WO2012071724A1

WO2012071724A1 - Methods and apparatus to generate a channel quality indicator with filtered interence in td-hsdpa systems

Info

Publication number: WO2012071724A1
Application number: PCT/CN2010/079344
Authority: WO
Inventors: Ruiming Zheng; Jianqiang Zhang; Mingxi Fan; Jiming Guo
Original assignee: Qualcomm Incorporated
Priority date: 2010-12-01
Filing date: 2010-12-01
Publication date: 2012-06-07

Abstract

Certain aspects of the present disclosure propose techniques for generating a channel quality indicator (CQI) with filtered interference in TD-HSDPA systems. Certain aspects provide a method that generally includes receiving a request for CQI information at a downlink time slot, calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots, and generating the CQI information based on the SNR.

Description

METHODS AND APPARATUS TO GENERATE A CHANNEL QUALITY INDICATOR WITH FILTERED INTERENCE IN TD-HSDPA SYSTEMS

BACKGROUND

Field

[0001] Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to generating channel quality indicator (CQI) information with filtered interference in TD-HSDPA (time division high speed downlink packet access) systems.

Background

[0002] Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD- SCDMA). For example, China is pursuing TD-SCDMA as the underlying air interface in the UTRAN architecture with its existing GSM infrastructure as the core network. The UMTS also supports enhanced 3G data communications protocols, such as High Speed Downlink Packet Data (HSDPA), which provides higher data transfer speeds and capacity to associated UMTS networks.

[0003] As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications. SUMMARY

[0004] In an aspect of the disclosure, a method for wireless communications is provided. The method generally includes receiving a request for channel quality indicator (CQI) information at a downlink time slot; calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and generating the CQI information based on the SNR.

[0005] In an aspect of the disclosure, an apparatus for wireless communications is provided. The apparatus generally includes means for receiving a request for channel quality indicator (CQI) information at a downlink time slot; means for calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and means for generating the CQI information based on the SNR.

[0006] In an aspect of the disclosure, an apparatus for wireless communications is provided. The apparatus generally includes at least one processor and a memory coupled to the at least one processor. The at least one processor is typically adapted to receive a request for channel quality indicator (CQI) information at a downlink time slot; calculate a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and generate the CQI information based on the SNR.

[0007] In an aspect of the disclosure, a computer-program product is provided. The computer-program product generally includes a computer-readable medium having code for receiving a request for channel quality indicator (CQI) information at a downlink time slot; calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and generating the CQI information based on the SNR.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Aspects and embodiments of the disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout. [0009] FIG. 1 is a block diagram conceptually illustrating an example of a telecommunications system in accordance with certain aspects of the present disclosure.

[0010] FIG. 2 is a block diagram conceptually illustrating an example of a frame structure in a telecommunications system in accordance with certain aspects of the present disclosure.

[0011] FIG. 3 is a block diagram conceptually illustrating an example of a Node B in communication with a user equipment device (UE) in a telecommunications system in accordance with certain aspects of the present disclosure.

[0012] FIG. 4 illustrates example operations for generating channel quality indicator (CQI) information based on interference measurements recorded at one or more previous downlink time slots, in accordance with certain aspects of the present disclosure.

[0013] FIG. 5 illustrates a subframe structure illustrating an example CQI-request HS-SCCH, in accordance with certain aspects of the present disclosure.

[0014] FIG. 6 illustrates an example of filtering previous received interference for generating CQI information, in accordance with certain aspects of the present disclosure.

DETAILED DESCRIPTION

[0015] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

AN EXAMPLE TELECOMMUNICATIONS SYSTEM

[0016] Turning now to FIG. 1, a block diagram is shown illustrating an example of a telecommunications system 100. The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example and without limitation, the aspects of the present disclosure illustrated in FIG. 1 are presented with reference to a UMTS system employing a TD-SCDMA standard. In this example, the UMTS system includes a radio access network (RAN) 102 (e.g., UTRAN) that provides various wireless services including telephony, video, data, messaging, broadcasts, and/or other services. The RAN 102 may be divided into a number of Radio Network Subsystems (RNSs) such as an RNS 107, each controlled by a Radio Network Controller (RNC) such as an RNC 106. For clarity, only the RNC 106 and the RNS 107 are shown; however, the RAN 102 may include any number of RNCs and RNSs in addition to the RNC 106 and RNS 107. The RNC 106 is an apparatus responsible for, among other things, assigning, reconfiguring and releasing radio resources within the RNS 107. The RNC 106 may be interconnected to other RNCs (not shown) in the RAN 102 through various types of interfaces such as a direct physical connection, a virtual network, or the like, using any suitable transport network.

[0017] The geographic region covered by the RNS 107 may be divided into a number of cells, with a radio transceiver apparatus serving each cell. A radio transceiver apparatus is commonly referred to as a Node B in UMTS applications, but may also be referred to by those skilled in the art as a base station (BS), a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), or some other suitable terminology. For clarity, two Node Bs 108 are shown; however, the RNS 107 may include any number of wireless Node Bs. The Node Bs 108 provide wireless access points to a core network 104 for any number of mobile apparatuses. Examples of a mobile apparatus include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The mobile apparatus is commonly referred to as user equipment (UE) in UMTS applications, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. For illustrative purposes, three UEs 110 are shown in communication with the Node Bs 108. The downlink (DL), also called the forward link, refers to the communication link from a Node B to a UE, and the uplink (UL), also called the reverse link, refers to the communication link from a UE to a Node B.

[0018] The core network 104, as shown, includes a GSM core network. However, as those skilled in the art will recognize, the various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable access network, to provide UEs with access to types of core networks other than GSM networks.

[0019] In this example, the core network 104 supports circuit- switched services with a mobile switching center (MSC) 112 and a gateway MSC (GMSC) 114. One or more RNCs, such as the RNC 106, may be connected to the MSC 112. The MSC 112 is an apparatus that controls call setup, call routing, and UE mobility functions. The MSC 112 also includes a visitor location register (VLR) (not shown) that contains subscriber- related information for the duration that a UE is in the coverage area of the MSC 112. The GMSC 114 provides a gateway through the MSC 112 for the UE to access a circuit- switched network 116. The GMSC 114 includes a home location register (HLR) (not shown) containing subscriber data, such as the data reflecting the details of the services to which a particular user has subscribed. The HLR is also associated with an authentication center (AuC) that contains subscriber-specific authentication data. When a call is received for a particular UE, the GMSC 114 queries the HLR to determine a location of the UE and forwards the call to the particular MSC serving that location.

[0020] The core network 104 also supports packet-data services with a serving GPRS support node (SGSN) 118 and a gateway GPRS support node (GGSN) 120. GPRS, which stands for General Packet Radio Service, is designed to provide packet- data services at speeds higher than those available with standard GSM circuit- switched data services. The GGSN 120 provides a connection for the RAN 102 to a packet-based network 122. The packet-based network 122 may be the Internet, a private data network, or some other suitable packet-based network. The primary function of the GGSN 120 is to provide the UEs 110 with packet-based network connectivity. Data packets are transferred between the GGSN 120 and the UEs 110 through the SGSN 118, which performs primarily the same functions in the packet-based domain as the MSC 112 performs in the circuit-switched domain.

[0021] The UMTS air interface is a spread spectrum Direct-Sequence Code Division Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMA spreads user data over a much wider bandwidth through multiplication by a sequence of pseudorandom bits called chips. The TD-SCDMA standard is based on such direct sequence spread spectrum technology and additionally calls for a time division duplexing (TDD), rather than a frequency division duplexing (FDD) as used in many FDD mode UMTS/W-CDMA systems. TDD uses the same carrier frequency for both the uplink (UL) and downlink (DL) between a Node B 108 and a UE 110, but divides uplink and downlink transmissions into different time slots in the carrier.

[0022] FIG. 2 shows a frame structure 200 for a TD-SCDMA carrier. The TD- SCDMA carrier, as illustrated, has a frame 202 that is 10 ms in length. The frame 202 has two 5 ms subframes 204, and each of the subframes 204 includes seven time slots, TS0 through TS6. The first time slot, TS0, is usually allocated for downlink communication, while the second time slot, TS1, is usually allocated for uplink communication. The remaining time slots, TS2 through TS6, may be used for either uplink or downlink, which allows for greater flexibility during times of higher data transmission times in either the uplink or downlink directions. A downlink pilot time slot (DwPTS) 206, a guard period (GP) 208, and an uplink pilot time slot (UpPTS) 210 (also known as the uplink pilot channel (UpPCH)) are located between TS0 and TS1. Each time slot, TS0-TS6, may allow data transmission multiplexed on a maximum of 16 code channels. Data transmission on a code channel includes two data portions 212 separated by a midamble 214 and followed by a guard period (GP) 216. The midamble 214 may be used for features, such as channel estimation, while the GP 216 may be used to avoid inter-burst interference.

[0023] FIG. 3 is a block diagram of a Node B 310 in communication with a UE 350 in a RAN 300, where the RAN 300 may be the RAN 102 in FIG. 1, the Node B 310 may be the Node B 108 in FIG. 1, and the UE 350 may be the UE 110 in FIG. 1. In the downlink communication, a transmit processor 320 may receive data from a data source 312 and control signals from a controller/processor 340. The transmit processor 320 provides various signal processing functions for the data and control signals, as well as reference signals (e.g., pilot signals). For example, the transmit processor 320 may provide cyclic redundancy check (CRC) codes for error detection, coding and interleaving to facilitate forward error correction (FEC), mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase- shift keying (M-PSK), M- quadrature amplitude modulation (M-QAM), and the like), spreading with orthogonal variable spreading factors (OVSF), and multiplying with scrambling codes to produce a series of symbols. Channel estimates from a channel processor 344 may be used by a controller/processor 340 to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor 320. These channel estimates may be derived from a reference signal transmitted by the UE 350 or from feedback contained in the midamble 214 (FIG. 2) from the UE 350. The symbols generated by the transmit processor 320 are provided to a transmit frame processor 330 to create a frame structure. The transmit frame processor 330 creates this frame structure by multiplexing the symbols with a midamble 214 (FIG. 2) from the controller/processor 340, resulting in a series of frames. The frames are then provided to a transmitter 332, which provides various signal conditioning functions including amplifying, filtering, and modulating the frames onto a carrier for downlink transmission over the wireless medium through smart antennas 334. The smart antennas 334 may be implemented with beam steering bidirectional adaptive antenna arrays or other similar beam technologies.

[0024] At the UE 350, a receiver 354 receives the downlink transmission through an antenna 352 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 354 is provided to a receive frame processor 360, which parses each frame, and provides the midamble 214 (FIG. 2) to a channel processor 394 and the data, control, and reference signals to a receive processor 370. The receive processor 370 then performs the inverse of the processing performed by the transmit processor 320 in the Node B 310. More specifically, the receive processor 370 descrambles and despreads the symbols, and then determines the most likely signal constellation points transmitted by the Node B 310 based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor 394. The soft decisions are then decoded and deinterleaved to recover the data, control, and reference signals. The CRC codes are then checked to determine whether the frames were successfully decoded. The data carried by the successfully decoded frames will then be provided to a data sink 372, which represents applications running in the UE 350 and/or various user interfaces (e.g., display). Control signals carried by successfully decoded frames will be provided to a controller/processor 390. When frames are unsuccessfully decoded by the receiver processor 370, the controller/processor 390 may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames.

[0025] In the uplink, data from a data source 378 and control signals from the controller/processor 390 are provided to a transmit processor 380. The data source 378 may represent applications running in the UE 350 and various user interfaces (e.g., keyboard). Similar to the functionality described in connection with the downlink transmission by the Node B 310, the transmit processor 380 provides various signal processing functions including CRC codes, coding and interleaving to facilitate FEC, mapping to signal constellations, spreading with OVSFs, and scrambling to produce a series of symbols. Channel estimates, derived by the channel processor 394 from a reference signal transmitted by the Node B 310 or from feedback contained in the midamble transmitted by the Node B 310, may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor 380 will be provided to a transmit frame processor 382 to create a frame structure. The transmit frame processor 382 creates this frame structure by multiplexing the symbols with a midamble 214 (FIG. 2) from the controller/processor 390, resulting in a series of frames. The frames are then provided to a transmitter 356, which provides various signal conditioning functions including amplification, filtering, and modulating the frames onto a carrier for uplink transmission over the wireless medium through the antenna 352.

[0026] The uplink transmission is processed at the Node B 310 in a manner similar to that described in connection with the receiver function at the UE 350. A receiver 335 receives the uplink transmission through the antenna 334 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 335 is provided to a receive frame processor 336, which parses each frame, and provides the midamble 214 (FIG. 2) to the channel processor 344 and the data, control, and reference signals to a receive processor 338. The receive processor 338 performs the inverse of the processing performed by the transmit processor 380 in the UE 350. The data and control signals carried by the successfully decoded frames may then be provided to a data sink 339 and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor 340 may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames.

[0027] The controller/processors 340 and 390 may be used to direct the operation at the Node B 310 and the UE 350, respectively. For example, the controller/processors 340 and 390 may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer- readable media of memories 342 and 392 may store data and software for the Node B 310 and the UE 350, respectively. A scheduler/processor 346 at the Node B 310 may be used to allocate resources to the UEs and schedule downlink and/or uplink transmissions for the UEs.

AN EXAMPLE METHOD TO GENERATE A CHANNEL QUALITY INDICATOR WITH FILTERED INTERFERENCE IN TD-HSDPA SYSTEMS

[0028] In current TD-HSDPA (time division high speed downlink packet access) systems, a node B may transmit an HS-SCCH (high speed shared control channel) directed towards a user equipment (UE) when the node B determines to schedule the particular UE. After at least five slots of HS-SCCH transmission, the scheduled UE may receive a corresponding data packet in an HS-PDSCH (high speed physical downlink shared channel) according to the payload size, modulation format and the packet resource utilization (time/codes) specified in the HS-SCCH. At least nine slots after the received HS-PDSCH, the UE may transmit an HS-SICH (high speed shared information channel) to the serving node B in an uplink time slot, which carries feedback channel quality indicator (CQI) information. The generation of CQI may be based on a signal-to-noise ratio (SNR) calculated based on the received HS-PDSCH SNR. The UE may feed back the CQI information with the maximum data rate in terms of block size and modulation format that the UE could reliably receive assuming the same code, time, and power resource allocated to the received data packet.

[0029] Based on the existing TD-HSDPA configuration, the CQI information of each UE may be transmitted only when the UE is scheduled. The limitation on CQI transmission may result in lower system throughput. As a result, the node B may transmit CQI-request HS-SCCHs (high speed shared control channels) to get more adequate channel information at the node B scheduler.

[0030] The UE that receives the CQI-request HS-SCCH may update the CQI information based on the CQI-request HS-SCCH channel SNR, but the interference measurement of the CQI-request HS-SCCH may not reflect the accurate HS-PDSCH interference variation. For current TD-HSDPA systems, the antenna beams from the surrounding interference cell may cause a serious fluctuation of interference to the desired user. Therefore, there may be an issue that the instantaneous CQI-request HS- SCCH SNR may not track the channel efficiently due to fluctuant interference.

[003l | For some embodiments, a filter may be added on the UE received interference in HS-PDSCH slots. In other words, the UE may filter the received interference in HS-PDSCH slots or every downlink time slot, and the UE may use this filtered interference power when calculating the CQI-request HS-SCCH SNR.

[0032] For some embodiments, to generate an accurate CQI capture HS-PDSCH slot channel information, the UE may add a filter on the previous received interference in HS-PDSCH slots for generating CQI-request HS-SCCH CQI. For a typical configuration, a CQI-request HS-SCCH may be assigned on any downlink slot for a particular UE by a node B.. Traditionally, the CQI-request HS-SCCH SNR may be calculated by instantaneous received serving cell power RSCP(n) and instantaneous total received interference power ISCP(n) on n-th TTI (transmission time interval). Therefore, the CQI-request HS-SCCH SNR per chip may be expressed as,

SNR(n) = ^RSCP(n)

ISCP(n)

10033] The CQI-request HS-SCCH CQI based on the instantaneous SNR may not follow the channel efficiently, due to the large channel variation caused by the beam forming of a surrounding interference cell. For some embodiments, the UE may use filtered interference power instead of instantaneous power when the UE calculates a CQI-request HS-SCCH SNR, as will be described further herein.

[0034] The UE may record received interference power ISCP(n) of previous HS- PDSCH slots when the UE is scheduled a data packet or every slots by node B on «-th TTI. The received interference power at the HS-PDSCH slots may be fed into an infinite impulse response (IIR) filter to get the filtered interference power ISCP(n) . The IIR filter may be defined as,

ISCP(n) = ISCP(n - m) x a ^m + ISCP(n) x ( 1 - a ^m )

[0035] where m is the most recent time scheduling, and « is an IIR filter factor to be specified by signaling. The UE may use the filtered interference power to calculate SNR when the UE receives a CQI-request HS-SCCH. In other words, the UE may use the filtered interference power ISCP(n) instead of instantaneous received interference power:

SNR(„) =≤¾

ISCP(n)

[0036] Once the UE finishes calculating the SNR of the CQI-request HS-SCCH, a CQI filter may be deployed to filter the above SNR value. After that, the UE may normalize the filtered CQI value and report the normalized CQI information at the proper uplink HS-SICH timing line.

[0037] FIG. 4 illustrates example operations 400 in accordance with certain aspects of the present disclosure. The operations 400 may be performed, for example, by a UE in generating channel quality indicator (CQI) information based on interference measurements recorded at one or more previous downlink time slots. At 402, the UE may receive a request for CQI information at a downlink time slot. At 404, the UE may calculate a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots. The interference measurements may be filtered using an IIR filter. At 406, the UE may generate the CQI information based on the SNR.

[0038] FIG. 5 shows a subframe structure 500 illustrating an example CQI-request HS-SCCH. For a typical CQI-request HS-SCCH configuration, there may be one UE scheduled by the node B for data transmission in the downlink. The node B may add one additional CQI-request HS-SCCH 502 on TS3. The transmitted power may be set as a pre-determined open loop power at the node B. [0039] FIG. 6 shows an example of filtering previous received interference for generating CQI information. For some embodiments, the UE may record received interference power (ISCPl 602, ISCP2 604, ISCP3 606...) of previous HS-PDSCH time slots when the UE is scheduled a data packet by the node B or every downlink time slot. Then the received interference power of HS-PDSCH slots may be fed into an IIR filter to get the HS-PDSCH filtered interference power ISCP(n) . Upon receiving the

CQI-request HS-SCCH 502, the UE may use the filtered interference power ISCP(n) to calculate the SNR and generate the CQI information.

10040] The above-described embodiments may also be used to generate the CQI based on an HS-PDSCH data packet. The UE may record interference of HS-DPSCH slots when the UE is scheduled by the node B. Then the recorded interference may be fed into the IIR filter to generate the filtered interference power. The CQI based on the HS-PDSCH packet may use this filtered previous interference value instead of instantaneous interference to generate accurate CQI information.

10041 ] For current TD-HSDPA system, the channel information may not be predicted due to the serious fluctuation of interference cased by beam forming from the surrounding interference cell. With the proposed CQI generation method of filtered interference, the UE may be aware of more adequate information to feed back proper CQI information.

[0042] Several aspects of a telecommunications system have been presented with reference to a TD-SCDMA system. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards. By way of example, various aspects may be extended to other UMTS systems such as W- CDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+) and TD-CDMA. Various aspects may also be extended to systems employing Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra- Wideband (UWB), Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

[0043] Several processors have been described in connection with various apparatuses and methods. These processors may be implemented using electronic hardware, computer software, or any combination thereof. Whether such processors are implemented as hardware or software will depend upon the particular application and overall design constraints imposed on the system. By way of example, a processor, any portion of a processor, or any combination of processors presented in this disclosure may be implemented with a microprocessor, microcontroller, digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gated logic, discrete hardware circuits, and other suitable processing components configured to perform the various functions described throughout this disclosure. The functionality of a processor, any portion of a processor, or any combination of processors presented in this disclosure may be implemented with software being executed by a microprocessor, microcontroller, DSP, or other suitable platform.

[0044] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. A computer- readable medium may include, by way of example, memory such as a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., compact disc (CD), digital versatile disc (DVD)), a smart card, a flash memory device (e.g., card, stick, key drive), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, or a removable disk. Although memory is shown separate from the processors in the various aspects presented throughout this disclosure, the memory may be internal to the processors (e.g., cache or register).

[0045] Computer-readable media may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

[0046] It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

[0047] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless specifically stated otherwise, the term "some" refers to one or more. A phrase referring to "at least one of a list of items refers to any combination of those items, including single members. As an example, "at least one of: a, b, or c" is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is recited using the phrase "step for."

Claims

1. A method for wireless communications, comprising:

receiving a request for channel quality indicator (CQI) information at a downlink time slot;

calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and

generating the CQI information based on the SNR.

2. The method of claim 1, wherein the interference measurements are filtered using an infinite impulse response (IIR) filter.

3. The method of claim 1, further comprising:

normalizing the CQI information; and

reporting the normalized CQI information.

4. The method of claim 1, wherein receiving the request comprises receiving a CQI-request high speed shared control channel (HS-SCCH).

5. The method of claim 1, wherein receiving the request comprises receiving a high speed physical downlink shared channel (HS-PDSCH) packet.

6. The method of claim 1, wherein the recorded interference measurements comprise received interference power of one or more previous high speed physical downlink shared channel (HS-PDSCH) slots.

7. The method of claim 1, wherein the one or more previous downlink time slots comprise downlink transmissions.

8. An apparatus for wireless communications, comprising:

means for receiving a request for channel quality indicator (CQI) information at a downlink time slot;

means for calculating a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and

means for generating the CQI information based on the SNR.

9. The apparatus of claim 8, wherein the interference measurements are filtered using an infinite impulse response (IIR) filter.

10. The apparatus of claim 8, further comprising:

means for normalizing the CQI information; and

means for reporting the normalized CQI information.

11. The apparatus of claim 8, wherein the means for receiving the request comprises means for receiving a CQI-request high speed shared control channel (HS-SCCH).

12. The apparatus of claim 8, wherein the means for receiving the request comprises means for receiving a high speed physical downlink shared channel (HS-PDSCH) packet.

13. The apparatus of claim 8, wherein the recorded interference measurements comprise received interference power of one or more previous high speed physical downlink shared channel (HS-PDSCH) slots.

14. The apparatus of claim 8, wherein the one or more previous downlink time slots comprise downlink transmissions.

15. An apparatus for wireless communications, comprising:

at least one processor adapted to:

receive a request for channel quality indicator (CQI) information at a downlink time slot;

calculate a signal-to-noise ratio (SNR) based on interference measurements recorded at one or more previous downlink time slots; and

generate the CQI information based on the SNR; and

a memory coupled to the at least one processor.

16. The apparatus of claim 15, wherein the interference measurements are filtered using an infinite impulse response (IIR) filter.

17. The apparatus of claim 15, wherein the at least one processor is adapted to: normalize the CQI information; and

report the normalized CQI information.

18. The apparatus of claim 15, wherein the at least one processor adapted to receive the request comprises receiving a CQI-request high speed shared control channel (HS- SCCH).

19. The apparatus of claim 15, wherein the at least one processor adapted to receive the request comprises receiving a high speed physical downlink shared channel (HS- PDSCH) packet.

20. The apparatus of claim 15, wherein the recorded interference measurements comprise received interference power of one or more previous high speed physical downlink shared channel (HS-PDSCH) slots.

21. The apparatus of claim 15, wherein the one or more previous downlink time slots comprise downlink transmissions.

22. A computer-program product, comprising:

a computer-readable medium comprising code for:

generating the CQI information based on the SNR.

23. The computer-program product of claim 22, wherein the interference measurements are filtered using an infinite impulse response (IIR) filter.

24. The computer-program product of claim 22, further comprising code for:

normalizing the CQI information; and

reporting the normalized CQI information.

25. The computer-program product of claim 22, wherein the code for receiving the request comprises code for receiving a CQI-request high speed shared control channel (HS-SCCH).

26. The computer-program product of claim 22, wherein the code for receiving the request comprises code for receiving a high speed physical downlink shared channel (HS-PDSCH) packet.

27. The computer-program product of claim 22, wherein the recorded interference measurements comprise received interference power of one or more previous high speed physical downlink shared channel (HS-PDSCH) slots.

28. The computer-program product of claim 22, wherein the one or more previous downlink time slots comprise downlink transmissions.