Interleaving circuit for a multiband OFDM transceiver

1. Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of an ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (N CBPS ) of encoded bits, said interleaving circuit comprising:

(a) a symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;

(b) an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) an intra-symbol cyclic shift unit which shifts cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein each OFDM symbol is forwarded by said interleaving circuit to a frequency spreading unit which depending on data rate spreads the OFDM symbols in the frequency domain with an adjustable frequency spreading factor (FSF);

wherein the frequency spreading unit is connected to an OFDM modulator which performs for each sub-carrier of the frequency band depending on the data rate either a DCM modulation or a QPSK modulation;

wherein the OFDM modulator is connected to a time spreading unit which depending on an operation mode of said OFDM transceiver spreads the OFDM symbols in the time domain with a time spreading factor (TSF);

wherein the time spreading unit is connected to a transmitter which transmits each interleaved OFDM symbol in different frequency bands according to a predetermined frequency hopping pattern comprising a corresponding pattern periodicity (P);

wherein the least common multiple of the set of frequency hopping pattern periodicities (P max ) is six.

2. The interleaving circuit according to claim 1 wherein the number of frequency bands is three.

3. The interleaving circuit according to claim 1 wherein each frequency band comprises a center frequency and a predetermined number of sub-carriers.

4. The interleaving circuit according to claim 3 wherein the sub-carriers of each frequency band comprises pilot sub-carriers, guard sub-carriers and data sub-carriers.

5. The interleaving circuit according to claim 3 wherein the number of sub-carriers within each frequency band is 122.

6. The interleaving circuit according to claim 4 wherein the number of data sub-carriers within each frequency band is 100.

7. The interleaving circuit according to claim 1 wherein the input-output relationship between the output bits S(i) output by said symbol interleaving unit and the input bits U(i) applied to the symbol interleaving unit is given by

S ( i )= U {Floor( i/N CPPS )+ M Mod( i, N CBPS )}  (1)

wherein M=P max /TSF

8. The interleaving circuit according to claim 1 wherein the input-output relationship between the output bits T(i) output by said tone interleaving unit and the input bits S(i) applied to the tone interleaving unit is given by:

T ( i )= S {Floor( i/N TINT )+10Mod( i, N TINT )}  (2)

wherein N TINT =N CBPS /10

9. The interleaving circuit according to claim 1 wherein the input-output relationship between the output bits V(i) output by said cyclic shift unit and the input bits T(i) applied to said cyclic shift unit is given by:

V ( i )= T{b , Mod( i+k ( b ), N CBPS )}  (3)

wherein K is the shift value depending from an OFDM symbol index b.

10. The interleaving circuit according to claim 9 wherein the shift value K employed by the cyclic shift unit is given by:

k ( b )= b ·round( N CBPS /M )   (4)

wherein

b is an OFDM symbol index

with b=0, 1, 2, . . . , M−1

and

M=P max ,TSF

wherein P max is the least common multiple of the set of frequency hopping pattern periodicities and TSF is the time spreading factor of the time spreading unit, wherein

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wherein

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OFDM

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symbol

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11. Method for interleaving encoded bits within a multi band OFDM (orthogonal frequency division multiplexing) transceiver of a ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein the method comprises the following steps:

(a) receiving an input bitstream of encoded bits and permuting adjacent bits of said input bitstream across different OFDM symbols;

(b) permuting further adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) shifting cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein each OFDM symbol is forwarded by said interleaving circuit to a frequency spreading unit which depending on data rate spreads the OFDM symbols in the frequency domain with an adjustable frequency spreading factor (FSF);

wherein the frequency spreading unit is connected to an OFDM modulator which performs for each sub-carrier of the frequency band depending on the data rate either a DCM modulation or a QPSK modulation;

wherein the OFDM modulator is connected to a time spreading unit which depending on an operation mode of said OFDM transceiver spreads the OFDM symbols in the time domain with a time spreading factor (TSF);

wherein the time spreading unit is connected to a transmitter which transmits each interleaved OFDM symbol in different frequency bands according to a predetermined frequency hopping pattern comprising a corresponding pattern periodicity (P); and

wherein the least common multiple of the set of frequency hopping pattern periodicities (P max ) is six.

12. Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of an ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (N CBPS ) of encoded bits, said interleaving circuit comprising:

(a) a symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;

(b) an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) an intra-symbol cyclic shift unit which shifts cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein each OFDM symbol is forwarded by said interleaving circuit to a frequency spreading unit which depending on data rate spreads the OFDM symbols in the frequency domain with an adjustable frequency spreading factor (FSF);

wherein the frequency spreading unit is connected to an OFDM modulator which performs for each sub-carrier of the frequency band depending on the data rate either a DCM modulation or a QPSK modulation;

wherein the OFDM modulator is connected to a time spreading unit which depending on an operation mode of said OFDM transceiver spreads the OFDM symbols in the time domain with a time spreading factor (TSF);

wherein the time spreading unit is connected to a transmitter which transmits each interleaved OFDM symbol in different frequency bands according to a predetermined frequency hopping pattern comprising a corresponding pattern periodicity (P);

wherein each frequency band comprises a center frequency and a predetermined number of sub-carriers;

wherein the number of sub-carriers within each frequency band is 122 or the number of data sub-carriers within each frequency band is 100.

13. Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of an ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (N CBPS ) of encoded bits, said interleaving circuit comprising:

(a) a symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;

(b) an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) an intra-symbol cyclic shift unit which shifts cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein the input-output relationship between the output bits S(i) output by said symbol interleaving unit and the input bits U(i) applied to the symbol interleaving unit is given by

S ( i )= U {Floor( i/N CPPS )+ M Mod( i, N CBPS )}  (6)

wherein M=P max /TSF

14. Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of an ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (N CBPS ) of encoded bits, said interleaving circuit comprising:

(a) a symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;

(b) an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) an intra-symbol cyclic shift unit which shifts cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein the input-output relationship between the output bits T(i) output by said tone interleaving unit and the input bits S(i) applied to the tone interleaving unit is given by

T ( i )= S {Floor( i/N TINT )+10Mod( i, N TINT )}  (7)

wherein N TINT =N CBPS /10

15. Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of an ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (N CBPS ) of encoded bits, said interleaving circuit comprising:

(a) a symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;

(b) an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers;

(c) an intra-symbol cyclic shift unit which shifts cyclically N CBPS bits of each OFDM symbol depending on a shift value (K) which is changed between adjacent OFDM symbols;

wherein the input-output relationship between the output bits V(i) output by said cyclic shift unit and the input bits T(i) applied to said cyclic shift unit is given by:

V ( i )= T{b , Mod( i+k ( b ), N CBPS )}  (8)

16. The interleaving circuit according to claim 15 wherein the shift value K employed by the cyclic shift unit is given by:

k ( b )= b ·round( N CBPS /M )   (9)

wherein

b is an OFDM symbol index

with b=0, 1, 2, . . . , M−1

and

M=P max ,TSF

wherein P max is the least common multiple of the set of frequency hopping pattern periodicities and TSF is the time spreading factor of the time spreading unit, wherein

k

⁡

(

b

)

=

{

0

for

⁢

⁢

b

=

0

,

1

,

2

round

⁡

(

N

CBPS

/

M

)

for

⁢

⁢

b

=

3

2

·

round

⁡

(

N

CBPS

/

M

)

for

⁢

⁢

b

=

4

,

5

,

6

⁢

⁢

wherein

⁢

⁢

b

⁢

⁢

is an

⁢

OFDM

⁢

  symbol  index

⁢

⁢

and

⁢

⁢

M

=

P

m

⁢

⁢

ax

/

TSF