TRANSMITTER SYSTEM WITH DIGITAL PHASE ROTATOR USED FOR APPLYING DIGITAL PHASE ROTATION TO CONSTELLATION DATA AND RELATED SIGNAL TRANSMISSION METHOD THEREOF

• US 20140348217A1
• Filed: 05/19/2014
• Published: 11/27/2014
• Est. Priority Date: 05/21/2013
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Hsieh, Ming-Yu, Wang, Chi-Hsueh, Chang, Pou-Chi
• Granted Patent: US 9,094,004 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: G01R 21/06 by measuring current and voltage G01R21/08 - G01R21/133 take precedence
• CPC Class Codes: G01R 23/00 Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 1/24 in discharge-tube amplifiers
• CPC Class Codes: H03F 2203/21154 An output signal of a power amplifier being controlled by controlling voltage signal
• CPC Class Codes: H03F 3/2178 using more than one switch or switching amplifier in parallel or in series H03F3/2173, H03F3/2175 take precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03K 19/017509 Interface arrangements
• CPC Class Codes: H03K 19/017581 programmable
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04B 2001/045 with means for improving efficiency
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end
• CPC Class Codes: H04L 25/08 Modifications for reducing interference; Modifications for reducing effects due to line faults ; Receiver end arrangements for detecting or overcoming line faults
• CPC Class Codes: H04L 27/2053 using more than one carrier, e.g. carriers with different phases
• CPC Class Codes: H04L 27/2067 with more than two phase states H04L27/2064 takes precedence
• CPC Class Codes: H04L 27/3411 reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set
• CPC Class Codes: H04L 27/3444 by applying a certain rotation to regular constellations
• CPC Class Codes: H04L 7/0037 : Delay of clock signal
• CPC Class Codes: H04L 7/0091 : Transmitter details
• CPC Class Codes: H04W 24/02 : Arrangements for optimising operational condition

Abstract

A transmitter system includes a digital phase rotator, a phase rotation controller, and a digital radio-frequency (RF) transmitter. The digital phase rotator receives a first constellation data, and applies a digital phase rotation to the received first constellation data to generate a second constellation data. The phase rotation controller configures the digital phase rotation. The digital RF transmitter receives a digital input data derived from the second constellation data, and converts the digital input data into an analog RF output.

Claims

1. A transmitter system, comprising:

a digital phase rotator, arranged to receive a first constellation data and apply a digital phase rotation to the received first constellation data to generate a second constellation data;

a phase rotation controller, arranged to configure the digital phase rotation; and

a digital radio-frequency (RF) transmitter, arranged to receive a digital input data derived from the second constellation data, and convert the digital input data into an analog RF output.

2. The transmitter system of claim 1, wherein the phase rotation controller is arranged to refer to a constellation type of the first constellation data to set a phase rotation angle employed by the digital phase rotation.

3. The transmitter system of claim 2, wherein when the constellation type corresponds to a first modulation scheme, the phase rotation controller sets the phase rotation angle by a first angle value;

and when the constellation type corresponds to a second modulation scheme different from the first modulation scheme, the phase rotation controller sets the phase rotation angle by a second angle value different from the first angle value.

4. The transmitter system of claim 2, wherein the phase rotation controller comprises:

a lookup table, arranged to record a plurality of predetermined constellation types and a plurality of pre-built phase rotation angles, where the pre-built phase rotation angles are mapped to the predetermined constellation types, respectively; and

a selector, arranged to search the lookup table for the constellation type, and utilize a pre-built phase rotation angle of a predetermined constellation type that matches the constellation type as the phase rotation angle.

5. The transmitter system of claim 1, wherein a configuration of the digital phase rotation is dependent upon transmitter architecture employed by the digital RF transmitter.

6. The transmitter system of claim 1, wherein a configuration of the digital phase rotation is dependent upon inherent characteristics of digital power amplifier(s) of the digital RF transmitter.

7. The transmitter system of claim 1, wherein a peak-to-average power ratio (PAPR) of the digital RF transmitter generating the analog RF output based on the digital input is lower than a PAPR of the digital RF transmitter generating an analog RF output based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.

8. The transmitter system of claim 1, wherein a power efficiency of the digital RF transmitter generating the analog RF output based on the digital input is higher than a power efficiency of the digital RF transmitter generating an analog RF output based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.

9. The transmitter system of claim 1, wherein a spectrum of the analog RF output generated by the digital RF transmitter based on the digital input is less distorted than a spectrum of an RF output generated by the digital RF transmitter based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.

10. A signal transmission method, comprising:

receiving a first constellation data;

configuring a digital phase rotation;

applying the digital phase rotation to the received first constellation data to generate a second constellation data; and

utilizing a digital radio-frequency (RF) transmitter to receive a digital input data derived from the second constellation data and convert the digital input data into an analog RF output.

11. The signal transmission method of claim 10, wherein the step of configuring the digital phase rotation comprises:

referring to a constellation type of the first constellation data to set a phase rotation angle employed by the digital phase rotation.

12. The signal transmission method of claim 11, wherein when the constellation type corresponds to a first modulation scheme, the phase rotation angle is set by a first angle value;

and when the constellation type corresponds to a second modulation scheme different from the first modulation scheme, the phase rotation angle is set by a second angle value different from the first angle value.

13. The signal transmission method of claim 11, wherein the step of referring to the constellation type to set the phase rotation angle comprises:

searching a lookup table for the constellation type, wherein the lookup table records a plurality of predetermined constellation types and a plurality of pre-built phase rotation angles, and the pre-built phase rotation angles are mapped to the predetermined constellation types, respectively; and

utilizing a pre-built phase rotation angle of a predetermined constellation type that matches the constellation type as the phase rotation angle.

14. The signal transmission method of claim 10, wherein a configuration of the digital phase rotation is dependent upon transmitter architecture employed by the digital RF transmitter.

15. The signal transmission method of claim 10, wherein a configuration of the digital phase rotation is dependent upon inherent characteristics of digital power amplifier(s) of the digital RF transmitter.

16. The signal transmission method of claim 10, wherein a peak-to-average power ratio (PAPR) of the digital RF transmitter generating the analog RF output based on the digital input is lower than a PAPR of the digital RF transmitter generating an analog RF output based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.

17. The signal transmission method of claim 10, wherein a power efficiency of the digital RF transmitter generating the analog RF output based on the digital input is higher than a power efficiency of the digital RF transmitter generating an analog RF output based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.

18. The signal transmission method of claim 10, wherein a spectrum of the analog RF output generated by the digital RF transmitter based on the digital input is less distorted than a spectrum of an RF output generated by the digital RF transmitter based on a digital input derived from the first constellation data without the digital phase rotation applied thereto.