Energy-Detection UWB Receivers with Multiplel Energy Measurements

1. Energy-Detection UWB Receivers with Multiplel Energy Measurements E. Arias-de-Reyna Department of SP and Communications University of Seville Spain A.A.D’Amico and U.Mengali Department of Information Engineering University of Pisa Italy UWB4SN 2005, Lausanne

2. Outline • Conventional Energy-Detection (ED) Receiver • Comparisons with other schemes • Improved ED Receiver • Performance evaluation • Conclusions

3. noise a =0 a a K-1 =1 =1 K K+1 Optimal decision strategy (1/2) t Assumptions • Channel Response (CR) is unknown • Perfect synchronization Problem Joint estimation of CR and data symbols

4. noise t r (t) r (t) 2 2 r(t) x 0 y 0 x x 0 0 > . 2 0 if a = k y < 1 if 0 y 0 Solution

5. “1” “o” . UWB channel Compare T b synch 2 ( ) Conventional ED Receiver A.Rabbachin and I.Oppermann, UWBST, 2004 M.Weisenhorn and W.Hirt, UWBST, 2004 C.Carbonelli and U.Mengali, TWC 2005/06

6. T s +1 +1 -1 D t Transmitted reference (TR)

7. T -1 s -1 +1 t Differential transmitted reference (DTR)

8. Performance comparisons ED/TR DTR

9. . Compare ED synch 2 ( ) TR/DTR synch D Complexity comparisons

10. r (t) r (t) 2 2 x x x 0 N-1 0   t t   y y y N-1 0 0 x x x x y y n 0 n n 0 n > 0 if > 0 if a = a = k k y < 1 if 0 y < 1 if 0 Small energy chips

11. r (t) 2 t x s s x N-1 0 0 N-1 s t x y y y 0 N-1 Problem: Given , what is the optimal decision strategy based on the observation of and ? s y x Side information

12. a =0 k s y p( , | ) x s y p( , | ) x y s x y s s x s n n n n n n n n > 0 if a = k a =1, a =0, a =1 k k k     < 1 if Optimal decision strategy Optimal Approximation (energy correlation)

13. s k “1” “o” . UWB channel Compare 2 ( ) synch T b Improved ED receiver

14. conventional conventional improved improved 2 dB 2 dB Performance (1/3)

15. Performance (2/3)

16. s s estimated k k known Performance (3/3)

17. “1” r(t) “o” A function of and 2 ( ) w(t) 2 2  (t)  (t)  0 T b . UWB channel Compare synch Another approach (Weisenhorn and Hirt, ICUW, Sept. 2005) Problem: Given and the channel average power-delay profile , which is the ML decision rule?

18. ED WH method WH method Improved Improved Performance comparisons ED

19. noise y T T s s x x k b b k k k k y k = E{ - } k-th bins Estimation of s (1/2)

20. t s y s x x (n) (n) k k k k k y (0) x (0) x y (1) (1) y (N-1) x (N-1) k k k k k k N-1 S y 1 k K=0 ^ N = E{ - } = - Estimation of s (2/2)

21. Conclusions • Pros: • Improved performance over conventional ED • Automatic adaptation to channel statistics • Cons: • Higher complexity (sampling rate)