / or Δ _min values for the packet format.

After the calculations are completed in step 506, the procedure 500 ends in step 508, in which the bandwidth and / or transmit power is adjusted (for example, by the transmission adjustment component 312) based at least in part on the calculation performed in step 506. In accordance with with one aspect, the first delta value (eg, Δ _slow ) can be calculated in step 506 based on slow OSI from a neighboring access point. The first delta value can be used as the maximum value for other parameters calculated in step 506, and / or as feedback information for the serving sector separately or in combination with power reserve, interference reports and / or other feedback information for future resource assignments. In one example, at step 506, a second delta value (eg, Δ _tx ) can be further calculated and used to adjust transmit power and / or bandwidth at step 508.

In accordance with another aspect, resource adjustments at 508 can be made based on the Δ _tx value as follows. First, for each interlace i , a quantitative measure of the power PM _i can be defined as the product of the received CoT value from the serving sector and the assigned bandwidth in the interlace, for example, PM _i = CoT _i × BW _i . Then, the maximum and minimum quantitative indicators of power for each rotation can be calculated, as follows:

(9)

Then, based on these values, a quantitative indicator of power for alternating i can be set as follows:

,

, (10)

subject to the limiting condition

∆ _{min, i} ≤ ∆ _{tx, i} ≤ ∆ _{assigned, i} (eleven)

Additionally and / or alternatively, the transmission PSD used to transmit data on the reverse link over a physical channel (eg, R-DCH) may be adjusted in step 508 based on the assignment from the serving sector as follows:

PSD _R-DCH = PSD _R-PICH + ∆ _tx + AttemptBoost _j (12)

where j is the index of the subpacket, and AttemptBoost _j is the power increase parameter assigned by the serving sector.

In accordance with a further aspect, the data channels used by each sector in system 300 may be multiplexed so as to be orthogonal to each other. However, despite this multiplexing, some loss of orthogonality may occur due to inter-carrier interference (ICI), intersymbol interference (ISI) and / or other causes that may result in intra-sector interference. In order to mitigate interference within the PSD sector, the transmission of terminal 310 may be adjusted by transmission adjustment component 312 so that the amount of interference within the sector that terminal 310 can cause to other terminals in the same sector is maintained within an acceptable level. This can be achieved, for example, by holding the delta of the PSD transmission, ΔP ( n ), within the corresponding range

∆P ( n ) ∈ [∆P _min , ∆P _max ], where ∆P _min and ∆P _max respectively are the minimum and maximum delta PSD transmission, valid for a given data channel.

FIG. 6 shows a procedure 600 for adjusting reverse link transmission resources to reduce interference in a wireless communication system (eg, system 300). It should be appreciated that the method execution procedure 600 may be performed, for example, by a terminal (eg, terminal 310) and / or any other suitable network entity in a wireless communication system. Procedure 600 begins at block 602, in which reverse link transmission is performed to a serving sector (eg, serving sector 320). Then, at step 604, it is determined whether an OSI metric has been received (e.g., from prevailing interference sector 330). In one example, if transmission of a packet by an entity performing procedure 600 causes interference in a neighboring sector, this sector may transmit an OSI metric requesting that the transmission power used for subsequent retransmission be reduced. This can be done, for example, by interleaving the OSI metric with the transmission in block 602.

If the OSI metric is received at 604, procedure 600 may proceed to 606, which selects the smallest amount of transmit power used within the predefined time period that generates the OSI. In one example, an entity performing procedure 600 may check for other adjustments that have been made within a predetermined number of interlaces or another predetermined time period, and select the smallest adjusted power value that has been marked as an OSI measure. Then, the routine 600 can end at block 608, where the transmit power (for example, the transmit power used for retransmission of the block passed at block 602) is adjusted by subtracting the delta offset value from the transmit power selected at block 606.

Alternatively, if the OSI metric is not received at 604, procedure 600 may instead proceed to 610, which selects the highest transmit power used within the predefined time period that did not generate the OSI. In one example, an entity performing procedure 600 may check for other adjustments that have been made within a predetermined number of interlaces or another predetermined time period, and select the largest of the corrected power values that has been marked as not generating an OSI metric. Then, the routine 600 can end at block 612, where the transmit power (for example, the transmit power used for retransmission of the block passed at block 602) is adjusted by adding the delta offset value to the block power selected at block 610.

FIG. 7 shows a procedure 700 for performing power control and interference control of a reverse link in a wireless communication system (eg, in system 200). It should be appreciated that procedure 700 may be performed, for example, by an access point (eg, base station 220) and / or any other suitable network entity in a wireless communication system. Procedure 700 begins at block 702, where a communication request and / or power control feedback information from a terminal (e.g., terminal 210) is received. Then, the procedure 700 proceeds to step 704, which receives a report on the OSI activity generated by the terminal. In one example, information received in steps 702 and 704 may be received jointly in a common message or in separate messages. Additionally, the report received at block 704 may be communicated to an entity performing procedure 700, a terminal, or other appropriate entity in the system (eg, an adjacent base station).

Then, at step 706, transmission power and / or bandwidth for the terminal can be assigned (for example, power control component 224) based on information received at steps 702 and 704. In one specific example, ΔP ( n ) and / or other parameters used to generate resource assignments for the terminal can be calculated at 706 based on the reference level PSD P _ref ( n ), the power of the signals received on the channel quality indication channel and / or the request channel in the reverse link, and / or other factors. In this example, the offset of the carrier power to interference ratio can be determined along with the amount of interference minus the rise above the thermal noise power, and these values can be used to offset the power of signals received on the reverse link from the terminal and / or transmitted as power control commands by step 708. In one example, the offset of the carrier power to interference ratio can be defined as a function of interference within a sector and other terminals in a given sector. In addition, IoT values may be calculated at 706 and / or received from other access points or sectors. Additionally and / or alternatively, RoT values may be calculated at 706, as is known. In another example, the offsets used in step 706 may be incremental, otherwise changing, and / or may be system-dependent delta coefficients. After the assignments are completed at step 706, the procedure ends at step 708, where the assigned transmit power and / or bandwidth is communicated to the terminal.

In FIG. 8 is a block diagram illustrating an example wireless communication system 800 in which one or more of the embodiments described herein may function. In one example, system 800 is a multi-input multi-output (MIMO) system that includes a transmitter system 810 and a receiver system 850. It should be appreciated that the transmitter system 810 and / or receiver system 850 may also applied to a system with multiple inputs and one output, in which, for example, multiple transmit antennas (e.g., at a base station) can transmit one or more symbol streams to a device with one antenna (e.g., a mobile station). Additionally, it should be appreciated that aspects of the transmitter system 810 and / or receiver system 850 described herein could be used with an antenna system with one output and one input.

In accordance with one aspect, information exchange data for multiple data streams in a transmission system 810 is provided from a data source 812 to a transmit (TX) data processor 814. In one example, each data stream may then be transmitted through a respective transmit antenna 824. Additionally, the transmit data processor 814 may format, encode, and interleave the data exchange information for each data stream based on a particular coding scheme selected for each respective data stream to provide encoded data. In one example, the encoded data for each data stream may then be multiplexed with pilot data using OFDM technologies. The pilot data may, for example, be a known combination of data that is processed in a known manner. Additionally, pilot data may be used at receiver system 850 to estimate channel response. In transmitting system 810, the multiplexed pilot and encoded data for each data stream may be modulated (i.e., mapped to symbols) based on a particular modulation scheme (e.g., BPSK (binary phase shift keying), QPSK (quadrature phase shift keying), M- PSK (M-Level Phase Shift Keying), or M-QAM (M-Level Quadrature Amplitude Modulation)) selected for each respective data stream to provide modulation symbols. In one example, the data rate, coding, and modulation for each data stream may be determined by instructions executed on and / or from processor 830.

After that, the modulation symbols for all data streams can be provided to the processor 820 MIMO transmission (TX), which can further process the modulation symbols (for example, for OFDM). Then, the MIMO transmission processor 820 may provide N _T modulation symbol streams to N _T transmitters (TMTR) 822a-822t. In one example, each transmitter 822 may receive and process a respective symbol stream to provide one or more analog signals. Each transmitter 822 can then perform additional preprocessing (e.g., amplification, filtering, and up-conversion) of the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. Thus, N _T modulated signals from transmitters 822a through 822t can then be transmitted from N _T antennas 824a through 824t, respectively.

In accordance with another aspect, the transmitted modulated signals may be received at the receiving system 850 using N _R antennas 852a-852r. Then, the received signal from each antenna 852 can be provided to a respective receiver (RCVR) 854. In one example, each receiver 854 can pre-process (e.g., filter, amplify and down-convert) the corresponding received signal, digitize the pre-processed a signal to provide samples, and then process samples to provide a corresponding “received” stream of characters. The data / MIMO (RX) reception processor 860 can then receive and process N _R symbol streams received from N _R receivers 854 based on the processing technology of a particular receiver to provide N _T “detected” symbol streams. In one example, each detected symbol stream may include symbols that are estimates of the modulation symbols transmitted for the corresponding data stream. Then, the receiving processor 860 can process each symbol stream at least partially by demodulating, deinterleaving, and decoding each detected symbol stream to recover information exchange data for the corresponding data stream. Thus, processing by the reception processor 860 may be complementary to the transmission MIMO processor 820 and the transmission data processor 814 in the transmission system 810. The reception processor 860 may further provide processed symbol streams to the data reception device 864.

In accordance with one aspect, a channel response estimate generated by a receive processor 860 may be used to perform spatio / temporal processing on a receiver, adjust power levels, change coefficients or modulation schemes, and / or other appropriate actions. In addition, the reception processor 860 may further evaluate channel characteristics such as signal-to-noise interference-to-noise ratios (SNRs) of the detected symbol streams. Then, the receiving processor 860 may present the estimated channel characteristics to the processor 870. In one example, the receiving processor 860 and / or processor 870 may further obtain an estimate of the “effective” SNR for the system. Processor 870 may then provide channel status information (CSI), which may contain information regarding the communication channel and / or the received data stream. This information may include, for example, the current SNR. The CSI can then be processed by the transmit data processor 818, modulated by a modulator 880, pre-processed by transmitters 854a-854r, and transmitted back to the transmit system 810. In addition, the data source 816 in the receiving system 850 may provide additional data that will be processed by the transmit data processor 818.

Returning to transmitter system 810, modulated signals from receiver system 850 can then be received by antennas 824, pre-processed by receivers 822, demodulated by demodulator 840, and processed by receive data processor 842 to recover the CSI reported by receiver system 850. In one example, the reported CSI can then be provided to processor 830 and used to determine the data rate, as well as coding and modulation schemes that are used for one or more data streams. Then, established coding and modulation schemes may be provided to transmitters 822 for quantization and / or use in later transmissions to receive system 850. Additionally and / or alternatively, the reported CSI may be used by processor 830 to generate various directives for transmit data processor 814 and a 820 MIMO transmission processor. In another example, CSI and / or other information processed by the receive data processor 842 may be provided to the data receive device 844.

In one example, processor 830 in transmitter system 810 and processor 870 in receiver system 850 operate directly on their respective systems. In addition, the storage device 832 in the transmitting system 810 and the storage device 872 in the receiving system 850 can provide storage of program codes and data used by processors 830 and 870, respectively. Additionally, various processing techniques may be used at receiver system 850 to process N _R received signals to detect N _T transmitted symbol streams. These processing technologies at the receiving device may include spatial and spatio-temporal processing technologies at the receiving device, which may also be referred to as equalization technologies, and / or processing technologies at the receiving device of the “sequential zeroing / equalization and interference suppression”, which may also be referred to as processing technologies on the receiving device "sequential interference suppression" or "sequential suppression".

FIG. 9 is a block diagram of a system 900 that provides reverse link power control in a wireless communication system in accordance with various aspects. In one example, system 900 includes an access terminal 902. As shown, access terminal 902 may receive signal (s) from one or more access points 904 and transmit to one or more access points 904 via antenna 908. Additionally, access terminal 902 may include a receiver 910 that receives information from antenna 908. B in one example, receiver 910 may be operatively coupled to a demodulator 912 that demodulates received information. The demodulated symbols may then be analyzed by the processor 914. The processor 914 may be coupled to a memory 916, which may store data and / or program codes related to the access terminal 902. Additionally, access terminal 902 may use processor 914 to perform procedures 500, 600, and / or other suitable procedures. In addition, access terminal 902 may include a demodulator 918 that can multiply a signal for transmission by transmitter 920 through antenna 908 to one or more access points 904.

FIG. 10 is a block diagram of a system 1000 that coordinates power control and reverse link interference control in a wireless communication system in accordance with various aspects described herein. In one example, system 1000 includes a base station or access point 1002. As shown, access point 1002 may receive signal (s) from one or more access terminals 1004 through a receive antenna 1006 and transmit to one or more access terminals 1004 through transmit antenna 1008.

Additionally, access point 1002 may include a receiver 1010 that receives information from receive antenna 1006. In one example, receiver 1010 may be operatively coupled to a demodulator 1012 that demodulates received information. The demodulated symbols may then be analyzed by processor 1014. Processor 1014 may be coupled to memory 1016, which may store information related to code blocks, access terminal assignments, associated correspondence tables, unique scrambling sequences, and / or other applicable types of information. In one example, access point 1002 may use processor 1014 to perform method 700 and / or other suitable procedures. In addition, access point 1002 may include a demodulator 1018 that can multiply a signal for transmission by transmitter 1020 through transmit antenna 1008 to one or more access terminals 1004.

FIG. 11 shows an apparatus 1100 that provides initial adjustments to transmission resources in a wireless communication system (eg, in system 200). It should be appreciated that device 1100 is displayed as including functional blocks, which may be functional blocks that represent functions implemented by a processor, software, or a combination thereof (e.g., firmware). The device 1100 may be implemented at a terminal (eg, terminal 210) and / or another suitable network entity and may include a module 1102 for transmitting on the reverse link to the serving sector. Additionally, device 1100 may include a module 1104 for determining whether transmission has occurred outside of a temporary threshold value. In addition, the device may include a module 1106 for calculating an open loop delta value, an open loop delta value based on an assigned bandwidth and / or bandwidth based on a delta value, if positive. In addition, device 1100 may include a module for 1108 adjusting bandwidth and / or transmit power to calculated values when positively determined.

FIG. 12 shows an apparatus 1200 that provides reverse-link transmission resource adjustment for interference control in a wireless communication system. You must take into account that the device 1200 is displayed as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or a combination thereof (e.g., firmware). Device 1200 may be implemented at a terminal and / or other suitable network entity and may include module 1202 for transmitting on the reverse link to a serving sector. Additionally, device 1200 may include a module 1204 for determining whether an OSI metric has been received, and a module 1206 for adjusting transmit power and / or bandwidth based, at least in part, on the determination.

FIG. 13 shows a device 1300 that provides power control and reverse link interference control in a wireless communication system. You must take into account that the device 1300 is displayed as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or a combination thereof (e.g., firmware). The device 1300 may be implemented at an access point (eg, base station 220) and / or another suitable network entity in a wireless communication system and may include a module 1302 for receiving request and / or power control feedback information from a terminal. Additionally, the device 1300 may include a module 1304 for receiving an OSI activity report generated by the terminal, a module 1306 for allocating resources for communicating with the terminal based on the received information, and a module 1308 for communicating the assigned communication resources to the terminal.

It should be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, firmware, or any combination thereof. When systems and / or methods are implemented in software, firmware, middleware, or microcode, program code, or code segments, they can be stored in a computer-readable medium, for example, a storage component. A code segment can be a procedure, function, subprogram, program, standard program, standard subprogram, module, program package, class, or any combination of instructions, data structures, or program statements. A code segment may be associated with another code segment or hardware circuitry by sending and / or receiving information, data, arguments, parameters, or contents of a storage device. Information, arguments, parameters, data, etc. can be forwarded, forwarded or transmitted using any suitable means, including memory sharing, message forwarding, hand-off data transmission, network transmission, etc.

With a software implementation, the technologies described herein can be implemented by modules (e.g., procedures, functions, and so on) that perform the functions described in this document. Software codes can be stored in memory cells and executed by processors. The memory cell can be implemented inside the processor or be external to the processor, in which case they can be communicatively connected using one or another means known in the art.

The above includes examples of one or more embodiments. Of course, it is not possible to describe every possible combination of components or procedures for carrying out the methods in order to describe the above embodiments, but one skilled in the art will understand that many additional combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to encompass all such changes, modifications, and variations that fall within the spirit and scope of the appended claims. Additionally, in the sense in which the term “includes” is used either in the description of an embodiment of the invention or in the claims, this term is intended to include in itself, similarly to the term “contains”, as, for example, “contains” is interpreted when applied in as a transition word in a claim. In addition, the term “or”, which is used in the detailed description or in the claims, means “non-exclusive or”.

Claims (20)

1. A method of power control in a wireless communication system, comprising the steps of:
calculating one or more of the open loop delta value, the open loop delta value based on the assigned bandwidth, and the strip width based on the delta value, the calculation being based on the rotation time corresponding to the terminal, the terminal being currently unplanned ; and
correct one or more parameters intended for use for future transmission at least partially based on the calculated values,
wherein the delta value is at least one of a power offset value from a predetermined power reference value or a bandwidth offset value from a predetermined reference bandwidth, wherein one or more parameters include at least one of transmission power or bandwidth transmission. 2. The method according to claim 1, in which the correction of one or more parameters intended for use for future transmission includes adjusting the offset of the transmission power intended for use for future transmission. 3. The method according to claim 1, in which the adjustment of one or more parameters intended for use for future transmission includes adjusting the bandwidth used for future transmission. 4. The method according to claim 1, in which the adjustment of one or more parameters intended for use for future transmission includes
power spectral density correction (PSD) as a function of the calculated open loop delta value; and
adjusting the transmit power intended for use for future transmission based on the adjusted PSD. 5. The method according to claim 1, in which the adjustment of one or more parameters intended for use for future transmission includes
determining whether another sector interference indicator (OSI) has been received corresponding to the interlace reception time; and
adjusting one or more parameters intended to be used for future transmission at least in part based on whether an OSI pointer has been received. 6. The method according to claim 1, in which the correction of one or more parameters intended for use for future transmission includes
receiving an assignment for one or more parameters intended for use for future transmission from the access point and
adjusting one or more parameters based on the purpose. 7. The method according to claim 1, further comprising the step of reporting one or more of the calculated values and adjusted parameters to the access point. 8. A wireless communication device comprising
a storage device that stores data related to the rotation time corresponding to the terminal, the terminal being unplanned at the current moment; and
a processor configured to calculate one or more of an open loop delta value, an open loop delta value based on an assigned bandwidth, and a delta value based bandwidth, and to adjust a parameter to be used for transmissions based on calculated values
wherein the delta value is at least one of a power offset value from a predetermined power reference value or a bandwidth offset value from a predetermined reference bandwidth, wherein one or more parameters include at least one of transmission power or bandwidth transmission. 9. The wireless communications apparatus of claim 8, wherein the processor is further configured to adjust a transmission power offset intended for use for transmissions based on the calculated values. 10. The wireless communications apparatus of claim 8, wherein the processor is further configured to adjust the bandwidth used for transmissions based on the calculated values. 11. The wireless communications apparatus of claim 8, wherein the storage device further stores destination-related data for a parameter intended for use for transmissions, and the processor is further configured to adjust the parameter based on the destination. 12. The wireless communications apparatus of claim 11, wherein the processor is further configured to determine whether the assignment for the parameter to be used for transmissions corresponds to the calculated open loop value. 13. The wireless communications apparatus of claim 12, wherein the processor is further configured to suspend transmission or to calculate a new open loop value if the assignment does not match the calculated open loop value. 14. The wireless communications apparatus of claim 8, wherein the processor is further configured to report one or more of the calculated open loop value and the adjusted parameter for transmissions to the access point. 15. A device for controlling power in a wireless communication system, comprising
means for calculating one or more of an open loop delta value, an open loop delta value, or a bandwidth based on a delta value, the calculation being based on an alternation time corresponding to the terminal, the terminal being currently unplanned; and
means for adjusting a parameter used to make transmissions to the serving sector based on the calculated value,
wherein the delta value is at least one of a power offset value from a predetermined power reference value or a bandwidth offset value from a predetermined reference bandwidth, wherein one or more parameters include at least one of transmission power or bandwidth transmission. 16. The device according to clause 15, in which the means for adjusting includes means for adjusting one or more of the offset transmission power and bandwidth used to perform transmissions to the serving sector. 17. The device according to clause 15, in which the means for adjusting includes
means for adjusting the power spectral density (PSD) based on the calculated value and
means for adjusting the transmission power used to complete the transmissions to the serving sector based on the adjusted PSD. 18. The device according to clause 15, in which the means for adjusting includes
means for receiving the assigned parameter from the serving sector and
means for adjusting a parameter used to communicate with the serving sector based on the assigned parameter. 19. The device according to clause 15, further comprising means for reporting one or more of the calculated values and adjusted parameters to the serving sector. 20. Computer-readable media containing
a code for causing the computer to calculate one or more of the open loop delta value, the open loop delta value based on the assigned bandwidth and the bandwidth based on the delta values, the calculation being based on the rotation time corresponding to the terminal, the terminal being unplanned at the current moment; and
code for causing the computer to correct one or more of the bandwidth and transmit power used for future transmissions to the base station at least partially based on calculated parameters based on an open loop delta value,
wherein the delta value is at least one of a power offset value from a predetermined power reference value or a bandwidth offset value from a predetermined reference bandwidth, wherein one or more parameters include at least one of transmission power or bandwidth transmission.

Images