In the market of wireless communication, high data-rate
transmission and high spectral efficiency have been the trend. The
IEEE 802.11 a/g standards working at 5GHz/2.4GHz ISM bands can
support data rate up to 54Mbits/s using OFDM modulation. The newly
proposed 802.11n technology now uses 64-QAM to achieve higher
spectral efficiency. The DVB and many other systems will also use
QAM for its data transmission.
The cost of achieving this higher spectral efficiency using
higher order QAM is that the transmitter and receiver requires a
higher signal to noise ratio (SNR) with the same level of error
rate performance (relative to a baseline BPSK, QPSK and other
systems). One of the dominant vectors on SNR degradation is I/Q
image rejection (I/Q gains and phases imbalance).
There are a lot of factors that degrade the matching of gains
and phases between I/Q signals: the instinct layout mismatch, the
random mismatch of the devices, the different temperatures over the
I/Q signal paths. IQ Calibration Techniques For CMOS Radio
Transceivers describes a fully-analog compensation technique
without baseband circuitry to control the calibration process. This
book will use an 802.11g transceiver design as an example to give a
detailed description on the I/Q gains and phases imbalance
auto-calibration mechanism.
General
Is the information for this product incomplete, wrong or inappropriate?
Let us know about it.
Does this product have an incorrect or missing image?
Send us a new image.
Is this product missing categories?
Add more categories.
Review This Product
No reviews yet - be the first to create one!