发明名称 |
Digital transmitter |
摘要 |
An equalizer provided in a digital transmitter compensates for attenuation in a signal channel to a digital receiver. The equalizer generates signal levels as a logical function of bit history to emphasize transition signal levels relative to repeated signal levels. The preferred equalizer includes an FIR transition filter using a look-up table. Parallel circuits including FIR filters and digital-to-analog converters provide a high speed equalizer with lower speed circuitry. The equalizer is particularly suited to in-cabinet and local area network transmissions where feedback circuitry facilitates adaptive training of the equalizer using signal levels in sequences to represent different frequencies. |
申请公布号 |
US8761235(B2) |
申请公布日期 |
2014.06.24 |
申请号 |
US201313914350 |
申请日期 |
2013.06.10 |
申请人 |
Massachusetts Institute of Technology |
发明人 |
Dally William J. |
分类号 |
H04B1/38;H03H7/40;H04L27/01;H04L25/49 |
主分类号 |
H04B1/38 |
代理机构 |
Hamilton, Brook, Smith & Reynolds, P.C. |
代理人 |
Hamilton, Brook, Smith & Reynolds, P.C. |
主权项 |
1. A semiconductor device for use in transmitting a signal over a conductive path to a receiver, the semiconductor device comprising:
a semiconductor chip; a transmit circuit on the semiconductor chip; the transmit circuit to transmit a first sequence of signal levels representing bits to the receiver, where a rate of change of binary state in the signal levels in the first sequence represents a first frequency; the transmit circuit also to transmit a second sequence of signal levels representing bits to the receiver, where a rate of change of binary state in the signal levels in the second sequence represents a second frequency; circuitry to receive programming, the programming being responsive to measurement of the first and second sequences at the receiver.
|
地址 |
Cambridge MA US |