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51.发明公开
公开(公告)号：EP1836820A1
公开(公告)日：2007-09-26
申请号：EP05855376.9
申请日：2005-12-21
发明人： WANG, Michael Mao , VRCELJ, Bojan , MUKKAVILLI, Krishna Kiran , KRISHNAMOORTHI, Raghuraman , VIJAYAN, Rajiv
IPC分类号： H04L27/26
CPC分类号： H04L5/0048 , H04L5/0007 , H04L5/0083 , H04L27/261
摘要： The embodiments utilize OFDM symbols to communicate network IDs. The IDs are encoded into symbols utilizing the network IDs as seeds to scramble respective pilots that are then transmitted by utilizing the symbols. The pilots can be structured into a single OFDM symbol and/or multiple OFDM symbols. The single symbol structure for transmitting the network IDs is independent of the number of network ID bits and minimizes frequency offset and Doppler effects. The multiple symbol structure allows a much coarser timing accuracy to be employed at the expense of transmitting additional symbols. Several embodiments employ a search function to find possible network ID candidates from a transmitted symbol and a selection function to find an optimum candidate from a network ID candidate list.
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公开(公告)号：EP1678851A2
公开(公告)日：2006-07-12
申请号：EP04795970.5
申请日：2004-10-22
发明人： MURALI, Ramaswamy , LING, Fuyun , VIJAYAN, Rajiv , WALKER, Kent G. , MANTRAVADI, Ashok , SUBRAMANIAM, Anand, D.
IPC分类号： H04H1/00
CPC分类号： H04L5/0041 , H04L5/0007 , H04L5/0044 , H04L5/0048 , H04L12/189 , H04W72/005
摘要： 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.
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53.发明公开PEAK-TO-AVERAGE POWER RATIO MANAGEMENT FOR MULTI-CARRIER MODULATION IN WIRELESS COMMUNICATION SYSTEMS 有权管理上到平均水平的表现欲了解更多支持调制在无线通信系统中的关系
公开(公告)号：EP1595345A2
公开(公告)日：2005-11-16
申请号：EP04711906.0
申请日：2004-02-17
发明人： VIJAYAN, Rajiv , AGRAWAL, Avneesh , JHA, Sanjay K.
IPC分类号： H04J1/00
CPC分类号： H04W72/0453 , H04L5/0007 , H04L5/0037 , H04L5/0066 , H04L27/2614 , H04W52/343 , H04W52/367
摘要： Techniques for managing peak-to-average power ratio (PAPR) for multi-carrier modulation in wireless communication systems. Different terminals in a multiple-access system may have different required transmit powers. The number of carriers to allocate to each terminal is made dependent on its required transmit power. Terminals with higher required transmit powers may be allocated fewer carriers (associated with smaller PAPR) to allow the power amplifier to operate at higher power levels. Terminals with lower required transmit powers may be allocated more carriers (associated with higher PAPR) since the power amplifier is operated at lower power levels. The specific carriers to assign to the terminals may also be determined by their transmit power levels to reduce out-of-band emissions. Terminals with higher required transmit powers may be assigned with carriers near the middle of the operating band, and terminals with lower required transmit powers may be assigned with carriers near the band edges.
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公开(公告)号：EP1579610A2
公开(公告)日：2005-09-28
申请号：EP03809055.1
申请日：2003-10-14
发明人： KADOUS, Tamer , AGRAWAL, Avneesh , VIJAYAN, Rajiv
IPC分类号： H04J1/00
CPC分类号： H04L5/006 , H04B7/0417 , H04L1/0003 , H04L1/0009 , H04L1/0071 , H04L1/0618 , H04L5/0023 , H04L5/0046 , H04L25/0206 , H04L25/0224 , H04L2025/03414 , H04W52/42
摘要： A 'power adaptive circular' (PAC) transmission scheme that can support both spatial multiplexing and transmit diversity for multi-carrier MIMO systems and has a number of desirable characteristics, including the ability to: transmit a variable number of symbol streams, provide transmit diversity for each transmitted symbol stream, support coded interference estimation technique at a receiver, and use power efficiently. In one method, at least one stream of symbols is received for transmission on a plurality of subbands and from a plurality of antennas. The at least one stream of symbols is multiplexed such that (1) the symbols in each stream are transmitted from the plurality of antennas (e.g., diagonally across the subbands and antennas) and (2) the at least one stream starts in the same subband. A stream of multiplexed symbols is formed for each antenna and further processed, and may be transmitted at full power available for the antenna.
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公开(公告)号：EP1570579A2
公开(公告)日：2005-09-07
申请号：EP03809054.4
申请日：2003-10-14
发明人： AGRAWAL, Avneesh , VIJAYAN, Rajiv , KADOUS, Tamer
IPC分类号： H04B1/00
CPC分类号： H04L1/0618 , H04B7/0417 , H04B7/0443 , H04B7/0465 , H04B7/0615 , H04B7/0891 , H04W52/34 , H04W52/42
摘要： A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas.; The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.
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公开(公告)号：EP1535404A1
公开(公告)日：2005-06-01
申请号：EP03752014.5
申请日：2003-09-04
发明人： GUPTA, Alok , VIJAYAN, Rajiv
CPC分类号： H04L25/0236
摘要： An improved channel estimation is disclosed. In one embodiment, initial channel estimation is performed using known training data sequence. The data packet received is demodulated based on the initial channel estimates, de-interleaved and decoded. The decoded data is then is re-encoded, interleaved and modulated to generate additional training symbols for updating the channel estimates throughout the received data packet.
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57.发明授权FREQUENCY TRACKING FOR COMMUNICATION SIGNALS USING M-ARY ORTHOGONAL WALSH MODULATION 失效率的影响对于新闻传输信号使用M档沃尔什正交调制
公开(公告)号：EP0829146B1
公开(公告)日：2005-03-02
申请号：EP97918684.8
申请日：1997-03-26
发明人： AGRAWAL, Avneesh , VIJAYAN, Rajiv
IPC分类号： H04B1/707
CPC分类号： H04B1/7085 , H04B1/709
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公开(公告)号：EP1121761A1
公开(公告)日：2001-08-08
申请号：EP99953179.1
申请日：1999-10-12
CPC分类号： H03M13/2957 , H03M13/2742 , H03M13/2757 , H03M13/2764 , H03M13/2771 , H03M13/2789 , H04L1/0043 , H04L1/005 , H04L1/0052 , H04L1/0066
摘要： The present invention is a novel and improved technique for performing coding with particular application to turbo, or iterative, coding techniques. In accordance with one embodiment of the invention, interleaving is performed by generating the address of a memory using a PN state generator. Data is written into a memory (26) in sequential order, and then read out using addresses specified by the PN state generator. To deinterleave, the interleaved data is written into a memory (16) using addresse specified by the PN state generator. To de interleave, the interleaved data is written into a memory (26) using addresses specified by the PN state generator, and then read out in sequential order. A set of PN state generators that provide excellent coding performance is provided.
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公开(公告)号：EP1112503A1
公开(公告)日：2001-07-04
申请号：EP99968717.1
申请日：1999-09-08
发明人： AGRAWAL, Avneesh , VIJAYAN, Rajiv , LEVANON, Nadav
IPC分类号： G01R29/08 , G01S1/04 , H04L27/233 , H03J7/04
CPC分类号： G01S1/045 , G01R29/0892 , H03J7/04 , H04L27/0014 , H04L2027/0067
摘要： An apparatus and method for generating an accumulated phase measurement (406) of a communication signal over a predetermined time interval. A frequency estimate of the signal is generate (402); the frequency estimate is then converted to a coarse phase measurement (404, 642). A phase error is generated based on the frequency estimate (644); the phase error is then converted to a fine phase measurement (646). The coarse and fine phase measurements are summed to yield an accumulated phase measurement (648).
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公开(公告)号：EP1031196A1
公开(公告)日：2000-08-30
申请号：EP98962804.5
申请日：1998-11-10
CPC分类号： H04B1/7077 , H04B1/70751 , H04B1/708 , H04B1/71 , H04B7/216 , H04B7/2637 , H04B2201/70702
摘要： The present invention is a system and method for increasing user capacity on a slotted random access channel in a spread spectrum communications system (100) by using a multi-part access probe (502). First and second parts (508, 510) of an access probe preamble (604) are modulated using a short PN code sequence (620), and the second part and remainder of the access probe (502) is modulated using a long PN code sequence. Information to be transmitted by the access probe (502) is modulated on the second part (606) of the access probe (502), and the access probe is transmitted so that the first part (508) of the probe preamble (604) falls within the boundaries of an access channel slot (402). In one embodiment, time slots (402) in access channels (400) used for access signal reception are made the length of the first part (508). In a further embodiment, time slots (402) in a plurality of adjacent access channels used for access signal reception may be longer than said first part (508) but are offset in time from each other by the length or period of the first part.
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