Shu (Marloon) Wang

What Is The Next for Mobile System Design? I A Single-Cell Model Perspective on Downlinks [How to Broadcast Multimedia Contents? I Introduction] [How to Broadcast Multimedia Contents? II Lessons from The Channel] [How to Broadcast Multimedia Contents? IV Hierarchical Modulation] [How to Broadcast Multimedia Contents? V Overloaded Transmission and IC] [How to Broadcast Multimedia Contents? VII Network Layer or Steam Layer Design] One most well-known space-time block coding (STBC) design is Alamouti code, which is the simplest open-loop orthogonal STBC. Alamouti code was designed for a two-transmit antenna system. It is a rate-1 code. It is the first open-loop encoding method with full diversity. Though orthogonal STBC has the advantages of relatively easy receiver design and full diversity, it is known that full-rate STBC don’t exist for more than 2 transmit antenna. From previous discussion, if two orthogobal STBCs are superimposed together and each of them experiences differen...

[How to Broadcast Multimedia Contents? I Introduction] [How to Broadcast Multimedia Contents? II Lessons from The Channel] [How to Broadcast Multimedia Contents? IV Hierarchical Modulation] [How to Broadcast Multimedia Contents? VI Open-Loop MIMO for BCMCS] [How to Broadcast Multimedia Contents? VII Network Layer or Steam Layer Design] [Precoded OFDM for BCMCS, 3GPP2 TSG-C NTAH C00-20080218-006R1] Though hierarchical modulations have been widely adopted for enhancing broadcast multicast services, several issues are still left for future enhancements. The first consideration is the inter-layer interference (ILI) between layers. The ILI from enhancement layer(s) to base layer(s) is not additive white Gaussian. The base-layer achievable spectral efficiency is actually dented by ILI more than expected. In addition, for example, when orthogonal frequency division multiplexing (OFDM) is employed on the carrier, there is a frequency selectivity issue on the layered transmission in fad...

Intellectual Property Values On August 9, 2000, CNN Money reported, a U.S. appeals court set a sooner-than-expected end to Eli Lilly and Co.'s reign as the sole marketer of Prozac, the popular antidepressant drug, a development that sent the pharmaceutical company's stock down by more than 30%. [“ Eli Lilly gets Prozac blues “, CNN ] It is about $36 billion in Lilly stock value, roughly a third of the pharmaceutical giant’s then market capitalization. On June 7, 2002, New York Times reported that royalties from inventions earn an estimated $150 billion/year worldwide and are expected to grow 30% annually over the next 5 years. [“ Trying to Cash in on Patents ”, New York Times] From 1993 to 2003, IBM alone was reported to earn well over $10 Billion in revenue from licensing out its patents and be awarded over 22,000 patents, more than the 10 largest U.S. IT companies combined, including Intel, Microsoft, Sun, Dell and Apple. Meanwhile, Microsoft was reported to spend about $8...

[How to Broadcast Multimedia Contents? I Introduction] [How to Broadcast Multimedia Contents? II Lessons from The Channel] [How to Broadcast Multimedia Contents? V Overloaded Tx and IC] [How to Broadcast Multimedia Contents? VI Open-Loop MIMO for BCMCS] [How to Broadcast Multimedia Contents? VII Network Layer or Steam Layer Design] [Contribution to 3GPP2 Next Generation Technologies Ad Hoc Group (NTAH) 2007] [On Enhancing Hierarchical Modulations, 2008 IEEE Int. Sym. on BMSB ] As shown in Figure 1, hierarchical modulation, also called layered modulation, is one of the techniques for multiplexing and modulating multiple data streams into one single symbol stream, where the base-layer symbols and enhancement-layer symbols are synchronously overlapped together before being transmitted. When hierarchical modulation is employed, users with good reception and advanced receiver can demodulate more than one layer of data streams. For a user with conventional receiver or poor receptio...

H.264 Network Abstract Layer Header [How to Broadcast Multimedia Contents? I Introduction] [How to Broadcast Multimedia Contents? II Lessons from The Channel] [How to Broadcast Multimedia Contents? IV Hierarchical Modulation] [How to Broadcast Multimedia Contents? V Overloaded Transmission and IC] [How to Broadcast Multimedia Contents? VI Open-Loop MIMO for Broadcast Multicast Services] It is very challenging to deliver multimedia contents through wireless links. Diverse receivers may request the same video with different bandwidths, spatial resolutions, frame rates, computational capabilities. Heterogeneous networks with unknown network conditions. Wired and wireless links, time-varying bandwidths. One Example is when you originally code the video you don’t know which client or network situation will exist in the future. Probably have multiple different situations, each requiring a different compressed bit stream. It needs a different compressed video matched to each situation...

[Frequency Selectivity of A 1.2288MHz, 3GPP2, TSG-C, Working Group 3, C30-20090511-028] How wide should a channel be before it is called wideband? Dictionary.com says it is " responding to or operating at a wide band of frequencies ". I guess this is pretty much the one in most people's mind. Wikipedia.org gives us a more technical definition," a system is typically described as wideband if the message bandwidth significantly exceeds the channel's coherence bandwidth ". Basically it says  whether  a channel can be called wideband channel or not largely depends on the multiple of coherence bandwidth it has. The question then becomes what is coherence bandwidth and how wide a typical coherence bandwidth can be. For example, should a CDMA2000 channel, which has a bandwidth of 1.22288MHz, be called wideband or not?  Why can a 5.0MHz WCDMA channel usually be called wideband? Let's find out here. Coherence Bandwidth Coherence bandwidth is a  statistica...

[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 MI...