Method and apparatus for identification of transmission antenna diversity in a receiver

• US 20050123082A1
• Filed: 10/14/2004
• Published: 06/09/2005
• Est. Priority Date: 10/15/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Mobile Communications GmbH (Intel Corporation)
• Inventors: Paul, Steffen, Ruprich, Thomas
• Granted Patent: US 8,102,957 B2
• Time in Patent Office: Days
• US Class Current: 375/347
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme

Abstract

In a method for identification of a multiple antenna transmission mode in a radio receiver, at least two antenna-decoupled data streams (s₀, s₁) are produced by means of an antenna decoupling unit in the receiver. Respective first variables (p₀, p₁) are calculated for both data streams, and are dependent on the phase change between the data in the respective data stream. An evaluation unit uses these first variables as the basis to decide whether a multiple antenna transmission mode is being used in the transmitter.

Claims

1. A method for identification of a multiple antenna transmission mode in a radio receiver, comprising:

producing at least two antenna-decoupled data streams in the receiver from a received data signal;

calculating a respective first variable for both data streams, wherein the first variable is dependent on a phase change between the data in the respective data stream; and

evaluating the two first variables to decide whether the multiple antenna transmission mode is being used in a transmitter that produced the data signal.

2. The method according to claim 1, wherein an argument of the first variable indicates a phase difference between successive data items in the respective data stream.

3. The method according to claim 1, wherein a magnitude of the first variable represents a measure of the signal strength in the respective data stream.

4. The method according to claim 1, wherein the first variable for the a-th antenna-decoupled data stream is given by the relationship:

p_a(2i)=s_a(i)·

S_a*(i+1),

where s_a(i) represents a data value relating to a time index “

i”

of the a-th antenna-decoupled data stream, wherein a=0,1.

5. The method according to claim 1, wherein evaluating the first variables comprises:

calculating a second variable that is dependent on a phase relationship between the two first variables; and

deciding whether a multiple antenna transmission mode is being used in the transmitter based on the calculated second variable.

6. The method according to claim 5, wherein the second variable comprises a product of the first variable, which is calculated for one data stream, and a complex-conjugate of the first variable, which is calculated for the other data stream, and wherein a decision is made that a multiple antenna transmission mode is present if a real part of the second variable is greater than or equal to zero.

7. The method according to claim 1, wherein evaluating the first variables comprises:

comparing a magnitude of the first variable associated with the first data stream which is characteristic of the signal power of the first transmission antenna and a magnitude of the first variable associated with the second data stream which is characteristic of the signal power of the second transmission antenna to a threshold value; and

deciding that a multiple antenna transmission mode is not present when at least one of the magnitudes which are characteristic of the signal power of the transmission antennas is or are less than the threshold value.

8. The method according to claim 1, wherein the data signal transmitted from the transmitter is coded using a scrambling code, further comprising identifying the transmitted scrambling code in the receiver by evaluating at least one of the two first variables.

9. The method according to claim 8, wherein the scrambling code is identified as a function of only one of the two first variables in a first identification mode, and the scrambling code is identified as a function of both first variables in a second identification mode.

10. An apparatus for identification of a multiple antenna transmission mode in a radio receiver, comprising:

an antenna decoupling unit configured to produce at least two antenna-decoupled data streams from a received data signal;

a calculation unit configured to receive the two antenna-decoupled data streams and calculate a first variable for each data stream, wherein each first variable is dependent on a phase change between the data in the respective data stream; and

an evaluation unit configured to receive the two first variables and decide as a function of the two variables whether a multiple antenna transmission mode is being used in a transmitter that produced the data signal.

11. The apparatus according to claim 10, wherein the first variable for an a-th antenna-decoupled data stream is given by the relationship:

p_a(2i)=s_a(i)·

S_a*(i+1),

where s_a(i) represents a data value relating to the time index “

i”

of the a-th antenna-decoupled data stream, wherein a=0,1.

12. The apparatus according to claim 10, wherein:

the calculation unit is configured to calculate a second variable, which is dependent on a phase relationship between the two first variables; and

the evaluation unit is configured to decide as a function of the calculated second variable whether a multiple antenna transmission mode is being used in the transmitter.

13. The apparatus according to claim 12, wherein the calculation unit is further configured to calculate a product of the first variable calculated for one data stream, and a complex-conjugate of the first variable calculated for the other data stream, and decide that a multiple antenna transmission mode is present if a real part of the second variable is greater than or equal to zero.

14. The apparatus according to claim 10:

wherein the evaluation unit is further configured to compare a magnitude of the first variable which is associated with the first data stream which is characteristic of the signal power of a first transmission antenna and a magnitude of the first variable which is associated with the second data stream which is characteristic of the signal power of a second transmission antenna to a threshold value; and

wherein the evaluation unit is configured to decide that a multiple antenna transmission mode is not being used in the transmitter if at least one of the magnitudes which are characteristic of the signal powers of the transmission antennas is or are less than the threshold value.

15. The apparatus according to claim 10, further comprising a further evaluation unit connected downstream from the calculation unit, and configured to evaluate at least one of the two first variables to identify a scrambling code which is being used by the transmitter for the coding of the transmitted data signal.

16. The apparatus according to claim 15, wherein the further evaluation unit is configured to be operated in two or more identification modes, wherein the scrambling code is identified as a function of only one of the two first variables in a first identification mode, and the scrambling code is identified as a function of both first variables in a second identification mode.