Pilot transmission and channel estimation for an OFDM system with excess delay spread
AssigneeQUALCOMM Incorporated
InventorsDhananjay Ashok Gore, Avneesh Agrawal
Life of this patent
Estimating the term…
Abstract
Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one example, a first set of pilot subands may be received in a first symbol period, and a second set of pilot subands may be received in a second symbol period. The first set of pilot subands and the second set of pilot subbands may be staggered in frequency.
Claims33
A method for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- transmitting a first set of pilot subbands in a first symbol period;
- and
- transmitting a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve over sampling in the frequency domain.
An apparatus for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- at least one processor configured to transmit a first set of pilot subbands in a first symbol period, and to transmit a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and
- wherein the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain;
- and
- a memory coupled to the at least one processor.
An apparatus for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- means for transmitting a first set of pilot subbands in a first symbol period;
- and
- means for transmitting a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain.
A computer program product, comprising a computer readable medium, for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- code for causing at least one computer to transmit a first set of pilot subbands in a first symbol period, and
- code for causing the at least one computer to transmit a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilots subbands are staggered in frequency, and the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain.
A method for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- receiving a first set of pilot subbands in a first symbol period;
- and
- receiving a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain.
An apparatus for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- at least one processor configured to receive a first set of pilot subbands in a first symbol period, and tp receive a second set of pilot subbands in a second symbol period, wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and wherein the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain;
- and
- a memory coupled to the at least one processor.
An apparatus for mitigating intersymbol interference and channel estimation errors in a wireless communication system, comprising:
- means for receiving a first set of pilot subbands in a first symbol period;
- and
- means for receiving a second set of pilot subbands in a second symbol period,
- wherein the first set of pilot subbands and the second set of pilot subbands are staggered in frequency, and the number of pilot subbands selected are greater than a cyclic prefix length (NPeff>Ncp) to achieve oversampling in the frequency domain.
Dependencies are inferred from the claim text.