JP5054142B2 - Method and apparatus for transmitting user data using a traffic channel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for constructing different transmission segment types of segment from air link resources such as e.g., traffic channels, for effectively use the novel structure. <P>SOLUTION: Different segment types 516 are constructed to achieve different performance characteristics. The segments 516 are aligned to deviated different starting times selected to suppress to a minimum variation in the maximum number of segments 516 starting in any of predetermined time slots 530-542. The segment starting times different from each other suppress to a minimum waste of non-used assignment messages caused by structural non-efficiency and balance traffic. Information collected for channel quality is used to classify users. Information stored for different segment types 516 having different advantages, respectively, is used for assignment processing for effectively matching the classified user to any suitable segment type. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to wireless communication systems, and more particularly, to a method and apparatus for constructing, organizing and allocating traffic channel segments in order to efficiently use air link resources.

  In a wireless communication system, air link resources typically include bandwidth over time or code over time. Airlink resources that carry data and / or voice traffic are called traffic channels. The design of the traffic channel, eg, how to partition the available bandwidth over time, as well as how to allocate the partitioned bandwidth over time between competing users is important. The reason is that the traffic channel generally occupies most of the system air link resources.

  Multiple users, such as wireless terminals, that span the entire cell of the system operate in unison and require the use of traffic channels for transmission of data and / or voice traffic, eg, segments of the system's (multiple) traffic channels To do. The number and type of users will change over time in the system and compete for these airlink resources. The level of resources required by different types of users, such as wireless data terminals versus mobile phones, will also vary. The level of resources required by one user changes over time. For example, a wireless terminal may transition from a sleep state to a hold state or an on state, each state requiring a different level of resources. Of acceptable, required or required performance by different users in terms of acceptable signal-to-noise level, acceptable error rate, acceptable delay time between resource requirements and resource supply, power requirements, and burst data rate The level may also change. The location of a user, e.g., a wireless terminal, with respect to the base station, adjacent cells / sectors that cause interference, and obstacles can affect the choice of how to split and allocate available air link resources.

  Certain types of traffic segments, such as high bandwidth per segment, are advantageous for a range of problems, while other types of structures, such as narrow bandwidth with long duration, are another concern. It is useful to deal with.

  Based on what has been discussed above, it is apparent that there is a need for improved methods and apparatus for segmenting and / or using communication resources.

  In a wireless communication system, an air link resource for transmitting information, eg, bandwidth over time or code over time, is called a channel. The description herein is in the context of an exemplary OFDM system. However, the present invention can also be applied to other types of communication systems such as CDMA. The communication system includes, for example, an uplink traffic channel for data and / or voice transmission from a wireless terminal to a base station, a downlink traffic channel, a request channel and an assignment for data and / or voice transmission from the base station to the wireless terminal. There can be multiple channels, such as channels.

  Transmission units that carry information are grouped into transmission segments. In the exemplary OFDM embodiment, the transmission unit may be in the form of tone-symbols, where one tone-symbol represents one tone allocated for use in one symbol transmission time. A transmission segment is the basic unit of a channel. A series of segments is assigned to each channel over time. The present invention efficiently uses air link resources, minimizes the level of interference between users, reduces overhead, saves user energy, balances the system, provides flexibility, A method and apparatus for constructing, organizing and assigning transmission segments to increase system performance is described. For example, the channel can be subdivided into tone sets for the frequency domain. A subdivided channel can be referred to as a secondary channel, or simply a channel. For example, the uplink traffic channel can be subdivided into multiple channels, for example, each channel having a series of assigned tones.

  Each channel can be subdivided into multiple segments for the time domain. In accordance with the present invention, there are a number of different transmission segment types. In order to realize different advantages, different transmission segment types are constructed according to the present invention. The information set defining each transmission segment type is stored in memory before assigning the segments of the transmission segment type to one or more transmitters.

  The information set defining the transmission segment type includes information specifying the number of transmission units to be transmitted over a period of time, for example, the number of tone-symbols per segment. This period is segmented into slots. A time slot can correspond to the time used to transmit any one transmission unit. For example, the time slot can be an OFDM symbol time. Alternatively, the time slot can be a fixed number of OFDM symbol times. Each transmission segment type segment includes a specific number of transmission units per unit time, for example, the total number of tone-symbols per time slot. The period during which one segment of the transmission segment is transmitted can be different for different transmission segment types. For example, some segments occupy more time than others. In some embodiments, the number of transmission units per unit time for one type of transmission segment may be the same as for another type of transmission segment. For example, there can be the same number of tone-symbols in each segment. In some embodiments, the number of transmission units per unit time for segments of different transmission segment types may be different. For example, some segments can occupy more tones in the frequency domain than others.

  In some embodiments, the number of transmission units per segment can be different for some segments. In some embodiments, the total number of transmission units per segment for one transmission segment type may be the same as for another transmission segment type. For example, the total number of tone-symbols in each segment is the same. This embodiment has the advantage of facilitating rapid retransmission. The reason is that any lost segment fits into any other segment, thereby reducing the delay in segment allocation for retransmission. This embodiment also allows the flexibility of assignment and has the advantage that relative characteristics can be pre-defined between different types of segments, as well as segments can be assigned to users to take advantage of these characteristics.

  According to the present invention, there are a plurality of N traffic channels, and an information set for each of these traffic channels can be defined and stored. Information about each traffic channel includes information defining a segment of a particular transmission segment type and information indicating the start time of the segment within the channel. According to the present invention, the start times of the segments in different channels can be different.

  In some embodiments, the start time of a segment in one channel can be different from the start time of a segment in another channel. While segment start time shifts are beneficial, they are not mandatory. If the start times of the segments are the same, users who generate requests randomly may have to wait until the next start time for allocation, which causes a significant delay. Staggering the start time of the segments tends to reduce these delays, thus improving performance. Also, if the start times are matched, considerable allocation processing can occur simultaneously. This is undesirable when resource processing is limited. In addition, if the segment start times occur simultaneously, the active segments tend to concentrate. If the start time deviates, it tends to disperse the transmission of active segments, reducing interference throughout the system.

  In accordance with the present invention, the start times of multiple segments in different channels are defined and stored so that the start times are distributed in order to minimize variations in the maximum number of segments starting in any of the predetermined time slots. be able to. By minimizing the variation in the maximum number of slots starting in any given slot, an allocation message structure can be efficiently formed, which requires less resources, such as bandwidth, thereby Other applications such as creating bandwidth that can be used for a lot of user data. If the variation in start time is large, the allocation channel allocates bandwidth to the maximum number of simultaneous start time messages. However, if a small number of segments are started, unused ones may become partially unused but still consume bandwidth and thus waste bandwidth. Airlink resources can be saved if the variation in start time is minimal.

  According to the present invention, in a comparison of transmission segment types having the same number of transmission units, for example tone-symbols, a segment that has many transmission units per unit time and may be referred to as a “high” segment For example, a segment with many tones and, as opposed to, a segment with few transmission units per unit time and may also be referred to as a “long” segment, eg a tone per symbol time The transmission segment type can be distinguished from a segment with a small segment duration.

  According to the present invention, the allocation of segments to different devices, such as wireless terminals, or users can be based on decisions made as to whether the user is in good transmission channel conditions. According to the present invention, users in good transmission channel conditions are assigned to segments with many transmission units per unit time, while other users are segments with few transmission units per unit time. Assigned to. Considerations such as the limited transmission power concerns of the wireless terminal can also be taken into account when allocating segments.

  According to the invention, the allocation of power per transmission unit to be used for transmitting segments of different transmission segment types is also the type of segment, e.g. the segment type has many transmission units per unit time, or Can be based on having fewer transmission units per unit time. In some embodiments, transmission segments having fewer transmission units per unit time are allocated more transmission power per transmission unit than transmission segments having more transmission units per unit time. In some cases, the power level difference between the two types of segments allocated per transmission unit is at least twice.

  In accordance with the present invention, the base station uses the segmentation and allocation method of the present invention to effectively use the air link resources. Base stations and wireless terminals exchange information with each other to classify users based on interference levels, channel quality reports and evaluations, power information, user requirements, and user priorities. If known performance advantages and disadvantages are associated with each type of segment, the base station uses structural information to segment the segmentation scheme, e.g. segment type, to match the user to the segment type and effectively balance the system and Keep it efficient.

Detailed description

  In one embodiment of the invention, the traffic channel includes a plurality of series of traffic channel segments. A traffic channel segment occupies a particular air link resource for a certain finite time duration. For example, an exemplary traffic segment can occupy a specific bandwidth at certain time intervals. There can always be multiple traffic channel segments in operation. For example, different traffic segments that occur simultaneously in time domain allocation using non-overlapping bandwidth can be assigned to different users.

  The amount of air link resources occupied by a traffic channel segment can vary from traffic channel segment to traffic channel segment. A graph 100 having frequency on the vertical axis 102 and time on the horizontal axis 104 is shown in FIG. The frequency domain includes two equally sized frequency units 106 and 108. The time domain includes four equal sized slots 110, 112, 114, 116. In FIG. 1, the exemplary first segment, segment A 118, represented by a shaded vertical line, occupies one time slot 110 and two frequency units 106, 110. An exemplary second segment, segment B120, represented by a shaded horizontal line, occupies three time slots 112, 114, 116 and one frequency unit 106. Segment A 118 can be assigned to the first user, user # 1, and used by user # 1. Segment B120 can be assigned to a second user, user # 2, and used by user # 2.

  Airlink resources can be established for code units over time. Similar to the exemplary diagram of FIG. 1, if the air link resource is described in terms of code units over time, segment A can be constructed to include one time slot and two code units, while Segment B can be constructed to include three time slots and one code unit.

  FIG. 2 shows a graph 200 of frequency on the vertical axis 202 versus time on the horizontal axis 204. For purposes of describing the present invention, graph 200 can be illustrated in the context of an exemplary OFDM system that uses traffic channel segments. In an OFDM system, the available bandwidth 206 is divided into a number of orthogonal tones 208. For example, FIG. 2 shows six tones. In OFDM symbol period 210, any of the tones 208 can be used to transmit a complex number representing the information to be conveyed. FIG. 2 shows five OFDM symbol periods 210. The basic unit of air link resources is a tone 208 in the OFDM symbol 210. This is referred to as a tone-symbol 214 and is shown as a square in FIG. The air link resource 212 of FIG. 2 includes 30 tone-symbols 214. Each of the tone-symbols 214 can be used to transmit modulation symbols that carry information. A segment includes one or more tone-symbols 214 over a fixed time interval. The present invention is described herein using an OFDM system as an exemplary system. It is clear that the present invention can be applied to other systems such as, for example, systems using code division multiple access (CDMA) or time division multiple access (TDMA).

  A traffic channel segment is the basic unit of traffic channel resources. In some embodiments, there are downlink traffic channel segments and uplink traffic channel segments. Traffic channel resources are allocated in the form of traffic segment allocation. That is, the base station receives a traffic channel so that the assigned user receives data / voice traffic for the assigned downlink traffic segment or transmits data / voice traffic for the assigned uplink traffic segment. Segments are assigned to users in the cell, for example wireless terminals. Traffic segment assignments can vary from segment to segment. For example, in FIG. 1, segment A 118 is assigned to user # 1, and segment B 120 is assigned to user # 2. To enhance system characteristics and user experience, in some embodiments, the time duration of the traffic segment is short, so the base station can quickly move the traffic channel segment to different users according to traffic needs and channel conditions that can generally change over time. Can be assigned to. Therefore, a traffic channel can be effectively shared and allocated dynamically between different users for each segment.

  In one embodiment, the amount of air link resources, i.e. the number of tone-symbols, of the individual traffic channel segments is the same. For example, one segment can have 10 tone-symbols over 5 OFDM symbol periods, while the other segment has 2 tone-symbols over 25 OFDM symbol periods. Can have. Having the same number of tone-symbols for all traffic channel segments can advantageously facilitate retransmission (ARQ: automatic repeat request). For example, assume that user data information is conveyed by a series of modulation symbols using a specific coding and modulation scheme. These modulation symbols are transmitted in the tone-symbols of the traffic channel segment. Assume that the receiver cannot successfully receive this segment. In this case, since each segment has the same number of tone-symbols, the same series of modulation symbols can be retransmitted in any subsequent traffic channel segment.

  One embodiment of building a traffic channel segment must first divide the traffic channel into multiple subchannels in frequency space, and then divide each of the subchannels into a series of segments in time space. FIG. 3 shows such a structure of traffic channel segments in an exemplary OFDM system. FIG. 3 includes a graph 300 of frequency on the vertical axis 302 versus time on the horizontal axis 304. Assume that the traffic channel occupies a certain number of tones. In FIG. 3, the exemplary traffic channel 322 occupies four tones, tone (1) 306, tone (2) 308, tone (3) 310, and tone (4) 312; in FIG. The tones are adjacent for illustration. In practice, these tones may or may not be adjacent. The series of traffic channel tones 306, 308, 310, 312 is divided into a few sub-sets of disparity, each of which is to be used by the secondary channel. Three subchannels: a subchannel (1) 324 represented by shaded shades, a subchannel (2) 326 represented by shaded shades, and a subchannel (3) represented by shaded horizontal lines 328 is shown in FIG. Note that the number of tones occupied by each secondary channel can be different. Subchannel (1) 324 occupies two tones, tone (3) 310 and tone (4) 312, and subchannel (2) 326 occupies one tone, tone (2) 308, and subchannel (3 ) 308 occupies one tone, tone (1) 306. Each secondary channel 324, 326, 328 is further divided into a series of myriad segments. FIG. 3 shows the first four time slots: slot (1) 314, slot (2) 316, slot (3) 318 and slot (4) 320. Assuming that the segments have the same size, eg, the same amount of air link resources, the time duration of the subchannel segment with a large number of tones is shorter than the time duration of the subchannel segment with a small number of tones. . Each of the “tall” segments 330, 332, 340, 344 of secondary channel (1) 324 occupies two tones (tone (3) 310 and tone (4) 312) over one time slot. To do. Each of the “short” segments 336, 338 of secondary channel (2) 326 occupies one tone (tone (2) 308) over two time slots. Each of the “short” segments 334, 342 of secondary channel (3) 328 occupies one tone (tone (1) 306) over two time slots.

  The reason for organizing the traffic channels in the segment is to increase the freedom to allocate traffic channels. US patent application Ser. No. 09 / 706,377 describes a system in which each traffic channel segment is assigned independently. Thus, in some cases, these segments can be quickly assigned to different users, thereby enabling high performance statistical multiplexing. In this system, there are assigned channels that are separate from the traffic channels. Each traffic channel segment is associated with an assigned channel segment that is used to send an assignment message that identifies the identifier of the user assigned to the traffic segment. In general, the allocation segment is transmitted without delay after the corresponding traffic segment. In one embodiment of this system, the time difference between the allocated segment and the corresponding traffic segment is constant, which means the minimum requirement for storing or decoding received control information.

  4 and 5 show two examples of arranging allocation channels and traffic channels. In both examples, each assigned channel segment has a certain number of information bits. While this is not always necessary, this arrangement may be desirable because each assigned segment can use the same encoding and modulation scheme.

  FIG. 4 includes a graph 400 of frequency on the vertical axis 402 versus time on the horizontal axis 404. The allocation segment 406 represented by the shadow of the point includes an allocation segment 410 and an allocation B segment 412. Traffic segment 408 is divided into secondary channels. The subchannel (1) 424 represented by the shaded area includes a traffic segment (# 1) 414 and a traffic segment (# 4) 420. The secondary channel (2) 426, represented by the shade of shading, includes a traffic segment (92) 416. The secondary channel (3) 428 represented by the shaded horizontal line includes a traffic segment (# 3) 418. In FIG. 4, the time domain is divided into slots, and a series of six slots 430, 432, 434, 436, 428, 440 are shown.

  In the first example of the illustrated allocation / traffic segment arrangement illustrated by FIG. 4, the secondary channel segments are constructed so that the number of traffic segments starting in any slot varies from one to three. For example, at the beginning of slot 434, three traffic segments 414, 416, 418 begin. However, at the beginning of time slot 436, one traffic segment 420 begins. Thus, each assigned channel segment 410, 412 includes the ability to include at least three assignment messages. Allocation A segment 410 carries three allocation messages for traffic segment (1) 414, traffic segment (2) 416, and traffic segment (3) 418. If only one traffic segment starts, the corresponding assignment segment contains only one assignment message, and the remaining information bits available for the other two assignment messages are not used. Allocation B segment 412 carries one allocation message for traffic segment (4) 420. Since the allocated channel has to be transmitted to the majority of users in the system, any information bits of the allocated channel generate significant power resources. Therefore, in the example of FIG. 4, unused information bits in the allocation channel, eg, allocation B segment 412, waste system resources.

  FIG. 5 includes a graph 500 of frequency on the vertical axis 502 versus time on the horizontal axis 504. Allocation segment 506 represented by the shadow of a point includes allocation A segment 510 and allocation B segment 512. The traffic segment 508 is divided into secondary channels. The subchannel (1) 524 represented by the shaded area includes a traffic segment (# 1) 514 and a traffic segment (# 3) 520. The secondary channel (2) 526 represented by the shade of shading includes a traffic segment (# 2) 516. The secondary channel (3) 528 represented by the shadow of the horizontal line includes a traffic segment (# 5) 518. In FIG. 5, the time domain is divided into slots, and a series of seven slots 530, 532, 534, 536, 538, 540, 542 are shown.

  FIG. 5 shows another exemplary embodiment of the present invention in which the secondary channel segments are staggered with respect to time so that the number of traffic segments starting in any slot has minimal variation.

  In particular, the secondary channel segments are constructed so that the number of traffic segments starting in any slot is two. For example, at the beginning of time slot 534, traffic channel segment (# 1) 514 and traffic channel segment (# 2) 516 start based on assignments from assignment A segment 510. At the beginning of time slot 536, traffic channel segment (# 3) 520 and traffic channel segment (# 4) 518 start based on assignments from assignment B segment 512. Thus, each allocation channel segment 510, 512 contains two allocation messages, leaving no information bits that are unused due to the structure. Therefore, the embodiment of FIG. 5 using 4 allocation message reservation bits (resources) per 4 traffic segments is the implementation of FIG. 4 using 6 allocation message reservation bits (resources) per 4 traffic segments. More efficient and better than form.

  Given the encoding and modulation schemes, different shaped traffic channel segments result in different burst data rates. Thus, these different shaped traffic channel segments can be assigned to meet the speed and delay requirements of different users. For example, a “tall” segment having a large number of tones over a short time interval, eg, segment 514 of FIG. 5, is a “long” segment having a small number of tones over a long time interval, eg, FIG. This produces a higher burst data rate than 5 segments 516. Thus, high length segments can be assigned to users who are sensitive to delay, while long segments can be assigned to users who do not respond to delay. In addition to the above traffic service considerations, physical layer considerations can also be taken into account when assigning traffic channel segments.

  In the uplink, when a user, eg, a wireless terminal, transmits a traffic channel segment to a desired base station, the user also causes interference to neighboring base stations. Broadly speaking, if the ratio of the signal power received at the desired base station to the interference power received at the neighboring base station is small, the user is considered to be in a “bad” position. If this ratio is large, the user is considered to be in the “good” position. In one embodiment, tall segments need to be assigned to users in good positions, whereas long segments need to be assigned to users in bad positions to control interference. Furthermore, due to battery power or power amplifier considerations, the transmit power capability of user terminals is often limited. In order to improve air link durability, it is desirable to allocate long segments to users far away from the base station in terms of path loss.

  In the downlink, when a user receives a traffic channel segment from a desired base station, the user also experiences interference from neighboring base stations. In general terms, if the ratio of the signal power transmitted from the desired base station to the interference power transmitted from adjacent base stations is small, the user is considered to be in a “bad” position. If this ratio is large, the user is considered to be in the “good” position. In the case of a user in a good position, even if the transmission power is doubled, the capacity of the communication channel may be much less than doubled (power saturation). Is often bandwidth limited. In the case of a bad user, even if the transmission bandwidth is doubled, the communication channel capacity may be much less than doubled (bandwidth saturation). Channel capabilities are often power limited. In one embodiment, multiple users are assigned to concurrent traffic segments each having a secondary channel. The series of designated users that occur at the same time includes users in good positions and users in bad positions. A user in a good position is assigned to a tall segment, while a user in a bad position is assigned to a long segment. Further, consider the normalized transmission power of these traffic segments. This normalized transmit power is defined as the power allocated to each tone-symbol of the segment. It is preferable that the normalized transmission power used for the high segment is less than the normalized transmission power used for the long segment. In one embodiment, each secondary channel is assigned a fixed amount that is part of the total transmitted power. Therefore, the transmission power of each subchannel segment is limited by this fixed amount.

  In some embodiments, users can be classified into multiple levels between the definitions of “good location” and “bad location”. Similarly, segment types can be classified into multiple levels between “tall segment” and “long segment”. In accordance with the present invention, the base station can selectively match multiple location definitions with multiple segment definitions to improve overall system performance and durability.

  FIG. 6 shows an exemplary communication system 600 using the apparatus and method according to the present invention. Exemplary communication system 600 includes a plurality of base stations, namely base station 1 (BS1) 602, base station N (BS (N)) 602 ′. BS (1) 602 is coupled to a plurality of end nodes (EN), ie, EN (1) 608 and EN (N) 610, via wireless links 612 and 614, respectively. Similarly, BS (N) 602 ′ is coupled to a plurality of end nodes (EN), ie, EN (1) 608 ′ and EN (N) 610 ′ via radio links 612 ′ and 614 ′, respectively. . Cell (1) 604 refers to a wireless service area where BS (1) 602 can communicate with an EN, eg, EN (1) 608. Cell (N) 606 means a wireless service area where BS (N) 602 ′ can communicate with an EN, for example, EN (1) 608 ′. EN 608, 610, 608 ′, 610 ′ can move within communication system 600. Base stations BS (1) 602 and BS (N) 602 ′ are coupled to network node 616 via network links 618 and 620, respectively. The network node 616 is coupled via a network link 622 to the Internet and another network node such as another base station, router, home agent node, authentication / authorization / accounting (AAA) server node, and the like. The network links 618, 620, 622 can be, for example, optical fiber cables. The network link 622 interfaces with the outside of the communication system 600 so that a user, eg, EN, can communicate with a node outside the system 600.

  FIG. 7 shows an exemplary base station 700 according to the present invention. Exemplary base station 700 may represent in detail base stations 602, 602 ′ of FIG. Exemplary base station 700 includes a receiver 702, a transmitter 704, a processor 706, such as a CPU, an I / O interface 708, and a memory 710, which are coupled via a bus 709. Various elements 702, 704, 706, 708, 710 can exchange data and information across the bus 709.

  Receiver 702 and transmitter 704 are coupled to antennas 703 and 705, respectively, to form a means for base station 700 to communicate with end nodes, eg, wireless terminals, in the cellular service area, for example, to exchange data and information. A receiver 702 including a decoder 712 receives and decodes signal transmissions encoded and transmitted by end nodes operating in the cell. Transmitter 704 includes an encoder 714 that encodes signal transmissions prior to transmission.

  Memory 710 includes routines 718 and data / information 720. The processor 706 executes routines 718 to execute the processes controlling the basic base station functions and to control and implement the novel features and improvements of the present invention, including user scheduling for traffic segments, in the memory 710 The operation of the base station 700 is controlled by operating the receiver 702, the transmitter 704, and the I / O interface 708 using the data / information 720. The I / O interface 708 connects the base station 700 to the Internet and another network node, such as an intermediate network node, a router, an AAA server node, a home agent node, etc., thereby communicating with the base station 700 through a wireless link. Can connect to, communicate with, and exchange data and information within the communication system, for example via the Internet, and with other peer nodes such as another end node outside the communication system.

  The routine 718 includes a communication routine 722 and a base station control routine 724. Base station control routine 724 includes a scheduler 726 having a segment alignment routine 728. Data / information 720 includes data 734, segment information 736 and user data / information 738. User data / information 738 includes a plurality of user information, that is, user 1 information 740 and user N information 754. Each user information, for example, user 1 information 740 includes terminal identification information (ID) 742, data 744, request information 746, status information 748, quality report information 750, and classification information 752.

  Data 734 includes data transmitted from the end node (wireless terminal), data to be transmitted to the end node, data to be processed, and data supporting the function of base station 700. Segment information 736 includes the number of segments, the type of segment, the state of the segment, the size of the segment, the series of tones within the segment, the number of tones-symbols per segment, the relative position of the segments, the segment categorization, the traffic Information on segment information 730 and allocated segment information 733 is included. Traffic segment information 730 includes segment type information for a plurality of predetermined segment types. Traffic segment information includes information defining segment slot times, which segments are “heavy segments”, eg, have many tones, and which segments are “long segments”, eg Information defining whether to have fewer tones at longer time intervals. In some embodiments, a set of information that defines aspects of individual traffic segment types is included. The traffic channel information 731 includes information regarding different traffic channels. Each traffic channel includes multiple segments that typically correspond to a segment type. Most traffic channels contain one segment at any time. For example, the height of a traffic channel is typically one segment. The traffic channel information 731 includes the traffic channel size and structure, and information defining the secondary channel complex. The traffic channel information 731 also includes information regarding the segment start time for each traffic channel.

  An exemplary set of traffic segment information 730 is shown in FIG. In the illustrated embodiment, the traffic segment information includes a plurality of X information sets, each of the X information sets defining a different type of traffic segment. Each of the traffic segment type definition information sets 780 and 780 ′ includes information 782 and 782 ′ indicating the number of transmission units per unit period included in the traffic segment. This information can be thought of as defining the height of the traffic segment. The reason is that this height indicates the number of units to be transmitted within the unit period, eg symbol time, of the type of segment defined by the information set 780, 780 ′. The traffic segment type information set 780, 780 ′ also includes total transmission unit number information 784, 784 ′. This information indicates the total number of transmission units of the type of segment defined by the traffic information set 780,781. The total number of transmission units can be specified as a fixed number, as the number of unit transmission periods, or in some other way. When specified as the number of unit transmission periods, the total number of transmission units of the specified type of segment is the transmission unit per unit time indicated by information 782, 782 ', and the corresponding unit indicated by information 78, 784'. Equal to the number of transmission periods multiplied. Each transmission segment is divided into one or more time slots. Each information set 780, 780 ′ includes information indicating in each time slot the number of transmission unit periods, eg, transmission symbol times, for a defined traffic segment type. When considered in combination with transmission unit information 782 and 784 per unit time, information 786, 786 'may be considered to indicate the number of transmission units per traffic segment time slot for a specified type of segment. it can. As will be described below, both the base station and the wireless terminal can store traffic segment information 730, which can be used in combination with the allocation information to determine the shape, duration and / or total data capacity of the allocated traffic segment. Can be determined.

  The traffic segment information 730 is used in combination with the traffic channel information 731. FIG. 10 shows an exemplary set of traffic channel information 731. The exemplary traffic channel information 731 includes N traffic channel information sets 990, 990 ′, each set corresponding to one of the N traffic channels, for example, including information defining this one. . The information set 990, 990 ′ corresponding to each traffic channel includes information 992, 992 ′ indicating the type of segment used for the traffic channel and information 994, 994 ′ indicating the start time of the segments forming the traffic channel. . In order to minimize the maximum delay between any two consecutive segment start times where a series of traffic channels are used, the segment start times of the different channels can be staggered and often staggered. Accordingly, the segment start time information 994, 994 ′ is usually different.

  Allocation segment information 733 includes information identifying the number of traffic segments that can be allocated at the beginning of a slot based on the traffic segment system structure, and timing information between the allocation segments and the traffic segments. The terminal ID 742 is identification information defined by the base station for a user, for example, a wireless terminal. Data 744 may include specific user data, such as data to be transmitted to user 1. Request information 746 may include requests from users for state changes, requests for additional bandwidth allocation, power requests, burst data rate requests, user sensitivity to delay, and the like. The status information 748 may include the user's current status, eg, sleep, hold, on, user power level status, and interference level experienced by the user. The quality report information 750 may include feedback information from the user regarding downlink channel quality, experienced interference level, and the like. The classification information 752 can include, for example, the category in which the user is placed regarding the type of traffic segment to be assigned, such as whether the wireless terminal is considered a “good location” unit or a “bad location” unit. .

  Communication routines 722 include various communication applications that can be used to provide specific services such as IP telephony services or interactive games to one or more end node users. Base station control routine 724 includes basic control of signal generation and reception, control of data and pilot hopping sequences, control of encoder 712 and decoder 714, scheduling, allocation of bandwidth to users, scheduling of users for terminal ID 744, In addition, functions including control of output transmission power from the base station 700 are executed.

  Further, the base station control routine includes a scheduler 726 that manages a schedule of a user, for example, a wireless terminal, related to the terminal ID 742. Scheduler 726 includes a segment alignment routine 728 that performs segment alignment, eg, assignment of traffic channel segments to wireless terminals, in accordance with the methods, features, techniques, and structures of the present invention.

  In some embodiments, the segment alignment routine allocates segments of different segment types as a function of the transmission channel. As part of the allocation process, the segment alignment routine determines which of the multiple devices, eg, the first and second wireless terminals, are in better transmission channel conditions. Typically this is determined from channel quality feedback information provided by each wireless terminal to the base station for power control and / or scheduling purposes. According to one such embodiment, the segment alignment routine assigns a first type of transmission segment to a wireless terminal in good channel condition and a second type of segment with a radio having a low quality communication channel. Assign to a terminal. The second type segment is usually longer than the first type segment. Thus, a wireless terminal in a relatively poor channel condition is more likely to be assigned to a segment that contains more symbol times but less tones per symbol time than a segment assigned to a wireless terminal in good channel conditions . According to the invention, the first and second type segments are often transmitted simultaneously. For example, different types of segments are assigned to different wireless terminals.

  The power allocation routine 729 allocates power to be used when transmitting segments. In some embodiments, the routine allocates a first amount of power per transmission unit for use in transmitting a first type of segment and per transmission unit for use in transmitting a second type of segment. A second power amount is allocated. In some cases, the second amount of power per transmission unit is at least twice the first amount of power per transmission unit. Since the second type segment contains fewer tones per symbol period, the amount of power allocated to the second channel and relatively large compared to the first channel does not overburden the total transmitted power of the base station. . Moreover, since the first type of transmission segment is used to transmit to a wireless terminal in a relatively good channel condition, the power transmission is lower per tone than the power level used when transmitting the second type of segment. Still have adequate transmission quality. By assigning a large number of tones to devices in good channel conditions and assigning a relatively small number of tones to devices in inferior channel conditions, effective utilization of the limited total transmit power can be achieved.

  In various embodiments, the schedule matching routine 728 uses segment information 736 and user data / information 738 to identify user requests for traffic segments based on information such as classification 752, request information 746 and quality report information 750. Try to align with the segment. Segment alignment routine 728 attempts to balance user requirements while attempting to maintain an overall high level of performance throughout the system.

  FIG. 8 illustrates an exemplary end node 800 in accordance with the present invention. The example end node 800 may represent in detail the end nodes 608, 610, 608 ′, 610 ′ of FIG. An exemplary end node 800, eg, a wireless terminal, can be a mobile terminal, mobile, mobile node, fixed wireless device, and the like. In this specification, reference to the end node 800 may change to, for example, a wireless terminal, a mobile node, etc., and these may be used interchangeably. Exemplary end node 800 includes a receiver 802, a transmitter 804, a processor 806, eg, a CPU, and a memory 808, which are coupled via a bus 810. Various elements 802, 804, 806, 808 can exchange data and information across the bus 810.

  Receiver 802 and transmitter 804 are coupled to antennas 803 and 805, respectively, to form a means for end node 800 to communicate with base station 700 via a wireless link. Receiver 802 includes a decoder 812. Receiver 802 receives and decodes signal transmissions, such as data transmissions, encoded and transmitted by base station 700. Transmitter 804 includes an encoder 816 that encodes signal transmissions prior to transmission.

  Memory 808 includes routines 820 and data / information 822 as well as traffic segment information 730 and traffic channel information 731. This information may be the same as or similar to the information included in the base station. A processor 806 performs processing to control basic wireless terminal functions and to control and implement the novel features and improvements of the present invention, including signaling and processing for traffic segment requests and assignments according to the present invention. And the operation of the end node 800 is controlled by operating the receiver 802 and the transmitter 804 using the data / information 822 in the memory 808.

  The routine 820 includes a communication routine 824 and a wireless terminal control routine 826. Data / information 822 includes user data 832 and user information 834. User data 832 may include data to be transmitted to base station 700 and data transmitted from base station 700, eg, data transmitted in traffic segments. The terminal ID information 836 includes a user ID assigned to the base station. Base station ID information 838 includes information about the wireless terminal, for example, an inclination value, in order to specify the basic state. Wireless terminal 800 can determine a data / control and pilot tone hopping sequence using terminal ID 836 and base station ID 838.

  The terminal ID 836 can also be used to identify with the allocated segment that resources are allocated to the wireless terminal 800. Interference information 840 can include measured levels or interference experienced by the wireless terminal. The state information 842 can include wireless terminal states such as sleep, hold, and on. Request information 844 can include requests from wireless terminals for state changes, additional resources such as traffic segments, requests for additional power, requests for high burst data rates, and the like. Quality channel report 846 includes collected information such as signal-to-noise ratio, downlink channel information, and information regarding the state of wireless terminal 800 that can be fed back to base station 700. The traffic channel assignment information 848 includes information regarding the assignment segments as well as predetermined relationships with the traffic segments of the various traffic channels. Traffic channel assignment information 848 may also include received assignment information, eg, received information from one or more assignment segments that indicate the assignment of a particular traffic channel segment to the wireless terminal. The received allocation information is combined with traffic segment information 730 and traffic channel information 731 to determine the traffic segments that can be used to transmit and / or receive data and the start times of the allocated segments of the various channels. Used by wireless terminals.

  Communication routines 824 include various communication applications that can be used to provide specific services such as IP telephony services or interactive games to one or more end node users.

  The wireless terminal control routine 826 controls basic functions of the wireless terminal 800 including operations of the transmitter 804 and receiver 802, generation and reception of signals including data / control hopping sequences, state control and power control. The wireless terminal control routine 826 includes a device status control and signal transmission module 828 and a data and data signal transmission module 830. Device state control and signal transmission module 828 uses data / information 822 including state information 842 and request information 844 to signal a change in state including a request for additional bandwidth, eg, a request for a traffic segment according to the present invention. Perform operations including transmission and processing control. The radio terminal control routine 826 may process and evaluate user information 834 including interference information 840, generate quality report information 846, and signal the information contained in the report information 846 to the base station 700 in accordance with the present invention. it can. The data and data signal transmission module 830 uses the data / information 822 including the terminal ID 836 and the traffic channel assignment 848 to recognize the assigned traffic segments and to perform operations including signal transmissions associated with these traffic segments. Follow the instructions.

  The present invention can be implemented in hardware and / or software. For example, some aspects of the invention can be implemented as program instructions executed by a processor. Alternatively or in addition, some aspects of the present invention may be implemented as an integrated circuit, such as an ASIC.

FIG. 3 shows two exemplary traffic channel segments indicating that the air link resources occupied by traffic segments can vary from segment to segment. FIG. 2 illustrates air link resources in the context of an exemplary OFDM system. FIG. 6 illustrates one embodiment of building a traffic channel segment in which a traffic channel is divided into a plurality of subchannels in frequency space and each subchannel is divided into a series of segments in time space according to the present invention. FIG. 6 shows an example of arranging allocation channels and traffic channels according to the present invention. FIG. 6 illustrates another example of arranging allocation channels and traffic channels such that traffic channel segments are staggered to achieve efficient use of the allocation channel segments in accordance with the present invention. FIG. 2 illustrates an exemplary system using the methods and apparatus of the present invention. FIG. 3 illustrates an exemplary base station implemented in accordance with the present invention. FIG. 2 illustrates an exemplary end node (wireless terminal) implemented in accordance with the present invention. FIG. 6 illustrates an example set of traffic segment information that can be stored in a base station and / or wireless terminal prior to traffic segment assignment. A set of traffic channel information that can be stored in a base station and / or a wireless terminal and can be used to perform or determine assignment of traffic channel segments that can correspond to different traffic channels for which predetermined information is stored For example, it is a diagram showing predetermined traffic channel information.

600 communication system, 602, 602 ′, 700 base station, 604, 606 cell, 608, 608 ′, 610, 610 ′, 800 end node, 618, 620, 622 network link

Claims (23)

A plurality of information sets, each defining one of a plurality of different transmission segment types, is stored in memory, the plurality of information sets assigning a segment corresponding to one of the transmission segment types to at least one of a plurality of transmitters. Remembered before assigning
A first information set of the plurality of information sets defines a first transmission segment type, and the first number of transmission units that the first information set is to transmit per unit time in the first type segment. And indicates a first total number of transmission units to be transmitted as part of the first type of segment over a first period in which the information is divided into time slots;
The second information set of information sets defining a second transmission segment type, the second transmission unit to be transmitted per unit time segment of the second information set is the second type Defining a number and indicating a second total number of transmission units to be transmitted as part of the second type of segment over a second period in which the information is divided into time slots;
Simultaneously transmitting information using segments of the first and second types,
Allocating a first amount of power per transmission unit for use in transmitting a segment of the first transmission segment type; and
Allocating a second amount of power per transmission unit for use in transmitting a segment of the second transmission segment type, wherein the second amount of power per transmission unit is the first amount per transmission unit. Greater than one amount of power,
Communication method.   The communication method according to claim 1, wherein the first number of transmission units per unit time is different from the second number of transmission units per unit time. The first transmission segment type segment includes more transmission units per unit time than the second transmission segment type segment , and the communication method further includes the first transmission segment type segment and the first transmission segment type segment . further comprising allocating two segments of the transmission segment type to the first and second devices, said step of assigning is,
Determining which of the first and second devices is in a better transmission channel condition;
Assigning a segment of said first transmission segment type to the device determined to be in a better transmission channel conditions, segments of the second transmission segment type remaining one of said first and second device The communication method according to claim 2, further comprising: The communication method according to claim 1 , wherein the second amount of power per transmission unit is at least twice the first amount of power per transmission unit. A plurality of information sets, each defining one of a plurality of different transmission segment types, is stored in memory, the plurality of information sets assigning a segment corresponding to one of the transmission segment types to at least one of a plurality of transmitters. Remembered before assigning
A first information set of the plurality of information sets defines a first transmission segment type, and the first number of transmission units that the first information set is to transmit per unit time in the first type segment. And indicates a first total number of transmission units to be transmitted as part of the first type of segment over a first period in which the information is divided into time slots;
The second information set of information sets defining a second transmission segment type, the second transmission unit to be transmitted per unit time segment of the second information set is the second type Defining a number and indicating a second total number of transmission units to be transmitted as part of the second type of segment over a second period in which the information is divided into time slots;
Simultaneously transmitting information using segments of the first and second types,
Further comprising storing N information sets defining a plurality of N traffic channels;
The first of the N information sets defines a first traffic channel, the first traffic channel is defined to include a segment of the first transmission segment type, and the first traffic The channel includes at most one segment of the first type at any given time;
A second one of the N information sets defines a second traffic channel, the second traffic channel is defined to include a segment of the second transmission segment type, and the second traffic The channel includes at most one segment of the second segment type at any given time;
The first of the N information sets defining the first traffic channel further comprises information indicating a start time of a segment in the first traffic channel;
Communication method. 6. The communication method according to claim 5 , wherein a second one of the N information sets defining the second traffic channel further comprises information indicating a start time of a segment in the second traffic channel. . The communication method according to claim 6 , wherein at least some of the start times of the segments in the first traffic channel are different from the start times of the segments in the second traffic channel. The communication method according to claim 6 , wherein the first number of transmission units to be transmitted per unit time is different from the second number of transmission units to be transmitted per unit time. The communication method according to claim 6 , wherein the indicated start time of the segment in the second channel deviates from the indicated start time of the segment in the first channel. Stored information defining a plurality of N channels, includes information indicating the N segments start time, each of the N segment start times being associated with one of N channels, said N The communication method according to claim 7 , wherein the segment start times are distributed to minimize variations in the maximum number of segments starting in any of the predetermined time slots. The communication method according to claim 10 , wherein each time slot corresponds to a time used to transmit any one transmission unit. The communication method according to claim 11 , wherein each time slot corresponds to an orthogonal frequency division multiplex symbol transmission period. A memory comprising a plurality of information sets each defining one of a plurality of different transmission segment types, before a segment corresponding to one of the transmission segment types is assigned to at least one of a plurality of transmitters A memory for storing the plurality of information sets;
A first information set of the plurality of information sets defining a first transmission segment type, the first information set defining a first number of transmission units to be transmitted per unit time in the first type segment; Information set, and information indicating a first total number of transmission units to be transmitted as part of the first type segment over a first period divided into time slots;
A second information set of the plurality of information sets defining a second transmission segment type, the second information set defining a second number of transmission units to be transmitted per unit time in the second type segment Information set, and information indicating a second total number of transmission units to be transmitted as part of the second type segment over a second period divided into time slots;
A transmitter coupled to the memory for simultaneously transmitting data of the first and second types of segments ;
The memory further comprises N information sets defining a plurality of N traffic channels;
The first of the N information sets defines a first traffic channel, the first traffic channel is defined to include a segment of the first transmission segment type, and the first A traffic channel includes at most one segment of the first type at any given time;
A second one of the N information sets defines a second traffic channel, the second traffic channel is defined to include a segment of the second transmission segment type, and the second A traffic channel includes at most one segment of the second segment type at any given time;
The first of the N information sets defining the first traffic channel further comprises information indicating a start time of a segment in the first traffic channel;
Communication device. The communication apparatus according to claim 13 , wherein a second one of the N information sets defining the second traffic channel further comprises information indicating a start time of a segment in the second traffic channel. . The communication device according to claim 14 , wherein at least some of the start times of the segments in the first traffic channel are different from the start times of the segments in the second traffic channel. The communication device according to claim 14 , wherein the first number of transmission units to be transmitted per unit time is different from the second number of transmission units to be transmitted per unit time. The communication device of claim 14 , wherein the indicated start time of a segment in the second channel is offset from the indicated start time of a segment in the first channel. Stored information defining a plurality of N channels, includes information indicating the N segments start time, each of the N segment start times being associated with one of N channels, said N 16. The communication device of claim 15, wherein the segment start times are distributed to minimize variations in the maximum number of segments starting in any of the predetermined time slots.   The communication device according to claim 18, wherein each time slot corresponds to a time used to transmit any one transmission unit. A memory comprising a plurality of information sets each defining one of a plurality of different transmission segment types, before a segment corresponding to one of the transmission segment types is assigned to at least one of a plurality of transmitters A memory for storing the plurality of information sets;
A first information set of the plurality of information sets defining a first transmission segment type, the first information set defining a first number of transmission units to be transmitted per unit time in the first type segment; Information set, and information indicating a first total number of transmission units to be transmitted as part of the first type segment over a first period divided into time slots;
A second information set of the plurality of information sets defining a second transmission segment type, the second information set defining a second number of transmission units to be transmitted per unit time in the second type segment Information set, and information indicating a second total number of transmission units to be transmitted as part of the second type segment over a second period divided into time slots;
A transmitter coupled to the memory for simultaneously transmitting data of the first and second types of segments ;
Means for allocating a first amount of power per transmission unit for use in transmitting a segment of the first transmission segment type;
Means for allocating a second amount of power per transmission unit for use in transmitting a segment of the second transmission segment type, wherein the second amount of power per transmission unit is the per unit of transmission Greater than the first amount of power,
Communication device. 21. The communication device according to claim 20 , wherein the second amount of power per transmission unit is at least twice the first amount of power per transmission unit. The communication apparatus according to claim 21 , wherein the communication apparatus is a base station. The communication device according to claim 22 , wherein the communication device is a wireless terminal.

Images