Digital data receiver for edge cellular standard with DC offset correction, channel impulse response estimation, I/Q phase imbalance compensation, interference estimation, and selective equalization

1. A method of performing operations of a digital receiver unit comprising:

receiving data and storing the data in a sample buffer;

computing an average of the sampled data in said sample buffer so as to aid in estimating an initial DC offset of said sampled data;

subtracting said initial DC offset from said sampled data to form a second set of data;

performing an I/Q phase imbalance estimation and correction on said second set of data to form an third data set;

performing a joint DC offset and channel impulse response (CIR) estimation on said third data set and subtracting said DC offset to form a fourth data set;

performing an estimation of the number and position of the remaining CIR taps with respect to the largest energy tap associated with the fourth data set to form a fifth data set;

performing an estimation of the interference associated with said fifth data set so as to suppress adjacent channel interference (ACI) and co-channel interference (CCI);

performing a filtering operation to remove the interference in accordance with whether said fifth data set is associated with ACI or CCI interference to form a sixth data set;

performing a channel impulse response estimation on said sixth data set to form a seventh data set; and

computing the CIR length and SNR value of said seventh data set so as to determine which of at least two low complexity equalization modules are used for processing.

2. The method of claim 1 , wherein said I/Q phase imbalance estimation is defined as

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where I and Q are said data stored in said sample buffer.

3. The method of claim 1 , wherein said channel impulse response estimation comprises a timing estimation obtained by cross-correlation with midamble, including position of the main tap of channel impulse response.

4. The method of claim 1 , wherein said channel impulse response estimation comprises unknown composite channel taps estimation, number of taps, signal to noise ratio in a burst and quality indicator in the burst.

5. The method of claim 1 , wherein said channel impulse response estimation is conducted jointly with DC offset estimation to ensure necessary quality of the DC offset estimate for a 8-PSK signal.

6. The method of claim 1 , wherein suppression of said ACI interference comprises utilizing an estimated 2-tap whitening filter to form a filtered signal.

7. The method of claim 1 , wherein suppression of said CCI interference comprises utilizing a fixed 2-tap IIR or tweak filter to formed a filtered signal.

8. The method of claim 6 , wherein suppression of said ACI interference comprises performing a channel impulse estimation on said filtered signal.

9. The method of claim 7 , wherein suppression of said CCI interference comprises performing a channel impulse estimation on said filtered signal.

10. A method of performing operations of a digital receiver unit comprising:

receiving data and storing the data in a sample buffer;

computing an average of the sampled data in said sample buffer so as to aid in estimating an initial DC offset of said sampled data;

subtracting said initial DC offset from said sampled data to form a second set of data;

performing an I/Q phase imbalance estimation and compensation on said second set of data to form an third data set;

performing an estimation of the interference associated with said third data set so as to suppress adjacent channel interference (ACI) and co-channel interference (CCI) to form a fourth data set;

performing a filtering operation to remove the interference in accordance with whether said fourth data set is associated with ACI or CCI interference to form a fifth data set;

performing a channel impulse response estimation on said fifth data set to form a sixth data set; and

computing the CIR length and SNR value of said sixth data set so as to determine which of at least two low complexity equalization modules are used for processing.

11. The method of claim 10 , wherein said I/Q phase imbalance estimation is defined as

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where I and Q are said data stored in said sample buffer.

12. The method of claim 10 , wherein suppression of said ACI interference comprises utilizing an estimated 2-tap whitening filter to form a filtered signal.

13. The method of claim 10 , wherein suppression of said CCI interference comprises utilizing a fixed 2-tap IIR or tweak filter to formed a filtered signal.

14. The method of claim 12 , wherein suppression of said ACI interference comprises performing a channel impulse estimation on said filtered signal.

15. The method of claim 13 , wherein suppression of said CCI interference comprises performing a channel impulse estimation on said filtered signal.