Shu (Marloon) Wang

[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] Many broadcast/multicast infrastructures are engineered for delivering a wide range of contents, such as streaming media, multicast media and even IP datacast. Though all of them have the similar capabilities of delivering a pretty-much same set of services,  their bear technologies and network layer or stream layer designs are varied. In terms of physical layer, ATSC uses 8 VSB while DVB, FLO and ISDB use OFDM in their air interface designs. In terms of stream layer design, DVB-H uses IP, ISDB uses MPEG TS, T-DMB and FLO use their own mapping between application layer and MAC layer logic channels.

In wireless broadcast multicast services (BMS), a standard assumption is that each receiver knows something about the channel h, usually referred as channel side information (CSI) or channel quality information (CQI). This is a pretty reasonable assumption when the channel is fading slowly inside the design boundary since there are pilot symbols available for the receiver to estimate CQI. Since the channel and transmitted signals are independent to each other, the ergodic capacity of the fading channel with receiver side information is given by C fading ( SNR, h ) = E log( 1 + |h| 2 SNR ) ≤ C AWGN ( E(|h| 2 ) SNR ). This means fading hurts or reduces the capacity in general if the transmitter knows nothing of the fading. This is different to the case that assumes the transmitter can estimate channel through CQI feedback and therefore can do some precoding on broadcast signals. Since a statistic analysis on a log(*) probability function is non-trivial, one approach is to apply the

Instead of the traditional single-coverage model, a layered broadcast model with a two-layer coverage is considered here. In this model, the broadcast station (BS) broadcast two layers of signal to all mobile stations (MS) in the covered area. The signal for the inner coverage has the achievable rate of R 1 and the achievable rate for the outer coverage is R 2 , where R 1 > R 2 . The MS's located near to the outer coverage edge may only be able to reliably decode the data stream of a low rate R 2 while the MS's close to the BS can decode both data streams with a high sum rate R 1 . There many ways for achieving this two-layer broadcasting, including frequency-division multiplexing (FDM), time-division multiplexing (TDM) and superposition precoding (SPC).  Figure 1. Achievable capacity region of broadcast channel. The coverage difference is 6dB.  One key aspect of studying two-layer broadcast is the finding of the achievable broadcast channel capacity, which states

Broadcast multicast service (BMS) has increasingly been popular for delivering multimedia content to mobile users. BMS can be implemented through either a dedicated digital broadcast infrastructure like DVB-T/H/S2, MediaFLO and DMB or a 3rd generation and beyond radio access network like UMTS or cdma2000 network. Traditional digital broadcast air interface and network are designed with the tradeoff between the achievable capacity and intended coverage in mind. The actual throughput is limited by the maximum transmit power and the worst channel condition so that each user in the coverage area can reliably receive services. Therefore, all covered users share services with same quality. The users under good reception condition may not have advantages, even though their achievable throughput can be much higher. In addition, there are also rising interests in upgrading existing digital broadcast systems with more services for new users while be able to keep existing users unchanged, deliver

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