Shu (Marloon) Wang

[How Much Feedback Is Enough for MIMO? I Introduction] [How Much Feedback Is Enough for MIMO? II Channel Estimation] [How Much Feedback Is Enough for MIMO? III Codebook Design] [How Much Feedback Is Enough for MIMO? IV Channel Quantization] [How Much Feedback Is Enough for MIMO? V Feedback Reliabilities] [3GPP2 TSG-C WG3 C30-20090511-030] [3GPP2 TSG-C WG3 C30-20090511-032] The adoption of multi-antenna techniques is believed to be able to provide additional antenna gain, diversity gain, multiplexing gain and interference cancellation gain. They can help improve link quality and increase link throughput. Multi-antenna techniques are believed to be critical in meeting the demand of high data rate and high link quality and can be employed for both forward link and reverse link transmission. However, there are many issues which should be carefully considered when multi-antenna techniques are implemented. These issues include the rank deficiency of actual MIMO channels, the limitat

[How Much Feedback Is Enough for MIMO? I Introduction] [How Much Feedback Is Enough for MIMO? II Channel Estimation] [How Much Feedback Is Enough for MIMO? III Codebook Design] [How Much Feedback Is Enough for MIMO? IV Channel Quantization] [How Much Feedback Is Enough for MIMO? VI Rank Deficiency] Figure 1. A Noisy Feedback Channel Model The reverselink channel model is a concatenation of a Gaussian channel and binary erasure channel, which are independent to each other. In generally, the reliability of reverselink is controlled by both channel fading and received SNR. When the erasure rate ε r is high, it means the amount of fading of reverselink is very high. Higher erasure rate also means it takes the forwardlink transmitter longer time to accurately filter out a proper forwardlink precoding word and it usually yields higher MIMO precoding mismatch given a certain channel coherent time. Since the unreliable symbols are erased based on their received SNR, the left symbols