Abstract:
Frame structures and transmission techniques for a wireless communication system are described. In one frame structure, a super-frame includes multiple outer-frames, and each outer-frame includes multiple frames, and each frame includes multiple time slots. The time slots in each super-frame are allocated for downlink and uplink and for different radio technologies (e.g., W-CDMA and OFDM) based on loading. Each physical channel is allocated at least one time slot in at least one frame of each outer-frame in the super-frame. An OFDM waveform is generated for each downlink OFDM slot and multiplexed onto the slot. A W-CDMA waveform is generated for each downlink W-CDMA slot and multiplexed onto the slot. A modulated signal is generated for the multiplexed W-CDMA and OFDM waveforms and transmitted on the downlink. Each physical channel is transmitted in bursts. The slot allocation and coding and modulation for each physical channel can change for each super-frame.
Abstract:
En un sistema de OFDM (Multiplexación por División Ortogonal de Frecuencia), un transmisor efectúa la difusión de un primer piloto en TDM (Multiplexación por División de Tiempo) en un primer conjunto de sub-bandas seguido por un segundo piloto en TDM en un segundo conjunto de sub-bandas en cada cuadro. Las sub-bandas en cada conjunto son seleccionados entre N-sub-bandas totales tal que 1) un símbolo de OFDM para el primer piloto de TDM contiene al menos S1 secuencias idénticas de piloto-1 de longitud L1 y 2) un símbolo de OFDM para el segundo piloto de TDM contiene al menos S2 secuencias idénticas de piloto-2 de longitud L2, donde L2 > L1, S1 x L1 = N, y S2 x L2 = N. El transmisor puede también difundir un piloto de FDM (Multiplexación por División Ortogonal de Frecuencia). Un receptor procesa el primer piloto TDM para obtener el tiempo del cuadro (por ejemplo, llevando a cabo la correlación entre secuencias diferentes de piloto-1) y además procesar el segundo piloto de TDM para obtener el tiempo del símbolo (por ejemplo, al detectar para el inicio de un estimado de respuesta de impulso del canal derivado del segundo piloto de TDM).
Abstract:
Para difundir diferentes tipos de transmisión que tienen diferentes hileras de cobertura en una red de difusión inalámbrica, cada estación de base procesa los datos para una transmisión de área de acuerdo con un primer modo (o esquema de codificación y modulación) para generar los símbolos de datos para una transmisión de área amplia, y para procesar los datos para una transmisión local de acuerdo con un segundo modo para generar los símbolos de datos para la transmisión local. Los modos primero y segundo se seleccionan sobre la base de una cobertura deseada para las transmisiones de área amplia y locales, respectivamente. La estación de base también genera pilotos e información de encabezamiento para las transmisiones de área local y de área amplia. Los datos, pilotos, e información de encabezamiento para las transmisiones de área amplia y local se efectúan en multiplexión hacia sus recorridos de transmisión, los que pueden ser diferentes conjuntos de sub-bandas de frecuencia, diferentes segmentos de tiempo o diferentes grupos de sub-bandas en diferentes segmentos de tiempo. Es posible también efectuar la multiplexión y la difusión de más de dos tipos diferentes de transmisión.
Abstract:
Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in ~super-frames ~. Each super-frame has a predetermined time duration and is further divided in to multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partition ed into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frame s of the same super-frame, one subblock per frame. Each data stream is allocat ed a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can selec t and receive individual data streams.
Abstract:
Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in “super-frames”. Each super-frame has a predetermined time duration and is further divided into multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partitioned into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frames of the same super-frame, one subblock per frame. Each data stream is allocated a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can select and receive individual data streams.
Abstract:
In an OFDM system, a transmitter (120) broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least Sl identical pilot-1 sequences of length Ll and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2 > Ll, Sl x Ll = N, and S2 x L2 = N. The transmitter (120) may also broadcast an FDM pilot. A receiver ( 170) processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from teh second TDM pilot).
Abstract:
Techniques to seamlessly switch reception between multimedia programs are described. For "continued decoding", a wireless device continues to receive, decode, decompress, and (optionally) display a current program, even after a new program has been selected, until overhead information needed to decode the new program is received. After receiving the overhead information, the wireless device decodes the new program but continues to decompress the current program. The wireless device decompresses the new program after decoding this program. For "early decoding", the wireless device receives a user input and identifies a program with potential for user selection. The identified program may be the one highlighted by the user input or a program anticipated to be selected based on the user input. The wireless device initiates decoding of the identified program, prior to its selection, so that the program can be decompressed and displayed earlier if it is subsequently selected.