Patent application number | Description | Published |
20080232504 | Methods and Systems For Ofdm Multiple Zone Partitioning - Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols. According to various embodiments of the invention, the zones of the first and second types can be partitioned in the OFDM frame based on time division multiplexing (TDM), frequency division multiplexing (FDM) or combined TDM/FDM. Examples of types of transmissions that could be transmitted in different zones of a single OFDM frame are OFDM multiple input multiple output (MIMO) transmissions and OFDM beam forming transmissions. | 09-25-2008 |
20080253469 | Methods and Systems for Ofdm Using Code Division Multiplexing - In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions. | 10-16-2008 |
20080268907 | Switching in a Distributed Access Network - The present invention provides conversion between SDUs transmitted between a central network controller and base stations and PDUs transmitted between the base stations and mobile terminals. For downlink communications, SDUs are transmitted from the central network controller and forwarded to the base stations in an active set. One base station will break down the SDUs to create PDUs to transmit to the mobile terminal. For uplink communications, the base station will receive PDUs from the mobile terminal, create SDUs from the PDUs, and transmit the SDUs to the central network controller. During switching events, continuity information received from a previously serving base station is processed by the mobile terminal and used to create continuity information to send to the currently serving base station and used to determine the appropriate PDU from which to start transmissions to the mobile terminal after the switching event. | 10-30-2008 |
20090022098 | MULTIPLEXING SCHEMES FOR OFDMA - Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic, in some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issuea such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems. | 01-22-2009 |
20090023468 | METHOD AND SYSTEM FOR PRIORITY-BASED STATE TRANSITION FOR HIGH SPEED DATA TRANSMISSION AND WIRELESS ACCESS NETWORKS - Apparatus and methods are provided for transitioning wireless devices between a plurality of states having increasing resource intensity from a least resource intensive state to a most resource intensive second state. All power-on wireless devices are ranked. A respective subset of the power-on wireless devices is assigned to each state, the power-on wireless devices of the subsets having rankings which increase with resource intensity of the state. Signalling is generated to the wireless devices to instruct them to implement any change in state. The priorities which are calculated for the purpose of state scheduling are preferably the same as those, or at least based upon the priorities used for packet scheduling. | 01-22-2009 |
20090060081 | Systems and methods for ofdm channelization - Systems and methods for OFDM channelization are provided that allow for the co-existence of sub-band channels and diversity channels. Methods of defining diversity sub-channels and sub-band sub-channels are provided, and systematic channel definition and labeling schemes are provided. | 03-05-2009 |
20090067405 | COMMUNICATION OF CONTROL INFORMATION IN WIRELESS COMMUNICATION SYSTEMS - A wireless system has a high rate data channel for time multiplexed communications to multiple mobile stations (MSs). Control channels include a forward link common power control channel and reverse link feedback channels for pilot, forward channel quality, and data acknowledgements from each MS. An MS can have an active state for data communications, for which these control channels are used at the full (time slot) rate, or a control hold state, in which acknowledgements are not needed and the others of these control channels can be shared among a plurality of MSs in the control hold state and each using a reduced rate such as ½, ¼, or ⅛ of the full rate. The arrangement can support an increased number of active MSs, facilitating an increased total throughput on the high rate data channel, without increasing system resources for the control channels. | 03-12-2009 |
20090129334 | Soft handoff in Ofdma system - The soft handoff in an OFDMA system. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone have subcarriers with a subchannel definition, for example, an identical permutation. | 05-21-2009 |
20090285163 | Resource Assignment Systems and Methods - In a wireless communication system, a base station assigns resources to mobile stations using indices. Each index is associated with an assignment schedule for assigning resources. Once the base station determines an assignment schedule to assign particular resources, it encodes the schedule into an index and transmits it. A mobile station receives the index and decodes it to recover the assignment schedule. Both the base station and the mobile station may use look-up tables and/or algorithms for storing or generating indices associated with assignment schedules. To assign resources so as to indicate transmission characteristics over the resources, the base station transmits assignment blocks. Each assignment block indicates original transmission, retransmission, persistent assignment, non-persistent assignment, HARQ signaling, RAS-HARQ signaling, DRCH assignment, and/or LRCH assignment. | 11-19-2009 |
20090303918 | ZONES FOR WIRELESS NETWORKS WITH RELAYS - Methods and systems are provided for use with wireless networks having once or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for an RS to initially access the network, access of the RS by MSs initially accessing the network, methods of allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions, and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e. | 12-10-2009 |
20090307484 | WIRELESS ACCESS POINT SECURITY FOR MULTI-HOP NETWORKS - Security in wireless communication networks that employ relay stations to facilitate communications between base stations and mobile stations is enhanced. In one embodiment, resource information provided to one or more relay stations from a base station or another relay station is encrypted prior to being delivered to the one or more relay stations. Only authorized relay stations are allocated an appropriate key necessary to decrypt the resource information. As such, only appropriate relay stations are able to access and use the resource information to effect communications directly or indirectly between the base stations and the mobile stations. In certain embodiments, the resource information is delivered between the various base and relay stations using either unicast or multicast delivery techniques. | 12-10-2009 |
20110026461 | COMMUNICATING OVER A WIRELESS LINK USING A DATA CONTAINER STRUCTURE THAT HAS PARTITIONS OF DIFFERENT TYPES - A wireless communications node communicates, over a wireless link, data in a data container structure that includes a configurable concatenation of partitions of different types. The partitions of different types in the data container structure carry information according to different wireless access technologies. | 02-03-2011 |
20110086662 | METHODS FOR CONTROL SIGNALING FOR WIRELESS SYSTEMS - To effectively and efficiently provide control information, a broadcast pointer channel (BPCH) may be used to identify the type and perhaps relative location of control information that is being provided in a given frame structure, such as a sub-frame, frame, or superframe. A sub-frame (or like framing entity, such a frame or superframe) may have a BPCH and a corresponding system control information segment in which control information may reside. The system control information segment may have any number of control information blocks, wherein each control information block that is present may correspond to a particular type of control information. The BPCH is used to identify the type of control information that is present in a corresponding system control information segment, and if needed or desired, the relative locations of the various control information. | 04-14-2011 |
20120026974 | LOAD BALANCING FOR AN AIR INTERFACE PROTOCOL ARCHITECTURE WITH A PLURALITY OF HETEROGENEOUS PHYSICAL LAYER MODES - A system and method for dynamic traffic load balancing with a multiple physical layer modes of an air interface protocol architecture, the protocol architecture residing in a base station and/or an access network that includes a base station and access gateway that include distributed and centralized components of the air interface protocol architecture. The traffic load balancing supports various multiplexing scenarios for scheduling communication data under time division multiple access and frequency division multiple access techniques for use in the multi-carrier wireless network. | 02-02-2012 |
20120224659 | PILOT DESIGN FOR WIRELESS SYSTEM - The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In the preferred embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy. | 09-06-2012 |
20120231776 | Communicating a Broadcast Message to Change Data Rates of Mobile Stations - A wireless communications network includes a base station to communicate with plural mobile stations over a wireless link. A broadcast message is sent to the plural mobile stations, with the broadcast message containing an indication for indicating to the plural mobile stations that the mobile stations are to change data rates for transmissions over a reverse wireless link. | 09-13-2012 |
20120281676 | SOFT HANDOFF IN OFDMA SYSTEM - Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation. | 11-08-2012 |
20120327905 | SOFT HANDOFF IN OFDMA SYSTEM - Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation. | 12-27-2012 |
20130003526 | MULTIPLEXING SCHEMES FOR OFDMA - Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic. In some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issues such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems. | 01-03-2013 |
20130003649 | METHODS AND SYSTEMS FOR WIRELESS NETWORKS WITH RELAYS - Methods and systems are provided for use with wireless networks having one or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e. | 01-03-2013 |
20130010679 | METHODS AND SYSTEMS FOR WIRELESS NETWORKS WITH RELAYS - Methods and systems are provided for use with wireless networks having one or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for an RS to initially access the network, access of the RS by MSs initially accessing the network, methods of allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions, and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e. | 01-10-2013 |
20130010729 | MULTIPLEXING SCHEMES FOR OFDMA - Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic. In some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issues such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems. | 01-10-2013 |
20130016603 | MULTIPLEXING SCHEMES FOR OFDMA - Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic. In some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issues such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems. | 01-17-2013 |
20130016650 | METHODS AND SYSTEMS FOR WIRELESS NETWORKS WITH RELAYS - Methods and systems are provided for use with wireless networks having one or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e. | 01-17-2013 |
20130022020 | MULTIPLEXING SCHEMES FOR OFDMA - Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic. In some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issues such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems. | 01-24-2013 |
20130028122 | METHODS AND SYSTEMS FOR WIRELESS NETWORKS WITH RELAYS - Methods and systems are provided for use with wireless networks having one or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for an RS to initially access the network, access of the RS by MSs initially accessing the network, methods of allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions, and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e. | 01-31-2013 |
20130077468 | Preambles in OFDMA System - The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems. | 03-28-2013 |
20130077469 | Preambles in OFDMA System - The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-I and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems. | 03-28-2013 |
20130246784 | WIRELESS ACCESS POINT SECURITY FOR MULTI-HOP NETWORKS - Security in wireless communication networks that employ relay stations to facilitate communications between base stations and mobile stations is enhanced. In one embodiment, resource information provided to one or more relay stations from a base station or another relay station is encrypted prior to being delivered to the one or more relay stations. Only authorized relay stations are allocated an appropriate key necessary to decrypt the resource information. As such, only appropriate relay stations are able to access and use the resource information to effect communications directly or indirectly between the base stations and the mobile stations. In certain embodiments, the resource information is delivered between the various base and relay stations using either unicast or multicast delivery techniques. | 09-19-2013 |
20130301685 | Methods and Systems for OFDM using Code Division Multiplexing - In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions. | 11-14-2013 |
20130301761 | Methods and Systems for Orthogonal Frequency Division Multiplexing (OFDM) Multiple Zone Partitioning - Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols. | 11-14-2013 |
20130322399 | SOFT HANDOFF IN OFDMA SYSTEM - Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation. | 12-05-2013 |
20130329818 | PILOT DESIGN FOR WIRELESS SYSTEM - The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy. | 12-12-2013 |
20140010268 | PILOT DESIGN FOR WIRELESS SYSTEM - The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy. | 01-09-2014 |
20140064243 | Method and Systems for OFDM Using Code Division Multiplexing - In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions. | 03-06-2014 |
20140161068 | Method and System for Providing an Uplink Structure and Minimizing Pilot Signal Overhead in a Wireless Communication Network - A method and system are provided having an uplink control structure and a pilot signal having minimal signal overhead for providing channel estimation and data demodulation in a wireless communication network. The uplink control structures enable mobile terminals to communicate with corresponding base stations to perform various functions including obtaining initial system access, submitting a bandwidth request, triggering a continuation of negotiated service, or providing a proposed allocation re-configuration header. A dedicated random access channel is provided to communicatively couple the base station and the mobile terminal so that the mobile terminal can select a random access signaling identification. A resource request is received at the base station to uplink resource information from the mobile terminal and an initial access information request is received from the mobile terminal to configure the base station connection. Pilot signals with varying density configurations are provided to include low density symbol patterns for multiple contiguous resource blocks and high density symbol patterns for single resource blocks. | 06-12-2014 |
20140269489 | System and Method for Unbalanced Relay-Based Wireless Communications - A method and system for wireless communication with a mobile device in which wireless communication is established with the mobile device. A base station is used to transmit directly to the mobile device in a downlink direction. A relay node is used to transmit to the base station communications received in an uplink direction from the mobile station. The relay node relays at least a portion of the uplink traffic received from the mobile station to the base station. | 09-18-2014 |
20140348271 | Methods and Systems for Orthogonal Frequency Division Multiplexing (OFDM) Multiple Zone Partitioning - Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols. | 11-27-2014 |
20150055725 | Pilot Design for Wireless System - The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy. | 02-26-2015 |
20150085821 | Methods and Systems for OFDM using Code Division Multiplexing - In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions. | 03-26-2015 |
20150085945 | Systems and Methods for OFDM Channelization - Systems and methods for OFDM channelization are provided that allow for the coexistence of sub-band channels and diversity channels. Methods of defining diversity sub-channels and sub-band sub-channels are provided and systematic channel definition and labeling schemes are provided. | 03-26-2015 |
20150085961 | Pilot Design for Wireless System - The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy. | 03-26-2015 |