Control channel detection

1. A wireless device comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause the wireless device to:

i) generate a first signal, by at least demodulating, descrambling and decoding signals received on a plurality of OFDM subcarriers in a first OFDM symbol;

ii) produce a processed first signal, by at least encoding, scrambling, modulating and scaling said first signal;

iii) generate a second signal, by subtracting said processed first signal from received signals on said plurality of OFDM subcarriers in said first OFDM symbol;

iv) produce a control format indicator, by at least demodulating, descrambling and decoding said second signal; and

v) determine number of OFDM symbols of a control region of a base station employing said control format indicator.

2. The wireless device of claim 1 , wherein said control format indicator comprises two bits of information.

3. The wireless device of claim 1 , wherein said control format indicator is encoded employing a repetition code.

4. The wireless device of claim 1 , wherein said control format indicator is received over sixteen modulation symbols.

5. A wireless device comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause the wireless device to:

i) generate a first signal, by at least demodulating, descrambling and decoding signals received on a plurality of OFDM subcarriers in a first OFDM symbol;

ii) produce a processed first signal, by at least encoding, scrambling, modulating and scaling said first signal;

iii) generate a second signal, by subtracting said processed first signal from received signals on said plurality of OFDM subcarriers in said first OFDM symbol;

iv) produce a physical broadcast message, by at least demodulating, descrambling and decoding said second signal; and

v) determine a plurality of system parameters of a base station employing said physical broadcast message.

6. The wireless device of claim 5 , wherein said physical broadcast message is encoded employing:

a) a convolutional code; and

b) a repetition code.

7. The wireless device of claim 5 , wherein said physical broadcast message reception reoccurs periodically with a fixed period.

8. The wireless device of claim 5 , wherein said physical broadcast message is received over seventy-two OFDM subcarriers substantially in the center of a carrier.

9. The wireless device of claim 5 , wherein said plurality of system parameters comprise:

a) system bandwidth information;

b) HARQ indicator channel structure information; and

c) eight most significant bits of a system frame number.

10. A wireless device comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause the wireless device to:

i) produce a first plurality of correlation values, by correlating received signals with a first plurality of predetermined synchronization signals, said received signals received on a plurality of OFDM subcarriers in a subset of OFDM symbols;

ii) identify a first synchronization signal transmitted by a first base station, employing said first plurality of correlation values;

iii) process said first synchronization signal, by at least scaling said first synchronization signal by a scaling factor;

iv) generate an updated received signal, by subtracting said processed first synchronization signal from received signals on said plurality of OFDM subcarriers in said subset of OFDM symbols; and

v) identify a second synchronization signal transmitted by a second base station, employing said updated received signal.

11. The wireless device of claim 10 , wherein said second base station is of a different base station type than said first base station.

12. The wireless device of claim 10 , wherein said first synchronization signal has a highest correlation value among said first plurality of correlation values.

13. The wireless device of claim 10 , wherein said first synchronization signal is transmitted over seventy-two OFDM subcarriers substantially in the center of said carrier.

14. The wireless device of claim 10 , wherein said scaling factor is a function of characteristics of a wireless channel.

15. The wireless device of claim 10 , wherein said instructions further cause the wireless device to obtain timing information of said second base station, employing said second synchronization signal.