Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L27/00—Modulated-carrier systems
  • H04L27/26—Systems using multi-frequency codes
  • H04L27/2601—Multicarrier modulation systems
  • H04L27/2602—Signal structure
  • H04L27/261—Details of reference signals
  • H04L27/2613—Structure of the reference signals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/0001—Arrangements for dividing the transmission path
  • H04L5/0003—Two-dimensional division
  • H04L5/0005—Time-frequency
  • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0037—Inter-user or inter-terminal allocation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals

Definitions

• BACKGROUND In wireless communications systems, when schedule based access is used to allocate physical radio resources to mobile stations (MSs), the scheduler at the base station (BS) requires some critical information. For example, an uplink scheduler needs to know which MS needs PHY resources and how much and how urgent the MS needs the PHY resources. For another example, a downlink scheduler may need to know which modulation and code rate should be applied to the PHY resources for sending data to an MS.
• Such systems include present and future Institute for Electrical and Electronic Engineers (IEEE) 802.16e, LTE and 802.16m standards.
• bandwidth request indicator (e.g. IEEE802.16e or LTE)
• a MS sends the bandwidth indicator first and if the indicator is captured by the BS, in the next step the BS may grant PHY resources for the MS to send the bandwidth request.
• an UL bandwidth request indicator (or schedule request in LTE terminology) is sent in a periodically allocated PHY resource (refer to as polling hereafter). Polling has a major drawback when the bandwidth request rate is low.
• VoIP Voice over Internet Protocol
• 0.4 BWREQ/user/second is needed to tell the BS a UL talk spurt starts.
• a MS needs to have one periodical PHY resource every 5ms no matter if it has a bandwidth request to send or not.
• Another drawback is the large latency. Namely, the bandwidth request is sent after receiving a correct bandwidth indicator capture and successful PHY resources allocation for the bandwidth request.
• FIG. 1 depicts a quick access channel PHY structure according to an embodiment of the present invention.
• FIG. 2. illustrates a BS ordered quick feedback procedure according to embodiments of the present invention.
• plality and a plurality as used herein may include, for example, “multiple” or “two or more”.
• the terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like.
• a plurality of stations may include two or more stations.
• Embodiments of the present invention provide preamble sequence selection methods for quick channel access that can evenly distributed users among all sequences while also avoiding sequence collision.
• Embodiments of the present invention provide a quick 3-step access concept to IEEE802.16m, although the present invention is not limited in this respect.
• Embodiments of the present invention may be implemented as shown generally as 100 of FIG. 1 as follows:
• One quick access channel will be mapped to one distributed resource unit that consists of three 6x6 control tiles 110, 120 and 130.
• the 6x6 tile spreads across 6 consecutive sub-carriers and 6 consecutive OFDMA symbols.
• Each 6x6 control tile 110, 120 and 130 and 19 sub carriers may be used to send bandwidth indicators and 17 sub carriers may be used to send bandwidth request messages.
• N is 12 by default, although the present invention is not limited to this.
• M full MAC Ids are ⁇ Ido, Idi ,
• One channel has K unique PHY address ⁇ Aro , Ari , Ar 2 , • • • , Ar ⁇ -i ⁇ M ⁇ K; 3) One channel has L unique orthogonal sequence indexes ⁇ 0, 1 , 2,...18 ⁇ ;
• the information loading algorithm should distribute the sequence collision probability equally among all L sequences.
• the information loading algorithm should also ensure if two MSs select the same sequence for time t, the probability they select the same sequence for time t+1 is low. This prevents the sequence collision from repeating over time. If two MSs access the channel at the same time, the chance that both MSs select the same sequence should be designed to be up bounded by 1/L. There are multiple methods to load the information to all available code words.
• a drawback for this method is that BS may need to perform exhaustive search, i.e., calculating h(m, t), among for all possible m values at a given time t, and look up the unique valid m value or determine a collision when multiple m values generate the same output.
• the third method is described in this paragraph.
• the third method loads PHY address in message and load signaling bits in preamble and message.
• the third method can be viewed as a hybrid method for method 1 and method 2, the collision probability is better than method 1 but worse than method 2, but BS doesn't need to calculate all h(m,t) as in method 2.
• the BS and the MS can use additional synchronized state information shared between them as input to function f() to enhance the randomness of its outputs.
• state information is the security context.
• Another example is the history of output p previously successfully processed.
• f(m,j,t) mod(mod(j,L)+mod(m, L)+mod(floor(m/L) X t,L), L)
• f(m,j,t) mod(mod(j,L)+mod(m, L)+mod(floor(m/L) X t,L), L)
• the BS ordered quick feedback procedure is illustrated generally as 200 of FIG. 2 with BS 230 and MS 240 and BS order 210 and quick feedback 220.
• the major benefit is coming from that the load of one quick access channel is controllable and predictable. When the load is low, using the quick access channel to send small amount of signaling bits will save PHY resources for data traffic. Further, there may be many BS initiated MS signaling feedbacks. Many of them happen infrequently and can be encoded using a small number of code words. One example is event driven CQI to assist the scheduling for persistent scheduling. Another example could be MS power headroom reporting. When ordering feedback from multiple MSs at the same time, the BS knows beforehand which MS can use which preamble to send quick feedback. So there is no confusing at the BS side on who has sent the ordered quick feedback.
• the information element defining for BS ordered quick feedback can be further related to the information element in the BS order.

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• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Mobile Radio Communication Systems (AREA)

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• 2009
  • 2009-10-31 EP EP09824206.8A patent/EP2394375A4/de not_active Withdrawn
  • 2009-10-31 CN CN200980153567XA patent/CN102273099A/zh active Pending
  • 2009-10-31 WO PCT/US2009/062902 patent/WO2010051516A2/en active Application Filing

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