TEST UNIT FOR TESTING THE FREQUENCY CHARACTERISTIC OF A TRANSMITTER

• US 20100014570A1
• Filed: 12/15/2006
• Published: 01/21/2010
• Est. Priority Date: 12/15/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Hue, Xavier, Mongin, Lionel, Dupis, Francois, Trichet, Jacques
• Granted Patent: US 8,311,494 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• CPC Class Codes: H04B 17/101 for measurement of specific parameters of the transmitter or components thereof
• CPC Class Codes: H04B 17/15 Performance testing

Abstract

A test unit for testing the frequency characteristics of one or more components of a transmitter of modulated signals. The test unit includes a data source for generating a test pattern of data. A test unit output is connected to the data source and connectable to an input of one or more of the components, for inputting the test pattern of data to the one or more components. The test unit includes a memory in which a first predetermined data sequence and a second predetermined data sequence are stored. The data source is connected with an data input to the memory, and the data source is arranged to generating the test pattern of data including the predetermined data sequences. When a modulated signal is generated in accordance with the test pattern of data will include a first signal part with a first frequency spectrum caused by the first predetermined data sequence and a second signal part after the first signal part, which second signal part has a second frequency spectrum caused by the second predetermined data sequence.

Claims

1. A test unit for testing the frequency characteristics of at least one component of a transmitter of modulated signals, comprising:

a data source for generating a test pattern of data;

a test unit output connected to said data source and connectable to an input of at least one of said components, for inputting said test pattern of data to said at least one components;

a memory, the memory for storing in which a first predetermined data sequence and a second predetermined data sequence;

wherein said data source is connected with an data input to said memory, and said data source is arranged to generating said test pattern of data including said predetermined data sequences;

wherein when a modulated signal is generated in accordance with said test pattern of data will include a first signal part with a first frequency spectrum caused by said first predetermined data sequence and a second signal part after said first signal part, which second signal part has a second frequency spectrum caused by said second predetermined data sequence.

2. A test unit as claimed in claim 1, including:

a receiving unit connectable to said at least one component, for receiving a signal outputted by said component in response to inputting said test pattern in said component.

3. A test unit as claimed in claim 1, wherein said first signal part and said second signal part are modulated signals;

said first signal part having at least one frequency component with a first frequency above a carrier frequency with a higher intensity than a corresponding frequency component in the second signal part; and

said second signal part having at least one frequency component with a second frequency below said carrier frequency with a higher intensity than a corresponding frequency component in the first signal part.

4. A test unit as claimed in claim 3, wherein said frequency component of the first signal part is the first upper side band of the modulated signals above the carrier frequency and wherein said frequency component of the second signal part is the first side band of the modulated signals below the carrier frequency.

5. A test unit as claimed in claim 3, wherein said first signal part and said second signal part each exhibit a frequency spectrum of a single-sideband modulated signal.

6. A test unit as claimed in claim 1, wherein said signal source is arranged to generate a phase modulated signal, such as a phase shift keying modulated signal.

7. A test unit as claimed in claim 6, wherein said first data sequence includes at least two different symbols and wherein a transition between two successive symbols corresponds in said first signal part with a first phase shift in a first direction and said second data sequence includes at least two different symbols, and a transition between a symbol to a following symbol corresponding to a second phase shift in a second direction opposite to said first direction.

8. A test unit as claimed in claim 7, wherein said first data sequence and said second data sequence each include at least three symbols and wherein said first and second phase shifts have the same magnitude for each transition from a symbol to a following symbol.

9. A test unit as claimed in claim 7, wherein said first and second phase shifts are in the range of larger than zero and smaller than 180 degrees, such as 157.5 degrees.

10. A test unit as claimed in claim 1, wherein said signal source is a source of m-PSK modulated signals with a phase offset of pπ

/q radians, and wherein m is an integer number and m,p and q satisfy the relationship;

11. A test unit as claimed in claim 1, wherein said signal source is a source of 8-PSK modulated signals with a 3π

/8 offset, and said first data sequence and/or said second data sequence are selected from the group of symbol sequences consisting of;

7214, 6305, 5630, 4721, 3056, 2147, 1472, 0563, 70431625, 62570431, 57043162, 43162570, 31625704, 25704316, 16257043, and 04316257.

12. A test unit as claimed in claim 1, wherein said signal source has a burst mode for outputting at least one signal burst and wherein said signal source is arranged to output said first and second signal part in the same signal burst.

13. A test unit as claimed in claim 1, wherein said signal source includes a data processor for assembling a data packet which includes said test pattern.

14. A test unit as claimed in claim 13, wherein said data processor is arranged to include said test pattern in a part of the data packet selected from the group consisting of:

tail, data, mid-amble, guard.

15. A test unit as claimed in claim 1, wherein said test pattern of data includes compensating data, for compensating a parameter of the test signal for an effect on said parameter caused by the first predetermined data sequence, second predetermined data sequence, or the first predetermined data sequence and the second predetermined data sequence.

17. A transmitter unit including a test unit as claimed in claim 1.

16. (canceled)

18. A method for testing a frequency behaviour of at least one component of a transmitter of modulated signals, comprising:

generating a test signal from a test pattern of data, which test pattern includes a first predetermined data sequence and a second predetermined data sequence, in which test signal a first signal part with a first frequency spectrum is caused by said first predetermined data sequence and a second signal part with a second frequency spectrum is caused said second predetermined data sequence

inputting said test signal in said at least one component.

20. A component of a transmitter unit tested or optimised with a method as claimed in claim 18.

21. A computer program product loadable in a memory of a programmable apparatus, which computer program product includes program code portions for executing a method as claimed in claim 18 when run by said programmable apparatus

19. A method for optimising a frequency behaviour of at least one component of a transmitter of modulated signals, comprising:

receiving a signal outputted by said component in response to inputting said test pattern in said component;

determining frequency components in the received signal caused by the first signal part and the second signal part;

comparing the determined frequency components with desired frequency components and

adjusting at least one parameter of said component when said comparison meets an adjust criterion.