A method and device for implementing digital predistortion in a base station

Abstract

The invention discloses a digital pre-distortion realization method of a base station and an apparatus thereof. A digital signal processing unit and a near-end radio frequency processing unit are arranged at a base station side; and the digital signal processing unit can receives a base band signal from a base band unit (BBU) that is also at the base station side by a cable and there is no need to use a digital optical module; therefore, restriction of the rate of the digital optical module on a radio frequency bandwidth can be eliminated and scalability of a transmitted carrier wave and a transmitted frequency range of the base station can also be improved. Besides, an optical signal that is converted by a radio frequency signal is transmitted between the near-end radio frequency processing unit and a far-end radio frequency processing unit by a fiber; and a radio over fiber technology is used to realize digital pre-distortion of the base station; therefore, efficiency of a power amplifier in the far-end radio frequency processing unit that is at a far end is enhanced. Because the radio frequency signal that is corresponded to the optical signal in the fiber is an analog signal as well as radio frequency band widths of optical transceivers in the near-end radio frequency processing unit and the far-end radio frequency processing unit can reach over 1 GHz, so that circuit combination demands of different frequency ranges can be met.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a method and device for realizing digital predistortion of a base station. Background technique [0002] The 3G (3rd Generation, third-generation mobile communication technology) network uses a large number of distributed base station architectures. The base station architecture includes two parts: BBU (Base Band Unit, baseband processing unit) and RRU (Radio Remote Unit, radio remote unit). Among them, the BBU is installed in a suitable location in the equipment room, and the RRU is installed at the antenna end. By separating the BBU from the RRU, the maintenance work can be simplified to the BBU. One BBU can support multiple RRUs, which not only saves space, but also reduces installation costs, improves networking efficiency, and can well solve the indoor coverage of large venues. [0003] Since the peak-to-average ratio signal is likely to cause nonlinear disto...

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Problems solved by technology

[0003] Since the peak-to-average ratio signal can easily cause nonlinear distortion during the amplification process, resulting in a decrease in the quality of the communication signal, therefore, the RRU usually adopts a power back-off method for the power amplifier to meet the required high linearity requirements

For example, for a power amplifier with an output power of 20W, it is often necessary to use a FET with a power of 200W and make it work in a class A state that consumes a lot of power, which is likely to bring high power consumption and low A series of problems such as efficiency (less than 10%), high heat generation, low reliability and high cost

If the carrier and frequency band continue to expand, higher rate digital optical modules are required, which increases the difficulty and cost of digital optical modules and baseband processing.

In addition, the existing RRU combines the power amplifier with the baseband processing unit and radio frequency processing unit, which is difficult to design and not easy to maintain; and the RRU has poor adaptability to frequency bands, and one RRU can only support two frequency bands. Use more than two frequency bands, you need to use multiple RRU

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