Cascade connection networking method based on xWDM wavelength-division multiplex RF far-drawing unit

Abstract

The present invention discloses a cascade network building method based on the wavelength division multiplexing (xWDM) radio frequency remote unit, and mainly comprises the following steps: 1, the wavelength division multiplex (xWDM) is used in a radio frequency remote type BTS system for the cascade radio frequency remote unit RRU; 2, the wavelength division multiplex (xWDM) and the time division multiplex (TDM) are compounded and then used in the radio frequency remote type system, and different wavelengths are adopts to form the logical star connection between the BTS and different RRUs; 3, the wavelength division multiplex (xWDM) is used in the RRU of the cascade radio frequency remote type BTS system and in the base station system BTS; 4, the wavelength division multiplex (xWDM) is used in the cascade optical transmission system from the one-point main equipment to the multi-point auxiliary equipment. The network building method greatly saves the transmission resources of the system, enlarges the transmission capacity of the system, prevents the problem of gradual declination of the clocks which are restored and transmitted step by step in the TDM multiplexing mode, simplifies the problems in the estimation of time delay between the cascade systems, and is suitable for the base station system of multi-mode communication modes.

Description

Technical field [0001] The invention relates to a networking method for cascading remote radio unit RRUs by applying wavelength division multiplexing xWDM transmission equipment in a remote radio frequency wireless communication system. technical background [0002] With the rapid development of cellular mobile communication systems, competition among different communication systems and operators has become increasingly fierce. Operators are not only concerned about the cost of the equipment itself, but also about the construction and operating costs of the base station system. The main problem with traditional network construction methods is that operators have to spend a lot of time and expense on renting computer rooms, and a large number of ideal site computer rooms cannot be obtained because they are far away from residences, which also delays the speed of network construction. Especially for those new mobile operators, if they use this method of network construction without...

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Problems solved by technology

[0007] (2) Since the reference clock of the RRU is recovered from the transmit clock on the BBU side and passed down step by step, the cascaded RRUs will cause the reference clock recovered from the line to deteriorate step by step, resulting in subsequent There may be problems with the synchronization of level RRUs;

[0008] (3) For a time division duplex (TDD) system, the BBU also performs delay compensation for the transmission of each RRU (or RRU for delay compensation) to ensure the synchronization of different RRU transmission signals. Multi-level cascading will lead to The complexity of delay estimation is increasing and the error is gradually expanding;

[0009] (4) Due to the time-division multiplexing of data of different RRUs and the limited line rate level, the line rate also limits the number of RRUs, especially for width and multi-antenna systems. The existing RRU cascading method can only support few RRU

[0010] Each of the above problems is a big problem for the remote radio system based on TDM

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