NR PUSCH功率控制双环机制与TPC命令博弈

┌─────────────────────────────────────────────────────────────┐
│                   PUSCH 功率控制双环架构                      │
│                                                             │
│  ┌──────────────────┐          ┌──────────────────┐        │
│  │  开环环 (OLPC)    │          │  闭环环 (CLPC)    │        │
│  │                  │          │                  │        │
│  │  P0 + α·PL +     │  基准    │  ∑ TPC命令       │        │
│  │  10log10(M) +    │───────→  │  累积修正        │        │
│  │  ΔTF + ΔMCSS    │          │  (DCI format 0_1)│        │
│  └──────────────────┘          └──────────────────┘        │
│         │                              │                    │
│         └──────────┬───────────────────┘                    │
│                    ▼                                        │
│         PUSCH发射功率 = min{PCMAX, PPUSCH}                  │
│                    │                                        │
│                    ▼                                        │
│              gNB测量SINR                                    │
│                    │                                        │
│         ┌─────────┴──────────┐                              │
│         │  TPC命令生成        │                              │
│         │  DCI 0_1 / DCI 2_2 │                              │
│         └────────────────────┘                              │
└─────────────────────────────────────────────────────────────┘

graph TD
    A[P_O_PUSCH 二维结构] --> B[P_O_NOMINAL_PUSCH<br/>小区级广播]
    A --> C[P_O_UE_PUSCH<br/>UE级专用]

    B --> B1[SIB1下发<br/>所有UE共享]
    B --> B2[RRC重配更新<br/>半静态调整]

    C --> C1[初始接入: 由Msg2配置]
    C --> C2[连接态: RRCReconfiguration]
    C --> C3[按UE位置/业务差异化]

    B1 --> D[设计意图:<br/>小区边缘UE vs 中心UE<br/>差异化功率基准]
    C3 --> D

    style A fill:#ff6b6b,color:#fff
    style D fill:#4ecdc4,color:#fff

sequenceDiagram
    participant UE as UE
    participant gNB as gNB
    participant Scheduler as 调度器

    Note over UE,gNB: 闭环功率控制流程

    gNB->>UE: DCI Format 0_1 (调度PUSCH)
    Note right of UE: P_PUSCH = OLPC + f(i-1)
    UE->>gNB: PUSCH传输 (功率P1)

    gNB->>Scheduler: 测量PUSCH SINR
    Scheduler->>Scheduler: 计算偏差 ΔSINR = SINR_target - SINR_measured
    Scheduler->>Scheduler: 生成TPC命令 δ_TPC

    alt 累积模式
        gNB->>UE: DCI 0_1 with TPC = +1dB
        Note right of UE: f(i) = f(i-1) + 1dB
    else 绝对模式
        gNB->>UE: DCI 0_1 with TPC = +3dB
        Note right of UE: f(i) = +3dB (直接替换)
    end

    UE->>gNB: PUSCH传输 (功率P2 = P1 + δ_TPC)

    Note over gNB: TPC命令映射表 (TS 38.213 Table 7.1.1-1)

graph LR
    subgraph DCI 2_2 Payload结构
        A[blockNumber 1] --> B[blockNumber 2]
        B --> C[...]
        C --> D[blockNumber N]
    end

    subgraph 每个block内容
        E[TPC命令 2bit] --> F[UE ID 指示<br/>通过RRC配置的<br/>tpc-PUSCH-Index]
    end

    subgraph 寻址方式
        G[TPC-PUSCH-RNTI<br/>组播RNTI] --> H[组内所有UE<br/>解码同一DCI]
    end

    style A fill:#3498db,color:#fff
    style E fill:#e74c3c,color:#fff
    style G fill:#2ecc71,color:#fff

stateDiagram-v2
    [*] --> 初始功率计算
    初始功率计算 --> Msg3首次传输: PREAMBLE_POWER_RAMPING_COUNTER=1

    Msg3首次传输 --> 检测Msg4响应
    检测Msg4响应 --> Msg3功率确定: 收到Msg4(RAR)
    检测Msg4响应 --> 重传判断: 未收到Msg4

    重传判断 --> Msg3功率爬升: preambleCounter < maxTransmissions
    重传判断 --> 随机接入失败: preambleCounter >= maxTransmissions

    Msg3功率爬升 --> Msg3重传: 功率 + POWER_RAMPING_STEP
    Msg3重传 --> 检测Msg4响应

    Msg3功率确定 --> 连接态功率控制: 切换到PUSCH闭环

    state Msg3功率爬升 {
        [*] --> 爬升计数器递增
        爬升计数器递增 --> Preamble重传
        Preamble重传 --> 等待RAR
    }

sequenceDiagram
    participant UE as UE
    participant gNB as gNB

    Note over UE: BWP1 (DL BWP ID=0)
    UE->>gNB: PUSCH (P0=-90dBm, α=0.8, PL=120dB)
    Note right of UE: P = -90 + 0.8×120 + 10log10(50)<br/>= -90 + 96 + 17 = 23dBm

    gNB->>UE: DCI 0_1 (BWP switch to BWP2)

    Note over UE: BWP2 (DL BWP ID=1)
    Note over UE: P0=-95dBm, α=0.6, PL=125dB (不同RS)
    UE->>gNB: PUSCH (BWP2首次传输)
    Note right of UE: P = -95 + 0.6×125 + 10log10(25)<br/>= -95 + 75 + 14 = -6dBm

    Note over gNB: 功率从23dBm骤降到-6dBm!<br/>gNB需要快速发送TPC命令修正

    gNB->>UE: DCI 2_2 TPC = +3dB (连续多次)
    UE->>gNB: PUSCH (功率逐步恢复)

Filter: nr-dci.format == "0_1" || nr-dci.format == "2_2"
Display: TPC Command field

P_PUSCH[i] = min(23, P0 + α×PL + 10log10(M[i]) + Δ_TF[i] + f(i))
f(i) = f(i-1) + δ_TPC[i]  // 累积模式

sequenceDiagram
    participant UE as UE
    participant gNB as gNB
    participant RRC as RRC层
    participant MAC as MAC层
    participant PHY as PHY层

    rect rgb(230, 245, 255)
    Note over UE,gNB: 阶段1: RRC参数配置
    RRC->>UE: RRCReconfiguration
    Note right of UE: p0-NominalWithoutGrant = -95dBm<br/>p0-AlphaSets {α=0.8, P0_UE=3dB}<br/>pathlossReferenceRS = SSB#0
    end

    rect rgb(255, 245, 230)
    Note over UE,gNB: 阶段2: 开环功率计算
    UE->>PHY: 测量SSB#0 RSRP
    PHY->>PHY: PL = ss-PBCH-BlockPower - RSRP<br/>= 23 - (-85) = 108dB
    PHY->>PHY: P_OLPC = P0 + α×PL<br/>= (-95+3) + 0.8×108<br/>= -92 + 86.4 = -5.6dBm
    end

    rect rgb(230, 255, 230)
    Note over UE,gNB: 阶段3: 闭环TPC控制
    loop 每个PUSCH调度周期
        gNB->>MAC: 调度PUSCH (M=25RB)
        MAC->>UE: DCI 0_1 (MCS=15, TPC=+1dB)
        UE->>PHY: P = min(23, -5.6 + 10log10(25) + ΔTF + f(i))
        Note right of UE: f(i) = f(i-1) + 1dB
        PHY->>gNB: PUSCH传输

        gNB->>PHY: 测量SINR
        alt SINR < SINR_target
            PHY->>UE: DCI 0_1 TPC = +1dB (提高功率)
        else SINR > SINR_target
            PHY->>UE: DCI 0_1 TPC = -1dB (降低功率)
        else SINR ≈ SINR_target
            PHY->>UE: DCI 0_1 TPC = 0dB (维持)
        end
    end
    end

    rect rgb(255, 230, 255)
    Note over UE,gNB: 阶段4: BWP切换功率重配
    gNB->>UE: DCI 0_1 (BWP switch to BWP1)
    Note right of UE: 新参数组: P0=-98dBm, α=0.6<br/>PL参考: CSI-RS#2
    UE->>PHY: 重新计算OLPC
    gNB->>UE: DCI 2_2 TPC = +3dB (补偿)
    UE->>gNB: PUSCH (BWP1首次传输)
    end