Base station assisted frequency domain equalization
A method for wireless communication is described. The method includes receiving a burst that includes controlled sequence symbols transmitted in a guard period. The controlled sequence symbols include the last predetermined number symbols of a training sequence. The burst is demodulated based on the controlled sequence symbols. Other aspects, embodiments, and features are also claimed and described.
1. A method for wireless communication, comprising:
receiving a burst that comprises controlled sequence symbols, wherein:
the burst comprises a first guard period, first data, a training sequence, second data, and a second guard period,
a first predetermined number of first symbols of the training sequence are the same as the first predetermined number of last symbols of the training sequence,
a first half of the burst comprises the first guard period, the first data, and the first predetermined number of first symbols of the training sequence, the first guard period being included at the beginning of the first half of the burst and the first data being between the first guard period and the training sequence,
a second half of the burst comprises a second predetermined number of last symbols of the training sequence, the second data, and the second guard period, the second guard period being included at the end of the second half of the burst and the second data being between the training sequence and the second guard period,
the controlled sequence symbols comprise the second predetermined number of last symbols of the training sequence,
the first predetermined number is greater than the second predetermined number, and
the first guard period and the second guard period comprise the controlled sequence symbols; and
demodulating the burst based on the controlled sequence symbols.
2. The method of claim 1 , wherein the second predetermined number is in the range of 1 to 8.
3. The method of claim 1 , wherein the controlled sequence symbols in the first guard period are used as a cyclic prefix for the first half of the burst.
4. The method of claim 3 , wherein the cyclic prefix comprises an orthogonal frequency division multiplexing cyclic prefix.
5. The method of claim 1 , wherein the burst is received as a Global System for Mobile Communications transmission.
6. The method of claim 1 , wherein the demodulating comprises performing a frequency domain equalization.
7. The method of claim 6 , wherein the frequency domain equalization is performed based on a circular convolution.
8. The method of claim 1 , wherein the demodulating is performed by an orthogonal frequency division multiplexing receiver.
9. The method of claim 1 , wherein the demodulating is based on forward regression and backward regression.
10. The method of claim 1 , wherein the demodulating comprises determining a bit state probability for each received bit based on all received bits.
11. The method of claim 1 , further comprising decoding the demodulated burst.
12. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, the instructions being executable by the processor to:
receive a burst that comprises controlled sequence symbols, wherein:
the burst comprises a first guard period, first data, a training sequence, second data, and a second guard period,
a first predetermined number of first symbols of the training sequence are the same as the first predetermined number of last symbols of the training sequence,
a first half of the burst comprises the first guard period, the first data, and the first predetermined number of first symbols of the training sequence, the first guard period being included at the beginning of the first half of the burst and the first data being between the first guard period and the training sequence,
a second half of the burst comprises a second predetermined number of last symbols of the training sequence, the second data, and the second guard period, the second guard period being included at the end of the second half of the burst and the second data being between the training sequence and the second guard period,
the controlled sequence symbols comprise the second predetermined number of last symbols of the training sequence,
the first predetermined number is greater than the second predetermined number, and
the first guard period and the second guard period comprise the controlled sequence symbols; and
demodulate the burst based on the controlled sequence symbols.
13. The apparatus of claim 12 , wherein the second predetermined number is in the range of 1 to 8.
14. The apparatus of claim 12 , wherein the controlled sequence symbols in the first guard period are used as a cyclic prefix for the first half of the burst.
15. The apparatus of claim 14 , wherein the cyclic prefix comprises an orthogonal frequency division multiplexing cyclic prefix.
16. The apparatus of claim 12 , wherein the instructions executable to demodulate comprise instructions executable to perform frequency domain equalization.
17. The apparatus of claim 16 , wherein the frequency domain equalization is performed based on a circular convolution.
18. The apparatus of claim 12 , wherein the instructions executable to demodulate comprise instructions executable to determine a bit state probability for each received bit based on all received bits.
19. A wireless device comprising:
means for receiving a burst that comprises controlled sequence symbols, wherein:
the burst comprises a first guard period, first data, a training sequence, second data, and a second guard period,
a first predetermined number of first symbols of the training sequence are the same as the first predetermined number of last symbols of the training sequence,
a first half of the burst comprises the first guard period, the first data, and the first predetermined number of first symbols of the training sequence, the first guard period being included at the beginning of the first half of the burst and the first data being between the first guard period and the training sequence,
a second half of the burst comprises a second predetermined number of last symbols of the training sequence, the second data, and the second guard period, the second guard period being included at the end of the second half of the burst and the second data being between the training sequence and the second guard period,
the controlled sequence symbols comprise the second predetermined number of last symbols of the training sequence,
the first predetermined number is greater than the second predetermined number, and
the first guard period and the second guard period comprise the controlled sequence symbols; and
means for demodulating the burst based on the controlled sequence symbols.
20. The wireless device of claim 19 , wherein the controlled sequence symbols in the first guard period are used as a cyclic prefix for the first half of the burst.
21. The wireless device of claim 20 , wherein the second predetermined number is in the range of 1 to 8.
22. The wireless device of claim 19 , wherein the means for demodulating comprise means for performing frequency domain equalization.
23. A non-transitory computer-readable medium having instructions thereon, the instructions comprising:
code for causing a wireless communication device to receive a burst that comprises controlled sequence symbols, wherein:
the burst comprises a first guard period, first data, a training sequence, second data, and a second guard period,
a first predetermined number of first symbols of the training sequence are the same as the first predetermined number of last symbols of the training sequence,
a first half of the burst comprises the first guard period, the first data, and the first predetermined number of first symbols of the training sequence, the first guard period being included at the beginning of the first half of the burst and the first data being between the first guard period and the training sequence,
a second half of the burst comprises a second predetermined number of last symbols of the training sequence, the second data, and the second guard period, the second guard period being included at the end of the second half of the burst and the second data being between the training sequence and the second guard period,
the controlled sequence symbols comprise the second predetermined number of last symbols of the training sequence,
the first predetermined number is greater than the second predetermined number, and the first guard period and the second guard period comprise the controlled sequence symbols; and
code for causing the wireless communication device to demodulate the burst based on the controlled sequence symbols.
24. The non-transitory computer-readable medium of claim 23 , wherein the second predetermined number is in the range of 1 to 8.
25. The non-transitory computer-readable medium of claim 23 , wherein the controlled sequence symbols in the first guard period are used as a cyclic prefix for the first half of the burst.
26. The non-transitory computer-readable medium of claim 23 , wherein the code for causing the wireless communication device to demodulate comprises code for causing the wireless communication device to perform frequency domain equalization.