Most modern integrated circuit transceivers, especially wireless LAN, utilize a direct conversion radio architecture. While this approach is highly advantageous from the perspectives of cost and flexibility, there exist several performance impairments, including gain and phase imbalances between the in-phase (I) and quadrature (Q) of a transmitter (TX) or receiver (RX). The dissertation presents several signal processing methodologies for compensation of I/Q imbalance for a direct conversion packet-switched OFDM communications system, whichl accounts for TX I/Q imbalance, RX I/Q imbalance, phase/frequency error, and dispersive multipath fading. Both frequency dependent I/Q imbalance and frequency independent cases are considered, covering both m00hvch1 j,lk and narrowband modulation. The proposed estimation algorithms operate within the fully compliant framework of existing multi-user OFDM radio standards (802.11a). It is shown that these algorithms accurately estimate and correct transceiver I/Q imbalance on a packet-by-packet basis, all within the RX's digital baseband.
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机译:大多数现代集成电路收发器,尤其是无线局域网,都采用直接转换无线电架构。尽管从成本和灵活性的角度来看,此方法非常有利,但存在一些性能损害,包括发射机(TX)或接收机(RX)的同相(I)和正交(Q)之间的增益和相位不平衡。论文提出了几种补偿直接转换分组交换OFDM通信系统I / Q不平衡的信号处理方法,其中包括TX I / Q不平衡,RX I / Q不平衡,相位/频率误差和色散多径衰落。考虑了频率相关的I / Q不平衡和频率独立的情况,涵盖了m00hvch1 j,lk和窄带调制。所提出的估计算法在现有的多用户OFDM无线标准(802.11a)的完全兼容的框架内运行。结果表明,这些算法在RX的数字基带内,逐个数据包准确地估计和纠正收发器I / Q不平衡。
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