Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
  • H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
  • H04L1/0045—Arrangements at the receiver end
  • H04L1/0055—MAP-decoding
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
  • H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
  • H03M13/27—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes using interleaving techniques
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
  • H04L1/0045—Arrangements at the receiver end
  • H04L1/0052—Realisations of complexity reduction techniques, e.g. pipelining or use of look-up tables
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
  • H04L1/0056—Systems characterized by the type of code used
  • H04L1/0071—Use of interleaving

Definitions

• the following description relates generally to wireless communications, and more particularly to storage design in order to reduce memory collisions within a portion of memory storage.
• Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems.
• a typical wireless communication system, or network can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power, ).
• shared resources e.g., bandwidth, transmit power, .
• a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
• FDM Frequency Division Multiplexing
• TDM Time Division Multiplexing
• CDM Code Division Multiplexing
• OFDM Orthogonal Frequency Division Multiplexing
• wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices.
• Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links.
• the forward link (or downlink) refers to the communication link from base stations to mobile devices
• the reverse link (or uplink) refers to the communication link from mobile devices to base stations.
• Wireless communication systems oftentimes employ one or more base stations that provide a coverage area.
• a typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to a mobile device.
• a mobile device within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream.
• a mobile device can transmit data to the base station or another mobile device.
• Area tracking within a wireless communication system enables a tracking area location for user equipment (e.g., mobile device, mobile communication apparatus, cellular device, smartphone, etc.) to be defined.
• a network can request or page the user equipment (UE) in which the UE can respond with such tracking area location. This enables the tracking area location of the UE to be communicated and updated to the network.
• UE user equipment
• Turbo code is oftentimes used for reliable communication in a wireless communication system, where the transmitter uses turbo encoder to encode information bits while the receiver decodes the transmitted bits using a turbo decoder (TDEC).
• a turbo decoder can include a portion of memory, typically A Posteriori Probability (APP) Random Access Memory (RAM), to exchange information between different parts of a turbo decoder.
• APP Posteriori Probability
• RAM Random Access Memory
• the turbo decoder can include two Maximum A Posteriori (MAP) decoders that can share the APP RAM. Due to the high throughput demand of the turbo decoder in order to support wide bandwidth and multiple-in-multiple-out (MIMO), memory collision and/or contention can occur.
• MAP Maximum A Posteriori
• sharing the APP RAM between MAP decoders can cause memory contention and/or collision based on the loading or unloading of values to/from APP RAM, which undesirably reduces the processing throughput of a turbo decoder. Therefore, there is a need to design APP RAM such that multiple MAP decoders can share the APP RAM without causing memory access contention.
• a method that facilitates employing a turbo decoder that provides contention free memory access can include identifying an A Posteriori Probability (APP) Random Access Memory (RAM).
• APP A Posteriori Probability
• RAM Random Access Memory
• the method can include organizing the APP RAM into at least two files. Moreover, the method can comprise dividing all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver. The method can additionally include mapping separate interleaving subgroups to separate RAM files.
• QPP Quadratic Permutation Polynomial
• the wireless communications apparatus can include at least one processor configured to identify an A Posteriori Probability (APP) Random Access Memory (RAM), organize the APP RAM into at least two files, divide all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver, and map separate interleaving sub-groups to separate RAM files.
• APP A Posteriori Probability
• QPP Quadratic Permutation Polynomial
• the wireless communications apparatus can include memory coupled to the at least one processor.
• the wireless communications apparatus can include means for identifying an A Posteriori Probability (APP) Random Access Memory (RAM). Additionally, the wireless communications apparatus can comprise means for organizing the APP RAM into at least two files. Further, the wireless communications apparatus can comprise means for dividing all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver. Moreover, the wireless communications apparatus can comprise means for mapping separate interleaving sub-groups to separate RAM files.
• APP A Posteriori Probability
• RAM Random Access Memory
• QPP Quadratic Permutation Polynomial
• Still another aspect relates to a computer program product comprising a computer-readable medium having stored thereon code causing at least one computer to identify an A Posteriori Probability (APP) Random Access Memory (RAM), organize the APP RAM into at least two files, divide all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver, and map separate interleaving sub-groups to separate RAM files.
• APP A Posteriori Probability
• RAM Random Access Memory
• QPP Quadratic Permutation Polynomial
• the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims.
• the following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments can be employed and the described embodiments are intended to include all such aspects and their equivalents.
• FIG. 1 is an illustration of a wireless communication system in accordance with various aspects set forth herein.
• FIG. 2 is an illustration of an example communications apparatus for employment within a wireless communications environment.
• FIG. 3 is an illustration of an example turbo decoder in accordance with the subject innovation.
• FIG. 4 is an illustration of an example A Posteriori Probability (APP)
• RAM Random Access Memory
• FIG. 5 is an illustration of a radix-2 configuration and a radix-4 configuration.
• FIG. 6 is an illustration of an example methodology that facilitates employing a turbo decoder that provides contention free memory access.
• FIG. 7 is an illustration of an example mobile device that facilitates organizing a portion of memory for a turbo decoder to avoid memory collisions in a wireless communication system.
• FIG. 8 is an illustration of an example system that facilitates partitioning
• APP Posteriori Probability Random Access Memory
• FIG. 9 is an illustration of an example wireless network environment that can be employed in conjunction with the various systems and methods described herein.
• FIG. 10 is an illustration of an example system that facilitates employing a turbo decoder that provides contention free memory access.
• module As used in this application, the terms "module,” “carrier,” “system,”
• a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer.
• an application running on a computing device and the computing device can be a component.
• One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers.
• these components can execute from various computer readable media having various data structures stored thereon.
• the components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal).
• a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal).
• CDMA code division multiple access
• TDMA time division multiple access
• FDMA frequency division multiple access
• OFDMA orthogonal frequency division multiple access
• SC-FDMA single carrier-frequency division multiple access
• a CDMA system can implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc.
• UTRA includes Wideband-CDMA (W-CDMA) and other variants of CDMA.
• CDMA2000 covers IS- 2000, IS-95 and IS-856 standards.
• a TDMA system can implement a radio technology such as Global System for Mobile Communications (GSM).
• GSM Global System for Mobile Communications
• An OFDMA system can implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash- OFDM, etc.
• E-UTRA Evolved UTRA
• UMB Ultra Mobile Broadband
• Wi-Fi IEEE 802.11
• WiMAX IEEE 802.16
• Flash- OFDM Flash- OFDM
• UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS).
• UMTS Universal Mobile Telecommunication System
• 3GPP Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink.
• SC-FDMA Single carrier frequency division multiple access
• SC-FDMA utilizes single carrier modulation and frequency domain equalization.
• SC-FDMA has similar performance and essentially the same overall complexity as those of an OFDMA system.
• a SC-FDMA signal has lower peak-to-average power ratio (PAPR) because of its inherent single carrier structure.
• PAPR peak-to-average power ratio
• SC-FDMA can be used, for instance, in uplink communications where lower PAPR greatly benefits access terminals in terms of transmit power efficiency.
• SC-FDMA can be implemented as an uplink multiple access scheme in 3 GPP Long Term Evolution (LTE) or Evolved UTRA.
• LTE Long Term Evolution
• a mobile device can also be called a system, subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user device, or user equipment (UE).
• a mobile device can be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, computing device, or other processing device connected to a wireless modem.
• SIP Session Initiation Protocol
• WLL wireless local loop
• PDA personal digital assistant
• a base station can be utilized for communicating with mobile device(s) and can also be referred to as an access point, Node B, or some other terminology.
• various aspects or features described herein can be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques.
• article of manufacture as used herein is intended to encompass a computer program accessible from any computer- readable device, carrier, or media.
• computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., compact disk (CD), digital versatile disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.).
• various storage media described herein can represent one or more devices and/or other machine-readable media for storing information.
• the term "machine- readable medium” can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.
• System 100 comprises a base station 102 that can include multiple antenna groups.
• one antenna group can include antennas 104 and 106, another group can comprise antennas 108 and 110, and an additional group can include antennas 112 and 114.
• Two antennas are illustrated for each antenna group; however, more or fewer antennas can be utilized for each group.
• Base station 102 can additionally include a transmitter chain and a receiver chain, each of which can in turn comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art.
• Base station 102 can communicate with one or more mobile devices such as mobile device 116 and mobile device 122; however, it is to be appreciated that base station 102 can communicate with substantially any number of mobile devices similar to mobile devices 116 and 122.
• Mobile devices 116 and 122 can be, for example, cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over wireless communication system 100.
• mobile device 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to mobile device 116 over a forward link 118 and receive information from mobile device 116 over a reverse link 120.
• mobile device 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to mobile device 122 over a forward link 124 and receive information from mobile device 122 over a reverse link 126.
• forward link 118 can utilize a different frequency band than that used by reverse link 120
• forward link 124 can employ a different frequency band than that employed by reverse link 126, for example.
• forward link 118 and reverse link 120 can utilize a common frequency band and forward link 124 and reverse link 126 can utilize a common frequency band.
• Each group of antennas and/or the area in which they are designated to communicate can be referred to as a sector of base station 102.
• antenna groups can be designed to communicate to mobile devices in a sector of the areas covered by base station 102.
• the transmitting antennas of base station 102 can utilize beamforming to improve signal-to- noise ratio of forward links 118 and 124 for mobile devices 116 and 122.
• base station 102 utilizes beamforming to transmit to mobile devices 116 and 122 scattered randomly through an associated coverage
• mobile devices in neighboring cells can be subject to less interference as compared to a base station transmitting through a single antenna to all its mobile devices.
• Base station 102 (and/or each sector of base station 102) can employ one or more multiple access technologies (e.g., CDMA, TDMA, FDMA, OFDMA, ). For instance, base station 102 can utilize a particular technology for communicating with mobile devices (e.g., mobile devices 116 and 122) upon a corresponding bandwidth. Moreover, if more than one technology is employed by base station 102, each technology can be associated with a respective bandwidth.
• multiple access technologies e.g., CDMA, TDMA, FDMA, OFDMA, .
• base station 102 can utilize a particular technology for communicating with mobile devices (e.g., mobile devices 116 and 122) upon a corresponding bandwidth.
• mobile devices e.g., mobile devices 116 and 122
• each technology can be associated with a respective bandwidth.
• GSM Global System for Mobile
• GPRS General Packet Radio Service
• EDGE Enhanced Data Rates for GSM Evolution
• UMTS Universal Mobile Telecommunications System
• W- CDMA Wideband Code Division Multiple Access
• cdmaOne IS-95
• CDMA2000 Evolution-Data Optimized
• UMB Ultra Mobile Broadband
• GSM Global System for Mobile
• GPRS General Packet Radio Service
• EDGE Enhanced Data Rates for GSM Evolution
• UMTS Universal Mobile Telecommunications System
• W- CDMA Wideband Code Division Multiple Access
• cdmaOne IS-95
• CDMA2000 Evolution-Data Optimized
• UMB Ultra Mobile Broadband
• WiMAX WiMAX
• DMB Digital Multimedia Broadcasting
• DVD-H Digital Video Broadcasting - Handheld
• Base station 102 can employ a first bandwidth with a first technology.
• base station 102 can transmit a pilot corresponding to the first technology on a second bandwidth.
• the second bandwidth can be leveraged by base station 102 and/or any disparate base station (not shown) for communication that utilizes any second technology.
• the pilot can indicate the presence of the first technology (e.g., to a mobile device communicating via the second technology).
• the pilot can use bit(s) to carry information about the presence of the first technology.
• information such as a SectorlD of the sector utilizing the first technology, a Carrierlndex indicating the first frequency bandwidth, and the like can be included in the pilot.
• the pilot can be a beacon (and/or a sequence of beacons).
• a beacon can be an OFDM symbol where a large fraction of the power is transmitted on one subcarrier or a few subcarriers (e.g., small number of subcarriers).
• the beacon provides a strong peak that can be observed by mobile devices, while interfering with data on a narrow portion of bandwidth (e.g., the remainder of the bandwidth can be unaffected by the beacon).
• a first sector can communicate via CDMA on a first bandwidth and a second sector can communicate via OFDM on a second bandwidth.
• the first sector can signify the availability of CDMA on the first bandwidth (e.g., to mobile device(s) operating utilizing OFDM on the second bandwidth) by transmitting an OFDM beacon (or a sequence of OFDM beacons) upon the second bandwidth.
• the subject innovation can employ partition techniques for a portion of memory utilized within a turbo decoder in order to reduce and/or eliminate memory collisions during read and/or write operations within a clock cycle.
• An A Posteriori Probability (APP) Random Access Memory (RAM) can be evaluated in order to identify a partitioning and/or an organization of the APP RAM into files.
• the goal of the partition and/or organization is such that the turbo decoder never accesses (reads or writes) more than one address of any of the files within any clock cycle. If the turbo decoder needs to access more than one address of any of the files, a memory access contention occurs. Such a contention will cause the turbo decoder to stop and wait while the contention is being resolved. This will inevitably reduce the processing throughput of the turbo decoder.
• the communications apparatus 200 can be a base station or a portion thereof, a mobile device or a portion thereof, or substantially any communications apparatus that receives data transmitted in a wireless communications environment. It is to be appreciated that the
• communications apparatus 200 can be a base station (e.g., access point, Node B, eNode B, etc.) and/or a user equipment (e.g., mobile station, mobile device, and/or any number of disparate devices (not shown)).
• the communications apparatus 200 can transmit information over a forward link channel or downlink channel; further the communications apparatus 200 can receive information over a reverse link channel or uplink channel; further the communications apparatus 200 can transmit information over a reverse link channel or uplink channel; further the communications apparatus 200 can receive information over a forward link channel or downlink channel.
• communications apparatus 200 can be utilized in a MIMO system.
• the communications apparatus 200 can operate in an OFDMA wireless network (such as 3GPP, 3GPP2, 3GPP LTE, etc., for example).
• the communications apparatus 200 employ components described below to evaluate A Posteriori Probability (APP) Random Access Memory (RAM) and create a partitioning of the memory based on the evaluation in order to reduce memory collisions.
• APP Posteriori Probability
• RAM Random Access Memory
• the communications apparatus 200 can include an evaluation module
• the evaluation module 204 can evaluate the APP RAM 202 in order to collect information such as, but not limited to, size, number of MAP decoders sharing the APP RAM 202, etc.
• the communications apparatus 200 can further include an organization module 206 that can partition and/or segment the APP RAM 202. For example, the organization module 206 can segment and/or partition the APP RAM 202 based upon the evaluation of the APP RAM 202.
• the organization module 206 can create two or more files based upon the size of the APP RAM 202, and/or the number and the implementation of MAP decoders.
• the organization module 206 can divide all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver.
• QPP Quadratic Permutation Polynomial
• the organization module 206 can map separate interleaving sub-groups to separate RAM files.
• the evaluation of APP RAM partition and APP RAM organization can also be fixed.
• the organization module 206 can organize the APP RAM
• the organization module 206 can organize the APP RAM 202 into eight RAM files.
• the first file can contain the APP values of P[8i]
• the second file can contain the APP values for P[8i+1]
• the third file can contain the APP values for P[8i+2], ...
• the last file can contain the APP values for P[8i+7], where i is the index of the entries within each file.
• communications apparatus 200 can include memory that retains instructions with respect to identifying an A Posteriori Probability (APP) Random Access Memory (RAM), organizing the APP RAM into at least two files, and the like. Further, communications apparatus 200 can include a processor that may be utilized in connection with executing instructions (e.g., instructions retained within memory, instructions obtained from a disparate source, ).
• APP A Posteriori Probability
• RAM Random Access Memory
• communications apparatus 200 can include a processor that may be utilized in connection with executing instructions (e.g., instructions retained within memory, instructions obtained from a disparate source, ).
• the turbo decoder 300 can include a MAP decoder 302, a MAP decoder 304, an APP RAM 306, a hard decision unit 308, a read interleaver 310, a write interleaver 312, a write interleaver 314, a read interleaver 316, and a hard decision unit 318. It is to be appreciated that both the MAP decoder 302 and the MAP decoder 304 access the APP RAM 306 for read and/or write APP values.
• the subject innovation can provide segmenting or partitioning the APP RAM 306 into files in order to prevent memory collisions and/or memory contention.
• Internal TDEC implementations can have various features.
• one MAP decoder covers the first half of the trellises (from 0 to N/2-1), the other MAP decoder covers the second half trellises (from N/2 to N-1), where N is the length of a (Turbo) code block.
• N is the length of a (Turbo) code block.
• the two MAP decoders defines their trellis directions in opposite ways.
• the forward trellis for the first MAP decoder is from 0 to N/2-1
• the reverse trellis is from N/2-1 to N. This is so because the initial state at zero is known (all-zero state).
• the trellis directions are the opposite.
• the forward trellis for the second MAP decoder is from N-1 to N/2, and the reverse trellis is from N/2 to N-1. This is so because the ending state at N is also known (all-zero state). [0041] Rather than computing the forward and reverse state metrics of the entire
• N/2 trellis which would require tremendous amount of memory to store all state metrics
• the length N/2 trellises for each MAP decoder can be further split into M non- overlapping windows, each of length L , forward and reverse state metrics calculations are carried out first for the first window, then the second window, and so on.
• the MAP decoders 302 and 304 can be implemented using radix-4 trellis. That is, two contiguous radix-2 trellises are aggregated as one single radix-4 trellis (See
• the above example implementation processes 4 code trellis transitions every clock cycle with two transitions done in the first Radix-4 MAP decoder and two transitions in the other MAP decoder. In order to fully exploit this processing capability, the follow two criteria need to be satisfied.
• Criteria 1 Four sets of input samples can be read each clock cycle without memory access contention, where the each set of input sample include sample for one or zero systematic bit (one for the first constituent code (CC) and zero for the second CC), two samples for parity bits (due to 1/3 CC code rate), and one APP value. Depending on whether the MAP decoding corresponds to the first constituent code or the second constituent code, the addresses of these four sets are either
• the first two addresses are next to each other (either without turbo interleaver or with turbo interleaver) due to Radix-4 implementation. Similarly, the last two addresses.
• Criteria 2 Four APP values can be written in each clock cycle without memory access contention.
• the addresses of these APP values are in a format of m - L + 2k, m - L + 2k + ⁇ , n - L + L - ⁇ - 2k, and n - L + L - 2 - 2k or ⁇ -L + lk), n ⁇ m-L + 2k + ⁇ ), ⁇ -L + L-l-lk), and ⁇ ( ⁇ + ⁇ -2-2 ⁇ ), depending whether the MAP decoding corresponds to the first constituent code or the second constituent code.
• m,n, and k are defined as previously.
• turbo interleaver for LTE is defined using Quadratic Permutation Polynomial (QPP).
• QPP Quadratic Permutation Polynomial
• a QPP interleaver is defined as follows:
• a polynomial is said to be a permutation polynomial if it defines a one-to-one mapping of ⁇ 0,l,--,N-l ⁇ — > ⁇ 0,l,--,N-l ⁇
• the parameters of the QPP interleavers defined for LTE can be identified for various code block sizes. There can be a total of 188 interleaver sizes defined for LTE. All interleaver sizes can be at least byte-aligned. When 40 ⁇ ⁇ ⁇ 512, interleaver sizes are all multiples of 8. When 512 ⁇ ⁇ ⁇ 1024, interleaver sizes are all multiples of 16. When 1024 ⁇ K ⁇ 2048, interleaver sizes are all multiples of 32. When 2048 ⁇ K ⁇ 6144, interleaver sizes are all multiples of 64.
• ⁇ is also a permutation polynomial modulo pTM for any 0 ⁇ m ⁇ n i .
• ⁇ addresses from 0 to ⁇ -1 can be divided into M subgroups, where the k-th sub-group includes the addresses of ⁇ lj ⁇ Then all the addresses in a sub-group remain as one sub ⁇
• addresses in different sub-groups belong to different sub-group after interleaving. That is, turbo interleaving is effectively within each sub-group.
• the TDEC needs to access APP values with indices m-L + 2k, m-L + 2k + l, n ⁇ L + L -I- 2k, and n-L + L- 2-2kor (m-L + 2k), n ⁇ m-L + 2k + ⁇ ), ⁇ -L + L-l-lk), and n ⁇ n-L + L-2-2k), including four reads and four writes per clock cycle.
• Typical value for L is 32/64/128. It is easy to check that with these values for L the four addresses, either:
• dual-port RAM in the above example can be avoided by dividing the APP values into eight interleaving sub-groups with each sub-group stored in a separate single -port RAM file.
• Single port RAM can either be read or written at any time. Four reads and four writes per clock cycle can still be archived by reading eight values, one from each RAM file, in one clock cycle and writing eight values, one for each RAM file, in the next clock cycle, and so on.
• Random Access Memory (RAM) design 400 that includes four sub-groups in accordance with the subject innovation is illustrated.
• the APP RAM design 400 can include four files (e.g., indicated by RAMO, RAMI, RAM2, and RAM3).
• the APP values are divided into four interleaving sub-group with each sub-group stored in one RAM file.
• TDEC needs to calculate the interleaver or the deinterleaver addresses during Turbo iterations. The calculation is straightly based on the QPP. QPP calculation logic needs to be instantiated multiple times, one for each sub-group, in order to calculate one interleaver address for each sub-group within each clock cycle.
• FIG. 5 An illustration 500 of a radix-2 configuration and a radix-4 configuration are depicted.
• a radix-2 502 can be illustrated as well as a radix-4 504.
• the MAP decoders within a turbo decoder can be implemented as a radix-4 configuration.
• two trellis transitions can be traveled in one clock cycle.
• more complicated state metric calculations exist.
• two values from APP RAM are accessed within each clock cycle.
• FIG. 6 a methodology relating to segmenting RAM to reduce errors during read or write operations is illustrated. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments.
• a methodology 600 that facilitates employing a turbo decoder that provides contention free memory access.
• an A Posteriori Probability (APP) Random Access Memory (RAM) can be identified.
• the APP RAM can be organized into at least two files.
• all the APP values can be divided into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver.
• QPP Quadratic Permutation Polynomial
• separate interleaving sub-groups can be mapped to separate RAM files.
• Fig. 7 is an illustration of a mobile device 700 that facilitates organizing a portion of memory for a turbo decoder to avoid memory collisions in a wireless communication system.
• Mobile device 700 comprises a receiver 702 that receives a signal from, for instance, a receive antenna (not shown), performs typical actions on (e.g., filters, amplifies, downconverts, etc.) the received signal, and digitizes the conditioned signal to obtain samples.
• Receiver 702 can comprise a demodulator 704 that can demodulate received symbols and provide them to a processor 706 for channel estimation.
• Processor 706 can be a processor dedicated to analyzing information received by receiver 702 and/or generating information for transmission by a transmitter 716, a processor that controls one or more components of mobile device 700, and/or a processor that both analyzes information received by receiver 702, generates information for transmission by transmitter 716, and controls one or more components of mobile device 700.
• Mobile device 700 can additionally comprise memory 708 that is operatively coupled to processor 706 and that can store data to be transmitted, received data, information related to available channels, data associated with analyzed signal and/or interference strength, information related to an assigned channel, power, rate, or the like, and any other suitable information for estimating a channel and communicating via the channel.
• Memory 708 can additionally store protocols and/or algorithms associated with estimating and/or utilizing a channel (e.g., performance based, capacity based, etc.).
• nonvolatile memory can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable PROM (EEPROM), or flash memory.
• Volatile memory can include random access memory (RAM), which acts as external cache memory.
• RAM is available in many forms such as synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (E SDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM
• DRRAM DRRAM
• the memory 708 of the subject systems and methods is intended to comprise, without being limited to, these and any other suitable types of memory.
• Processor 706 can further be operatively coupled to an evaluation module 710 and/or an organization module 712.
• the evaluation module 710 can identify and examine a portion of APP RAM.
• the organization module 712 can segment or partition the APP RAM such that a segment can correspond to a MAP decoder within the turbo decoder in order to prevent memory contention and/or memory collision.
• the organization module 712 can divide all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver.
• QPP Quadratic Permutation Polynomial
• the organization module 712 can map separate interleaving subgroups to separate RAM files
• Mobile device 700 still further comprises a modulator 714 and transmitter 716 that respectively modulate and transmit signals to, for instance, a base station, another mobile device, etc.
• a modulator 714 and transmitter 716 that respectively modulate and transmit signals to, for instance, a base station, another mobile device, etc.
• the evaluation module 710, organization module 712, demodulator 704, and/or modulator 714 can be part of the processor 706 or multiple processors (not shown).
• FIG. 8 is an illustration of a system 800 that facilitates partitioning A
• the system 800 comprises a base station 802 ⁇ e.g., access point, ...) with a receiver 810 that receives signal(s) from one or more mobile devices 804 through a plurality of receive antennas 806, and a transmitter 824 that transmits to the one or more mobile devices 804 through a transmit antenna 808.
• Receiver 810 can receive information from receive antennas 806 and is operatively associated with a demodulator 812 that demodulates received information. Demodulated symbols are analyzed by a processor 814 that can be similar to the processor described above with regard to Fig.
• a memory 816 that stores information related to estimating a signal ⁇ e.g., pilot) strength and/or interference strength, data to be transmitted to or received from mobile device(s) 804 (or a disparate base station (not shown)), and/or any other suitable information related to performing the various actions and functions set forth herein.
• Processor 814 is further coupled to an evaluation module 818 and/or an organization module 820.
• the evaluation module 818 can identify APP RAM and as size associated therewith.
• the organization module 820 can create at least two files and sub-groups within each file within the APP RAM in order to ensure isolation between each file and/or sub-group.
• the organization module 820 can divide all the APP values into at least two interleaving sub-groups based on a Quadratic Permutation Polynomial (QPP) turbo interleaver.
• QPP Quadratic Permutation Polynomial
• the organization module 820 can map separate interleaving sub-groups to separate RAM files.
• the evaluation module 818, organization module 820, demodulator 812, and/or modulator 822 can be part of the processor 814 or multiple processors (not shown).
• Fig. 9 shows an example wireless communication system 900.
• the wireless communication system 900 depicts one base station 910 and one mobile device 950 for sake of brevity.
• system 900 can include more than one base station and/or more than one mobile device, wherein additional base stations and/or mobile devices can be substantially similar or different from example base station 910 and mobile device 950 described below.
• base station 910 and/or mobile device 950 can employ the systems (Figs. 1-3 and 7-8), techniques/configurations (Figs. 4-5) and/or methods (Fig. 6) described herein to facilitate wireless communication there between.
• traffic data for a number of data streams is provided from a data source 912 to a transmit (TX) data processor 914.
• TX data processor 914 formats, codes, and interleaves the traffic data stream based on a particular coding scheme selected for that data stream to provide coded data.
• the coded data for each data stream can be multiplexed with pilot data using orthogonal frequency division multiplexing (OFDM) techniques. Additionally or alternatively, the pilot symbols can be frequency division multiplexed (FDM), time division multiplexed (TDM), or code division multiplexed (CDM).
• the pilot data is typically a known data pattern that is processed in a known manner and can be used at mobile device 950 to estimate channel response.
• the multiplexed pilot and coded data for each data stream can be modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols.
• BPSK binary phase-shift keying
• QPSK quadrature phase-shift keying
• M-PSK M-phase-shift keying
• M-QAM M-quadrature amplitude modulation
• the data rate, coding, and modulation for each data stream can be determined by instructions performed or provided by processor 930.
• modulation symbols for the data streams can be provided to a TX
• TX MIMO processor 920 which can further process the modulation symbols (e.g., for OFDM). TX MIMO processor 920 then provides ⁇ modulation symbol streams to ⁇ transmitters (TMTR) 922a through 922t. In various embodiments, TX MIMO processor 920 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.
• Each transmitter 922 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. Further, ⁇ modulated signals from transmitters 922a through 922t are transmitted from ⁇ antennas 924a through 924t, respectively.
• the transmitted modulated signals are received by the mobile device 950.
• N R antennas 952a through 952r and the received signal from each antenna 952 is provided to a respective receiver (RCVR) 954a through 954r.
• Each receiver 954 conditions (e.g., filters, amplifies, and downconverts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.
• An RX data processor 960 can receive and process the N R received symbol streams from N R receivers 954 based on a particular receiver processing technique to provide ⁇ "detected" symbol streams. RX data processor 960 can demodulate, deinterleave, and decode each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 960 is complementary to that performed by TX MIMO processor 920 and TX data processor 914 at base station 910.
• a processor 970 can periodically determine which precoding matrix to utilize as discussed above. Further, processor 970 can formulate a reverse link message comprising a matrix index portion and a rank value portion. [0074] The reverse link message can comprise various types of information regarding the communication link and/or the received data stream. The reverse link message can be processed by a TX data processor 938, which also receives traffic data for a number of data streams from a data source 936, modulated by a modulator 980, conditioned by transmitters 954a through 954r, and transmitted back to base station 910.
• the modulated signals from mobile device 950 are received by antennas 924, conditioned by receivers 922, demodulated by a demodulator 940, and processed by a RX data processor 942 to extract the reverse link message transmitted by mobile device 950. Further, processor 930 can process the extracted message to determine which precoding matrix to use for determining the beamforming weights.
• Processors 930 and 970 can direct (e.g., control, coordinate, manage, etc.) operation at base station 910 and mobile device 950, respectively. Respective processors 930 and 970 can be associated with memory 932 and 972 that store program codes and data. Processors 930 and 970 can also perform computations to derive frequency and impulse response estimates for the uplink and downlink, respectively.
• the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof.
• the processing units can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.
• ASICs application specific integrated circuits
• DSPs digital signal processors
• DSPDs digital signal processing devices
• PLDs programmable logic devices
• FPGAs field programmable gate arrays
• processors controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.
• a code segment can represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements.
• a code segment can be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.
• the techniques described herein can be implemented with modules ⁇ e.g., procedures, functions, and so on) that perform the functions described herein.
• the software codes can be stored in memory units and executed by processors.
• the memory unit can be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.
• System 1000 that employs a turbo decoder that provides contention free memory access.
• system 1000 can reside at least partially within a base station, mobile device, etc.
• system 1000 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof ⁇ e.g., firmware).
• System 1000 includes a logical grouping 1002 of electrical components that can act in conjunction.
• the logical grouping 1002 can include an electrical component for identifying an A Posteriori Probability (APP) Random Access Memory (RAM) 1004.
• APP A Posteriori Probability
• RAM Random Access Memory
• the logical grouping 1002 can comprise an electrical component for organizing the APP RAM into at least two files 1006.
• the logical grouping 1002 can include an electrical component for dividing all the APP values into at least two interleaving sub-groups based on a
• the logical grouping 1002 can comprise an electrical component for mapping separate interleaving sub-groups to separate RAM files 1010.
• system 1000 can include a memory 1012 that retains instructions for executing functions associated with electrical components 1004, 1006, 1008, and 1010. While shown as being external to memory 1012, it is to be understood that one or more of electrical components 1004, 1006, 1008, and 1010 can exist within memory 1012.

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• 2009
  • 2009-10-29 US US12/608,919 patent/US8255759B2/en not_active Expired - Fee Related
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