Mastering 5G PHY: Complete Development Training

Explore how cyclic redundancy checks detect transmission errors in 5G by performing modulo-two division with a CRC polynomial, attaching the remainder, and validating at the receiver.

Enhance reliability by adding redundancy to information bits to correct errors caused by wireless channel. Power LDPC for shared channels; polar codes control channels; Reed-Muller aids PUCCH for small blocks.

Learn rate matching for polar codes through subblock interleaving, bit selection, and final bit interleaving to produce the rate match output, with K, N, and E definitions.

Explore LDPC rate matching for 5G PHY, covering limited and full buffer rate matching, redundancy versions, and the bit interleaver, with each topic discussed in its own video.

Explore limited buffer rate matching (lbrm) and full buffer rate matching (fbrm), via a circular buffer. See how PDSCH and LDPC BG sizes influence buffer use and memory requirements.

Learn how redundancy versions select bits from a circular buffer based on code rate, covering rv0–rv3, and identify self-decodable rv0 and rv3 with LDPC systematic and parity bits.

Apply bit interleaving in LDPC rate matching to mitigate burst errors by arranging rate-matched bits into rows based on modulation order and reading them column-wise, e.g., 16-QAM.

Generate a Gold PN sequence by XOR-ing two m-sequences for 5G scrambling and DMRS, using seed and c init controls to ensure good autocorrelation and low cross-correlation.

Introduce the zad off chu sequence and its papr use in 5g uplink. Outline constant amplitude, zero autocorrelation, and constant cross-correlation, plus generating the base sequence xq(m) and extending length.

Scrambling randomizes transmitted bits with a pseudo random PN sequence to reduce inter-cell interference and preserve the channel code's processing gain, with descrambling reversing the process at the receiver.

Explore how 5G modulation mappers convert bits to complex samples and modulate the OFDM waveform, covering BPSK, pi/2 BPSK, QPSK, and 16/64/256 QAM, with throughput and error tradeoffs.

Explore orthogonal frequency division multiplexing, or OFDM, used in LTE, 4G, and 5G, detailing subcarriers, complex symbols, modulation, and timing with cyclic prefix.

Learn how cyclic prefix adds the last part of the signal at start to mitigate delay spread, intersymbol interference, and inter-carrier interference in 5G and ofdm, using fft-based receivers.

Explore 5G numerology by detailing subcarrier spacings (15, 30, 60, 240 kHz), their effect on symbol time and FFT size, and implications for FR1/FR2 and URLLC.

Explore the 5g time axis, defining frames, slots, subframes, and ofdm symbols, with normal versus extended cp, and show how numerology mu and subcarrier spacing shape symbol and slot durations.

Learn how 5g maps the frequency axis using point a as the reference, defines common resource blocks, and uses resource grids with offset to carrier across numerologies and ports.

Explore the bandwidth part (BWP) concept, its start, size, and inside-PRB numbering, and explain how BWP switching enables per-carrier, per-direction optimization and power savings for a UE.

Understand antennas, antenna elements, and arrays; learn how dual polarization and beamforming create narrow vertical and wide horizontal beams, with digital, analog, and hybrid approaches.

Demodulation reference signals (DMRS) provide pre-known signals for channel estimation at the receiver, enabling accurate equalization in OFDM systems by measuring the channel across time and frequency.

Explains the ss block with pss in the first symbol and sss in the third. Describes pbch around MIB, four ofdm symbols, 240 subcarriers, and five ms ssburst.

Explore the primary synchronization signal (PSS) and how it enables radio frame synchronization, symbol timing, and cell ID detection using m-sequences, bpsk modulation, and correlation-based blind decoding.

Enables SSS, the secondary synchronization signal, accompanying PSS and PBCH in the SSB, using a 127-subcarrier m-sequence OFDM symbol to yield 1008 cell IDs for frame synchronization.

Describe how PBCH carries the MIB and DMRS, detailing the 24-bit MIB, additional bits, CRC-24, polar encoding, rate matching, and the DMRS placement dependent on cell ID and SSB index.

Learn time and frequency locations of SS blocks, with Lmax beam limits by operating band, and place SS bursts using offset to point A and kSSB in FR1 and FR2.

Explore the PDCCH transmitter chain, including DCI construction with CRC and RNTI masking, interleaving with polar encoding, rate matching, scrambling, QPSK modulation, and DMRS generation for uplink and downlink configurations.

Learn how dci is carried by the pdcch. Identify the four key dci—0_0, 0_1, 1_0, 1_1—for uplink and downlink, and the four group dci 2_0–2_3 with position in dci.

Explore how a coreset enables PDCCH allocation by detailing REG and CCE definitions, 54 data REs per CCE, frequency bitmaps, and non-interleaved versus interleaved mappings.

Explore search space as the PRB and symbol region where the UE hunts PDCCH DCI within a coreset, using start symbol, monitored candidates, and aggregation levels, including CSS and USS.

Explore PDCCH blind decoding and how the receiver uses aggregation level, search space, and coreset to identify candidate CCE indices and blindly decode DCI with RNTI.

Explain DMRS for PDSCH and PUSCH, including frequency and time allocation, config types 1 and 2, overhead, CDM groups, and mapping types A and B with single/double symbol DMRS.

Explore the physical layer processing of PDSCH and PUSCH, including transport block handling, CRC selection, LDPC coding with base graphs BG1/BG2, rate matching, scrambling, modulation, and layer mapping.

Explain how PDSCH and PUSCH data are mapped to resource blocks and subcarriers, including DMRS interleaving. Highlight mapping types, start symbols, and SLIV with slot offsets k0 and k2.

Learn frequency domain resource allocation for PDSCH and PUSCH, including group-based (type zero) and continuous (type one) allocations with interleaved mapping, to enhance diversity while considering channel conditions and feedback.

Explore PDSCH and PUSCH MCS tables, linking modulation orders from QPSK to 256 QAM, code rates and spectral efficiency, with tables one to three, and transform precoding enabled cases.

calculate transport block size for pdsch and pusch by counting resource elements in prbs, accounting for dmrs and overhead, then apply n_info, n_info' and tb sizing rules.

Explore the basics of multiple antenna systems (MIMO) across SISO, MISO, SIMO configurations, transmit/receive diversity, precoding, and how rank and channel conditions determine maximum data streams or layers.

Apply short-term zero-forcing precoding for mimo to remove the channel effect on pdsch and pusch, using P = H(H^H H)^{-1} and X = PS.

Explore UE multiplexing for PDSCH and PUSCH across time, frequency, and space, using rectangular allocations defined by start symbols and PRBs with varying layers and independent MCS per UE.

Compare single-user MIMO and multi-user MIMO, illustrating how spatial multiplexing with multiple beams and antennas boosts capacity. Learn how channel rank, beamforming, and CSI-RS-based user pairing enable efficient resource allocation.

Explore DFT-s-OFDM transform precoding in PUSCH, detailing how data undergoes DFT and IDFT, the impact on PAPR, and contrasts with CP-OFDM, including DMRS and PTRS considerations.

Explore uplink mimo for pusch, including antenna placement, panel configurations, and beamforming. Learn coherent, non-coherent, and partially coherent schemes, codebook and non-codebook mimo, and how gNB selects TPMI and antennas.

Explore non code book based MIMO for PUSCH, where the UE signals capabilities, selects antenna panels, and uses SRS and CSI-RS for precoding and layers guiding gnodeB.

Prach, physical random access channel, is the first uplink from a UE to the gnodeb, guided by SIB1, with long and short formats that adapt to cell radius and timing.

Learn how PRACH signals are generated at the UE with ZC sequences for short and long formats, lengths 139 or 839, root indices, cyclic shifts, FFT-based OFDM transmission.

Learn how PRACH generates preambles with a root sequence index u and cv. Explore how timing offset, NCS, and restricted versus unrestricted sets influence detection and cell size.

Master Prach long formats, including formats zero through three, their 1.25 and 5 kHz subcarrier spacings, and varying cyclic prefix lengths and sequence lengths. Evaluate how CP length, repetition, and overhead shape cell radius, coverage, and uplink–downlink timing in Prach deployments.

Explore nine prach short formats (a1–c2), their 139-length sequences, and the subcarrier spacings (15/30/60/120 kHz), CP effects, repetitions, and cell radius implications.

Explore prach time and frequency allocations in fr1 unpaired spectrum, including b4 format config index decisions, starting symbols, prach slots, and ssb per rach occasion mappings.

Analyze Prach receiver processing on the gNodeB side, from CP removal and downsampling to FFT-based detection, ZC sequence correlation, and timing advance estimation for multiple UEs.

Explore PUCCH, the uplink control channel carrying UCI, HARQ-ACK, SR, and CSI. The lecture covers five formats F0–F4, their short or long timing, capacity, and UE multiplexing rules.

Understand pucch format 0 signal generation and resource mapping, with 1 prb and 1–2 symbols, ack, nack, and sr, and frequency hopping for diversity using zc sequences.

Explain how pucch format 0 multiplexes UEs by varying m0 and cyclic shifts, encoding with alpha, mcs, and ncs, and how the gnodeb receiver detects harq and sr via correlation.

Discover how pucch format 1 generates and maps zc-sequence signals, applies dmrs multiplexing, and uses alpha, ncs, and root sequence hopping to allocate data and dmrs in a PRB.

Learn how pucch format 1 dmrs is generated and mapped with zadoff-chu sequences, group hopping, cyclic shifts, and orthogonal code covers, then mapped to resources by k and l.

Explain how pucch format 1 encodes harq and sr data, multiplexes multiple ues with orthogonal cover codes and cyclic shifts, and how the receiver estimates channels and decodes them.

Explore bit processing for pucch formats 2/3/4, including uci handling, crc, reed molar and polar coding, rate matching, scrambling, modulation, and CSI part 1/2 with harq and sr.

Explore pucch format 2 dmrs: generating dmrs from pn sequences, seed-based cinit, qpsk modulation, and interleaved dmrs and data for f2 resource mapping.

Explore how pucch f3 and f4 dmrs are generated from a zc sequence, using ncs, alpha, and the ru,v^(alpha,delta) formulation, and how they are mapped to resources.

Explore pucch f3 signal generation and reception, including crc encoding, rate matching, scrambling, pi/2 bpsk or qpsk modulation, and transform precoding via dft to reduce papr and guide data mapping.

Generate pucch f4 signals and multiplex to four ues with cover codes and dmrs, using transform precoding to reduce papr. Apply channel estimation, equalization, and decoding to recover uci bits.

Explore CSI-RS, the channel state information reference signal, and how it enables CQI, RI, and PMI feedback to optimize MCS and layers, refine beams, and support time and frequency synchronization.

Learn the code division multiplexing concept and how orthogonal sequences enable multi-port CSI-RS and DMRS. See how to test orthogonality, build base sequences, and map CDM across time and frequency.

Learn CSI-RS sequence generation and mapping using PN-based QPSK signals, with UE-specific seeds, and map CSI-RS to PRBs using CDM groups and orthogonal codes.

Explore CSI-RS resource mapping with a concrete example, detailing how 12 ports are allocated across CDM groups using k-bar, k', l-bar, l', and bitmap calculations.

Learn how CSI-IM configures interference measurement by using CSI-RS IM on zero-power REs to gauge cross-cell interference, with two RE patterns and reporting results to the gNB.

Explore how CQI and RI direct base stations to select the right MCS and MIMO layers, using CSI-RS measurements and wideband or subband CQI.

Anticipate the upcoming CSI-RS: PMI content in the mastering 5G PHY course, and we will upload the video soon; please check back after August 25.

Unlock how sounding reference signal (SRS) lets GnodeB estimate uplink channels from the UE for channel-based scheduling and downlink reciprocity in TDD, using ZC sequences and cyclic shifts.

Explore sequence generation for SRS using zadoff-chu base sequences, cyclic shifts, and U and V group and sequence hopping to create orthogonal SRS signals across antenna ports and cells.

Map the ZC sequence to SRS resources by port, frequency, and time indices, applying scaling and subcarrier rules to place the sequence in the SRS resource grid.

Understand how gNodeB receives SRS, estimates per-prb channels and SNR, and uses TDD reciprocity to precode downlink with antenna switching and SRS multiplexing.

Understand phase noise, its generation by nonideal local oscillators, and its impact on OFDM and 16QAM; learn PTRS design to mitigate noise, especially at mmWave and high MCS.

Learn PTRS signal generation and resource mapping for downlink and uplink, using DMRS from PDSCH and PUSCH, with time and frequency density rules and RNTI-based PRB selection.

Generate and map ptrs for pusch with transform precoding, using pn sequences modulated by pi/2 bpsk and orthogonal cover codes, with time-domain multiplexing guiding subcarrier indexing.

Design a PTRS receiver to correct phase noise in 5G NR signals by using DMRS-based channel estimation and PTRS phase correction across OFDM symbols to recover PDSCH/PUSCH data.