| The next generation of local area networks (LANs) operates at data rates of up to several hundred megabits, or gigabits per second. In order to minimize the cost, use of the existing unshielded twisted-pair cable (similar to telephone copper wire) to connect the network terminals to central hubs is desirable. Among all of the LAN standards, Gigabit Ethernet on category 5 unshielded twisted pair (UTP) is the most popular and economical, since it is the next generation standard of commonly-used 10/100Base-T Ethernet.; Due to the high data bandwidth on medium-quality copper line, and simultaneous data transmission on four twisted-pair cables, advanced signal processing—such as channel equalization and echo/crosstalk cancellation—is required to recover the signal from noisy channels. In order to meet the stringent bit-error-rate specifications of Gigabit Ethernet, designers of 1000Base-T must use complex digital signal processing as well as high resolution A/D converters to reduce impairments due to highly-corrupted channels.; Until now, full digital signal processing has been considered the only possible solution to implement 1000Base-T transceivers. This research has investigated analog adaptive circuits to cancel noise and perform channel equalization in the analog front end. In addition to the circuit implementation, a custom C program is written to emulate the transceiver in order to determine the specifications of each analog building block.; An adaptive mixed-signal echo canceller and a linear channel equalizer are proposed in this work to boost the signal-to-noise ratio. With the aid of these two building blocks, the A/D converter design requirement and the digital signal processor complexity are both reduced.; In contrast to fully digital or analog implementations, the Gigabit Ethernet transceiver can be implemented by lower power consumption and smaller silicon die size with this hybrid architecture. |
