Telescoping window based equalization

• US 7,400,692 B2
• Filed: 12/20/2004
• Issued: 07/15/2008
• Est. Priority Date: 01/14/2004
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Reznik, Alexander
• Primary Examiner(s): Bocure; Tesfaldet
• Application Number:
  US11/018,097
• Publication Number:
  US 20050152295A1
• Time in Patent Office: 1,303 Days
• Field of Search: 375/316, 375/340, 375/343, 375/130, 375/140, 375/142, 375/144, 375/147, 375/148, 375/150, 370/335, 370/441, 370/342
• US Class Current: 375/316
• CPC Class Codes: H04B 1/7105 Joint detection techniques, e.g. linear detectors
• CPC Class Codes: H04B 2201/709727 GRAKE type RAKE receivers
• CPC Class Codes: H04L 2025/03375 Passband transmission
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference

Abstract

At least one wireless communication is received and sampled to produce samples. A channel response is estimated corresponding to the at least one wireless communication. An initial channel correlation matrix is produced based on the received samples and the channel response. The initial channel correlation matrix is factorized to produce a Cholesky factor. Forward substitution is performed using the Cholesky factor and received samples to produce initial values for the at least one wireless communication. The Cholesky factor is updated using additional channel correlation matrix values, producing an updated Cholesky factor. Subsequent values for the at least one wireless communication are produced using the updated Cholesky factor.

Claims

1. A method comprising:

receiving at least one wireless communication and sampling the received wireless communication producing samples;

estimating a channel response corresponding to the samples of the at least one wireless communication;

producing an initial channel correlation matrix based on the received samples and the channel response;

factorizing the initial channel correlation matrix to produce a Cholesky factor;

performing forward substitution using the Cholesky factor and received samples to produce initial values for the at least one wireless communication;

updating the Cholesky factor using additional channel correlation matrix values producing an updated Cholesky factor; and

producing subsequent values for the at least one wireless communication using the updated Cholesky factor.

2. The method of claim 1 further comprising performing backward substitution on a result of the forward substitution to produce the initial values for the at least one wireless communication.

3. The method of claim 1 wherein the initial and subsequent values are spread symbols and the spread symbols are despread to produce soft symbols of the at least one communication.

4. The method of claim 1 wherein the initial and subsequent values are soft symbols.

5. The method of claim 1 wherein the producing subsequent values is sequentially performed so that only one subsequent value is produced at a time.

6. The method of claim 1 wherein backward substitution is not performed to detect symbols of the at least one communication.

7. A wireless transmit/receive unit (WTRU) comprising:

an antenna or antenna array for receiving at least one wireless communication;

a sampling device configured to receive the at least one wireless communication and produce samples of the at least one received wireless communication;

a channel estimation device for estimating a channel response corresponding to the samples of the at least one wireless communication;

a channel correlation computation device configured to receive the channel response and produce an initial channel correlation matrix and update values for the initial channel correlation matrix;

a Cholesky decomposition device configured to receive the initial channel correlation matrix and produce an initial Cholesky factor;

a forward substitution device configured to receive initial samples of the samples and the initial Cholesky factor and perform forward substitution and producing initial values of the at least one wireless communication;

a Cholesky factor update device configured to receive the update values for the initial channel correlation matrix and the initial Cholesky factor and produce values of an updated Cholesky factor;

a forward substitution update device for receiving the updated Chole sky factor and a result of the forward substitution device and produce subsequent values of the at least one communication.

8. The WTRU of claim 7 further comprising a backward substitution device configured to receive an output of the forward substitution device, an output of the forward substitution update device, the initial Cholesky factor and the updated Cholesky factor and perform backward substitution.

9. A base station comprising:

an antenna or antenna array for receiving at least one wireless communication;

a sampling device configured to receive the at least one wireless communication and produce samples of the at least one received wireless communication;

a channel estimation device for estimating a channel response corresponding to the samples of the at least one wireless communication;

a channel correlation computation device configured to receive the channel response and produce an initial channel correlation matrix and update values for the initial channel correlation matrix;

a Cholesky decomposition device configured to receive the initial channel correlation matrix and produce an initial Cholesky factor;

a forward substitution device configured to receive initial samples of the samples and the initial Cholesky factor and perform forward substitution and producing initial values of the at least one wireless communication;

a Cholesky factor update device configured to receive the update values for the initial channel correlation matrix and the initial Cholesky factor and produce values of an updated Cholesky factor;

a forward substitution update device for receiving the updated Cholesky factor and a result of the forward substitution device and produce subsequent values of the at least one communication.

10. The base station of claim 9 further comprising a backward substitution device configured to receive an output of the forward substitution device, an output of the forward substitution update device, the initial Cholesky factor and the updated Cholesky factor and perform backward substitution.

11. An integrated circuit comprising:

an input configured to receive samples of at least one wireless communication;

a channel estimation device for estimating a channel response corresponding to the samples of the at least one wireless communication;

a channel correlation computation device configured to receive the channel response and produce an initial channel correlation matrix and update values for the initial channel correlation matrix;

a Cholesky decomposition device configured to receive the initial channel correlation matrix and produce an initial Cholesky factor;

a forward substitution device configured to receive initial samples of the samples and the initial Cholesky factor and perform forward substitution and producing initial values of the at least one wireless communication;

a Cholesky factor update device configured to receive the update values for the initial channel correlation matrix and the initial Cholesky factor and produce values of an updated Cholesky factor;

a forward substitution update device for receiving the updated Cholesky factor and a result of the forward substitution device and produce subsequent values of the at least one communication.

12. The integrated circuit of claim 11 further comprising a backward substitution device configured to receive an output of the forward substitution device, an output of the forward substitution update device, the initial Cholesky factor and the updated Cholesky factor and perform backward substitution.