Method of compensating for energy loss and eliminating inter-symbol interference and inter-chip interference and rake receiver for WLAN adopting the same

1. A rake receiver for a wireless local area network comprising:

an inter-chip interference detector detecting inter-chip interference information of a symbol based on first correlation values extracted from a received symbol stream and outputting the inter-chip interference information;

a code determination unit extracting a peak of a symbol from second correlation values extracted from the received symbol stream and inter-symbol interference information of a previous symbol and outputting code data corresponding to the peak; and

an inter-symbol interference detector detecting the inter-symbol interference information of the previous symbol using the code data.

2. The rake receiver of claim 1 , wherein the received symbol stream is composed of complementary code keying symbols.

3. The rake receiver of claim 2 , wherein each of the complementary code keying symbols is composed of eight chips.

4. The rake receiver of claim 1 , wherein the code data is eight bit complementary code keying data.

5. The rake receiver of claim 1 , further comprising:

a channel matched filter receiving the received symbol stream, match filtering the received symbol stream, and outputting a matched filtered signal;

an equalizer receiving the matched filtered signal, performing distortion compensation, and outputting a distortion compensated signal; and

a first correlator receiving the distortion compensated signal, calculating and outputting the first correlation values.

6. The rake receiver of claim 5 , wherein the equalizer comprises:

a feed forward filter filtering the matched filtered signal and outputting a first finite impulse response filtered signal;

a subtracting unit subtracting a second finite impulse response filtered signal from the first finite impulse response filtered signal and outputting the distortion compensated signal;

a chip determination unit determining a logic state of each bit value of the distortion compensated signal and outputting a digital signal based on the determined logic state value; and

a feed back filter filtering the digital signal and outputting the second finite impulse response filtered signal.

7. The rake receiver of claim 6 , wherein each of the feed forward filter and the feed back filter delays an input signal by a predetermined sampling of time, generates delayed signals, multiplies each of the delayed signals by predetermined coefficients, adds the multiplied signals, and outputs the result.

8. The rake receiver of claim 1 , further comprising

a delay unit delaying a matched filtered signal for a predetermined period of time and outputting a delayed signal;

a first subtracting unit subtracting interference information from the delayed signal and outputting a subtracted signal;

a correlator receiving the subtracted signal from the subtracting unit, and calculating and outputting second correlation values; and

an adding unit adding the inter-chip interference information and the inter-symbol interference information of the previous symbol and outputting the result as the interference information.

9. The rake receiver of claim 8 , wherein the predetermined period of time is a period of one symbol.

10. A method of compensating for energy loss and eliminating inter-symbol interference and Inter-chip interference in a rake receiver for a wireless local area network, the method comprising;

detecting inter-chip interference information of a symbol based on first correlation values extracted from a received symbol stream;

extracting a peak of a symbol from second correlation values extracted from the received symbol stream and inter-symbol interference information of a previous symbol and generating code data corresponding to the peak; and

detecting the inter-symbol interference information of the previous symbol using the code.

11. The method of claim 10 , wherein the received symbol stream is composed of complementary code keying symbols.

12. The rake receiver of claim 11 , wherein each of the complementary code keying symbols is composed of eight chips.

13. The rake receiver of claim 10 , wherein the code data is eight bit complementary code keying data.

14. The method of claim 10 , further comprising:

match filtering the received symbol stream;

performing distortion compensation on the match-filtered signal; and

calculating the first correlation values from the distortion compensated signal.

15. The method of claim 14 , wherein the distortion compensation comprises:

filtering the matched filtered signal, thereby generating a first finite impulse response filtered signal;

subtracting a second finite impulse response filtered signal from the first finite impulse response filtered signal, thereby generating the distortion compensated signal;

determining a logic state of each bit value of the distortion compensated signal and generating a digital signal having the determined logic state values; and

filtering the digital signal, thereby generating a second finite impulse response filtered signal.

16. The method of claim 15 , wherein each of the first finite impulse response filtering and the second finite impulse response filtering comprises delaying an input signal by a predetermined sampling of time, generating delayed signals, multiplying each of the delayed signals by predetermined coefficients, and adding the multiplied signals.

17. The method of claim 10 , further comprising:

delaying the matched filtered signal for a predetermined period of time;

subtracting interference information from the delayed signal;

calculating second correlation values based on the subtracted signal; and

adding the inter-chip interference information and the inter-symbol interference information of the previous symbol and the result as the interference information.

18. The method of claim 17 , wherein the predetermined period of time is a period of one symbol.