Generating method for short training field in IEEE 802.11n communication systems
View Patent ↗The present invention discloses a generating method for short training field in IEEE 802.11n communication systems, mainly comprising the steps of: storing only a first set of time-domain HT-STF sequences in the memory; and deriving a second set of the time-domain HT-STF sequences from the first set of the time-domain HT-STF sequences. The first set of time-domain HT-STF sequences is the time-domain HT-STF sequences either for lower 20 MHz of 40 MHz BW or upper 20 MHz of 40 MHz BW. According to the invention, it is shown that only one set of time-domain HT-STF sequence needs to be stored in the memory. The other three sets of time-domain HT-STF sequence can be generated easily from simple calculation. Therefore, the saving in buffer size to implement all four configurations is significant.
1. A generating method for short training field in IEEE 802.11n communication systems, comprising the steps of:
storing only a first set of time-domain High-Throughput Short Training Field (HT-STF) sequences in a memory; and
deriving a second set of the time-domain HT-STF sequences from the first set of the time-domain HT-STF sequences;
wherein the first set of time-domain HT-STF sequences is a time-domain HT-STF sequences (y n ) for lower 20 MHz of 40 MHz bandwidth (BW) configuration, based on the relation as
y
n
=
1
128
∑
k
=
-
64
63
Y
k
W
128
-
nk
;
where
W
128
=
ⅇ
-
j2π
/
128
;
n
=
0
,
1
,
2
,
…
31
;
wherein j is √{square root over (−1)} and Y k is a first set of frequency-domain HT-STF sequences (Y k ) for lower 20 MHz of 40 MHz BW configuration defined as:
Y −64,63 =√{square root over (1/2)}{0,0,0,0,0,0,0,0,1+ j ,0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,−1− j, 0,0,0,−1− j, 0,0,0,1+ j, 0,0,0, 0,0,0,0,−1− j, 0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,1+ j, 0,0,0,1+ j ,0,0,0,1+ j ,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}.
2. The generating method as claimed in claim 1 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (z n ) for upper 20 MHz of 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as z n =(−1) n y n ; n=0, 1, 2, 3, . . . , 31.
3. The generating method as claimed in claim 1 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (x n ) for 20 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as x n =2(−1) n y 2n ; n=0, 1, 2, 3, . . . , 15.
4. The generating method as claimed in claim 1 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (g n ) for 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as g n =[1+j(−1) n ]y n ; n=0, 1, 2, . . . , 31.
5. A generating method for short training field in IEEE 802.11n communication systems, comprising the steps of:
storing only a first set of time-domain High-Throughput Short Training Field (HT-STF) sequences in a memory; and
deriving a second set of the time-domain HT-STF sequences from the first set of the time-domain HT-STF sequences;
wherein the first set of time-domain HT-STF sequences is a time-domain HT-STF sequences (y n ) for lower 20 MHz of 40 MHz bandwidth (BW) configuration, based on the relation as
y
n
=
1
256
∑
k
=
-
128
127
Y
k
W
256
-
nk
;
where
W
256
=
ⅇ
-
j2π
/
256
;
n
=
0
,
1
,
2
,
…
63
wherein j is √{square root over (−1)} and Y k is the first set of frequency-domain HT-STF sequences (Y k ) for the lower 20 MHz of 40 MHz BW configuration defined as:
Y −64,63 =√{square root over (1/2)}{0,0,0,0,0,0,0,0,1+ j ,0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,−1− j, 0,0,0,−1− j, 0,0,0,1+ j, 0,0,0, 0,0,0,0,−1− j, 0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,1+ j, 0,0,0,1+ j ,0,0,0,1+ j ,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}.
6. The generating method as claimed in claim 5 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (z n ) for upper 20 MHz of 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as z n =(j) n y n ; n=0, 1, 2, . . . 63.
7. The generating method as claimed in claim 5 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (x n ) for 20 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as x n =2(j) n y 2n ; n=0, 1, 2, 3, . . . , 31.
8. The generating method as claimed in claim 5 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (g n ) for 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as g n =[1+(j) n+1 ]y n ; n=0, 1, 2, . . . , 63.
9. A generating method for short training field in IEEE 802.11n communication systems, comprising the steps of:
storing only a first set of time-domain High-Throughput Short Training Field (HT-STF) sequences in a memory; and
deriving a second set of the time-domain HT-STF sequences from the first set of the time-domain HT-STF sequences;
wherein the first set of time-domain HT-STF sequences is a time-domain HT-STF sequences (z n ) for upper 20 MHz of 40 MHz BW configuration, based on the relation as
z
n
=
1
128
∑
k
=
-
64
63
Z
k
W
128
-
nk
=
1
128
∑
k
=
0
63
Z
k
W
128
-
nk
;
n
=
0
,
1
,
2
,
…
31
;
wherein j is √{square root over (−1)} and Z k is the frequency-domain HT-STF sequences for upper 20 MHz of 40 MHz BW configuration defined as:
Z −64,63 =√{square root over (1/2)}{0,0,0,0,0,0,0,0,1+ j ,0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,−1− j, 0,0,0,−1− j, 0,0,0,1+ j, 0,0,0, 0,0,0,0,−1− j, 0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,1+ j, 0,0,0,1+ j ,0,0,0,1+ j ,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}.
10. The generating method as claimed in claim 9 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (y n ) for lower 20 MHz of 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as y n =(−1) n z n ; n=0, 1, 2, 3, . . . , 31.
11. The generating method as claimed in claim 9 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (x n ) for 20 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as x n =2(−1) n z 2n ; n=0, 1, 2, 3, . . . , 15.
12. The generating method as claimed in claim 9 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (g n ) for 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as g n =[(−1) n +j]z n ; n=0, 1, 2, . . . , 31.
13. A generating method for short training field in IEEE 802.11n communication systems, mainly comprising the steps of:
storing only a first set of time-domain High-Throughput Short Training Field (HT-STF) sequences in a memory; and
deriving a second set of the time-domain HT-STF sequences from the first set of the time-domain HT-STF sequences;
wherein the first set of time-domain HT-STF sequences is a time-domain HT-STF sequences (Z n ) for upper 20 MHz of 40 MHz BW configuration, based on the relation as
z
n
=
1
256
∑
k
=
-
128
127
Z
k
W
256
-
nk
=
1
256
∑
k
=
0
63
Z
k
W
256
-
nk
;
n
=
0
,
1
,
2
,
…
63
;
wherein j is √{square root over (−1)} and Z k is the frequency-domain HT-STF sequences for upper 20 MHz of 40 MHz BW configuration defined as:
Z −64,63 =√{square root over (1/2)}{0,0,0,0,0,0,0,0,1+ j ,0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,−1− j, 0,0,0,−1− j, 0,0,0,1+ j, 0,0,0, 0,0,0,0,−1− j, 0,0,0,−1− j ,0,0,0,1+ j, 0,0,0,1+ j, 0,0,0,1+ j ,0,0,0,1+ j ,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}.
14. The generating method as claimed in claim 13 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (y n ) for lower 20 MHz of 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as y n =(−j) n z n ; n=0, 1, 2, . . . 63.
15. The generating method as claimed in claim 13 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (x n ) for 20 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as x n =2(−j) n z 2n ; n=0, 1, 2, 3, . . . , 31.
16. The generating method as claimed in claim 13 , wherein the second set of time-domain HT-STF sequences is the time-domain HT-STF sequences (g n ) for 40 MHz BW configuration and the step of deriving the second set of time-domain HT-STF sequences is based on the relation as g n =[(−j) n +j]z n ; n=0, 1, 2, . . . , 63.