WO2017074537A1

WO2017074537A1 - Apparatuses for evolved node bs configured to communicate using robust puncturing-based multiplexing

Info

Publication number: WO2017074537A1
Application number: PCT/US2016/047192
Authority: WO
Inventors: Alexei Davydov; Christian Ibars Casas; Hong He; Seunghee Han; Gregory Morozov
Original assignee: Intel IP Corporation
Priority date: 2015-10-30
Filing date: 2016-08-16
Publication date: 2017-05-04
Also published as: CN108141312B; DE112016004931T5; HK1256112A1; CN108141312A

Abstract

Disclosed are apparatuses for an evolved Node B (eNB). An apparatus for an eNB includes control circuitry configured to puncture at least a portion of orthogonal frequency domain multiplexing (OFDM) symbols with a shortened transmission time interval (TTI) symbol and control a communication device of the eNB to transmit the OFDM symbols and the shortened TTI symbol, wherein mapping of communication data to resource elements of the OFDM symbols and the puncturing of the at least a portion of the OFDM symbols is carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as or less than a ratio of a number of systematic bits in the communication data to a number of parity bits in the communication data.

Description

APPARATUSES FOR EVOLVED NODE BS CONFIGURED TO COMMUNICATE USING ROBUST PUNCTURING-BASED MULTIPLEXING

Related Applications

[0001]This application claims priority to U.S. Provisional Patent 62/331 ,773, filed May 4, 2016, and U.S. Provisional Patent 62/248,899, filed October 30, 2015, the entire disclosure of each of which is hereby incorporated herein by this reference.

Technical Field

[0002] The disclosure relates generally to punctured downlink communications, and more specifically to downlink data symbols punctured by shortened transmission time interval (TTI) downlink data symbols.

Background

[0003] In recent years, demand for access to fast mobile wireless data for mobile electronic devices has fueled the development of the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) communication system (hereinafter "LTE system"). End users access the LTE system using mobile electronic devices (known as "user equipment" or equivalently "UE") including appropriate electronics and software modules to communicate according to standards set forth by 3GPP.

Brief Description of the Drawings

[0004] FIG. 1 is a simplified illustration of a normal TTI PDSCH punctured by shortened TTI PDSCH.

[0005] FIG. 2 is a simplified block diagram of a convolution turbo code of LTE.

[0006] FIG. 3 is a simplified flowchart illustrating interleaving and multiplexing of coded bits.

[0007] FIG. 4 is a simplified block diagram of a wireless communication system, according to some embodiments.

[0008] FIG. 5 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments.

[0009] FIG. 6 is a simplified flow diagram illustrating an example of multiplexing of systematic bits and parity bits according to some embodiments.

[0010] FIG. 7 is a simplified illustration of an example of locations of reserved OFDM symbols, according to some embodiments.

[0011] FIG. 8 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments. [0012] FIG. 9 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments.

[0013] FIG. 10 is a simplified illustration of example ordering of code blocks for HARQ retransmission according to the method of FIG. 9.

[0014] FIG. 1 1 is a block diagram illustrating components, according to some example embodiments.

[0015] FIG. 12 illustrates, for some embodiments, example components of an electronic device.

[0016] FIG. 13 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments.

[0017] FIG. 14 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments.

[0018] FIG. 15 is a simplified flowchart illustrating a method of operating a UE, according to some embodiments.

[0019] FIG. 16 is a simplified flowchart illustrating a method of operating an eNB, according to some embodiments.

Detailed Description of Preferred Embodiments

[0020] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the disclosure made herein. It should be understood, however, that the detailed description and the specific examples, while indicating examples of embodiments of the disclosure, are given by way of illustration only, and not by way of limitation. From the disclosure, various substitutions, modifications, additions, rearrangements, or combinations thereof within the scope of the disclosure may be made and will become apparent to those of ordinary skill in the art.

[0021] In accordance with common practice, the various features illustrated in the drawings may not be drawn to scale. The illustrations presented herein are not meant to be actual views of any particular apparatus (e.g., device, system, etc.) or method, but are merely idealized representations that are employed to describe various embodiments of the disclosure. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may be simplified for clarity. Thus, the drawings may not depict all of the components of a given apparatus or all operations of a particular method.

[0022] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents,

electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Some drawings may illustrate signals as a single signal for clarity of presentation and description. It should be understood by a person of ordinary skill in the art that the signal may represent a bus of signals, wherein the bus may have a variety of bit widths, and the present disclosure may be

implemented on any number of data signals including a single data signal.

[0023] The various illustrative logical blocks, modules, circuits, and algorithm acts described in connection with embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and acts are described generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the embodiments of the disclosure described herein.

[0024] In addition, it is noted that the embodiments may be described in terms of a process that is depicted as a flowchart, a flow diagram, a structure diagram, a signaling diagram, or a block diagram. Although a flowchart or signaling diagram may describe operational acts as a sequential process, many of these acts can be performed in another sequence, in parallel, or substantially concurrently. In addition, the order of the acts may be rearranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. Furthermore, the methods disclosed herein may be implemented in hardware, software, or both. If

implemented in software, the functions may be stored or transmitted as one or more computer-readable instructions (e.g., software code) on a computer-readable medium. Computer-readable media includes both computer storage media (i.e., non-transitory media) and communication media including any medium that facilitates transfer of a computer program from one place to another.

Low latency is a key parameter in the development of LTE. Due to properties of internet protocols, lower latency over wireless interfaces is used to realize higher data rates in conjunction with carrier-aggregation enhancements. With the recent increasing data rates in LTE, it is important to ensure that latency evolves in a similar manner. In addition, lower latency should also enable support for new applications. Some of the envisioned applications, such as traffic safety/control and control of critical infrastructure and industry processes, may employ very low latency.

Examples of technologies to provide low latency in LTE systems include instant uplink access, transmission-time interval (TTI) shortening (to 7, 2 or even 1 OFDM symbols), and reduced processing time in terminals (e.g., UEs) and base stations (e.g., eNBs).

It should be noted that the shortened TTI should properly co-exist with legacy TTI. That is, multiplexing of the conventional resource allocation and the resource allocation with shortened TTI should have a minimum impact on each other. The conventional approach supporting such co-existence relies on puncturing shortened TTI physical downlink shared channel (PDSCH) to the legacy PDSCH region or frequency division multiplexing (FDM) between shortened TTI and legacy TTI. The puncturing option to the legacy PDSCH region is usually efficient in terms of resource utilization since both shortened TTI and legacy TTI PDSCHs can be scheduled on demand. Puncturing of the PDSCH with shortened TTI to legacy TTI may, however, create strong intra-cell interference on the received PDSCH.

Accordingly, the PDSCH puncturing at the UE receiver should be handled properly to decrease the impact of such interference.

[0025] In various embodiments, the evolved Node B (eNB) should support

simultaneous operation of downlink PDSCH with normal and shortened TTIs. More specifically, within a single downlink subframe, the PDSCH of different TTIs should be multiplexed with each other. Due to a limited number of orthogonal

frequency-division multiplexing (OFDM) symbols, resource allocation of the PDSCH with shortened TTI is likely to be wideband. As a result, the PDSCH with normal TTI is likely to be punctured by the PDSCH with shortened TTI as illustrated in FIG. 1 .

[0026] FIG. 1 is a simplified illustration of a normal TTI PDSCH 1 10 punctured by shortened TTI PDSCH 1 12. As illustrated in FIG. 1 , the shortened TTI PDSCH 1 12 overlaps the normal TTI PDSCH 1 10 in both bandwidth and time. For legacy user equipment (UEs) receiving the normal TTI PDSCH 1 10, bits punctured by the shortened TTI PDSCH 1 12 will not be properly received because these bits have been punctured.

[0027] In 3GPP, the input bit sequence prior to turbo encoding, depending on the size of the transport block, can be segmented into two or more code blocks. The segmentation is applied when the transport block size is above 6144 bits. The coded bit sequence after segmentation is denoted as

cr0> ^crl> ^cr2> ^cr3> ^■■■ > ^cr(K_r-L-l) -

If the transport block size is less than or equal to 6144 bits, segmentation may not be used.

[0028] FIG. 2 is a simplified block diagram of a convolution turbo code 200 of LTE. The convolution turbo code 200 is a systematic parallel concatenated convolutional code including two eight-state constituent encoders 230 and one turbo code internal interleaver 240. Each constituent encoder 230 is independently terminated by tail bits.

[0029] For an input block size of K bits (i.e., "systematic bits," or equivalently

"information bits"), the output of a turbo encoder includes three length K streams corresponding to the systematic bits, and two parity bit streams (sometimes referred to herein as the "Systematic," "Parity 1 ," and "Parity 2" bits, respectively), as well as 12 tail bits due to trellis termination. Multiplexing of the systematic and parity bits is described in current 3GPP standards. After encoding according to the standards, the parity bits are interleaved using sub-block interleaving, and multiplexed in the coded bit sequence, as shown in FIG. 3.

[0030] FIG. 3 is a simplified flowchart illustrating interleaving and multiplexing of coded bits 312, 314, 316 (sometimes referred to herein separately as systematic bits 312, Parity 1 bits 314, and Parity 2 bits 316). The systematic bits 312 are input into the convolution turbo code 200 of FIG. 2, and the systematic bits 312, Parity 1 bits 314 and Parity 2 bits 316 are output by the convolution turbo code 200. The parity bits (Parity 1 and Parity 2) are interleaved and multiplexed 320 to produce

interleaved parity bits 318. Resulting coded bits 312, 318 include the systematic bits 312 and the interleaved parity bits 318. The systematic bits 312 are not interleaved with the parity bits. [0031] The coded bits 312, 318 are then modulated in accordance to one or more modulation schemes (e.g., QPSK, 16QAM, 64QAM, 256QAM, etc.). The modulated coded bits are then mapped on the PDSCH resource elements in a frequency first order. In other words, the modulated coded bits are mapped to PDSCH resource elements across all subcarriers in one OFDM symbol, and then across OFDM symbols. As a result, one or more of the OFDM symbols may be heavily laden with modulated coded bits corresponding to the systematic bits 312 as opposed to modulated coded bits corresponding to the Parity 1 bits 314 and the Parity 2 bits 316.

[0032] Considering multiplexing of the coded bits and the frequency first mapping of PDSCH to resource element (RE) mapping, the systematic and parity bits would be non-uniformly distributed across OFDM symbols. For example, some of the OFDM symbols may be more loaded by the systematic bits 312, and the other OFDM symbols may be more loaded by the parity bits 314, 316. In such non-uniformly distributed circumstances, PDSCH puncturing of symbols containing most of the systematic bits 312 would deteriorate the PDSCH performance because

reconstruction of the punctured systematic bits 312 at receiving UEs using the parity bits would be more computationally intensive than if the systematic bits 312 were received, even assuming that enough non-punctured parity bits 314, 316 are received to reconstruct the systematic bits 312.

[0033] Disclosed herein are apparatuses for eNBs that are configured to provide normal TTI PDSCH communications that are punctured with low TTI PDSCH communications, but that are more robust to the drawbacks of puncturing than legacy eNBs.

[0034] In some embodiments, disclosed is a computer-readable storage medium including computer-readable instructions stored thereon. The computer-readable instructions are configured to instruct at least one processor to map communication data including systematic bits and parity bits to resource elements of orthogonal frequency domain multiplexing (OFDM) symbols. The parity bits are generated from the systematic bits. The computer-readable instructions are also configured to instruct the at least one processor to map other communication data to a shortened transmission time interval (TTI) symbol having a shorter TTI than a TTI of the OFDM symbols. The computer-readable instructions are further configured to instruct the at least one processor to puncture at least a portion of the OFDM symbols with the shortened TTI symbol, and control a communication device to transmit the OFDM symbols and the shortened TTI symbol. The mapping of the communication data to the resource elements of the OFDM symbols and the puncturing of the at least portion of the OFDM symbols is carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as or less than a ratio of a number of systematic bits in the communication data to a number of parity bits in the communication data.

[0035] In some embodiments, disclosed is an apparatus for an evolved Node B (eNB) including one or more processors, and one or more data storage devices operably coupled to the one or more processors. The one or more data storage devices include computer-readable instructions stored thereon. The

computer-readable instructions are configured to instruct the one or more processors to generate information correlated to a degree of puncturing of soft channel bits of previously transmitted orthogonal frequency domain multiplexing OFDM symbols that have been punctured with shortened transmission time interval (TTI) symbols. The shortened TTI symbols have a TTI that is shorter than a TTI of the OFDM symbols. The information is configured to enable a user equipment (UE) to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold. The computer-readable instructions are also configured to control a communication device to transmit the information.

[0036] In some embodiments, disclosed is an apparatus for an evolved Node B (eNB) including a communication device and control circuitry. The control circuitry is configured to puncture orthogonal frequency domain multiplexing (OFDM) symbols including a plurality of code blocks with shortened transmission time interval (TTI) symbols having a TTI that is shorter than a TTI of the OFDM symbols. The plurality of code blocks are subjected to the puncturing in a first order. The control circuitry is also configured to control a communication device to transmit the OFDM symbols to a user equipment (UE). The control circuitry is further configured to puncture the plurality of code blocks for a retransmission, the plurality of code blocks subjected to the puncturing in a second order that is different from the first order, and control the communication device to retransmit the OFDM symbols subjected to the puncturing according to the second order in a hybrid automatic repeat request (HARQ) process. [0037] In some embodiments, disclosed is an apparatus for a user equipment (UE). The UE includes a central processing unit (CPU) configured to process OFDM symbols received from an evolved Node B (eNB), and process information received from the eNB. The information is correlated to a degree of puncturing of soft channel bits of previously transmitted OFDM symbols that have been punctured with shortened transmission time interval (TTI) symbols. The shortened TTI symbols have a TTI that is shorter than a TTI of the OFDM symbols. The UE also includes baseband circuitry configured to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

[0038] FIG. 4 is a simplified block diagram of a wireless communication system 400, according to some embodiments. The wireless communication system 400 includes an evolved Node B (eNB) 410 (also referred to sometimes herein as "base station" 410) and user equipment (UEs) 420 (e.g., cellular communications enabled electronic devices). The base station 410 includes communication elements 418 (e.g., an antenna, transmission circuitry, receiving circuitry, etc.) configured to engage in wireless communication with communication elements 428 (e.g., a communication device) of the UEs 420.

[0039] The base station 410 and the UEs 420 include control circuitry 412, 422, respectively, configured to perform functions of embodiments described herein. By way of non-limiting example, the control circuitry 412, 422 is configured to employ one or more of various approaches for minimizing performance loss of PDSCH with normal TTI due to PDSCH puncturing by PDSCH with shortened TTI. For example, in some embodiments, the control circuitry 412 is configured to employ at least one of interleaving or randomizing of the puncturing between systematic and parity bits. In some embodiments, such interleaving or randomizing may be performed by PDSCH mapping in time domain first (across OFDM symbols). In some

embodiments, such interleaving or randomizing may be performed through additional interleaving and /or multiplexing across systematic and parity bits. As a result, a more equal distribution of the punctured bits may correspond to parity bits 318 instead of a non-uniform amount of punctured bits corresponding to the systematic bits (e.g., 1/3 systematic bits 312, 1/3 Parity 1 bits 314, and 1/3 Parity 2 bits 316; 1/2 systematic bits 312 and 1/2 parity bits 318). In some embodiments, the puncturing and/or mapping may be performed such that less than or equal to half the punctured bits correspond to systematic bits (e.g., including none of the systematic bits being punctured). In some embodiments, the puncturing and/or mapping may be performed such that less than or equal to one-third of the punctured bits correspond to systematic bits.

[0040]Another approach the control circuitry 412 may employ for minimizing performance loss of PDSCH with normal TTI due to PDSCH puncturing by PDSCH with shortened TTI employs mapping of PDSCH starting from protected OFDM symbols where PDSCH puncturing is not used. In other words, certain normal TTI OFDM symbols are reserved, and the reserved OFDM symbols are not punctured. Systematic bits 312 (e.g., the most critical of the systematic bits 312) may be mapped to these reserved OFDM symbols first so that the systematic bits 312 are not interfered with.

[0041] Still another approach the control circuitry 412 may employ for minimizing performance loss of PDSCH with normal TTI due to PDSCH puncturing by PDSCH with shortened TTI employs transmitting information correlated to a degree of puncturing of soft channel bits of previously transmitted OFDM symbols that have been punctured with low TTI symbols. The information is configured to enable a UE to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold. In other words, the control circuitry may schedule, with control signaling, flushing of the previously received soft channel bits for a given HARQ process (disabling of soft combining). Accordingly, a UE 420 may not expend its resources to try to combine a heavily punctured OFDM symbol, which does not include the intended information, with a retransmission of the OFDM symbol, which may include the intended information. As a result, efficiency may be improved.

[0042] The control circuitry 422 of the UE 420 is configured to process the OFDM symbols transmitted by the eNB 410. In embodiments where the eNB transmits information correlated to the degree of puncturing of soft channel bits of previously transmitted OFDM symbols, the control circuitry 422 may disable soft combining of the soft channel bits with bits of a retransmission responsive to the degree of puncturing of the soft channel bits being greater than the predetermined threshold. [0043] Yet another approach the control circuitry 412 may employ for minimizing performance loss of PDSCH with normal TTI due to PDSCH puncturing by PDSCH with shortened TTI employs reordering code blocks for HARQ retransmission if PDSCH is transmitted using multiple code blocks (i.e., the transport block size is above 6144 bits). In other words, the order of the code blocks for HARQ retransmission may be different from the order of the code blocks in the initial transmission. Accordingly, given a puncturing pattern used by the eNB 410, different bits of the OFDM symbols may be punctured in the retransmission than the initial transmission because the code blocks are subjected to the puncturing pattern in a different order. As a result, a number of retransmissions of the code blocks may be reduced because the code blocks that are heavily punctured are alternated for retransmissions.

[0044] The control circuitry 412, 422 may be configured to perform one or more processes. By way of non-limiting example, the control circuitry 412, 422 may be configured to perform one or more of the methods 500, 600, 800, 900, 1300, 1400, 1500, and 1600 illustrated in FIGS. 5, 6, 8, 9, 13, 14, 15, and 16, respectively. By way of non-limiting example, these functions may be performed using application circuitry 1202 (FIG. 12), baseband circuitry 1204 (FIG. 12), hardware resources 1 100 (FIG. 1 1 ), other circuitry, or combinations thereof.

[0045] The control circuitry 412, 422 includes one or more processors 414, 424 (sometimes referred to herein as "processor" 414, 424) operably coupled to one or more data storage devices 416, 426 (sometimes referred to herein as "storage" 416, 426). The processor 414, 424 includes any of a central processing unit (CPU), a microcontroller, a programmable logic controller (PLC), a programmable device, other processing devices, or combinations thereof. In some embodiments the processor 414, 424 also includes one or more hardware elements (not shown) configured to perform at least a portion of the functions the control circuitry 412, 422 is configured to perform. By way of non-limiting example, the processor 414, 424 may include an application specific integrated circuit (ASIC), a system on chip (SOC), an array of logic gates, an array of programmable logic gates (e.g., a field programmable gate array (FPGA)), other hardware elements, or combinations thereof. The processor 414, 424 is configured to execute computer-readable instructions stored on the storage 416, 426. [0046] The storage 416, 426 may include non-transitory computer-readable storage media. By way of non-limiting example, the storage 416, 426 includes volatile storage (e.g., random access memory (RAM)), non-volatile storage (e.g., read only memory (ROM)), or combinations thereof. In some embodiments, the processor 414, 424 may be configured to transfer computer-readable instructions stored in nonvolatile storage of the storage 416, 426 to volatile storage of the storage 416, 426 for execution. By way of non-limiting example, the storage 416, 426 may include dynamic RAM (DRAM), electrically programmable read-only memory (EPROM), a hard drive, a solid state drive, a Flash drive, a magnetic disc, removable media (e.g., memory cards, thumb drives, optical discs, etc.), or other storage devices.

[0047] The computer-readable instructions stored on the storage 416, 426 are configured to instruct the processor 414, 424 to perform at least a portion of the operations the control circuitry 412, 422 is configured to perform. By way of non-limiting example, the computer-readable instructions may be configured to instruct the processor 414, 424 to perform one or more of the methods 500, 600, 800, 900, 1300, 1400, 1500, and 1600 illustrated in FIGS. 5, 6, 8, 9, 13, 14, 15, and 16, respectively. Further description of examples of the control circuitry 412, 422 is provided below with reference to FIGS. 1 1 and 12.

[0048] FIG. 5 is a simplified flowchart 500 illustrating a method of operating an eNB 410 (FIG. 4), according to some embodiments. The method 500 includes mapping 510 communication data including systematic bits and parity bits to resource elements of OFDM symbols. The parity bits are generated from the systematic bits (e.g., using the convolution turbo code 200 of FIG. 2). The method 500 also includes mapping 520 other communication data to a shortened transmission time interval (TTI) symbol. The method 500 further includes puncturing 530 at least a portion of the OFDM symbols with the shortened TTI symbol.

[0049] Mapping 520 of the communication data to the resource elements of the OFDM symbols and puncturing 530 of the at least a portion of the OFDM symbols are carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as a ratio of a number of systematic bits in the communication data to a number of parity bits in the

communication data (e.g., in embodiments where there are an equal number of systematic bits, Parity 1 bits, and Parity 2 bits, the ratio may be about 1/3). In some embodiments, puncturing 530 at least a portion of the OFDM symbols with the shortened TTI symbol includes puncturing bits of the at least a portion of the OFDM symbols randomly. In some embodiments, mapping 520 of the communication data to the resource elements of the OFDM symbols includes interleaving the parity bits with the systematic bits within the OFDM symbols. In some embodiments, mapping 520 of the communication data to the resource elements of the OFDM symbols includes mapping the communication data to the resource elements of the OFDM symbols in a time domain first across the OFDM symbols.

[0050] In some embodiments, mapping 520 of the communication data to the resource elements of the OFDM symbols and puncturing 530 of the at least a portion of the OFDM symbols includes reserving some of the OFDM symbols, puncturing only non-reserved OFDM symbols with the shortened TTI symbol, and mapping the systematic bits of the communication data to the reserved OFDM symbols before mapping remaining ones of the systematic bits to the non-reserved OFDM symbols. In other words, PDSCH is mapped starting from the protected OFDM symbols where PDSCH puncturing is not used. An example of such embodiments is illustrated in FIG. 7. In some embodiments, the method 500 further includes identifying a subset of the systematic bits as important systematic bits, and mapping the important systematic bits to the reserved OFDM symbols before mapping others of the systematic bits to the reserved OFDM symbols.

[0051] In some embodiments, mapping 520 of the communication data to the resource elements of the OFDM symbols includes mapping the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index. In some embodiments, mapping the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index includes mapping the communication data to the resource elements of the OFDM symbols in an order of 4, 7, 8, 1 1 , 2, 3, 5, 6, 9, 10, 12, 13 symbol index within a subframe.

[0052] The method 500 also includes transmitting 540 the OFDM symbols and the shortened TTI symbol to one or more user equipment (UEs).

[0053] In some embodiments, randomization of the puncturing between systematic and parity bits may be used. This may be accomplished by PDSCH mapping in the time domain first (across OFDM symbols). The mapping to resource elements (k, I) on antenna port p not reserved for other purposes is in increasing order of the index I, starting with the first slot in a subframe and then over the index k over the assigned physical resource blocks.

[0054] In some embodiments, additional interleaving and /or multiplexing across systematic and parity bits may be used instead of, or in addition to, mapping in the time domain first. An example of this approach is illustrated in FIG. 6.

[0055] FIG. 6 is a simplified flow diagram illustrating an example of multiplexing 600 of systematic bits 612 and parity bits 614, 616, according to some embodiments. The systematic bits 612 are input into the convolution turbo code 200 of FIG. 2, and the systematic bits 612, Parity 1 bits 614 and Parity 2 bits 614 are output by the convolution turbo code 200. The parity bits (Parity 1 and Parity 2) are interleaved 620 to produce interleaved parity bits 618. Resulting coded bits 612, 618 include the systematic bits 612 and the interleaved parity bits 618.

[0056] The systematic bits 612 and the parity bits 618 are then interleaved and multiplexed 630 to produce coded bits 632. The coded bits 632 include the systematic bits 612 and the parity bits 618 interleaved together. Accordingly, even if the coded bits 632 are mapped to resource elements in an increasing order over the index k, there may be uniform puncturing over those of the coded bits 632 that correspond to the systematic bits 612, the Parity 1 bits 614, and the Parity 2 bits 616. As a result, punctured OFDM symbols will not necessarily be heavy laden with systematic bits 612, and less reconstruction of systematic bits 612 with parity bits 618 at the receiver may be employed, increasing overall efficiency.

[0057] FIG. 7 is a simplified illustration of an example of locations of reserved OFDM symbols 750, according to some embodiments. In some embodiments, PDSCH may have a shortened TTI to be overlapped with zero power (ZP) channel state

information reference signal (CSI-RS) resource(s). In such embodiments, some of the OFDM symbols of PDSCH with normal TTI may never be punctured (e.g. , reserved OFDM symbols 750), and therefore, may be more protected than other OFDM symbols. In such embodiments, a PDSCH resource element mapping for normal TTI should be modified in such a way as to place the more important systematic bits on the reserved OFDM symbols 750 first. The remaining bits may be placed on the other OFDM symbols, which may be punctured by PDSCH with shortened TTI. For example, the PDSCH resource element mapping may be mapped to OFDM symbols in the order 4,7,8, 1 1 ,2,3,5,6,9, 10, 12, 13, as shown in FIG. 7). [0058] FIG. 8 is a simplified flowchart illustrating a method 800 of operating an eNB 410 (FIG. 4), according to some embodiments. The method 800 includes puncturing 810 one or more OFDM symbols with one or more shortened TTI symbols. The method 800 also includes transmitting 820 the OFDM symbols and the shortened TTI symbols to one or more UEs. The method 800 further includes transmitting 830 information correlated to a degree of puncturing of soft channel bits of the previously transmitted OFDM symbols to the one or more UEs. In some embodiments, transmitting 830 information correlated to a degree of puncturing includes

transmitting the information in a downlink control information (DCI) message. The method 800 also includes retransmitting 840 the one or more OFDM symbols.

[0059] The information is configured to enable the one or more UEs to disable soft combining of the soft channel bits with bits of a retransmission of the one or more OFDM symbols for a HARQ process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold. In some

embodiments, the predetermined threshold is about 30%. In some embodiments, the predetermined threshold is 0% (e.g., if puncturing happened on the first transmission the OFDM symbol should not be used for combining with the

re-transmission.) The predetermined threshold may depend upon eNB

implementation and used modulation and coding schemes (MCS). For example, if the coding rate was relatively low (e.g., 1/6), a relatively high threshold may be used. If the coding rate was relatively high (e.g., 3/4), a relatively low threshold may be used (e.g., 5%).

[0060] In some embodiments, the information correlated to the degree of puncturing may indicate the degree of puncturing, which specific resource elements have been punctured, other information, or combinations thereof. In such embodiments, the UE itself may make the determination of whether and which soft bits should be used to combine with the retransmitted bits in the HARQ process.

[0061] In some embodiments, PDSCH is scheduled with control signaling (e.g., using (DCI) messaging) indicating that the previously received soft channel bits for a given HARQ process should be flushed (disabling of soft combining). Accordingly, the information correlated to the degree of puncturing of the soft channel bits may include a command or indicator indicating whether the soft channel bits should be used in recombination in the HARQ process. In some embodiments, the DCI message may instruct the UE to flush the received soft channel bits for a given HARQ process received previously. The DCI message may instruct the UE to not perform soft combining of the scheduled PDSCH with previously transmitted

PDSCH. Such operation may be used if significant puncturing was used in the original PDSCH transmission. Given that the eNB may not be aware of the potential PDSCH puncturing during the scheduling decision, this approach would be helpful for the eNB to indicate to the UE that the previous PDSCH transmission did not include information that should be used for the soft bits combining.

[0062] FIG. 9 is a simplified flowchart illustrating a method 900 of operating an eNB, according to some embodiments. The method 900 includes puncturing 910 OFDM symbols including a plurality of code blocks with low TTI symbols. The plurality of code blocks are subjected to the puncturing in a first order. The method 900 also includes transmitting 920 the OFDM symbols to a UE.

[0063] The method 900 further includes puncturing 930 the plurality of code blocks for a retransmission, the plurality of code blocks being subjected to the puncturing in a second order that is different from the first order. The method 900 includes retransmitting 940 the OFDM symbols subjected to the puncturing according to the second order in a HARQ process.

[0064] FIG. 10 is a simplified illustration 1000 of example ordering of code blocks 1060 for HARQ retransmission according to the method 900 of FIG. 9. If PDSCH is transmitted using multiple code blocks 1060 (i.e., the transport block 1070 size is above 6144 bits), the order of the code blocks for HARQ retransmission may be different from the order of the code block in the initial transmission. In FIG. 10, the indices of the code blocks 1060 for different transmissions are denoted by

{k₀, k_lt ... , k_c__x, }, {i₀, i_lt ... , i_c__lt }, and {j₀,j_lt ... ,}_c__x, }. Accordingly, in some embodiments, the order of the code blocks may be different for each successive transmission of the HARQ process.

[0065] FIG. 1 1 is a block diagram illustrating components, according to some example embodiments, that are able to read instructions from a machine-readable or computer-readable medium (e.g., a machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, FIG. 1 1 shows a diagrammatic representation of hardware resources 1 100 including one or more processors (or processor cores) 1 1 10, one or more memory/storage devices 1 120, and one or more communication resources 1 130, each of which is

communicatively coupled via a bus 1 140. [0066] The processors 1 1 10 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 1 1 12 and a processor 1 1 14. The memory/storage devices 1 120 may include main memory, disk storage, or any suitable combination thereof.

[0067] The communication resources 1 130 may include interconnection and/or network interface components or other suitable devices to communicate with one or more peripheral devices 1 104 and/or one or more databases 1 106 via a network 1 108. For example, the communication resources 1 130 may include wired

communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components.

[0068] Instructions 1 150 may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors 1 1 10 to perform any one or more of the methodologies discussed herein. The instructions 1 150 may reside, completely or partially, within at least one of the processors 1 1 10 (e.g., within the processor's cache memory), the memory/storage devices 1 120, or any suitable combination thereof. Furthermore, any portion of the instructions 1 150 may be transferred to the hardware resources 1 100 from any combination of the peripheral devices 1 104 and/or the databases 1 106. Accordingly, the memory of processors 1 1 10, the memory/storage devices 1 120, the peripheral devices 1 104, and the databases 1 106 are examples of computer-readable and machine-readable media. By way of non-limiting example, the instructions 1 150 may be configured to instruct any of the processors 1 1 10 to perform any of the operations or functions discussed herein.

[0069] As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

[0070] Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. FIG. 12 illustrates, for some embodiments, example components of an electronic device 1200. In some embodiments, the electronic device 1200 may be, may implement, may be incorporated into, or otherwise may be a part of a user equipment (UE) (e.g., the UEs 420 of FIG. 4), a cellular base station (e.g., the base stations 1 10 of FIG. 1 ), or some other suitable electronic device. In some embodiments, the electronic device 1200 may include application circuitry 1202, baseband circuitry 1204, Radio

Frequency (RF) circuitry 1206, front-end module (FEM) circuitry 1208 and one or more antennas 1210, coupled together at least as shown in FIG. 12.

[0071] The application circuitry 1202 may include one or more application

processors. For example, the application circuitry 1202 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors

and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0072] The baseband circuitry 1204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 1204 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 1206 and to generate baseband signals for a transmit signal path of the RF circuitry 1206. Baseband processing circuity 1204 may interface with the application circuitry 1202 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 1206. For example, in some embodiments, the baseband circuitry 1204 may include a second generation (2G) baseband processor 1204A, third generation (3G) baseband processor 1204B, fourth generation (4G) baseband processor 1204C, and/or other baseband processor(s) 1204D for other existing generations, generations in development, or generations to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 1204 (e.g., one or more of baseband processors 1204A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 1206. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 1204 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 1204 may include convolution, tail-biting

convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC)

encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0073] In some embodiments, the baseband circuitry 1204 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 1204E of the baseband circuitry 1204 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry 1204 may include one or more audio digital signal processor(s) (DSP) 1204F. The audio DSP(s) 1204F may include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.

[0074] The baseband circuitry 1204 may further include memory/storage 1204G. The memory/storage 1204G may be used to load and store data and/or instructions for operations performed by the processors of the baseband circuitry 1204.

Memory/storage 1204G for one embodiment may include any combination of suitable volatile memory and/or non-volatile memory. The memory/storage 1204G may include any combination of various levels of memory/storage including, but not limited to, read-only memory (ROM) having embedded software instructions (e.g., firmware), random access memory (e.g., dynamic random access memory (DRAM)), cache, buffers, etc. The memory/storage 1204G may be shared among the various processors or dedicated to particular processors. [0075] Components of the baseband circuitry 1204 may be suitably combined in a single chip, combined in a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent

components of the baseband circuitry 1204 and the application circuitry 1202 may be implemented together, such as, for example, on a system on a chip (SOC).

[0076] In some embodiments, the baseband circuitry 1204 may provide for

communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 1204 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), or a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 1204 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0077] RF circuitry 1206 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 1206 may include switches, filters, amplifiers, etc., to facilitate the communication with the wireless network. RF circuitry 1206 may include a receive signal path, which may include circuitry to down-convert RF signals received from the FEM circuitry 1208 and provide baseband signals to the baseband circuitry 1204. RF circuitry 1206 may also include a transmit signal path, which may include circuitry to up-convert baseband signals provided by the baseband circuitry 1204 and provide RF output signals to the FEM circuitry 1208 for transmission.

[0078] In some embodiments, the RF circuitry 1206 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 1206 may include mixer circuitry 1206A, amplifier circuitry 1206B, and filter circuitry 1206C. The transmit signal path of the RF circuitry 1206 may include filter circuitry 1206C and mixer circuitry 1206A. RF circuitry 1206 may also include synthesizer circuitry 1206D for synthesizing a frequency for use by the mixer circuitry 1206A of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 1206A of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 1208 based on the synthesized

frequency provided by synthesizer circuitry 1206D. The amplifier circuitry 1206B may be configured to amplify the down-converted signals, and the filter circuitry 1206C may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 1204 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 1206A of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0079] In some embodiments, the mixer circuitry 1206A of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 1206D to generate RF output signals for the FEM circuitry 1208. The baseband signals may be provided by the baseband circuitry 1204 and may be filtered by filter circuitry 1206C. The filter circuitry 1206C may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0080] In some embodiments, the mixer circuitry 1206A of the receive signal path and the mixer circuitry 1206A of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 1206A of the receive signal path and the mixer circuitry 1206A of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 1206A of the receive signal path and the mixer circuitry 1206A of the transmit signal path may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 1206A of the receive signal path and the mixer circuitry 1206A of the transmit signal path may be configured for super-heterodyne operation.

[0081] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these embodiments, the RF circuitry 1206 may include analog-to-digital converter (ADC) and digital-to- analog converter (DAC) circuitry, and the baseband circuitry 1204 may include a digital baseband interface to communicate with the RF circuitry 1206.

[0082] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect. [0083] In some embodiments, the synthesizer circuitry 1206D may be a fractional-M synthesizer or a fractional N/N+1 synthesizer, although the scope of the

embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 1206D may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0084] The synthesizer circuitry 1206D may be configured to synthesize an output frequency for use by the mixer circuitry 1206A of the RF circuitry 1206 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 1206D may be a fractional N/N+1 synthesizer.

[0085] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 1204 or the application circuitry 1202 depending on the desired output frequency. In some embodiments, a divider control input (e.g., M) may be determined from a look-up table based on a channel indicated by the application circuitry 1202.

[0086] Synthesizer circuitry 1206D of the RF circuitry 1206 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some

embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry-out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements; a phase detector; a charge pump; and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0087] In some embodiments, synthesizer circuitry 1206D may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a local oscillator (LO) frequency (fLO). In some embodiments, the RF circuitry 1206 may include an IQ/polar converter.

[0088] FEM circuitry 1208 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 1210, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 1206 for further processing. FEM circuitry 1208 may also include a transmit signal path, which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 1206 for transmission by one or more of the one or more antennas 1210.

[0089] In some embodiments, the FEM circuitry 1208 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry 1208 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry 1208 may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 1206). The transmit signal path of the FEM circuitry 1208 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 1206), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 1210).

[0090] In some embodiments, the electronic device 1200 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

[0091] In embodiments where the electronic device 1200 is, implements, is incorporated into, or is otherwise part of a base station or a UE, the RF circuitry 1206 may be configured to receive and to send a signal. The baseband circuitry 1204 may be configured to implement the cellular base station 410 (FIG. 4), the UE 420 (FIG. 4), some other embodiment or example disclosed herein, or combinations thereof.

[0092] In some embodiments, the electronic device 1200 of FIG. 12 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. For example, the electronic device 1200 of FIG. 12 may be configured to implement the cellular base station 410 (FIG. 4), the UE 420 (FIG. 4), some other embodiment or example disclosed herein, or combinations thereof. [0093] In embodiments where the electronic device 1200 is, implements, is incorporated into, or is otherwise part of a user equipment (UE) 420, baseband circuitry 1204 and/or the RF circuitry 1206 may be configured to segment an input bit sequence of a PDSCH transmission across a first set of multiple code blocks that have a first order; transmit the PDSCH transmission via the first set of multiple code blocks; receive, based on the transmission of the first set of multiple code blocks, a request for a hybrid automatic repeat request (HARQ) re-transmission of the PDSCH transmission; segment the input bit sequence of the PDSCH transmission across a second set of multiple code blocks that have a second order that is different from the first order; and transmit the PDSCH transmission via the second set of multiple code blocks.

[0094] The eNB may determine, based on communication with a UE, a physical downlink shared channel (PDSCH) mapping in a time domain across one or more OFDM symbols, wherein the PDSCH mapping is to indicate that a resource element on an antenna port that is not reserved for other purposes is to increase by an order of a first index of the resource element starting with a first slot in a subframe and then increase by a second index of the resource element over assigned one or more physical resource blocks. The baseband circuitry 1204 may control the RF circuitry 1206 to receive a PDSCH transmission in accordance with the PDSCH mapping.

[0095] In some embodiments, the circuitry of apparatus 1200, for example the baseband circuitry 1204 and/or the RF circuitry 1206 may be configured to receive a physical downlink shared channel (PDSCH) transmission that includes a first set of multiple code blocks, the first set of multiple code blocks having a first order;

transmit, based on the received PDSCH transmission, a request for a hybrid automatic repeat request (HARQ) re-transmission of the PDSCH transmission; and means to receive, based on the request, a re-transmission of the PDSCH

transmission that includes a second set of multiple code blocks that have a second order that is different than the first order.

[0096] In embodiments where the electronic device 1200 is, implements, is incorporated into, or is otherwise part of a user equipment (UE), baseband circuitry 1204 may be to generate a physical downlink shared channel (PDSCH) mapping in a time domain across one or more OFDM symbols, wherein the PDSCH mapping is to indicate that a resource element on antenna port that is not reserved for other purposes is to increase by an order of a first index of the resource element starting with a first slot in a subframe and then increase by a second index of the resource element over assigned one or more physical resource blocks. The baseband circuitry 1204 may control the RF circuitry 1206 to transmit the PDSCH mapping to a UE and transmit one or more PDSCH transmissions in accordance with the PDSCH mapping.

[0097] In some embodiments, the process may include identifying or causing to identify a received physical downlink shared channel (PDSCH) transmission that includes a first set of multiple code blocks, the first set of multiple code blocks having a first order; and identifying or causing to identify a re-transmission of the PDSCH transmission that includes a second set of multiple code blocks that have a second order that is different than the first order.

[0098] In some embodiments, the electronic device 1200 of FIG. 12 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such method 1300 (i.e., process) is depicted in FIG. 13. FIG. 13 is a simplified flowchart illustrating a method 1300 of operating an eNB, according to some embodiments. For example, the method 1300 may include configuring 1310, in a higher layer, a UE to receive a robust PDSCH transmission from the serving cell or eNB. The method 1300 may also include signaling 1320 an indication of the robust PDSCH scheduling by the serving cell to the UE. The indication may be transmitted to the UE over a control channel of the serving cell. The process may include transmitting 1330 one or more robust PDSCH transmissions in accordance with the scheduling information transmitted over the control channel of the serving cell.

[0099] In some embodiments, the electronic device 1200 of FIG. 12 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such method 1400 is depicted in FIG. 14. FIG. 14 is a simplified flowchart illustrating a method 1400 of operating an eNB, according to some embodiments. For example, the method 1400 may include segmenting or causing to segment 1410 an input bit sequence of a physical downlink shared channel (PDSCH) transmission across a first set of multiple code blocks that have a first order; transmitting or causing to transmit 1420 the first set of multiple code blocks; segmenting or causing to segment 1430 the input bit sequence of the PDSCH transmission across a second set of multiple code blocks that have a second order that is different than the first order; and transmitting or causing to transmit 1440 the second set of multiple code blocks as a hybrid automatic repeat request (HARQ) re-transmission.

[0100] In some embodiments, the electronic device 1200 of FIG. 12 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such method 1500 is depicted in FIG. 15. FIG. 15 is a simplified flowchart illustrating a method 1500 of operating a UE, according to some embodiments. For example, the method 1500 may include determining 1510, based on communication with an eNB, a physical downlink shared channel (PDSCH) mapping in a time domain across one or more OFDM symbols. The PDSCH mapping may indicate that a resource element on an antenna port that is not reserved for other purposes is to increase by an order of a first index of the resource element starting with a first slot in a subframe and then increase by a second index of the resource element over assigned one or more physical resource blocks. The method 1500 may also include receiving 1520 a PDSCH transmission in accordance with the PDSCH mapping.

[0101] In some embodiments, the electronic device 1200 of FIG. 12 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such method 1600 is depicted in FIG. 16. FIG. 16 is a simplified flowchart illustrating a method 1600 of operating an eNB, according to some embodiments. For example, the method 1600 may include generating 1610 a PDSCH mapping in a time domain across one or more OFDM symbols. The PDSCH mapping may indicate that a resource element on an antenna port that is not reserved for other purposes is to increase by an order of a first index of the resource element starting with a first slot in a subframe and then increase by a second index of the resource element over assigned one or more physical resource blocks. The method 1600 may include transmitting 1620 the PDSCH mapping to a UE, and transmitting 1630, to the UE, one or more PDSCH transmissions in accordance with the PDSCH mapping.

Examples

[0102] The following is a list of example embodiments that fall within the scope of the disclosure. In order to avoid complexity in providing the disclosure, not all of the examples listed below are separately and explicitly disclosed as having been contemplated herein as combinable with all of the others of the examples listed below and other embodiments disclosed hereinabove. Unless one of ordinary skill in the art would understand that these examples listed below, and the above disclosed embodiments, are not combinable, it is contemplated within the scope of the disclosure that such examples and embodiments are combinable.

[0103] Example 1 : A computer-readable storage medium including computer- readable instructions stored thereon, the computer-readable instructions configured to instruct at least one processor to: map communication data including systematic bits and parity bits to resource elements of orthogonal frequency domain multiplexing (OFDM) symbols, the parity bits generated from the systematic bits; map other communication data to a shortened transmission time interval (TTI) symbol having a shorter TTI than a TTI of the OFDM symbols; puncture at least a portion of the OFDM symbols with the shortened TTI symbol; and control a communication device to transmit the OFDM symbols and the shortened TTI symbol; wherein the mapping of the communication data to the resource elements of the OFDM symbols and the puncturing of the at least a portion of the OFDM symbols is carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as or less than a ratio of a number of systematic bits in the communication data to a number of parity bits in the communication data.

[0104] Example 2: The computer-readable storage medium of Example 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to puncture bits of the at least a portion of the OFDM symbols randomly.

[0105] Example 3: The computer-readable storage medium according to any one of Examples 1 and 2, wherein the computer-readable instructions are configured to instruct the at least one processor to interleave the parity bits with the systematic bits within the OFDM symbols.

[0106] Example 4: The computer-readable storage medium according to any one of Examples 1 -3, wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in a time domain first across the OFDM symbols.

[0107] Example 5: The computer-readable storage medium according to any one of Examples 1 and 4, wherein the computer-readable instructions are configured to instruct the at least one processor to: reserve a plurality of OFDM symbols; puncture only non-reserved OFDM symbols with the shortened TTI symbol; and map the systematic bits of the communication data to the reserved OFDM symbols before mapping remaining ones of the systematic bits to the non reserved OFDM symbols. [0108] Example 6: The computer-readable storage medium of Example 5, wherein the computer-readable instructions are configured to instruct the at least one processor to: identify a subset of the systematic bits as important systematic bits; and map the important systematic bits to the reserved OFDM symbols before mapping others of the systematic bits to the reserved OFDM symbols.

[0109] Example 7: The computer-readable storage medium according to any one of Examples 1 -6, wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index.

[0110] Example 8: The computer-readable storage medium of Example 7, wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in an order of 4, 7, 8, 1 1 , 2, 3, 5, 6, 9, 10, 12, 13 symbol index within a subframe.

[0111] Example 9: The computer-readable storage medium according to any one of Examples 1 -8, wherein the computer-readable instructions are configured to instruct the at least one processor to control the communication device to transmit downlink control information to one or more user equipment (UEs) indicating that previously transmitted OFDM symbols should not be used for soft combining at the user equipment of the scheduled PDSCH with the previously received PDSCH for the same hybrid automatic repeat request (HARQ) process if the previously transmitted OFDM symbols were punctured with at least a threshold level of puncturing.

[0112] Example 10: The computer-readable storage medium of Example 9, wherein the threshold level of puncturing is at least about thirty percent (30%) of OFDM symbols of the previously transmitted OFDM symbols.

[0113] Example 1 1 : The computer-readable storage medium of Example 9, wherein the threshold level of puncturing is zero percent (0%) of OFDM symbols of the previously transmitted OFDM symbols.

[0114] Example 12: The computer-readable storage medium according to any one of Examples 9-1 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to control the communication device to transmit the downlink control information in a downlink control information (DCI) message. [0115] Example 13: The computer-readable storage medium according to any one of Examples 1 -12, wherein an order of code blocks of the OFDM symbols being subjected to a puncturing pattern for a hybrid automatic repeat request (HARQ) process retransmission is different from a previous order with which the code blocks of the OFDM symbols were subjected to the puncturing pattern for a previous transmission.

[0116] Example 14: An apparatus for an evolved Node B (eNB), including: one or more processors; and one or more data storage devices operably coupled to the one or more processors, the one or more data storage devices including computer- readable instructions stored thereon, the computer-readable instructions configured to instruct the one or more processors to: generate information correlated to a degree of puncturing of soft channel bits of previously transmitted orthogonal frequency domain multiplexing (OFDM) symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols, the information configured to enable a user equipment (UE) to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold; and control a communication device to transmit the information.

[0117] Example 15: The apparatus of Example 14, wherein the predetermined threshold is about thirty percent (30%).

[0118] Example 16: The apparatus of Example 14, wherein the predetermined threshold is about zero percent (0%).

[0119] Example 17: The apparatus according to any one of Examples 14-16, wherein the information correlated to the degree of puncturing includes an indicator indicating whether the UE should disable or enable the soft combining of the soft channel bits with the bits of the retransmission of the OFDM symbols for the HARQ process.

[0120] Example 18: The apparatus according to any one of Examples 14-17, wherein the information correlated to the degree of puncturing indicates the degree of puncturing. [0121] Example 19: The apparatus according to any one of Examples 14-18, wherein the information correlated to the degree of puncturing indicates which of the soft channel bits were punctured.

[0122] Example 20: The apparatus according to any one of Examples 14-19, wherein: the previously transmitted OFDM symbols include a plurality of code blocks; the code blocks of the previously transmitted OFDM symbols were subjected to puncturing in a first order; and the code blocks of the retransmission of the OFDM symbols for the HARQ process are subjected to the puncturing in a second order that is different from the first order.

[0123] Example 21 : An apparatus for an evolved Node B (eNB), including: a communication device; and control circuitry configured to: puncture orthogonal frequency domain multiplexing (OFDM) symbols including a plurality of code blocks with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols, the plurality of code blocks being subjected to the puncturing in a first order; control the communication device to transmit the OFDM symbols to a user equipment (UE); puncture the plurality of code blocks for a retransmission, the plurality of code blocks subjected to the puncturing in a second order that is different from the first order; and control the communication device to retransmit the OFDM symbols subjected to the puncturing according to the second order in a hybrid automatic repeat request (HARQ) process.

[0124] Example 22: The apparatus of Example 21 , wherein the control circuitry is configured to control the communication device to transmit, to the UE, information correlated to a degree of puncturing of soft channel bits of the OFDM symbols, the information configured to enable the UE to disable soft combining of the soft channel bits with bits of the retransmission of the OFDM symbols punctured according to the second order responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

[0125] Example 23: An apparatus for a user equipment (UE) including baseband circuitry including: one or more processors configured to: process orthogonal frequency domain multiplexing (OFDM) symbols received from an evolved Node B (eNB); process information received from the eNB, the information correlated to a degree of puncturing of soft channel bits of previously transmitted OFDM symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols; and disable soft combining of the soft channel bits with bits of a

retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

[0126] Example 24: The apparatus of Example 23, wherein the information includes a command instructing the UE to disable the soft combining.

[0127] Example 25: The apparatus according to any one of Examples 23 and 24, wherein the information indicates the degree of puncturing, and the one or more processors are configured to disable the soft combining if the degree of puncturing is greater than the predetermined threshold.

[0128] Example 26: A method of operating an evolved Node B (eNB), the method including: mapping communication data including systematic bits and parity bits to resource elements of orthogonal frequency domain multiplexing (OFDM) symbols, the parity bits generated from the systematic bits; mapping other communication data to a shortened transmission time interval (TTI) symbol having a shorter TTI than a TTI of the OFDM symbols; puncturing at least a portion of the OFDM symbols with the shortened TTI symbol; and controlling a communication device of the eNB to transmit the OFDM symbols and the shortened TTI symbol; wherein mapping communication data to resource elements of OFDM symbols and puncturing at least a portion of the OFDM symbols is carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as or less than a ratio of a number of systematic bits in the communication data to a number of parity bits in the communication data.

[0129] Example 27: The method of Example 26, wherein puncturing at least a portion of the OFDM symbols includes puncturing bits of the at least a portion of the OFDM symbols randomly.

[0130] Example 28: The method according to any one of Examples 26 and 27, further including interleaving the parity bits with the systematic bits within the OFDM symbols before mapping the communication data to the resource elements of OFDM symbols.

[0131] Example 29: The method according to any one of Examples 26-28, wherein mapping communication data to resource elements of OFDM symbols includes mapping the communication data to the resource elements of the OFDM symbols in a time domain first across the OFDM symbols. [0132] Example 30: The method according to any one of Examples 26 and 29, further including: reserving a plurality of OFDM symbols; puncturing only non- reserved OFDM symbols with the shortened TTI symbol; and mapping the

systematic bits of the communication data to the reserved OFDM symbols before mapping remaining ones of the systematic bits to the non reserved OFDM symbols.

[0133] Example 31 : The method of Example 30, further including: identifying a subset of the systematic bits as important systematic bits; and mapping the important systematic bits to the reserved OFDM symbols before mapping others of the systematic bits to the reserved OFDM symbols.

[0134] Example 32: The method according to any one of Examples 26-31 , wherein mapping communication data to resource elements of OFDM symbols includes mapping the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index.

[0135] Example 33: The method of Example 32, mapping the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index includes mapping the

communication data to the resource elements of the OFDM symbols in an order of 4, 7, 8, 1 1 , 2, 3, 5, 6, 9, 10, 12, 13 symbol index within a subframe.

[0136] Example 34: The method according to any one of Example 26-33, further including controlling the communication device to transmit downlink control information to one or more user equipment (UEs) indicating that previously

transmitted OFDM symbols should not be used for soft combining at the user equipment of the scheduled PDSCH with the previously received PDSCH for the same hybrid automatic repeat request (HARQ) process if the previously transmitted OFDM symbols were punctured with at least a threshold level of puncturing.

[0137] Example 35: The method of Example 34, wherein the threshold level of puncturing is at least about thirty percent (30%) of OFDM symbols of the previously transmitted OFDM symbols.

[0138] Example 36: The method of Example 34, wherein the threshold level of puncturing is zero percent (0%) of OFDM symbols of the previously transmitted OFDM symbols.

[0139] Example 37: The method according to any one of Examples 34-36, wherein controlling the communication device to transmit downlink control information includes controlling the communication device to transmit the downlink control information in a downlink control information (DCI) message.

[0140] Example 38: The method according to any one of Examples 26-37, wherein puncturing at least a portion of the OFDM symbols with the shortened TTI symbol includes subjecting code blocks of the OFDM symbols to puncturing for a hybrid automatic repeat request (HARQ) process retransmission that is different from a previous order with which the code blocks of the OFDM symbols were subjected to the puncturing for a previous transmission.

[0141] Example 39: A method of operating an evolved Node B (eNB), the method including: transmitting orthogonal frequency domain multiplexing (OFDM) symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols; transmitting information correlated to a degree of puncturing of soft channel bits of the transmitted OFDM symbols, the information configured to enable a user equipment (UE) to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold; and retransmitting the OFDM symbols for the HARQ process.

[0142] Example 40: The method of Example 39, wherein the predetermined threshold is about thirty percent (30%).

[0143] Example 41 : The method of Example 39, wherein the predetermined threshold is about zero percent (0%).

[0144] Example 42: The method according to any one of Examples 39-41 , wherein transmitting information correlated to a degree of puncturing includes transmitting an indicator indicating whether the UE should disable or enable the soft combining of the soft channel bits with the bits of the retransmission of the OFDM symbols for the HARQ process.

[0145] Example 43: The method according to any one of Examples 39-42, wherein transmitting information correlated to a degree of puncturing includes transmitting information indicating the degree of puncturing.

[0146] Example 44: The method according to any one of Examples 39-43, wherein transmitting information correlated to a degree of puncturing includes transmitting information that indicates which of the soft channel bits were punctured. [0147] Example 45: The method according to any one of Examples 39-44, wherein transmitting OFDM symbols includes transmitting OFDM symbols that include a plurality of code blocks, wherein the method further includes: subjecting the code blocks of the transmitted OFDM symbols to puncturing in a first order; and subjecting the code blocks of the retransmission of the OFDM symbols to the puncturing in a second order that is different from the first order.

[0148] Example 46: A method of operating an evolved Node B (eNB), the method including: puncturing orthogonal frequency domain multiplexing (OFDM) symbols including a plurality of code blocks with shortened transmission time interval (TTI) symbols having a TTI that is shorter than a TTI of the OFDM symbols, the plurality of code blocks being subjected to the puncturing in a first order; controlling a

communication device to transmit the OFDM symbols to a user equipment (UE); puncturing the plurality of code blocks for a retransmission, the plurality of code blocks subjected to the puncturing in a second order that is different from the first order; and retransmitting the OFDM symbols subjected to the puncturing according to the second order in a hybrid automatic repeat request (HARQ) process.

[0149] Example 47: The method of Example 46, further including transmitting, to the UE, information correlated to a degree of puncturing of soft channel bits of the OFDM symbols, the information configured to enable the UE to disable soft combining of the soft channel bits with bits of the retransmission of the OFDM symbols punctured according to the second order responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

[0150] Example 48: A method of operating a user equipment (UE), the method including: processing orthogonal frequency domain multiplexing (OFDM) symbols received from an evolved Node B (eNB); processing information received from the eNB, the information correlated to a degree of puncturing of soft channel bits of previously transmitted OFDM symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols; and disabling soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold. [0151] Example 49: The method of Example 48, wherein processing information received from the eNB includes processing a command instructing the UE to disable the soft combining.

[0152] Example 50: The method according to any one of Examples 48 and 49, wherein processing information received from the eNB includes processing the information to determine whether the degree of puncturing is greater than the predetermined threshold.

[0153] Example 51 : A computer-readable storage medium including computer- readable instructions stored thereon, the computer-readable instructions configured to instruct a processor to perform at least a portion of the method according to any one of Examples 26 50.

[0154] Example 52: A means for performing the method according to any one of Examples 26-50.

[0155] While certain illustrative embodiments have been described in connection with the figures, those of ordinary skill in the art will recognize and appreciate that embodiments encompassed by the disclosure are not limited to those embodiments explicitly shown and described herein. Rather, many additions, deletions, and modifications to the embodiments described herein may be made without departing from the scope of embodiments encompassed by the disclosure, such as those hereinafter claimed, including legal equivalents. In addition, features from one disclosed embodiment may be combined with features of another disclosed embodiment while still being encompassed within the scope of embodiments encompassed by the disclosure, as contemplated by the inventors.

Claims

1 . A computer-readable storage medium including computer-readable instructions stored thereon, the computer-readable instructions configured to instruct at least one processor to:

map communication data including systematic bits and parity bits to resource

elements of orthogonal frequency domain multiplexing (OFDM) symbols, the parity bits generated from the systematic bits;

map other communication data to a shortened transmission time interval (TTI)

symbol having a shorter TTI than a TTI of the OFDM symbols;

puncture at least a portion of the OFDM symbols with the shortened TTI symbol; and control a communication device to transmit the OFDM symbols and the shortened

TTI symbol;

wherein the mapping of the communication data to the resource elements of the OFDM symbols and the puncturing of the at least a portion of the OFDM symbols is carried out such that a ratio of a number of punctured systematic bits to a number of punctured parity bits is about the same as or less than a ratio of a number of systematic bits in the communication data to a number of parity bits in the communication data.

2. The computer-readable storage medium of claim 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to puncture bits of the at least a portion of the OFDM symbols randomly.

3. The computer-readable storage medium of claim 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to interleave the parity bits with the systematic bits within the OFDM symbols.

4. The computer-readable storage medium of claim 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in a time domain first across the OFDM symbols.

5. The computer-readable storage medium of claim 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to: reserve a plurality of OFDM symbols;

puncture only non-reserved OFDM symbols with the shortened TTI symbol; and map the systematic bits of the communication data to the reserved OFDM symbols before mapping remaining ones of the systematic bits to the non-reserved

OFDM symbols.

6. The computer-readable storage medium of claim 5, wherein the computer-readable instructions are configured to instruct the at least one processor to:

identify a subset of the systematic bits as important systematic bits; and

map the important systematic bits to the reserved OFDM symbols before mapping others of the systematic bits to the reserved OFDM symbols.

7. The computer-readable storage medium of claim 1 , wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in an order different from a uniformly increasing order of OFDM symbol index.

8. The computer-readable storage medium of claim 7, wherein the computer-readable instructions are configured to instruct the at least one processor to map the communication data to the resource elements of the OFDM symbols in an order of 4, 7, 8, 1 1 , 2, 3, 5, 6, 9, 10, 12, 13 symbol index within a subframe.

9. The computer-readable storage medium according to any one of claims 1 -8, wherein the computer-readable instructions are configured to instruct the at least one processor to control the communication device to transmit downlink control information to one or more user equipment (UEs) indicating that previously transmitted OFDM symbols should not be used for soft combining at the user equipment of the scheduled PDSCH with the previously received PDSCH for the same hybrid automatic repeat request (HARQ) process if the previously transmitted OFDM symbols were punctured with at least a threshold level of puncturing.

10. The computer-readable storage medium of claim 9, wherein the threshold level of puncturing is at least about thirty percent (30%) of OFDM symbols of the previously transmitted OFDM symbols.

1 1 . The computer-readable storage medium of claim 9, wherein the threshold level of puncturing is zero percent (0%) of OFDM symbols of the previously transmitted OFDM symbols.

12. The computer-readable storage medium of claim 9, wherein the computer-readable instructions are configured to instruct the at least one processor to control the communication device to transmit the downlink control information in a downlink control information (DCI) message.

13. The computer-readable storage medium according to any one of claims 1 -8, wherein an order of code blocks of the OFDM symbols being subjected to a puncturing pattern for a hybrid automatic repeat request (HARQ) process retransmission is different from a previous order with which the code blocks of the OFDM symbols were subjected to the puncturing pattern for a previous transmission.

14. An apparatus for an evolved Node B (eNB), comprising:

one or more processors; and

one or more data storage devices operably coupled to the one or more processors, the one or more data storage devices including computer-readable

instructions stored thereon, the computer-readable instructions configured to instruct the one or more processors to:

generate information correlated to a degree of puncturing of soft channel bits of previously transmitted orthogonal frequency domain multiplexing (OFDM) symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols, the information configured to enable a user equipment (UE) to disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold; and

control a communication device to transmit the information.

15. The apparatus of claim 14, wherein the predetermined threshold is about thirty percent (30%).

16. The apparatus of claim 14, wherein the predetermined threshold is about zero percent (0%).

17. The apparatus of claim 14, wherein the information correlated to the degree of puncturing includes an indicator indicating whether the UE should disable or enable the soft combining of the soft channel bits with the bits of the

retransmission of the OFDM symbols for the HARQ process.

18. The apparatus of claim 14, wherein the information correlated to the degree of puncturing indicates the degree of puncturing.

19. The apparatus of claim 14, wherein the information correlated to the degree of puncturing indicates which of the soft channel bits were punctured.

20. The apparatus of claim 14, wherein:

the previously transmitted OFDM symbols include a plurality of code blocks;

the code blocks of the previously transmitted OFDM symbols were subjected to

puncturing in a first order; and

the code blocks of the retransmission of the OFDM symbols for the HARQ process are subjected to the puncturing in a second order that is different from the first order.

21 . An apparatus for an evolved Node B (eNB), comprising:

a communication device; and

control circuitry configured to:

puncture orthogonal frequency domain multiplexing (OFDM) symbols

including a plurality of code blocks with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols, the plurality of code blocks being subjected to the puncturing in a first order;

control the communication device to transmit the OFDM symbols to a user equipment (UE);

puncture the plurality of code blocks for a retransmission, the plurality of code blocks subjected to the puncturing in a second order that is different from the first order; and

control the communication device to retransmit the OFDM symbols subjected to the puncturing according to the second order in a hybrid automatic repeat request (HARQ) process.

22. The apparatus of claim 21 , wherein the control circuitry is configured to control the communication device to transmit, to the UE, information correlated to a degree of puncturing of soft channel bits of the OFDM symbols, the information configured to enable the UE to disable soft combining of the soft channel bits with bits of the retransmission of the OFDM symbols punctured according to the second order responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

23. An apparatus for a user equipment (UE) comprising baseband circuitry including:

one or more processors configured to:

process orthogonal frequency domain multiplexing (OFDM) symbols received from an evolved Node B (eNB);

process information received from the eNB, the information correlated to a degree of puncturing of soft channel bits of previously transmitted OFDM symbols that have been punctured with shortened transmission time interval (TTI) symbols, the shortened TTI symbols having a TTI that is shorter than a TTI of the OFDM symbols; and

disable soft combining of the soft channel bits with bits of a retransmission of the OFDM symbols for a hybrid automatic repeat request (HARQ) process responsive to the degree of puncturing of the soft channel bits being greater than a predetermined threshold.

24. The apparatus of claim 23, wherein the information includes a command instructing the UE to disable the soft combining.

25. The apparatus of claim 23, wherein the information indicates the degree of puncturing, and the one or more processors are configured to disable the soft combining if the degree of puncturing is greater than the predetermined threshold.