Abstract: Techniques to transmit data with cyclic delay diversity and pilot staggering are described. For cyclic delay diversity, OFDM symbols having different cyclic delay durations are generated. The cyclic delay durations for the OFDM symbols may be selected to be time varying with respect to the cyclic delay durations for OFDM symbols transmitted by a neighboring base station. An FDM pilot is generated and multiplexed on multiple sets of subbands in different symbol periods. Waveforms for a second radio technology (e.g., W-CDMA) may be generated for data to be transmitted with this radio technology. The OFDM symbols are multiplexed onto time slots used for OFDM, and the waveforms for the second radio technology are multiplexed onto time slots used for this radio technology. One or multiple modulated signals may be generated based on the multiplexed OFDM symbols and waveforms. Each modulated signal is transmitted from a respective antenna.

Abstract: Techniques for transmitting overhead information to facilitate efficient reception of individual data streams are described. A base station may transmit multiple data streams on multiple data channels (or MLCs). The MLCs may be transmitted at different times and on different frequency subbands. The time-frequency location of each MLC may change over time. The overhead information indicates the time-frequency location of each MLC and may be sent as “composite” and “embedded” overhead information. The composite overhead information indicates the time-frequency locations of all MLCs and is sent periodically in each super-frame. A wireless device receives the composite overhead information, determines the time-frequency location of each MLC of interest, and receives each MLC at the indicated time-frequency location.

Abstract: Techniques to transmit data with cyclic delay diversity and pilot staggering are described. For cyclic delay diversity, OFDM symbols having different cyclic delay durations are generated. The cyclic delay durations for the OFDM symbols may be selected to be time varying with respect to the cyclic delay durations for OFDM symbols transmitted by a neighboring base station. An FDM pilot is generated and multiplexed on multiple sets of subbands in different symbol periods. Waveforms for a second radio technology (e.g., W-CDMA) may be generated for data to be transmitted with this radio technology. The OFDM symbols are multiplexed onto time slots used for OFDM, and the waveforms for the second radio technology are multiplexed onto time slots used for this radio technology. One or multiple modulated signals may be generated based on the multiplexed OFDM symbols and waveforms. Each modulated signal is transmitted from a respective antenna.

Abstract: Techniques for transmitting data in a wireless communication system are described. Physical channels to be sent in a super-frame are identified and allocated time slots in the super-frame. The coding and modulation for each physical channel are selected based on its capacity. The data for each physical channel is selectively encoded based on an outer code rate, e.g., for a Reed-Solomon code, and further encoded based on an inner code rate, e.g., for a Turbo code. The encoded data for each physical channel is mapped to modulation symbols based on a selected modulation scheme. The modulation symbols for each physical channel are further processed (e.g., OFDM modulated) and multiplexed onto the time slots allocated to the physical channel. Data to be sent using another radio technology (e.g., W-CDMA) is also processed and multiplexed onto time slots allocated for this radio technology.

Abstract: To transmit data in a manner to mitigate the deleterious effects of delay spread, the expected coverage areas for multiple transmissions to be sent in multiple time slots are initially determined. Cyclic prefix lengths for these transmissions are selected based on the expected coverage areas. The cyclic prefix length for each transmission may be selected from among a set of allowed cyclic prefix lengths based on the expected coverage area for that transmission, the pilot staggering used for the transmission, and so on. For example, a shorter cyclic prefix length may be selected for each local transmission, and a longer cyclic prefix length may be selected for each wide-area transmission. The selected cyclic prefix lengths may be signaled to the terminals. The transmissions are processed (e.g., OFDM modulated) based on the selected cyclic prefix lengths. The cyclic prefix lengths may be selected periodically, e.g., in each super-frame.

Abstract: Techniques for transmitting overhead information to facilitate efficient reception of individual data streams are described. A base station may transmit multiple data streams on multiple data channels (or MLCs). The MLCs may be transmitted at different times and on different frequency subbands. The time-frequency location of each MLC may change over time. The overhead information indicates the time-frequency location of each MLC and may be sent as “composite” and “embedded” overhead information. The composite overhead information indicates the time-frequency locations of all MLCs and is sent periodically in each super-frame. A wireless device receives the composite overhead information, determines the time-frequency location of each MLC of interest, and receives each MLC at the indicated time-frequency location.

Abstract: To transmit overhead information for broadcast and multicast services in a system that utilizes multiple radio technologies, time slots used for OFDM in a super-frame are initially ascertained. Overhead information for multiple streams to be sent in the time slots used for OFDM is generated. The overhead information conveys the time slots and the coding and modulation used for the streams and may be given in various forms. Multiple records may be formed for the overhead information for the streams. The overhead information for the streams is processed and time division multiplexed with the data for the streams in the super-frame. Information indicating the time slots used for OFDM in the super-frame may be sent separately or included in the overhead information. An indicator may also be appended to each stream to indicate whether there is any change in the overhead information for the stream in the next super-frame.

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.

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: 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: To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

Abstract: To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

Abstract: Techniques to transmit data with cyclic delay diversity and pilot staggering are described. For cyclic delay diversity, OFDM symbols having different cyclic delay durations are generated. The cyclic delay durations for the OFDM symbols may be selected to be time varying with respect to the cyclic delay durations for OFDM symbols transmitted by a neighboring base station. An FDM pilot is generated and multiplexed on multiple sets of subbands in different symbol periods. Waveforms for a second radio technology (e.g., W-CDMA) may be generated for data to be transmitted with this radio technology. The OFDM symbols are multiplexed onto time slots used for OFDM, and the waveforms for the second radio technology are multiplexed onto time slots used for this radio technology. One or multiple modulated signals may be generated based on the multiplexed OFDM symbols and waveforms. Each modulated signal is transmitted from a respective antenna.

Abstract: In an OFDM system, a transmitter 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 S1 identical pilot-1 sequences of length L1 and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2>L1, S1·L1=N, and S2·L2=N. The transmitter may also broadcast an FDM pilot. A receiver 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 the second TDM pilot).

Abstract: Iterative decoder employing multiple external code error checks to lower the error floor and/or improve decoding performance. Data block redundancy, sometimes via a cyclic redundancy check (CRC) or Reed Solomon (RS) code, enables enhanced iterative decoding performance. Improved decoding performance is achieved during interim iterations before the final iteration. A correctly decoded CRC block, indicating a decoded segment is correct with a high degree of certainty, assigns a very high confidence level to the bits in this segment and is fed back to inner and/or outer decoders (with interleaving, when appropriate) for improved iterative decoding. High confidence bits may be scattered throughout inner decoded frames to influence other bit decisions in subsequent iterations. Turbo decoders typically operate relatively well at regions where the BER is high; the invention improves iterative decoder operation at lower BERs, lowering the ‘BER floor’ that is sometimes problematic with conventional turbo decoders.

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: 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: 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.

Abstract: Iterative decoder employing multiple external code error checks to lower the error floor and/or improve decoding performance. Data block redundancy, sometimes via a cyclic redundancy check (CRC) or Reed Solomon (RS) code, enables enhanced iterative decoding performance. Improved decoding performance is achieved during interim iterations before the final iteration. A correctly decoded CRC block, indicating a decoded segment is correct with a high degree of certainty, assigns a very high confidence level to the bits in this segment and is fed back to inner and/or outer decoders (with interleaving, when appropriate) for improved iterative decoding. High confidence bits may be scattered throughout inner decoded frames to influence other bit decisions in subsequent iterations. Turbo decoders typically operate relatively well at regions where the BER is high; the invention improves iterative decoder operation at lower BERs, lowering the ‘BER floor’ that is sometimes problematic with conventional turbo decoders.

Abstract: An exemplary satellite communication system comprises a service provider unit communicably coupled to a number of subscriber units via satellite transmission. The service provider unit includes an encoder configured to encode source data into a serial transmit sequence, and is further capable of supporting at least two modes of operation. The serial transmit sequence includes a first unique word identifying a first mode of operation, and is followed by a first payload packet having a first number of channel symbols corresponding to a source packet encoded in accordance with the first mode of operation identified by the first unique word. The first payload packet is encapsulated by two unique words and the time interval between the two unique words is used to determine the first mode of operation identified by the first unique word.