发明授权
US07590190B2 System and method for forward path gain control in a digital predistortion linearized transmitter
有权
数字预失真线性化发射机中的前向路径增益控制系统和方法
- 专利标题: System and method for forward path gain control in a digital predistortion linearized transmitter
- 专利标题(中): 数字预失真线性化发射机中的前向路径增益控制系统和方法
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申请号: US11214191申请日: 2005-08-29
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公开(公告)号: US07590190B2公开(公告)日: 2009-09-15
- 发明人: Christian G. Luke , Ian Johnson , Mark Cope , Adrian Mansell , Steven Andrew Wood
- 申请人: Christian G. Luke , Ian Johnson , Mark Cope , Adrian Mansell , Steven Andrew Wood
- 申请人地址: US CA Santa Ana
- 专利权人: Powerwave Technologies, Inc.
- 当前专利权人: Powerwave Technologies, Inc.
- 当前专利权人地址: US CA Santa Ana
- 代理机构: Myers Andras Sherman LLP
- 主分类号: H04K1/02
- IPC分类号: H04K1/02
摘要:
A system and method for controlling the gain in the forward signal path of a digital predistortion linearizer is disclosed. The loop gain of the predistortion system is driven to unity, where a separately controlled constant-gain observation path allows accurate gain control of the forward path. This is divided into digital gain from the predistortion function and analog gain from a Voltage Variable Attenuator (VVA) in the transmitter. The invention balances the distribution between these two domains in order to maximize dynamic range and minimize noise in the forward signal path. In order to distribute the forward path gain accurately, the characteristic of the VVA must be well known. Since these devices tend to be non-linear, with variable characteristic over temperature and batch, the invention compensates for this non-linear behavior by tracking the varying transfer characteristic of the VVA, giving a predictable local characteristic. Another aspect of the disclosed invention is the ability to operate with very low transmit power and loop gain levels, allowing accurate gain control during such scenarios as cell initialization, that require operation over a wide dynamic range.
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