Multistage reception of code division multiple access transmissions
First Claim
1. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station reciever, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
- interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by;
selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages;
demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, andperforming MUD cancellation on UE connections selected for MUD processing in the current stage; and
commanding transmit power for each UE connection, by;
determining a base target Eb/N0 as a function of at least one data quality metric (DQM);
estimating a received Eb/N0 for each UE connection, for each UE connection designated for MUD processing, adjusting the base target E0/N0 upward;
for each UB connection not designated for MUD processing, where the estimated Eb/N0 is less than the base target Eb/N0, commanding increased UE connection transmit power; and
for each UE connection designated for MUD processing, where the estimated Eb/N0 is less than the adjusted base target Eb/N0, commanding increased UE connection transmit power.
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Accused Products
Abstract
Reducing multiple access interference in the radio frequency communications path between the network base station and UE. The preferred methods include interleaving STAP and MUD in a plurality of stages in a base station receiver. Specific embodiments accomplish this by selecting certain UE connections for MUD processing by stage. Then, in two or more stages, demodulating the UE connections selected for MUD processing using STAP, and MUD canceling UE connections selected for MUD processing. Within the latency requirements of the network, preferred embodiments of the present invention also command a transmit power for each UE connections in order to exploit the effect of interleaved STAP and MUD processing.
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Citations
20 Claims
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1. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station reciever, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and
commanding transmit power for each UE connection, by;determining a base target Eb/N0 as a function of at least one data quality metric (DQM); estimating a received Eb/N0 for each UE connection, for each UE connection designated for MUD processing, adjusting the base target E0/N0 upward; for each UB connection not designated for MUD processing, where the estimated Eb/N0 is less than the base target Eb/N0, commanding increased UE connection transmit power; and for each UE connection designated for MUD processing, where the estimated Eb/N0 is less than the adjusted base target Eb/N0, commanding increased UE connection transmit power.
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2. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
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interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and commanding transmit power for each UE connection, by; determining a base target Eb/N0 as a function of at least one data quality metric (DQM); estimating a received Eb/N0 for each UE connection, estimating a STAP gain for each UE connection, and adjusting the base target Eb/N0 down by the amount of estimated STAP gain for each UE connection where the estimated Eb/N0 is less than the adjusted base target Eb/N0, commanding increased UE connection transmit power.
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3. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, by; calculating a global block-adaptive STAP covariance inverse for each stage, wherein a single covariance matrix inverse is used in calculating the filter weight vector for each UE connection; and performing MUD cancellation on UE connections selected for MUD processing in the current stage.
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4. In a communication network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second, plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and acquiring new UE connections after at least one stage of MUD cancellation. - View Dependent Claims (5)
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6. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communication is path between the base station and at least one UE, the method comprising:
Interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; wherein performing MUD cancellation further comprises group-wise subtractive interference cancellation. - View Dependent Claims (7)
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8. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
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interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; wherein performing MUD cancellation further comprises canceling each UE connection selected for canceling down to the ambient multiple access interference level of voice UE connections in the network.
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9. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by selected, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; wherein at least one UE connection is characterized by a target Eb/N0 at least equal to a corresponding threshold target Eb/N0, and wherein selecting UE connections for MUD processing by stage comprises estimating the multiple access interference contribution of each UE connection having a target Eb/N0 at least equal to the corresponding threshold target Eb/N0; and whereby UE connections characterized by a target Eb/N0 at least equal to a corresponding threshold target Eb/N0 are selected for MUD processing in order of descending multiple access interference contribution. - View Dependent Claims (10, 11, 12, 13)
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14. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage, wherein at least one UE connection is characterized by a target Eb/N0 less than a corresponding threshold target Eb/N0, and wherein selecting UE connections for MUD processing by stage comprises; increasing the target EWNo of at least one UE connection characterized by the lowest spreading factor from among the UE characterized by a target Eb/N0 less than a corresponding threshold target Eb/N0, by an amount sufficient to characterize the UE having an increased target Eb/N0 at least equal to a corresponding threshold target Eb/N0. - View Dependent Claims (15)
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16. In a communications network comprising a base station and a plurality of user equipment (UE), the network at least one radio frequency communications path between each UE and the base station, the best station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; wherein the set of UE connections selected for MUD processing in a first stage of MUD processing are characterized by a range of target Eb/N0 not greater than 3 dB.
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17. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communication path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, by; multiplexing a plurality of UE connections into an aggregate UE connection, and performing MUD cancellation on the aggregate UE connection as on a non-aggregate user system connection; and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage.
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18. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at east one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and after a last said stage, demodulating remaining UE connections.
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19. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a first plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulating STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and if no high data rate UE connections then command one or more low rate burst-enabled UE to sequentially burst at higher data rates.
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20. In a communications network comprising a base station and a plurality of user equipment (UE), the network having at least one radio frequency communications path between each UE and the base station, the base station comprising a plurality of antennas and at least one base station receiver, a method of reducing multiple access interference in at least one radio frequency communications path between the base station and at least one UE, the method comprising:
interleaving space-time adaptive processing (STAP) and multi-user detection (MUD) in a plurality of stages in a base station receiver, by; selecting at least one UE connection for MUD processing by stage, and in a second plurality of stages; demodulating the UE connections selected for MUD processing in a current stage, the demodulation employing STAP, and performing MUD cancellation on UE connections selected for MUD processing in the current stage; and estimating the amount of cancellation on each MUD candidate by computing the difference between; symbol estimates used at the MUD processor and symbol estimates estimated post-FEC decoding.
Specification