Abstract:
A method and apparatus for processing in Read SystemInfo state in a wireless communication network, the method comprising issuing a ControlChannelMAC.Activate command, issuing a OverheadMessages.Activate command and determining if a SystemInfoBlock is received within T ISPSyncAcq  seconds.

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. § 119 
       [0001]    The present Application for Patent claims priority to Provisional Application Ser. No. 60/731,126, entitled “METHODS AND APPARATUS FOR PROVIDING MOBILE BROADBAND WIRELESS LOWER MAC”, field Oct. 27, 2005, assigned to the assignee hereof, and expressly incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present disclosure relates generally to wireless communications, and more particularly to methods and apparatus for processing in a Read System Information state in a wireless communication system. 
         [0004]    2. Background 
         [0005]    Wireless communication systems have become a prevalent means by which a majority of people worldwide have come to communicate. Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. The increase in processing power in mobile devices such as cellular telephones has lead to an increase in demands on wireless network transmission systems. Such systems typically are not as easily updated as the cellular devices that communicate there over. As mobile device capabilities expand, it can be difficult to maintain an older wireless network system in a manner that facilitates fully exploiting new and improved wireless device capabilities. 
         [0006]    Wireless communication systems generally utilize different approaches to generate transmission resources in the form of channels. These systems may be code division multiplexing (CDM) systems, frequency division multiplexing (FDM) systems, and time division multiplexing (TDM) systems. One commonly utilized variant of FDM is orthogonal frequency division multiplexing (OFDM) that effectively partitions the overall system bandwidth into multiple orthogonal subcarriers. These subcarriers may also be referred to as tones, bins, and frequency channels. Each subcarrier can be modulated with data. With time division based techniques, a each subcarrier can comprise a portion of sequential time slices or time slots. Each user may be provided with a one or more time slot and subcarrier combinations for transmitting and receiving information in a defined burst period or frame. The hopping schemes may generally be a symbol rate hopping scheme or a block hopping scheme. 
         [0007]    Code division based techniques typically transmit data over a number of frequencies available at any time in a range. In general, data is digitized and spread over available bandwidth, wherein multiple users can be overlaid on the channel and respective users can be assigned a unique sequence code. Users can transmit in the same wide-band chunk of spectrum, wherein each user&#39;s signal is spread over the entire bandwidth by its respective unique spreading code. This technique can provide for sharing, wherein one or more users can concurrently transmit and receive. Such sharing can be achieved through spread spectrum digital modulation, wherein a user&#39;s stream of bits is encoded and spread across a very wide channel in a pseudo-random fashion. The receiver is designed to recognize the associated unique sequence code and undo the randomization in order to collect the bits for a particular user in a coherent manner. 
         [0008]    A typical wireless communication network (e.g., employing frequency, time, and/or code division techniques) includes one or more base stations that provide a coverage area and one or more mobile (e.g., wireless) terminals that can transmit and receive data within the coverage area. A typical base station can simultaneously transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream is a stream of data that can be of independent reception interest to a mobile terminal. A mobile terminal within the coverage area of that base station can be interested in receiving one, more than one or all the data streams transmitted from the base station. Likewise, a mobile terminal can transmit data to the base station or another mobile terminal. In these systems the bandwidth and other system resources are assigned utilizing a scheduler. 
         [0009]    The signals, signal formats, signal exchanges, methods, processes, and techniques disclosed herein provide several advantages over known approaches. These include, for example, reduced signaling overhead, improved system throughput, increased signaling flexibility, reduced information processing, reduced transmission bandwidth, reduced bit processing, increased robustness, improved efficiency, and reduced transmission power. 
       SUMMARY 
       [0010]    The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later. 
         [0011]    According to one embodiment, a method is provided for issuing a ControlChannelMAC.Activate command, issuing a OverheadMessages.Activate command and determining if a SystemInfoBlock is received within T ISPSyncAcq  seconds. 
         [0012]    According to yet another embodiment, a computer readable medium is described which comprises a first set of instructions for issuing a ControlChannelMAC.Activate command, a second set of instructions for issuing a OverheadMessages.Activate command and a third set of instructions for determining if a SystemInfoBlock is received within T ISPSyncAcq  seconds. 
         [0013]    According to yet another embodiment, an apparatus is described which comprises means for issuing a ControlChannelMAC.Activate command, means for issuing a OverheadMessages.Activate command and means for determining if a SystemInfoBlock is received within T ISPSyncAcq  seconds. 
         [0014]    To the accomplishment of the foregoing and related ends, 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 embodiments of the one or more embodiments. These embodiments are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such embodiments and their equivalents. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]      FIG. 1  illustrates embodiments of a multiple access wireless communication system. 
           [0016]      FIG. 2  illustrates embodiments of a transmitter and receiver in a multiple access wireless communication system. 
           [0017]      FIGS. 3A and 3B  illustrate embodiments of superframe structures for a multiple access wireless communication system. 
           [0018]      FIG. 4  illustrates a communication link between an access terminal and an access network. 
           [0019]      FIG. 5A  illustrates a flow diagram of processing in Read SystemInfo State. 
           [0020]      FIG. 5B  illustrates one or more processors for processing in Read SystemInfo State. 
       
    
    
     DETAILED DESCRIPTION  
       [0021]    Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. 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 embodiments. It may be evident, however, that such embodiment(s) may 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. 
         [0022]    Referring to  FIG. 1 , a multiple access wireless communication system according to one embodiment is illustrated. A multiple access wireless communication system  100  includes multiple cells, e.g. cells  102 ,  104 , and  106 . In the embodiment of  FIG. 1 , each cell  102 ,  104 , and  106  may include an access point  150  that includes multiple sectors. The multiple sectors are formed by groups of antennas each responsible for communication with access terminals in a portion of the cell. In cell  102 , antenna groups  112 ,  114 , and  116  each correspond to a different sector. In cell  104 , antenna groups  118 ,  120 , and  122  each correspond to a different sector. In cell  106 , antenna groups  124 ,  126 , and  128  each correspond to a different sector. 
         [0023]    Each cell includes several access terminals which are in communication with one or more sectors of each access point. For example, access terminals  130  and  132  are in communication base  142 , access terminals  134  and  136  are in communication with access point  144 , and access terminals  138  and  140  are in communication with access point  146 . 
         [0024]    Controller  130  is coupled to each of the cells  102 ,  104 , and  106 . Controller  130  may contain one or more connections to multiple networks, e.g. the Internet, other packet based networks, or circuit switched voice networks that provide information to, and from, the access terminals in communication with the cells of the multiple access wireless communication system  100 . The controller  130  includes, or is coupled with, a scheduler that schedules transmission from and to access terminals. In other embodiments, the scheduler may reside in each individual cell, each sector of a cell, or a combination thereof. 
         [0025]    As used herein, an access point may be a fixed station used for communicating with the terminals and may also be referred to as, and include some or all the functionality of, a base station, a Node B, or some other terminology. An access terminal may also be referred to as, and include some or all the functionality of, a user equipment (UE), a wireless communication device, terminal, a mobile station or some other terminology. 
         [0026]    It should be noted that while  FIG. 1 , depicts physical sectors, i.e. having different antenna groups for different sectors, other approaches may be utilized. For example, utilizing multiple fixed “beams” that each cover different areas of the cell in frequency space may be utilized in lieu of, or in combination with physical sectors. Such an approach is depicted and disclosed in copending U.S. patent application Ser. No. 11/260,895, entitled “Adaptive Sectorization In Cellular System.” 
         [0027]    Referring to  FIG. 2 , a block diagram of an embodiment of a transmitter system  210  and a receiver system  250  in a MIMO system  200  is illustrated. At transmitter system  210 , traffic data for a number of data streams is provided from a data source  212  to transmit (TX) data processor  214 . In an embodiment, each data stream is transmitted over a respective transmit antenna. TX data processor  214  formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data. 
         [0028]    The coded data for each data stream may be multiplexed with pilot data using OFDM, or other orthogonalization or non-orthogonalization techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on one or more particular modulation schemes (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed on provided by processor  230 . 
         [0029]    The modulation symbols for all data streams are then provided to a TX processor  220 , which may further process the modulation symbols (e.g., for OFDM). TX processor  220  then provides N T  modulation symbol streams to N T  transmitters (TMTR)  222   a  through  222   t.  Each transmitter  222  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. N T  modulated signals from transmitters  222   a  through  222   t  are then transmitted from N T  antennas  224   a  through  224   t , respectively. 
         [0030]    At receiver system  250 , the transmitted modulated signals are received by N R  antennas  252   a  through  252   r  and the received signal from each antenna  252  is provided to a respective receiver (RCVR)  254 . Each receiver  254  conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream. 
         [0031]    An RX data processor  260  then receives and processes the N R  received symbol streams from N R  receivers  254  based on a particular receiver processing technique to provide N T  “detected” symbol streams. The processing by RX data processor  260  is described in further detail below. Each detected symbol stream includes symbols that are estimates of the modulation symbols transmitted for the corresponding data stream. RX data processor  260  then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor  218  is complementary to that performed by TX processor  220  and TX data processor  214  at transmitter system  210 . 
         [0032]    RX data processor  260  may be limited in the number of subcarriers that it may simultaneously demodulate, e.g. 512 subcarriers or 5 MHz, and such a receiver should be scheduled on a single carrier. This limitation may be a function of its FFT range, e.g. sample rates at which the processor  260  may operate, the memory available for FFT, or other functions available for demodulation. Further, the greater the number of subcarriers utilized, the greater the expense of the access terminal. 
         [0033]    The channel response estimate generated by RX processor  260  may be used to perform space, space/time processing at the receiver, adjust power levels, change modulation rates or schemes, or other actions. RX processor  260  may further estimate the signal-to-noise-and-interference ratios (SNRs) of the detected symbol streams, and possibly other channel characteristics, and provides these quantities to a processor  270 . RX data processor  260  or processor  270  may further derive an estimate of the “operating” SNR for the system. Processor  270  then provides channel state information (CSI), which may comprise various types of information regarding the communication link and/or the received data stream. For example, the CSI may comprise only the operating SNR. In other embodiments, the CSI may comprise a channel quality indicator (CQI), which may be a numerical value indicative of one or more channel conditions. The CSI is then processed by a TX data processor  278 , modulated by a modulator  280 , conditioned by transmitters  254   a  through  254   r,  and transmitted back to transmitter system  210 . 
         [0034]    At transmitter system  210 , the modulated signals from receiver system  250  are received by antennas  224 , conditioned by receivers  222 , demodulated by a demodulator  240 , and processed by a RX data processor  242  to recover the CSI reported by the receiver system. The reported CSI is then provided to processor  230  and used to (1) determine the data rates and coding and modulation schemes to be used for the data streams and (2) generate various controls for TX data processor  214  and TX processor  220 . Alternatively, the CSI may be utilized by processor  270  to determine modulation schemes and/or coding rates for transmission, along with other information. This may then be provided to the transmitter which uses this information, which may be quantized, to provide later transmissions to the receiver. 
         [0035]    Processors  230  and  270  direct the operation at the transmitter and receiver systems, respectively. Memories  232  and  272  provide storage for program codes and data used by processors  230  and  270 , respectively. 
         [0036]    At the receiver, various processing techniques may be used to process the N R  received signals to detect the N T  transmitted symbol streams. These receiver processing techniques may be grouped into two primary categories (i) spatial and space-time receiver processing techniques (which are also referred to as equalization techniques); and (ii) “successive nulling/equalization and interference cancellation” receiver processing technique (which is also referred to as “successive interference cancellation” or “successive cancellation” receiver processing technique). 
         [0037]    While  FIG. 2  discusses a MIMO system, the same system may be applied to a multi-input single-output system where multiple transmit antennas, e.g. those on a base station, transmit one or more symbol streams to a single antenna device, e.g. a mobile station. Also, a single output to single input antenna system may be utilized in the same manner as described with respect to  FIG. 2 . 
         [0038]    The transmission techniques described herein may be implemented by various means. For example, these techniques may be implemented in hardware, firmware, software, or a combination thereof. For a hardware implementation, the processing units at a transmitter may 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, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof. The processing units at a receiver may also be implemented within one or more ASICs, DSPs, processors, and so on. 
         [0039]    For a software implementation, the transmission techniques may be implemented with processors (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in a memory (e.g., memory  230 ,  272   x  or  272   y  in  FIG. 2 ) and executed by a processor (e.g., processor  232 ,  270   x  or  270   y ). The memory may be implemented within the processor or external to the processor. 
         [0040]    It should be noted that the concept of channels herein refers to information or transmission types that may be transmitted by the access point or access terminal. It does not require or utilize fixed or predetermined blocks of subcarriers, time periods, or other resources dedicated to such transmissions. 
         [0041]    Referring to  FIGS. 3A and 3B , embodiments of superframe structures for a multiple access wireless communication system are illustrated.  FIG. 3A  illustrates embodiments of superframe structures for a frequency division duplexed (FDD) multiple access wireless communication system, while  FIG. 3B  illustrates embodiments of superframe structures for a time division duplexed (TDD) multiple access wireless communication system. The superframe preamble may be transmitted separately for each carrier or may span all of the carriers of the sector. 
         [0042]    In both  FIGS. 3A and 3B , the forward link transmission is divided into units of superframes. A superframe may consist of a superframe preamble followed by a series of frames. In an FDD system, the reverse link and the forward link transmission may occupy different frequency bandwidths so that transmissions on the links do not, or for the most part do not, overlap on any frequency subcarriers. In a TDD system, N forward link frames and M reverse link frames define the number of sequential forward link and reverse link frames that may be continuously transmitted prior to allowing transmission of the opposite type of frame. It should be noted that the number of N and M may be vary within a given superframe or between superframes. 
         [0043]    In both FDD and TDD systems each superframe may comprise a superframe preamble. In certain embodiments, the superframe preamble includes a pilot channel that includes pilots that may be used for channel estimation by access terminals, a broadcast channel that includes configuration information that the access terminal may utilize to demodulate the information contained in the forward link frame. Further acquisition information such as timing and other information sufficient for an access terminal to communicate on one of the carriers and basic power control or offset information may also be included in the superframe preamble. In other cases, only some of the above and/or other information may be included in this superframe preamble. 
         [0044]    As shown in  FIGS. 3A and 3B , the superframe preamble is followed by a sequence of frames. Each frame may consist of a same or a different number of OFDM symbols, which may constitute a number of subcarriers that may simultaneously utilized for transmission over some defined period. Further, each frame may operate according to a symbol rate hopping mode, where one or more non-contiguous OFDM symbols are assigned to a user on a forward link or reverse link, or a block hopping mode, where users hop within a block of OFDM symbols. The actual blocks or OFDM symbols may or may not hop between frames. 
         [0045]      FIG. 4  illustrates communication between an access network  404  for transmitting a SystemInfo Block to the access terminal  402 . Using a communication link  406  and based upon predetermined timing, system conditions, or other decision criteria, the access network  404  transmits the SystemInfo Block message over a communication link  406  to the access terminal  402 . Communication between an access terminal (for example the transmitter system  250  of  FIG. 2 ) and an access point (for example the transmitter system  210  of FIG.  2 )occurs using a communication link and based upon predetermined timing, system conditions, or other decision criteria. The communication link may be implemented using communication protocols/standards such as World Interoperability for Microwave Access (WiMAX), infrared protocols such as Infrared Data Association (IrDA), short-range wireless protocols/technologies, Bluetooth® technology, ZigBee® protocol, ultra wide band (UWB) protocol, home radio frequency (HomeRF), shared wireless access protocol (SWAP), wideband technology such as a wireless Ethernet compatibility alliance (WECA), wireless fidelity alliance (Wi-Fi Alliance), 802.11 network technology, public switched telephone network technology, public heterogeneous communications network technology such as the Internet, private wireless communications network, land mobile radio network, code division multiple access (CDMA), wideband code division multiple access (WCDMA), universal mobile telecommunications system (UMTS), advanced mobile phone service (AMPS), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple (OFDM), orthogonal frequency division multiple access (OFDMA), orthogonal frequency division multiple FLASH (OFDM-FLASH), global system for mobile communications (GSM), single carrier (1×) radio transmission technology (RTT), evolution data only (EV-DO) technology, general packet radio; service (GPRS), enhanced data GSM environment (EDGE), high speed downlink data packet access (HSPDA), analog and digital satellite systems, and any other technologies/protocols that may be used in at least one of a wireless communications network and a data communications network. 
         [0046]    The access network  404  is configured to generate the SystemInfo Block and transmitting over a communication link  406 . The access network  404  may incorporate the SystemInfo Block into a data packet  412  or multiple data packets and the data packets  412  are transmitted on a communication link  406 . In another aspect, the SystemInfo Block may be transmitted without being incorporated in packets. The data packets comprise header information that indicates whether those data packets  412  contain the SystemInfo Block. The data packets  412  are transmitted on the link  406  using one or more channels. 
         [0047]    The access terminal  402  is configured to receive data packets on the communication link  406 , one of which may comprise the SystemInfo Block. Various methods may be used to extract the SystemInfo Block from the link. For example, once the access terminal  402  has extracted the data packets  412  from one of the channels of the link the access terminal  402  may check the header information of the data packets  412  to determine if the data packets  412  comprise the SystemInfo Block. If so, then the access terminal  402  extracts the designated bits of the message and stores the values in memory (such as memory  272  in  FIG. 2 ). 
         [0048]    Upon entering the Pilot Acquisition State, the access terminal will tune to the selected OFDMA channel and will search for the pilot. If the access terminal acquires the pilot, it will enter the Read SystemInfo State. 
         [0049]    Upon entering Read Systeminfo state, the access terminal will issue the ControlChannelMAC.Activate and OverheadMessages.Activate commands. 
         [0050]    If the access terminal fails to receive the SystemInfo block with T ISPSyncAcq  seconds of entering the Synchronization state, the access terminal will issue ControlChannelMAC.Deactivate and OverheadMessages.Deactivate commands and will enter the Network Determination State. While attempting to receive the SystemInfo block, the access terminal will discard any other messages received on the Control Channel. 
         [0051]    When the access terminal receives a SystemInfo block, if the access terminal&#39;s revision number is not in the range defined by the MinimumRevision and MaximumRevision fileds (inclusive) specified in the message, the access terminal will issue ControlChannelMAC.Deactivate and Overheadmessages.Deactivate commands and enter the Network Determination State. Otherwise, the access terminal will set the access terminal time to the time specified in the SystemInfo block. The time specified in the block is the time at the beginning of the superframe where the message transmission started. This time is accurate to the twelve least significant digits and is enough for the access terminal to read the ExtendedChannelInfo message (on the Forward Traffic Channel MAC) that contains the complete time. The access terminal also returns a NetworkAcquired indication and enters the Inactive State. 
         [0052]      FIG. 5A  illustrates a flow diagram of the process  500  of processing in Read SystemInfo State, according to an embodiment. At  502 , the access terminal issues ControlChannelMAC.Activate command. At  504 , the access terminal issues OverheadMessages.Activate command. At  506 , it is determined if SystemInfo block is received within T ISPSyncAcq  seconds. Determining if System SystemInfo block is received within T ISPSyncAcq  seconds increases access terminal&#39;s efficiency such that one or more of aforementioned embodiments need not occur. At  508 , if systemInfo block is received within T ISPSyncAcq  seconds, according to one embodiment, it is further determined if revision number is not in range specified in the SystemInfo block. Determining revision number increases the efficiency of the access terminal such that one or more of aforementioned embodiments need not occur. AT  510 , if the revision number is in range, according to one embodiment, time is set to the time in the SystemInfo block. AT  512 , a network acquired indication is retuned. At  514 , the access terminal enters the Inactive State. At  516 , if the SystemInfo Block is not received in T ISPSyncAcq  seconds or of revision number is not in range, the access terminal issues ControlChannelMAC.deactivate and Overhead Messages.deactivate commands. The access terminal further enters the Network determination State at  518 . 
         [0053]      FIG. 5B  illustrates a processor  550  for processing in Read SystemInfo state. The processor referred to may be electronic devices and may comprise one or more processors to carry out the methodologies for processing in Read SystemInfo state. A processor  552  is configured to issue ControlChannelMAC.Activate command. A processor  554  is configured to issue OverheadMessages.Activate command. A processor  556  is configured to determine if SystemInfo block is received within T ISPSyncAcq  seconds. Determining if System SystemInfo block is received within T ISPSyncAcq  seconds increases processing efficiency such that one or more of aforementioned embodiments need not occur. According to one embodiment a processor  558  is configured to determine if revision number is not in range specified in the SystemInfo block. Determining revision number increases the processing efficiency such that one or more of aforementioned embodiments need not occur. According to one embodiment a processor  560  is configured to set the time to the time in the SystemInfo block. A processor  562  is configured to return a network acquired indication. A processor  564  is configured to enter Inactive State. A processor  566  is configured to issue ControlChannelMAC.deactivate and Overhead Messages.deactivate commands. A processor  568  is configured to enter the Network determination State. The functionality of the discrete processors  552  and  568  depicted in the figure may be combined into a single processor  570 . A memory  572  is also coupled to the processor  570 . 
         [0054]    Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as a separate storage(s) not shown. A processor may perform the necessary tasks. A code segment may 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 may 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. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
         [0055]    Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the description is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.