Packets filling transmission gaps

ES 2 649 366 T3

DESCRIPTION

Packets filling transmission gaps

FIELD OF THE INVENTION

[0001] The present invention relates generally to a communication system and more specifically to techniques for the indication of gaps during a linked assignment.

BACKGROUND

[0002] Wireless communication systems are widely deployed to provide various types of communication, such as voice, data, etc. These systems can be multiple access systems capable of supporting communication with multiple users by sharing available system resources (eg, bandwidth and transmission power). Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and access systems. Orthogonal Frequency Division Multiple (OFDMA). Typically, a wireless communication system comprises several base stations, in which each base station communicates with the mobile station using a forward link and each mobile station (or access terminal) communicates with the base station using a reverse link.

[0003] In order to make communication between base stations and terminals more efficient, a concept of linked assignments is used. Bound assignments are useful in a scheduled data transmission system in cases where many users are competing for limited assignment message resources. A linked assignment is when a resource (eg, a channel) assigned to a particular user continues to be available to that user after the standard unit of transmission (eg, packet) has been completed. Therefore, a new assignment message is not necessary to allow that user to continue transmission. One way to continue transmission is described in US 2004/0120253 A1.

[0004] In general, when a transmitter of an access point or an access terminal completes the transmission of a set of real data and before transmitting another set of real data packet, a break occurs (also called a gap) in transmission. The data transmission gap refers to the length of time that no actual data is transmitted on the allocated resource (further discussed in FIG. 2). In a typical communication system, in the case of the access point transmitter, there is a possibility that the gap in transmission could be interpreted as a loss of the allocated resource. In this case, the access terminal may request an allocation even though the transmission resource is allocated to the access terminal. In the case of the access point, the gap can be interpreted as an indication that the access terminal no longer requires the allocated resource. In this case, the access point can assign the resource to another access terminal in the system. In both cases, it is inefficient and can decrease the quality and reliability of the communication system.

[0005] There is therefore a need for a system and method to provide an indication of a gap in transmission, so that the access point and access terminal do not interpret the gap in transmission as an indication that it does not require the transmission. assigned resources or as an indication that the assigned resources were no longer available.

SHORT SUMMARY

[0006] This need is satisfied by the subject matter of the independent claims. Accordingly, a method for managing an allocation of an allocated resource for transmitting data in a communication system, the method transmitting a first data pattern on the allocated resource when there is no data to transmit on the allocated resource.

[0007] In another aspect, a method of managing an allocation of one or more resources allocated for the communication of data in the communication system is provided, the procedure receiving one or more bits of information in the allocated resource, and maintaining the allocation of said allocated resource, if it is determined that said one or more bits of information represent a packet of erasure signatures.

[0008] A more complete appreciation of all the advantages and scope of the invention can be obtained from the accompanying drawings, description, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The characteristics, nature and advantages of the present invention will become more apparent from the detailed description set forth below when taken into consideration in conjunction with the drawings, in all of which identical reference characters identify the corresponding components

ES 2 649 366 T3 the same, and in which:

FIG. 1 shows a diagram of a wireless multiple access communication system;

FIG. 2 shows an illustration of data traffic on an allocated channel while using a linked allocation concept;

FIG. 3 shows a process for data transmission by an access point during a linked assignment of a resource on the forward link;

FIG. 4 shows a process for receiving data by an access point during a linked assignment of a resource on the reverse link; Y

FIG. 5 shows a block diagram of an embodiment of an access point and two terminals.

DETAILED DESCRIPTION

The term "exemplary" is used herein to mean serving as an example, instance, or illustration. Any embodiment or design described herein by way of example should not necessarily be considered to be preferred or advantageous over other embodiments or designs. The word listener is used herein to indicate that a receiving device (access point or access terminal) is receiving and processing data received on a given channel.

[0011] FIG. 1 shows a diagram of a wireless multiple access communication system 100 employing multi-carrier modulation. System 100 includes a series of access points (AP) 110 that communicate with one or more access terminals (AT) 120 (only two access points 110a and 110b are shown in FIG. 1, for simplicity). A 110x AP (110x is further discussed in FIG. 5, infra) is a fixed station used for communication with access terminals. A 110x AP can also be called a base station or some other terminology.

[0012] An access point, eg AP 110x, is an electronic device configured to communicate with one or more access terminals, eg AT 120x (AT 120x is further discussed in FIG. 5, infra). The access point 110x may also be referred to as an access node, access network, base station, base terminal, fixed terminal, fixed station, base station controller, controller, transmitter, or other terminology. The access point, the base terminal and the base station are used interchangeably in the following description. The access point can be a general purpose computer, a standard laptop, a fixed terminal, an electronic device configured to transmit, receive and process data according to wireless interface procedures defined by an OFDMA, CDMA, GSM, WCDMA system, etc. . The access point can be an electronic module comprising one or more computer chips controlled by a controller or a processor to transmit, receive and process data according to wireless interface procedures defined by an OFDMA, CDMA, GSM, WCDMA, etc. system.

[0013] An access terminal, for example AT 120x, is an electronic device configured to communicate with the AP 110x through a communication link. The AT 120x may also be referred to as a terminal, user terminal, remote station, mobile station, wireless communication device, receiver terminal, or some other terminology. Access terminal, mobile terminal, user terminal, terminal are used interchangeably in the following description. Each AT 120x can communicate with one or multiple access points on the downlink and / or uplink at any given time The downlink (i.e. forward link) refers to the transmission from the AP 110x to the AT 120x, and the uplink (ie, the reverse link) refers to the transmission from the AT 120x to the access point. The AT 120x can be any standard laptop, personal electronic organizer or assistant, a mobile phone, cell phone, an electronic device configured to transmit, receive and process data according to the wireless interface procedures defined by an OFDMA, CDMA, GSM system. , WCDMA, etc. The AT 120x can be an electronic module comprising one or more computer chips controlled by a controller or a processor to transmit, receive and process data according to wireless interface procedures defined by an OFDMA, CDMA, GSM, WCDMA, etc. system.

[0014] A system controller 130 is coupled to access points and may further couple to other systems / networks (eg, a packet data network). The system controller 130 provides coordination and control for the base stations connected to it. Through the access points, the system controller 130 further controls the routing of data between the terminals and between the terminals and other users coupled to the other systems / networks.

[0015] The techniques described herein for providing an indication of a gap in transmission can be implemented in various multiple access multi-carrier wireless communication systems. For example, system 100 can be an OFDMA, CDMA, GSM, WCDmA, etc. system that uses data transmission.

ES 2 649 366 T3

[0016] In one embodiment, linked assignments are used. Bound assignments allow the system controller 130 to reduce assignment requests. Linked assignments allow the recipient of a given resource to use the assigned resource for multiple communications (transmission or reception) without requesting a new assignment for each communication. For analysis purposes, the AT 120x requests a reverse link transmission resource to transmit data (real data, content, etc.) to the AP 110x, which is serving the AT 120x. Using an allocation message, the AP 110x provides the reverse link transmission resource allocation information, eg, a channel identification, to the AT 120x that requested the allocation. Once the allocation information is received, the AT 120x transmits actual data on the allocated reverse link channel (resource). In a linked assignment, the assigned channel is still assigned to the AT 120x. Therefore, at various times during the period a channel is assigned, no actual data is transmitted or received by the AT 120x or AP 110x. Therefore, a first data pattern, called an erasure signature packet, is used to fill in the transmission gaps. The length, construction, and data rate of the erasure signature packet may vary depending on available resources. The available resources can be determined by the system controller 130 or the AP that is in communication with the requesting AT. For example, if the receiving entity has the resources to process erasure signature packets that have more bits of information (eg, 3 bits), the length of the erase signature packet is adjusted to provide more bits of information. This can allow the receiving entity to easily determine that the received packet was an erasure signature packet. In addition, the power level at which the erase signature packets are transmitted can be varied to transmit the erase sequence at a power level low enough that the transmission of the erase sequence does not cause significant interference.

[0017] FIG. 2 shows an illustration 200 of data traffic on an allocated channel while using a linked allocation concept. The linked allocation duration 208 is generally between an allocation and a deallocation. During the linked assignment duration 208, several data transmissions may occur, for example 202a-202d, in which transmit data packets are transmitted. In general, the data is not always transmitted continuously for the duration of the linked assignment 208, thus leaving outgoing portions, eg 204a-204d. For analysis purposes, when AT 120x data processor TX 574, infra, is not sending data, TX 574 data processor is configured to transmit an erasure signature packet, eg 206a-206d. The erasure signature packet can be one or more bits representing a single pattern of data. In other words, the erase signature package fills the gap portions 204a-d with unique patterns and prevents resources from running out. The erasure signature packet may be a unique identifier that is known to both the transmitter and the receiver before using the erase signature packets. Furthermore, in order to reduce interference, the erasure signature packet can be transmitted at low power and / or low data rate.

[0018] FIG. 3 shows a process 300 for data transmission by a processor (data processor TX 574 of the AT data processor or TX 514 of the AP) configured to transmit data during a linked allocation of a transmission resource. For simplicity, TX data processor 514 will be used to analyze the execution of process steps 300 for data transmission on the forward link. Process 300 may also be implemented by TX processor 574 for data transmission on the reverse link (eg, data transmission to AP). At step 302, the forward link data channel assignment is completed and the TX data processor 514 is ready for the send data, eg, the transmit data packet. In step 304, TX data processor 514 determines whether any transmit data packets (eg, encoded data converted to data packets) are queued and ready to be transmitted. If it is determined that one or more data packets are ready for transmission, then in step 306, TX data processor 514 transmits the data packets using the allocated resource (i.e., a forward link data channel for AP 110x and a reverse link channel for terminal). Otherwise, in step 308, TX data processor 514 transmits a predetermined erasure signature packet using the assigned channel.

The erasure signature packet may be transmitted at a transmit power level that is less than a predetermined threshold. The threshold may be predetermined and indicates a transmit power level such that transmission above the threshold would cause interference. Erase signature packets can also be transmitted at a low data rate. After transmission of erasure packets or transmission data packets, TX data processor 514 repeats the process and executes step 304 until resources are deallocated or terminated.

[0020] FIG. 4 shows a process 400 for processing data reception by a processor (AT data processor RX 556 or AP RX 534 data processor) configured to receive data during a linked assignment of a resource. For simplicity, the RX 534 data processor will be used to analyze the execution of the process steps 400 for data reception on the reverse link. Process 400 can also be implemented by RX processor 556 for receiving data on the forward link (eg, receiving data from AP). In step 402, one or more bits of information are received through the assigned channel and are evaluated as data packets. In step 404, the RX data processor 534 determines whether the data packets represent actual data packets (encoded data transmitted by the transmitting entity). If so, then in step 406 the RX data processor 534 processes the data packets normally. Of what

In contrast, in step 408, the RX 534 data processor determines whether the data packets represent the erasure signature packets. If the data packets are erase signature packets, then the packets are discarded and the additional information bits are sampled in step 402. Otherwise, in step 410, the data processor RX 534 marks the data packets. as noise data and additional information bits are sampled in step 402. In an AP 110x embodiment, the RX 534 data processor may continue to monitor the noise data and may determine that the resources are wasted or it may determine that the transmitting entity does not require the allocated resources after receiving noise data during a predetermined time.

[0021] FIG. 5 shows a block diagram of an embodiment of an AP 110x and two ATs 120x and 120y in a multi-carrier multi-access communication system 100. In AP 110x, a transmission data processor (TX) 514 receives data traffic (ie, information bits) from a data source 512 and signaling and other information from a controller 520 and a programmer 530. For example, controller 520 can provide power control (PC) commands that are used to adjust the transmit power of active ATs, and programmer 530 can provide carrier assignments for ATs. These various types of data can be sent on different transport channels. TX data processor 514 encodes and modulates received data using multi-carrier modulation (eg OFDM) to provide modulated data (eg OFDM symbols). A transmitter unit (TMTR) 516 then processes the modulated data to generate a downlink modulated signal which is then transmitted from an antenna 518.

In each of the ATs 120x and 120y, the transmitted and modulated signal is received by an antenna 552 and is provided to a receiver unit (RCVR) 554. The receiver unit 554 processes and digitizes each received signal to provide samples. A received data processor (RX) 556 then demodulates and decodes the samples to provide decoded data, which may include retrieved traffic data, messages, signaling, etc. Traffic data can be provided to a data collector 558, and the carrier assignment and PC commands sent to the terminal are provided to a controller 560.

[0023] Controller 560 directs data transmission on the uplink using the specific carriers that have been assigned to the terminal and indicated in the received carrier assignment. Controller 560 further injects erasure signature packets when there is no actual data to transmit, but wants to conserve allocated resources.

[0024] For each active terminal 120, a TX data processor 574 receives traffic data from a data source 572 and signaling and other information from controller 560. For example, controller 560 may provide information indicative of the power of required transmit power, the maximum transmit power or the difference between the maximum and required transmit powers for the terminal. The various types of data are encoded and modulated by the TX data processor 574 using the assigned carriers and further processed by a transmitter unit 576 to generate an uplink modulated signal which is then transmitted from the antenna 552.

In AP 110x, the transmitted and modulated signals from the ATs are received by the antenna 518, processed by a receiver unit 532, and demodulated and decoded by an RX data processor 534. The receiver unit 532 can estimate the quality of the received signal (eg, the received signal-to-noise ratio (SNR)) for each terminal and provide this information to the controller 520. Controller 520 can then obtain the PC commands for each terminal such that the quality of the signal received for the terminal is kept within an acceptable range. RX data processor 534 provides the recovered response information (eg, required transmit power) for each terminal to controller 520 and programmer 530.

[0026] Scheduler 530 may provide an indication to controller 520 to maintain resources. This indication is provided if there is more data scheduled to be transmitted. For the AT 120x, the 560 controller can determine if the required resources should be maintained.

[0027] The techniques described herein can be implemented by various means. For example, these techniques can be implemented in hardware, software, or a combination of both. For a hardware implementation, the processing units (e.g. 520 and 570 controllers, TX and RX processors 514 and 534, etc.) for these techniques can be implemented within one or more application-specific integrated circuits (ASICs) , digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

[0028] For a software implementation, the techniques described herein can be implemented with modules (eg, procedures, functions, etc.) that carry out the functions described herein. The software codes can be stored in memory units (eg, memory 522 in FIG. 5) and executed by processors (eg, controllers 520). The unit of

ES 2 649 366 T3 memory can be implemented in the processor or external to the processor, in which case it can be communicatively coupled to the processor through various means, as is known in the art.

[0029] Titles are included herein for reference and to facilitate the location of certain sections. These titles are not intended to limit the scope of the concepts described herein, and these concepts may have applicability in other sections throughout the specification.

[0030] The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications of these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the scope of the invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is granted the broadest scope consistent with the novel principles and features disclosed herein.

[0031] Additional examples of the invention are described below to facilitate an understanding of the invention.

[0032] In a further example, a procedure for managing an allocation of an assigned resource for data transmission in a communication system is described, the procedure comprising the acts of transmitting a first data pattern on the assigned resource when there is no data to transmit on the assigned resource. The method may further comprise an act of selecting said first data pattern, wherein said act of selecting may comprise selecting one or more erasure signature packets. Said act of transmitting said one or more erasure signature packets may further comprise an act of transmitting each of said erasure signature packets at a power level below a threshold. Furthermore, said act of transmitting said one or more erasure signature packets may comprise an act of transmitting each of said erasure signature packets at a power level that does not cause significant interference. Furthermore, said act of transmitting said first data pattern may comprise an act of transmitting said data pattern at a power level that does not cause interference. Furthermore, the method may further comprise an act of selecting said first data pattern, wherein said act of selecting may comprise an act of selecting said data pattern having a length that varies as a function of available resources. Furthermore, said act of transmitting said first data pattern may comprise an act of transmitting said data pattern at a low data rate. Said act of transmitting said first data pattern on said assigned resource may also comprise an act of transmitting said data pattern using a direct link of the communication system. Furthermore, said act of transmitting said first data pattern on said assigned resource may comprise an act of transmitting said data pattern using a reverse link of the communication system. The act of transmission may further comprise an act of transmission according to a Code Division Multiple Access (CDMA) scheme. Furthermore, the transmission act may further comprise a transmission act according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme. The act of transmission may further comprise an act of transmission according to an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

[0033] In another additional example, a procedure for managing an allocation of one or more resources allocated for data communication in a communication system is described, the procedure comprising the acts of receiving one or more bits of information in the assigned resource and maintenance of the assignment of said assigned resource, if it is determined that said one or more bits of information represent a packet of erasure signatures. The method may further comprise an act of converting said one or more bits of information into said data packets having a predetermined length. Said act of receiving one or more bits of information may comprise an act of receiving said bits of information on a direct link of the communication system. Furthermore, said act of receiving one or more bits of information may comprise an act of receiving said bits of information on a reverse link of the communication system. Furthermore, said reception act may further comprise a reception act according to a Code Division Multiple Access (CDMA) scheme. Furthermore, said act of reception pu may comprise a reception act according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme. Furthermore, said reception act may further comprise a reception act according to an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

[0034] In yet another example, an apparatus is described for managing the allocation of one or more resources allocated for the transmission of data in the communication system, the apparatus comprising means for transmitting a first data pattern in the allocated resource when not there is data to transmit on that assigned resource. The apparatus may further comprise means for selecting said first data pattern before transmitting, wherein said first data pattern may comprise one or more erasure signature packets. Furthermore, said means for transmitting said one or more erasure signature packets may comprise means for transmitting each of said erasure signature packets at a power level below a threshold. Said means for transmitting said one or more erasure signature packets may also comprise means for transmitting each of said erasure signature packets at a power level that does not cause

ES 2 649 366 T3 significant interferences. Furthermore, said means for transmitting said first data pattern may comprise means for transmitting said data pattern at a power level that does not cause significant interference. Furthermore, the apparatus may comprise means for selecting said first data pattern before transmitting, wherein said first data pattern may comprise means for selecting said data pattern having a length based on available resources. Furthermore, said means for transmitting said first data pattern may comprise means for transmitting said data pattern at a low data rate.

In yet another example, an apparatus for managing an allocation of one or more allocated resources for data communication in a communication system is described, the apparatus comprising means for receiving one or more bits of information on an allocated resource and means for maintaining the allocation of said allocated resource, if it is determined that said one or more bits of information represent a packet of erasure signatures. Thus, said means for converting said one or more information bits may comprise means for converting said information bits into said data packets having a predetermined length. Furthermore, said means for receiving one or more bits of information may comprise means for receiving said bits of information on a direct link of the communication system. Furthermore, said means for receiving one or more bits of information may comprise means for receiving said bits of information in a reverse link of the communication system.

[0036] In yet another example an apparatus in a wireless communication system is described, comprising a first electronic device configured to transmit a first data pattern on an assigned resource when there is no data to transmit on said assigned resource. Thus, said first data pattern may comprise one or more erasure signature packets. Furthermore, said first electronic device may comprise a transmitter configured to transmit said one or more erasure signature packets at a power level below a threshold. Furthermore, the first electronic device may comprise a transmitter configured to transmit each of said erasure signature packets at a power level that does not cause significant interference. Said first electronic device may also comprise a transmitter configured to transmit said first data pattern at a power level that does not cause significant interference. Furthermore, the apparatus may comprise a processor configured to select said first data pattern having a length based on available resources. Furthermore, said first electronic device may comprise a transmitter configured to transmit said data pattern at a low data rate. Said first electronic device may also comprise a transmitter configured to transmit said data pattern using a direct link of the communication system. Furthermore, said first electronic device may comprise a transmitter configured to transmit said data pattern using a reverse link of the communication system.

[0037] In yet another example an apparatus in a wireless communication system is described, comprising a first electronic device configured to receive one or more bits of information in an assigned resource, and discarding said one or more bits of information and maintaining the allocation of said allocated resource if it is determined that said one or more bits of information match a first data pattern. In this way; said first electronic device may comprise a processor configured to convert said information bits into said data packets having a predetermined length. Furthermore, said first electronic device may comprise a processor configured to receive said bits of information on a direct link of the communication system. Said first electronic device may also comprise a processor configured to receive said bits of information in a reverse link of the communication system.

[0038] In yet another example, a machine-readable medium is described, comprising instructions that, when executed by a machine, cause the machine to perform operations, including the transmission of a first data pattern on an allocated resource when not there is data to transmit on said allocated resource. The machine-readable medium may further comprise a machine-readable instruction to cause the selection of said first data pattern, wherein said first data pattern may comprise one or more erasure signature packets. Furthermore, said machine-readable instruction to cause transmission of said one or more erase signature packets may comprise transmitting each of said erase signature packets at a power level below a threshold. Furthermore, said machine-readable instruction to cause transmission of said one or more erase signature packets may comprise transmitting each of said erase signature packets at a power level that does not cause significant interference. Said machine-readable instruction to cause transmission of said first data pattern may also comprise transmission of said data pattern at a power level that does not cause significant interference. Furthermore, the machine-readable medium may comprise a machine-readable instruction to cause the selection of said first data pattern having a length based on available resources. The machine-readable instruction for causing transmission of said first data pattern may comprise transmission of said data pattern at a low data rate. Furthermore, said machine-readable instruction to cause transmission of said first data pattern on said allocated resource may comprise transmission of said data pattern using a direct link of the communication system. Furthermore, said machine-readable instruction to cause transmission of said first data pattern on said allocated resource may comprise transmission of said data pattern using a reverse link of the communication system.

ES 2 649 366 T3

[0039] In yet another example a machine-readable medium is described, comprising instructions that, when executed by a machine, cause the machine to perform operations, including receiving one or more bits of information in an allocated resource and maintaining the allocation of said allocated resource, if it is determined that said one or more bits of information represent a packet of erasure signatures. The machine-readable medium may further comprise a machine-readable instruction to cause said one or more bits of information to be converted into said data packets having a predetermined length. Said machine-readable instruction to cause the reception of one or more bits of information may comprise the reception of said bits of information on a direct link of the communication system. Furthermore, said machine-readable instruction to cause the reception of one or more bits of information may comprise the reception of said bits of information on a reverse link of the communication system.