METHOD AND APPARATUS FOR EFFICIENT CONFIGURATION OF HYBRID SUB-CARRIER ALLOCATION
First Claim
1. A base station which operates in an orthogonal frequency division multiple access (OFDMA) system including at least one wireless transmit/receive unit (WTRU), the base station comprising:
- (a) a WTRU time scheduler;
(b) an allocation information memory electrically coupled to the WTRU time scheduler for receiving allocation information from the WTRU time scheduler; and
(c) a processor electrically coupled to the memory, wherein the processor allocates at least one cluster of sub-carriers to the WTRU by performing at least one of a pilot sub-carrier allocation function, a consecutive sub-carrier allocation (CSA) function and a distributed sub-carrier allocation (DSA) function.
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Accused Products
Abstract
In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and at least one wireless transmit/receive unit (WTRU), sub-carriers are allocated for data transmissions to multiple access WTRUs, where sub-carriers are allocated according to a consecutive sub-carrier allocation (CSA) type and a distributed sub-carrier allocation (DSA) type. Pilot signals with distributed pilot sub-carriers are transmitted and measured at each WTRU to obtain a channel quality metric for each pilot sub-carrier. Each WTRU sends feedback to the base station reporting channel quality based on the measured channel quality metrics. An allocation type is selected and adaptively switched according to channel variations in time and frequency domain.
67 Citations
31 Claims
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1. A base station which operates in an orthogonal frequency division multiple access (OFDMA) system including at least one wireless transmit/receive unit (WTRU), the base station comprising:
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(a) a WTRU time scheduler;
(b) an allocation information memory electrically coupled to the WTRU time scheduler for receiving allocation information from the WTRU time scheduler; and
(c) a processor electrically coupled to the memory, wherein the processor allocates at least one cluster of sub-carriers to the WTRU by performing at least one of a pilot sub-carrier allocation function, a consecutive sub-carrier allocation (CSA) function and a distributed sub-carrier allocation (DSA) function. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and a plurality of wireless transmit/receive units (WTRUs), a hybrid sub-carrier allocation method for data transmissions to multiple access WTRUs, the method comprising:
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(a) the plurality of WTRUs receiving data and pilot sub-carriers from the base station;
(b) the base station determining whether each WTRU has a large or small frequency domain variation;
(c) the base station determining whether each WTRU has a fast or slow time domain variation; and
(d) the base station determining whether to implement a distributed sub-carrier allocation (DSA) or a consecutive sub-carrier allocation (CSA) based on the determinations of steps (b) and (c). - View Dependent Claims (10)
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11. In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and a plurality of wireless transmit/receive units (WTRUs), a hybrid sub-carrier allocation method for data transmissions to multiple access WTRUs, where sub-carriers are allocated according to a first sub-carrier allocation type and a second sub-carrier allocation type, the method comprising:
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transmitting a pilot signal with distributed pilot sub-carriers;
measuring at each WTRU a channel quality metric for each pilot sub-carrier;
sending feedback from each WTRU to the base station reporting a channel quality indicator (CQI) based on the measured channel quality metrics; and
selecting either the first or the second sub-carrier allocation type for each individual WTRU based on the CQI. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. The method of claim 20 wherein F_large>
- F_small.
- View Dependent Claims (21)
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22. In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and a plurality of wireless transmit/receive units (WTRUs), a hybrid sub-carrier allocation method for data transmissions to multiple access WTRUs, the method comprising:
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(a) the plurality of WTRUs receiving data and pilot sub-carriers from the base station;
(b) each of the WTRUs performing channel quality measurements and sending feedback information to the base station based on the channel quality measurements;
(c) the base station determining whether each WTRU has a large or small frequency domain variation, Vf, based on the feedback information; and
(d) the base station determining whether each WTRU has a fast or slow time domain variation, Vt, based on the feedback information. - View Dependent Claims (23, 24)
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25. In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and at least one wireless transmit/receive unit (WTRU), a method comprising:
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(a) the WTRU receiving data and pilot sub-carriers from the base station;
(b) the WTRU measuring a variation of channel quality of at least one of the pilot sub-carriers in time domain to determine a time variation, Vt;
(c) the WTRU measuring a variation of channel qualities between the pilot sub-carriers at a time instance to determine a frequency variation, Vf; and
(d) the WTRU autonomously taking an action based on the values of Vt and Vf. - View Dependent Claims (26)
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27. In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and at least one wireless transmit/receive unit (WTRU), a method comprising:
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(a) the WTRU receiving data and pilot sub-carriers from the base station;
(b) the WTRU measuring a variation of channel quality of at least one of the pilot sub-carriers in time domain to determine a time variation, Vt;
(c) the WTRU measuring a variation of channel qualities between the pilot sub-carriers at a time instance to determine a frequency variation, Vf; and
(d) the WTRU reporting information derived from Vt and Vf to the base station. - View Dependent Claims (28, 29, 30, 31)
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Specification