Code division multiple access wireless system with closed loop mode using ninety degree phase rotation and beamformer verification
First Claim
1. A method of producing a phase angle in a wireless receiver, comprising the steps of:
- receiving a known signal corresponding to one of an even and an odd time slot from a remote transmitter;
calculating a measurement having real and imaginary parts corresponding to the known signal;
determining the phase angle is 0 when the real part of the measurement is positive in an even time slot;
determining the phase angle is π
when the real part of the measurement is negative in the even time slot;
determining the phase angle is π
/2 when the imaginary part of the measurement is positive in an odd time slot;
determining the phase angle is π
/2 when the imaginary part of the measurement is negative in the odd time slot; and
calculating a channel estimate from the remote transmitter in response to the phase angle.
2 Assignments
0 Petitions
Accused Products
Abstract
A wireless communication system (10). The system comprises a user station (12). The user station comprises despreading circuitry (22) for receiving and despreading a plurality of slots received from at least a first transmit antenna (A121) and a second transmit antenna (A122) at a transmitting station (14). Each of the plurality of slots comprises a first channel (DPCH) comprising a first set of pilot symbols and a second channel (PCCPCH) comprising a second set of pilot symbols. The user station further comprises circuitry (50) for measuring a first channel measurement (α1,n) for each given slot in the plurality of slots from the first transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (50) for measuring a second channel measurement (α2,n) for each given slot in the plurality of slots from the second transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (52) for measuring a phase difference value (φ2(n)) for each given slot in the plurality of slots in response to the first channel measurement and the second channel measurement for the given slot and in response to a ninety degree rotation of the given slot relative to a slot which was received by the despreading circuitry immediately preceding the given slot.
15 Citations
19 Claims
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1. A method of producing a phase angle in a wireless receiver, comprising the steps of:
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receiving a known signal corresponding to one of an even and an odd time slot from a remote transmitter; calculating a measurement having real and imaginary parts corresponding to the known signal; determining the phase angle is 0 when the real part of the measurement is positive in an even time slot; determining the phase angle is π
when the real part of the measurement is negative in the even time slot;determining the phase angle is π
/2 when the imaginary part of the measurement is positive in an odd time slot;determining the phase angle is π
/2 when the imaginary part of the measurement is negative in the odd time slot; andcalculating a channel estimate from the remote transmitter in response to the phase angle. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of calculating an estimated value in a wireless receiver, comprising the steps of:
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receiving at least one channel estimate; receiving a known signal corresponding to one of an even and odd time slot from a remote transmitter; calculating a product of the at least one channel estimate and the known signal, the product having real and imaginary parts; determining a phase angle is 0 when the real part of the product is positive in an even time slot; determining the phase angle is π
when the real part of the product is negative in the even time slot;determining the phase angle is −
π
/2 when the imaginary part of the product is positive in an odd time slot; anddetermining the phase angle is π
/2 when the imaginary part of the product is negative in the odd time slot. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A method of calculating an estimated value in a wireless receiver, comprising the steps of:
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receiving at least one channel estimate; receiving a known signal from a remote transmitter; calculating a product of the at least one channel estimate and the known signal; rotating the product by a plurality of phase angles, thereby producing a constellation of values, each value of the constellation of values having real and imaginary parts; detecting a maximum real part from the real part of each value of the constellation; and
producing the estimated value in response to the maximum real part. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification